M, BOWERS, C hy WASHINGTON GOVERNMENT PeINTINGoFIcE = t—=‘iSC a i Nie ‘ban as . ia > 2 7 es if am : == pare 2S i> DEPARTMENT OF COMMERCE AND LABOR BUREAU OF FISHERIES GEORGE M. BOWERS, Commissioner OYSTER CULTURE EXPERIMENTS AND INVESTIGATIONS IN LOUISIANA Bureau of Fisheries Document No. 731 WASHINGTON GOVERNMENT PRINTING OFFICE 1910 (ee aa ee i ‘ep ae. 7 as Pass a * ~ A ieee ellen r — Dg - a a 4 + _ ~ = =~ = i oseett { ‘ E ol ~~ 63 <5 — = & : = F ~ _ 5 = ; . oe. = ee oe ; os oe a r £->F— : = a = = e : es - = + a 5 a Ee ; ry = E i a}? == + : im - : Sc — = = : =e NGC 7 : ie = : £ . aS — = E : s Se = 2 es S35 = S i Zo Zz - 2 ; 3 = we en & = = - — a — = = i ; = 7 ceeds 3 4 = = = : : = 2 & @ . pitt = — = es = - . = = — = = = = i 25 = = => — : = 5 = = — Se I . > = = — = = ae? SE ———— sy = - —— = ‘ = = =, 2 ; = = — = _ | ; = : —— 1 = = = s = as a = : peice z : — aa 4 te a 3 . = i. . 5 = tae = Sue. 2 5 : o . Qi ; z = - z oy dieres pbs eee ee che ote oe fe eels ote pe 1.0113 84. 2 7,200 . 181 A JLdl bp?) eo ie OP 28 Aire ees Re SORE RN orec Sethe alate 1.0136 86 10, 200 - 420 December 1-223 4.. SESS = See Sees eso Rte eas o> eae teee eee 1.0131 53 1, 500 - 081 1908 i (hse aan een eee eae meh Sue aan. Saeed odatenesSonowcec 1.0141 7 35, 000 . 807 Duly Siegen atta: op ee ack + eee ati oe eninee wine eee cee ee rae 1. 0100 81 8, 100 . 209 1909. PaCS 20 ois resale ete eye oon ia sear me ees Ce ee ee eecrroretere 1.0172 68 21,750 . 673 INVETA OC). c aj rose nia Dake nie oe Renee ote Mean (Nee eet ae oe ae LP OL46i | Secs 10, 200 . 295 About 50 barrels of rough unculled oysters from the natural beds were planted in January, 1906, and in the latter part of the follow- ing April oyster and clam shells were planted after the manner of those deposited at Bayou St. Denis, followed by two similar plants in the latter parts of May and June, respectively. In all these the apparent set of spat was light, the number of shells bearing young oysters ranging between 15 and 35 per cent of those examined, the average of all plants being about 22 per cent. By the following spring all of these young oysters had disappeared. The results of the second year’s experiments were even more unfavorable, and spat transplanted from Bayou St. Denis were also killed within a few weeks. US Sy Baie —Docnvsile PLATE IV. ie ve 0) S ier i f \ fi BORERS, OR “SNAILS” (PURPURA H4MOSTOMA), THEIR EGG CASES, AND OYSTER SPAT DRILLED BY THEM. BAY TAMBOUR, LOUISIANA. [Figures natural size. ] OYSTER CULTURE EXPERIMENTS IN LOUISIANA. 23 It was observed that the few upper valves still adherent to the shells were perforated by small holes, and as the gasteropod Purpura, locally known as the “ borer” or “snail,” was abundant on the stakes marking the beds it was at once suspected to be the cause of the mortality. To test this hypothesis three boxes were constructed of one-fourth inch wire screening and planted on the beds on April 17, 1907; one, closed, containing both shells and borers; one, closed, con- taining shells alone; and the third, open, with shells only. On June 26 the contents of the boxes were examined with the following results: In the open box 18 per cent of the shells bore spat, of which several were dead, and there were 5 borers besides several fishes and crabs. In the closed box, containing shells and 12 borers, but 2 per cent of the shells bore live spat, and these were concealed either under the shells or by marine growths. In the closed box without borers 60 per cent of the shells bore live spat, averaging two to the shell. This box contained when taken up 14 very small borers which had evi- dently entered through the mesh. On June 26 two closed boxes were planted, one with clean shells and 9 large borers, and the other containing shells bearing spat from one-half to three-fourths inch long, but with no borers. When taken up on September 1 the shells in the first box were devoid of spat of appreciable size, the large borers were dead, and there were no small ones. In the other box there were 17 live borers between three-eighths and 14 inches long which must have crawled through the mesh when quite small; there were no dead borers, but 2 per cent of the spat had survived and all of the upper valves remaining attached showed the small perforation made by this enemy. The brood oysters planted in January, 1906, when they were be- tween 2 and 3 - iches long, at no time showed any greater mortality than was to be expected from the mere act of transplanting, and this fact in connection with the experiments just recounted shows without much doubt that the failure to obtain results from planting shells was due, not to the quality of the water, per se, but to the destructive habits of the borer. The largest spat killed was less than 14 inches in length, and it is safe to assume that seed oysters 2 inches long and probably as small as 14 inches will be immune. The borers lay their eggs in red or purple leathery capsules about one-half inch long, attached in dense clusters to shells, stakes, and other fixed bodies in the water. The capsules are demicylinders, usually more or less curved toward the convex surface and with flattened or slightly convex free ends. Each capsule contains several eggs and the young snails escape through holes less than one-fiftieth of an inch in diameter, which they cut in the free end of the capsule. 34455—10—_4 24 OYSTER CULTURE EXPERIMENTS IN LOUISIANA. These recently-hatched borers probably feed upon the very minute and newly-attached spat, though of this we have no certain knowl- edge. Growth is rapid, as is shown by the experiments with boxes. The mesh employed in these was one-fourth inch square, and the largest borer that could be pushed through measured seven-sixteenths of an inch in length. In closed boxes planted June 28 there were borers three-fourths to 14 inches long on September 1, an increase of from 75 to 190 per cent in length and of from 200 to 450 per cent in bulk within a period of about two months. The difficulties in fighting a small and insidious enemy such as this are very considerable. It is wholly impracticable to inclose the beds, as is done to prevent the inroads of drumfish and similar enemies, the little snails being able to travel through the finest prac- ticable mesh, and the only recourse is to wage unceasing warfare by destroying all borers and egg cases found. To tong or dredge the oysters especially for this purpose is commercially impracticable under the market conditions obtaining in Louisiana, and the obvious course for the oyster culturist in the more salt waters in which the borer abounds is to eschew all effort at planting shells and confine his activities to planting seed oysters at least 14 inches and preferably not less than 2 inches long. If he does this the presence of this enemy may even prove a boon in preventing the excessive attachment of spat to the older oysters, an occurrence which in some places on our coasts renders it impossible to grow oysters fit for market. As to the rate of growth: of oysters in the earlier stages at Bay Tambour little can be said for reasons which are apparent. The growth of the seed oysters planted at the beginning of the experi- ment was very satisfactory. In April, 1906, measurements of the length of a number of these averaged 2.6 inches. In June, 1907, the average length was a little less than 4 inches, and in May, 1908, it was about 5 inches. In less than two years, therefore, these oysters doubled in length, and despite the fact that they were not culled, the clusters automatically broke apart to some extent, owing to the dis- integration of the shells to which they were attached, and there was a corresponding improvement in shape. The growth here was about the same as at Bayou St. Denis, and indicates that however unsuit- able this part of the bay may be for spat culture, owing to the rea- sons before set forth, there is an excellent opportunity for the estab- lishment of an important and profitable industry in growing oysters from seed. The results attained by the work at Bay Tambour are applicable to all of that half of Barataria Bay lying nearer the gulf, our investi- gations having shown the conditions to be essentially similar through- out that region. During the last year or two of the experiments a U.S. B. F.—Doc. 731. PLATE V. OYSTER, AVERAGE SIZE, GROWN IN 29 MONTHS FROM SEED ABOUT 2: INCHES LONG. BAY TAMBOUR, LOUISIANA. [Figure natural size.] OYSTER CULTURE EXPERIMENTS IN LOUISIANA. 25 considerable area of bottom was taken up by planters in this region and most of the oysters shipped during the oyster season 1908-9 were grown on these leaseholds. It is understood that the business was very profitable and that the supply of Barataria oysters, despite their lack of previous reputation, was unequal to the demand. They were all contracted for at a price equivalent to $1.60 per barrel on the beds and could have commanded a higher price in the open market. It is the opinion of the authors that they are among the best produced on our entire coast. ST. BERNARD PARISH. St. Bernard Parish embraces the most productive natural oyster region in Louisiana and at the present time produces about 40 per cent of the total yield of the state. Its oyster beds lie principally in what is known as the “Louisiana marshes,” a low uninhabited expanse of sea marsh and prairie covering an area of between 400 and 500 square miles between Mississippi, Chandeleur, and Isle au Breton sounds. This region is cut up into innumerable islands by an intricate system of bays and bayous, most of which contain natural oyster beds, described and platted in some detail in the report of the investigations in 1898, previously alluded to. In the season of 1906-7 St. Bernard Parish produced upward of 1,000,000 bushels of oysters, but in the following season the produc- tion was somewhat smaller. Although there have been some attempts at oyster culture and there are extensive leaseholds, most of these oysters came from the natural beds. , In 1898 there were no leases of bottom in this region and few were granted prior to 1904, when what was practically the present oyster law went into operation. In the next five years 66 leases were issued, and in 1908 there were in force 48 leases, aggregating 5,395 acres, of which 44 leases and 4,456 acres were in the Louisiana marsh and 4 leases and 939 acres in Lake Borgne. Many of the leases are for plots less than 20 acres in extent, but 9 individuals, firms, and corporations have holdings of between 100 and 1,000 acres each, covered by 25 leases aggregating 4,858 acres. These have been planted in part with seed oysters and shells, but the business has not yet proved very profitable owing mainly to the fact that the set of spat has been so heavy as to cause overcrowding of the beds with the consequent failure of the oysters to fatten and grow to good shape. The salinity of the water varies considerably in the several parts of the region under discussion, being as a rule lower in Lake Borgne and the waters closer to Mississippi Sound and higher toward Chan- deleur Sound and the southern part of the parish. This is shown in 26 OYSTER CULTURE EXPERIMENTS IN LOUISIANA. the following table of the specific gravities observed during four calendar years: Spreciric GRAVITY OBSERVATIONS IN WATERS OF ST. BERNARD PARISH. Locality. | 1906. | 1907. 1908. | 1909. Lake (Boren: 4. .2. A naa tee ke eee aaa aes | TOOGSilie 1041s eae ae | 1.0051 MAISEMLOUtH BAY rr Seon ete eee ee ae eee | 1.0074 1.0058 | 1.0016 | ~— 1.0075 Three=milenB ayiscae see eee ae eens oe neers eat | 1.0070 | 1.0054} 1.0041 1. 0083 TreAaSUITe: Bay cise sacs mee einen aia ee eae eee eee eee ees || eOL06%) Ss0096n inne eee 1.0125 Big Musselub aye. ee eee eg Sie NAS eee Ue 1) OO | ests OLS) | See | 1.0128 WIGINB Ry Sates se MO RO. ak oe ak Se ea 101253 | WA O15 Oy|ene esos eee Saw: Baise se ae a een eee oe MDE BANS ea ae te eee ce ee Ve AOL 75) = SA OLS5) eee eee 1.0159 Blind, Bayey ene ee eee ay en em The tee 4 Eee [Pe atOTOSH ee 01G2) ae eeenee 1.0170 Caligo Raivio a. tiene miners ne ae ier ce ee Pieeibaraeee I O200 "|: eKONG2) See ean | 1.0159 In the northern localities the water is rather too fresh to produce palatable oysters for shell stock, though this does not affect their utility for shucking and canning purposes. In this region, as a whole, oyster food is abundant, a large number of observations indi- cating that it is about equal in this respect to that part of Placque- mines Parish adjoining it, east of the river, and only exceeded by the waters of Barataria Bay. It is considerably richer than either Terrebonne Parish or that part of Placquemines Parish, as a whole, lying about Bay Adam, Bayou Cook, and Bastien Bay. The richest waters are Falsemouth Bay and Treasure Bay and the poorest those lying near Three-mile Bayou. The depth of water ranges generally from 3 to 6 feet in the bays, but is often much deeper in the bayous. The bottoms are generally soft, in many places too soft to be used for oyster culture without special preparation, but there are also considerable areas of hard or moderately hard mud. Even the softest places may be made avail- able by strewing them with shells, sand, or gravel, but there is un- doubtedly enough naturally suitable bottom to Mie this unnecessary for some time to come. For experimental purposes in this region there were selected two localities not far apart but differing in all factors involved except- ing that of’ salinity. The localities, the experiments, and the results are described in the following: FALSEMOUTH BAY. Falsemouth Bay lies in the northwestern part of the Louisiana marsh and communicates with Mississippi Sound by means of Nine- mile Bayou, a channel from 100 to 300 yards in width, and with an average depth of about 24 feet. A smaller, though deep, bayou leads to Nine-mile Bay to the eastward, and there is wide communi- cation at the southeast end with the lower part of Nine-mile Bay and the upper part of Treasure Bay. ~I OYSTER CULTURE EXPERIMENTS IN LOUISIANA. 2 Writing in 1898 one of the authors said: It seems probable that the scarcity of oysters in Falsemouth Bay is due in large part to the lack of suitable places of attachment for the spat, and if this be so there is but little doubt that productive beds might be established by plant- ing shells, together with a sufficient number of brood oysters to furnish fry. We found here the largest area of firm bottom discovered anywhere within the limits of the reconnoissance. In most other parts of the district the hard bottom is distributed in small patches lying like islands in the midst of soft mud, but in Falsemouth Bay shells and seed could be deposited almost any- where without danger of becoming engulfed. The amount of oyster food is larger than almost anywhere else in the district, the average number of diatoms in each liter of water 1 foot above the bottom being about 22,000. The extreme fatness of the oysters is also ample evidence of the abundance of food, although, of course, the amount available for each individual would become less if planting were extensively undertaken. Although, as previously stated, considerable areas of bottom have been leased in contiguous and neighboring waters, the recommenda- tions just quoted have borne no fruit, and it was with the purpose of testing their validity that experiments were undertaken at this place. ~The site selected for the experimental work was in a small bight in the northeastern part of the bay, about one-third of a mile from the mouth of a deep cut-off running into Nine-mile Bayou. The water has a depth of about 34 feet at low tide. Pirate Point on one side and a chain of several small islands on the other form a somewhat funnel-shaped area with its small end opening into Nine-mile Bayou and its large end communicating with Treasure Bay and the waters to the eastward. The tidal flow enter- ing and leaving the interior waters in large part passes through this area, and, as the bayou communicating with Mississippi Sound is - wide and deep, the currents, especially in the northern part, where the plantation is located, are moderately strong and_ constant. Measurements on the planted beds indicate a current of about one- half mile per hour on moderate tides, and observation showed the rate to be approximately uniform over an area of several thousand acres in this vicinity and probably over the entire eastern part of the bay. The importance of this fact need not be indicated to prac- tical oyster planters. The salinity of the water is comparatively low, rendering the oys- ters rather insipid when used as “shell stock,” but not interfering with their value for the shucking trade. During the spring and summer of 1908 the water was nearly fresh, its specific gravity rang- ing about 1.0020, but at all other times during the experiment it was somewhat higher, fluctuating between 1.0030 and 1.0092, with an average of 1.0056 for the entire period and about 1.0070 in the oyster season. During the three years of the investigation there was 28 OYSTER CULTURE EXPERIMENTS IN LOUISIANA. nothing to indicate any mortality among the oysters due to the low salinity of the water. The floor of Falsemouth Bay is level and clean of all rubbish and débris. The bottom is quite uniformly composed of hard mud, much like that of the surrounding land, though there are occasional small patches of softer consistence. The bay has an area of about 11 square miles, and over practically all of it oysters and shells may be planted without danger of being engulfed. There are not now, nor, apparently, have there ever been, any natural reefs, and the few very scattering oyster growths observed in 1898 seem to have been exterminated. In oyster food Falsemouth Bay was found to be one of the richest places in Louisiana in 1898, and the results of the present examination show that it retains this rank. The average oyster-food content of its waters from May, 1906, to January, 1909, was higher than that of any other locality observed, excepting only the middle of Bara- taria Bay. Falsemouth Bay and Bayou St. Denis, in Jefferson Par- ish, were about on an equality. The following table shows the fluctuations in the observed food supply, together with the specific gravities and temperatures of the water at various times during the course of the experiments: Foop CONTENT, SPECIFIC GRAVITY, AND TEMPERATURE OF WATER IN FALSEMOUTH Bay. Food organisms per | Temper liter of water. Sea Pane - | Date. Density. ature. | | | Number. | Volume. 1906. ip de Cu. mm. Mayon. oh Ae reas 2 Ss ee eter Ea ache se eee neater ae 1. 0092 72.5 38, 000 1.594 Fares Pease eae Pena LS Soe Renee Wiehe “phy ene eR 1. 0064 86.0 5,500 - 201 Jtalyell72 e282 agi hs Ae ee ee se te fore De eee an, - 1. 0066 82.0 8, 000 . 216 1907. SEMEN ELT YQ. O15 tere tern eaete ta ec eet stage = ola cla eee eee 1. 0084 64.0 4,000 - 094 A] 0 1 (8 PR SR Neeser CoAor Hor SSR ab oepmcer mr aDonen Se eco cae ob 1. 0059 72.0 9, 000 . 316 Malice == boeken Roem hs 282 tales oo Be oy to eae a Seer eee 1.0030 77.0 14, 400 - 436 Tern Oishi Fe CS ee See a aaa eee taeyst ys 1. 0028 84. 2 7, 200 - 291 01 eRe ee dee Aer ee ee AE Oe 8 ook aa eoe 1.0079 87.8 2, 500 - 067 December 13). 22 3. fehl ose etek ass os ee ce ee ae 1.0070 54.5 5, 400 . 226 1908. Anil! 23-25. sae. tae cease tae eno ere ee ences eretetass 1.0020 79. 0 7, 200 372 JUS se Sie weed ea) eee eo Se Oe eee eer eee 1.0030 87.0 3, 750 173 July 12. oe bose ates ohn ae Oe ae Hee eee Se eee ee ers 1.0029 85.0 7,500 346 1909. January 24: 02.5 2h gare jase nen eee sae ae 32 SeE eS: | 1.0075 | 64.4 4, 800 -119 AVOTAP es oho tk eb tk ees SES Se ele ee ee eee ene Pome T30056)|EEe Sasa 9, 020 . 342 No oyster enemies whatever were observed in this locality. ‘The water is too fresh for the borer ever to become troublesome, but the drumfish, which operates in water of all degrees of saltness, might make occasional forays if oysters were numerous enough to be attract- UNS. Bak Docw7sil PLATE VI, OYSTERS, AVERAGE SIZE, 1 YEAR OLD, GROWN ON OYSTER SHELLS AT FALSEMOUTH BAY LOUISIANA. THE UPPER FIGURE SHOWS THE CHARACTERISTIC DEEP CUP [Figures natural size.] OYSTER CULTURE EXPERIMENTS IN LOUISIANA. 29 ive. There were a few mussels and barnacles attached to the planted oysters, but they were not abundant enough to be troublesome. The experiments in Falsemouth Bay began on May 6, 1906, and subsequent plantings were made on June 10 and July 17, 1906; April 12, May 16, June 9, and July 7, 1907, and April 23 and June 5, 1908. The final examination was made on January 23 and 24, 1909. In all, 14 plantings were made, of which 2 were of clam shells, both whole and broken, spread broadcast, 9 were of oyster shells, broadcast, and 2 of oyster shells in piles. The quantity of oyster shells planted varied from 200 to 1,000 bushels to the acre and the clam shells from 200 to 600 bushels per acre. The clam shells, which were hardly more than 11 inches in diameter, were obtained from neighboring shell banks, and many of them were fragmented by wave action. On the whole they did not prove satisfactory, the entire shells being scattered by the waves and the fragments soon becoming so covered with silt and mud that they offered very imperfect places for the attachment of the oyster spat. ‘The oysters produced on these shells were all single and of fine shape, but, as was also observed at Bayou St. Denis, they grew more slowly than those attached to oyster shells. If somewhat larger and heavier clam shells can be conveniently obtained, they would doubtless make excellent cultch, but the use of the local supply can not be recommended, except for the purpose of hardening the small areas of soft bottom which occasionally occur in the bay. From 60 to 90 per cent of the oyster shells were found to bear small oysters at the end of the season in which they were planted, the spat striking in every month from April 11 to July 17. Doubtless shells planted a month earlier and a month or two later would prove as effective as in Barataria Bay, but there is no positive evidence of the fact in this locality. The average number of oysters attached at the end of the season, after they had attained a length of 1 to 2 inches, was from two to three per shell, there being some larger clus- ters and a good proportion of single oysters. The set was much lighter than in the adjacent waters of Three- mile Bayou, owing undoubtedly to the relative remoteness of con- siderable beds of spawning oysters. This is of considerable advan- tage in avoiding crowding of the growing oysters and promoting a better shape and condition. Should the bay be used extensively for planting shells it will probably be found that the set will be much heavier than now occurs, and to secure the best results it may be necessary to break up the larger clusters produced so as to give the individual oysters room to grow and fatten. Under the present con- ditions from 400 to 500 bushels of cultch per acre appears to be the best quantity to plant, but with any heavy increase in the number of 80 OYSTER CULTURE EXPERIMENTS IN LOUISIANA. spawning oysters in the vicinity, as from extensive planting opera- tions, this quantity may probably be advantageously reduced. The yield per acre of the planted beds could not be determined, as prior to the final examination the oysters proved too attractive to the tongers, and most of the plantation was despoiled of both oysters and shells. Certain small areas which had been overlooked by the marauders, however, indicated that the growth on some sections at the end of about thirty months from the time the shells were planted was probably between 1,000 and 1,500 United States standard bushels per acre. The oysters were of good shape and very fat. Those grown on oyster shells were from 3% to 43 inches long and averaged about 200 to the bushel, while those on clam shells were of even finer shape and averaged about 3 inches in length. The shells were rather thin, but somewhat thicker in the clam-shell set than on that attached to the oyster shells, in the former consituting 70 per cent of the total volume of the unopened oyster, and in the latter 55 per cent. The oyster-shell set averaged about 200 oysters to the standard bushel, considerably more than oysters of the same length at Bayou St. Denis, the difference being due to the much thicker, heavier shells of the latter. These oysters, taken “the run of the bed,” without selection, shucked shghtly over 7 pints of completely drained meats per. standard bushel. The single oysters grown on clam shells were relatively fatter, but owing to their thicker shells would “ turn out ” no more meat per bushel. Taking all factors into consideration, Falsemouth Bay appears to possess very great advantages for planting operations on a large scale in connection with the shucking trade, but the salinity is too low and the shells are rather too thin, excepting those grown on clam. shells, for raising “ shell stock ” or “ counter ” oysters. The bottom is almost everywhere firm enough for planting, the rate of growth is rapid, the shape of the oysters is good, and the relatively thin shells, taken in connection with the plumpness of the meats, insures a large yield of shucked oysters per bushel, effecting economy in transportation and opening. The meats are also attrac: tive in appearance and should command a good price as “ extra selects.” The only drawback is that the shells are in some cases rather brit- tle and may break in opening, but this defect is more than counter- balanced by the large quantity of meats “turned out” per bushel. Either seed oysters from the natural reefs or cultch may be planted to advantage. In the latter case it is not unlikely that, if a consid- erable part of the bay is converted into oyster bottom, the set of spat. may be so heavy as to require the clusters to be broken up at the end of the first season’s growth. U. S. B. F.—Doc. 731. PLATE VII. OYSTER, AVERAGE SIZE, 33 MONTHS OLD, GROWN ON OYSTER AT FALSEMOUTH BAY, LOUISIANA. [Figure natural size.] SHELL G . - Fanan as. see as eet ae ‘ OYSTER CULTURE EXPERIMENTS IN LOUISIANA. 81 It is believed that over a large part of the bay the bottom is sufli- ciently. firm to permit the use of ight dredges on the planted beds. {In water so shallow as that in Falsemouth Bay the dredge, as com- pared with tongs, is not so economical as in deeper water, but it is believed that it would be cheaper to operate in case of a scarcity of labor. In Falsemouth Bay, as everywhere else, however, there is a lhmit to the quantity of good oysters that can be produced, and should the planting industry be established there care should be exercised that neither the density of growth nor the area planted should be- come excessive. The desire of persons already established to grow as many oysters as possible on a given area, and the equally strong desire of prospective planters to establish themselves in places where others have been successful has more than once brought difli- culties to all. THREE-MILE AND NINE-MILE BAYS. Three-mile Bay and its contiguous waters constitute the most im- portant oyster region of St. Bernard Parish. Three-mile Bayou is a broad, deep passage connecting Mississippi Sound with the inte- rior of the Louisiana marsh, and the vessels engaged in carrying oys- ters to the oyster houses and canneries on the mainland lie in the sheltered waters at its inner end to receive the cargoes brought there by the luggers engaged in oystering in the adjacent bays and bayous. In 1905 a large shucking house was erected on the shores of this bay, with the purpose of avoiding the transportation of the bulky, unshucked oysters to the mainland and the return of the shells for planting on the large area which the operating company had leased for that purpose in the waters adjacent to the establishment. Owing to the difficulty of obtaining employees to work in a locality so re- mote from settlement, and perhaps to other causes not stated, this establishment was soon abandoned. In addition to the bottom held by this company there are several thousand acres under lease in this vicinity and practically all of the leases issued in St. Bernard Parish are in these or immediately adjacent waters. It is an interesting observation that these planters have overlooked the advantages of the near-by bottoms in Falsemouth Bay to take up areas which are in almost every respect inferior, this action being dictated by the existence of natural beds in the one region and their absence in the other. The fact has been overlooked that the presence or absence of oysters is in many cases conditioned solely by the pres- ence or absence of clean, firm bodies to which the young may attach. Oyster culture in this region has consisted partly of planting seed 32 OYSTER CULTURE EXPERIMENTS IN LOUISIANA, oysters from the natural beds, but largely in the deposit of shells, neither having as yet proved very profitable for reasons which were developed by the result of the Bureau’s experiments. The experimental plantation was located about one-third mile west of Shell Point, practically on the border tine between Three- mile and Nine-mile bays, though rather in the latter than in the former. It is about 24 miles in a straight line from the Falsemouth Bay plantation, though the water route between the two, owing to the interposition of Pirate Point Island, is over 4 miles. South Bayou, a shallow body of water with sluggish currents, opens through the shore line about one-fourth mile distant. Between the plantation and Raccoon Island there is a scattering natural growth of oysters of fairly good shape and quality. The water at the plantation is about 34 feet deep, gradually shelving to 5 and 6,feet toward the middle of the bay. Tidal waters enter the bay from Nine-mile and Three-mile bayous, flood tides meeting and ebb tides dividing near the plantation, and as the flow through South Bayou is insignificant the currents in this particular region are sluggish. The conditions in this respect are better in both directions along shore, and in Nine-mile Bay near the entrance to the eastern fork of Nine-mile Bayou and in most of Three- mile Bay proper the water flows with fair velocity. The salinity of the water during the period of the experiments was approximately the same as in Falsemouth Bay, the specific gravity ranging from 1.0028 to 1.0088, with an average for all observations of 1.0057. The average salinity of the waters of Three-mile Bay proper is somewhat higher, the specific gravity off Shell Point aver- aging about 1.0076. The average during the oyster season was slightly less. The significance of this comparative freshness of the water in its effect upon the flavor of the oyster and the occurrence of enemies has been mentioned in connection with the description of Falsemouth Bay. Away from the immediate vicinity of the shore the depth of water in Three-mile and Nine-mile bays is between 4 and 6 feet, with some- what shoaler spots on some of the dense, natural reefs. The bottom on the plantation is composed of moderately soft mud, which grows softer offshore, though its consistency is such as to permit the success- ful planting of shells over a considerable area. The supply of oyster food in Nine-mile and Three-mile bays is comparatively low, on the plantation averaging but about one-half the quantity per unit of water found in Falsemouth Bay. Farther to the eastward, off Shell Point, the quantity is somewhat greater, and to the southward the quantity increases from the mouth of Falsemouth Bay to Treasure Bay, where the waters are approxi- OYSTER CULTURE EXPERIMENTS IN LOUISIANA. 33 mately as rich as on the Falsemouth Bay plantation or at Bayou St. Denis, in Jefferson Parish. The following table exhibits the observed data in respect to the oyster food supply, the specific gravities, and the temperatures of the water at the plantation: Foop CONTENT, SPECIFIC GRAVITY, AND TEMPERATURE OF WATER IN T'HREE-MILE AND NINE-MILE BAYS. Food organisms per F liter of water. I Specific | Tempera- Date. gravity. | ture. Number.) Volume. : | 1906. CY ie | Cu.mm May RS cee no eee eee ete as meh mete eee oa ds ose tees 1. 0054 TONSA eee oe jm esecs a3. Oe cease teste Nae feo Sate ose on ae ono a ees Sack ene es ae mwas se se 1.0065 | 72.5 11,000 | 0. 290 Jume' 98 ceW yee essed eek a quik asec eee coda geass eee cceew te. 1. 0082 | 86.0 , 500 | - 078 Uae 1G s,s ee a lo ee cir ec aa, She Wis eS ee ae oe 1. 0080 83.0 6,000 | 060 | } 1907. Jamudany: 5 fccke 1s nc etlsae ee eee eae sae eee abo, eS 1.0088 | 65. 0 | 2, 500 | 053 APE 2 a 8: Se Saw ee a ee Se oe Se Sere ne ae ees 1.0077 | 75.0 7,800 | . 203 Manyliici sy tease ht ee See ee rs eee mean LE 1. 0057 | 75.2 8, 250 | 307 G32 5.22 2.crate cic Oe re Re ES Ne cre ce dar 1.0038 | 68. 0 7,000 | 282 Tae 9 he c ! eb tees - SS SS Ee eee oe ea eee ee eee 1. 0028 84. 2 4, 500 210 Hl (RE le Py A 2 Fe RS OO eo ae oes fe 1.0090 | 84.2 2, 500 | 037 December lS; oes io. cathe se ake cee eR Oo Ee | 1.0071 55.0 | 4,500 | 238 1908. | | DIMES Dem 3 ero etic acts ae SE te ne tei ote Ce ee). 1.0040 | 87.0 750 . 040 Juahy gle see oe ee She 28 Sa epee SN ke | 1.0042 $4.0 4, 500 | od | 1909. | | | | JAMA OS eres Seer aso in oS aie SRL oe Se ee ee ode 1.0083 | 68.0 | 11,000 304 INVEYOEOL. Sooo e te oc coe ee Fk k Shai (st Bap | eae. *| 5,271 | ATi During the investigations of 1898 a few borers were found in Three-mile and Nine-mile bays, but none were observed during the experiments here dealt with, and it is probable that they are never destructive owing to the prevailing low salinity of the water. There were, however, many mussels attached to the oyster clusters, and in some cases they undoubtedly interfered materially with the growth of the oysters and seriously curtailed their food supply. The site for the experiment was selected partly for the sake of comparison with the work in Falsemouth Bay, and partly because it was located on leased bottom and under the care of a watchman. The plantings were made practically synchronously with those in Falsemouth Bay, and in essentially the same manner excepting that no clam shells were used. The first plant was made on May 8, 1906, and others followed on June 9 and July 16, 1906; April 12, May 15, June 9, and July 7, 1907, and on April 23 and June 6, 1908. In all, 16 plantings were made, of which in 11 cases the shells were spread broadcast, and in 5 cases in heaps of from one-half to 1 bushel each. As in Falsemouth Bay, the quantity of shells varied from 200 to 1,000 bushels per acre. 34 OYSTER CULTURE EXPERIMENTS IN LOUISIANA. The strike was much heavier than in Falsemouth Bay, a phenom- enon correlated with the greater number of breeding oysters in the vicinity and the consequent more general and copious distribution of the free-swimming young oysters. During the first year about 95 per cent of the shells tonged up after the lapse of a few months bore spat, and the average number of young oysters was 6 or 7 to the shell, but after the lapse of the first year the number of oysters per shell had decreased somewhat. In the second year the number of. shells receiving a strike was about the same, but there were fewer spat per shell. In the first year the clusters were composed of from 1 to 11 individuals, and in the second year of from 1 to 7 or 8. Considering the density of the set in these waters the experiments indicate that the shells should not be planted in greater quantities than from 200 to 400 bushels per acre, though on the softer bottoms, where some of the cultch will sink in the mud, the quantity may be increased with advantage to perhaps 500 bushels. On the bottom experimented with there was apparently no advantage in depositing the shells in piles and, in fact, the more evenly they are distributed, the less the chance that the oysters will become so massed as to inter- fere with their growth and nutrition. The yield per acre at the end of the thirty-two months was about 1,500 standard bushels of culled oysters, with about an equal amount of shells, fragments, and mussels. The oysters were badly clustered and the débris was made up largely of those which had died from overcrowding. They were long, narrow, thin-shelled, and in general of the type known to the oyster men as “ coony ” or raccoon oysters. These oysters were about 2? inches long at the end of eleven months, 34 inches in twenty months, and from 4 to 5 inches, with an average of about 44 inches, at the end of thirty-two months. Although they were longer than those of corresponding age raised in Falsemouth Bay, they were so narrow and flat that the latter were over 50 per cent more bulky in specimens of the same length. The volume of the shells in both cases bore about the same relation to the total volume, and the difference was solely in the deeper and more capacious cavity of the Falsemouth Bay oysters, which is correlated with the volume of the meats. By actual count the 32-months-old oysters raised on this plan- tation averaged about 240 to the standard bushel and they turned out about 84 and 4 pints of drained meats per bushel, approxi- mately half the quantity yielded by a bushel of Falsemouth Bay plants. This extremely low yield for such thin-shelled oysters- was due in part to the small size of the cavity, but also largely to their extremely poor condition as regards fatness. The experiment was tried of culling the oysters on half of one section of the planta- U, S. B. F.—Doe. 731. PLATE VIII. OYSTERS, AVERAGE SIZE, 33 MONTHS OLD, GROWN ON OYSTER SHELLS AT THREE-MILE BAY, LOUISIANA. [Figure natural size. ] OYSTER CULTURE EXPERIMENTS IN LOUISIANA. oo tion one year after the shells were planted and it was found that these oysters, broken in small clusters, improved somewhat in shape and yielded a larger return of meats per bushel, though they were not any fatter than the unculled oysters on the adjoining bottom. Owing to their shape, clustering, and poor condition, the oysters raised at this place were useless except for steaming. Planted oysters in other parts of the bay were found to be almost as poor in most respects, although perhaps a little fatter. These results are un- doubtedly due in part to the crowding of the oysters, and for that reason the breaking up of the clusters at the end of about nine or ten months would be advantageous, but more important factors are the sluggish currents in the places more remote from the discharges into Mississippi Sound and the general paucity of the microscopic life on which the oysters feed. So far as we have been able to learn the natural oysters in Three- mile Bay and immediately adjacent waters are never more than moderately fat and are often poor as measured by what is attained elsewhere, and it is evident that if oyster culture in this region is to be successful it must be prosecuted with caution. Care must be exer- cised to locate the planted beds in those places where the currents are strongest, as in the waters near Three-mile Bayou and the eastern fork of Nine-mile Bayou. Oysters and shells should be planted rather sparsely and effort made to prevent the formation of large clusters, or if they are formed they should be broken up as soon as the individuals attain a size and strength of shell to permit culling. Not only must an excessive density of oyster growth be guarded against but the total area planted should not be allowed to become so ereat as to overtax the powers of the water to produce food organ- isms. The authors do not regard this locality as a very promising field for oyster culture, though, undoubtedly, large quantities of oysters of rather poor quality can be produced. It may be that the place will prove valuable for the raising of seed oysters for transport to localities more favorable for fattening. TERREBONNE PARISH. Terrebonne Parish includes practically the whole oyster-producing region between Barataria Bay and the mouth of the Atchafalaya River, the product of Lafourche Parish, which adjoins the west side of Jefferson Parish, being insignificant. Several large bodies of water, the western part of Timbalier Bay, Terrebonne Bay, locally known as Cat Island or Wine Island Lake, Lake Pelto, Lake Barre, and Lake Felicity, are included within the limits of the parish, and there are numerous smaller bays, lakes, and bayous which now yield or have yielded oysters. The parish is the westernmost in 86 OYSTER CULTURE EXPERIMENTS IN LOUISIANA, ~ which good oysters are produced in considerable quantities, the beds in Iberia and St. Mary parishes furnishing oysters of low grade, few of which are useful for purposes other than steaming. In the oyster season of 1906-7 Terrebonne Parish produced about 190,000 bushels of oysters, and in the following season approximately 300,000 bushels, the increase being due to the beginning of productiveness of several extensive leaseholds. In 1897, 353,000 bushels of oysters were produced in the parish, practically all of which came from the natural beds. Mr. L. R. Jary * states that many of the productive natural beds examined by the senior author in 1898 had been almost obliterated in 1907, and that the greater part of the oysters produced in the parish in the latter year were derived from planted beds. . In 1898 there were in effect in this parish but 32 leases, the ageregate area of which could not, legally, have been in excess of 320 acres, and in reality was probably less. In 1908 there were in force about 430 leases, aggregating about 6,000 acres. Most of these were for parcels of less than 20 acres, but there were several holdings of between 100 and 1,000 acres. The recent tendency has been for the large leaseholders to surrender parts of their bottom, retaining such portions only as experience has indicated to be the most suitable and profitable for oyster culture. The methods of culture followed usually have not been such as to produce the best grade of oysters. Very few shells are planted and the seed obtained from the natural beds is usually planted without culling, the result being that the oysters grow in large clusters to the serious detriment of their shape and nutrition. If care were exercised to break up the clusters properly into smaller ones or single oysters, the product could be materially improved in shape, quality, and value. The salinity of the waters of Terrebonne Parish appears to have increased in recent years from the same causes that have operated to raise the density in the upper parts of Barataria Bay, changes in drainage due largely to improvements in the levee system. It is stated that at places in Terrebonne and other bayous where oysters now grow the water was formerly fresh enough for cattle to drink. This is confirmed by a comparison of recent salinity observations with those made in 1898, though the, latter were so few that they do not serve as a satisfactory criterion of conditions at that time. The average salinities observed during the present investigations are shown in the following table: «A preliminary study of the conditions of oyster culture in the waters of Terrebonne Parish, La. Bulletin 9, Gulf Biologic Station, Cameron, La. OYSTER CULTURE EXPERIMENTS IN LOUISIANA. at SALINITY RECORDS FOR WATERS IN TERREBONNE PARISH. Locality. 1906. 1907. 1908. | 1909. Sp. gr. | Sp. gr. Sp. gr. Sp. gr. MimlbAlierwBayyet . . 825.2 arabs deaageecte metre eet aiapeteispore ces = 1.0177 1.0156 1.0109 1.0194 Wace PHOLCIUY Eo. - cok cam nek wince oe eee nace oe Dae ee ee eeicee 1.0166 TRO 1 | ee ere ae ee ACW AET OD fare aioe cout Se meh eee anne ecion seal eceesina asics 1.0166 ROUGE: reer saa ao. se oers. c= PICA DROZ «oaths Gre o sree SCR eA ES See Ree emia oe clnaticl- 1. 0164 POUGIN tees Doe st sorte aaree= IB AVARLCINICKGs 2... uccccdek age eee 260 OE ee cietntine mena Vlas Seep LE 2OD) | ieee ee | se aie | ae ee eacep inal GTalsse yo pee eee ee ed ene eincaion enti d TOT G Aa ee ae etree |e ee a Slee aye Chammiplerbss, yang eee eaccer caaneee oem cna = fue seein: cig tel eee = ee WRONG Se So aemee SSeS Se MerreboOune: Bay; sane pee ene oe sees See eee Secncoecassinac hone 1.0172 TROUSON Meet see | sere ose bake sel tO we grace ae + oe acres oe i SEE SAE Lo RS Pe eae 1.0180 HE (CHESS iy | oa Senne UR Ee a a Pelican Wakeisse eos Rie Eph tare cee nas Sere a oad tae ee 1.0172 1.0161 1.0160 | 1.0192 The localities listed above are all in the region of higher salinities, and in most places it would probably be impossible, or at least im- practicable, to raise oysters on cultch, owing to the liability to attack by borers. It is probable that the disappearance of many of the natural reefs is as much due to these conditions as to overfishing, the two agencies together proving disastrous where either alone would be tolerated. In the region west of Pelican Lake, where the saltness of the water is mitigated by the discharge from Atchafalya River, and in Terrebonne, Little Caillou, and other bayous which carry fresh water from the interior, the conditions are apparently such as to permit the set and growth of young oysters on suitable planted material. Considered as a whole, that part of Terrebonne Parish under ob- servation during the present investigations was about as rich in oyster food as that part of Plaquemines Parish west of the Missis- sipp1 River, was considerably poorer than Barataria Bay, and was somewhat less prolific than the region east of the Mississippi in either Plaquemines or St. Bernard parishes. Food organisms were found to be most abundant in Timbalier Bay and Pelican Lake, where the supply was good, and least numerous in the open waters of Terrebonne Bay. The depth ranges from 3 to 10 feet in the larger bodies of water, but is much deeper in many passes and bayous. There appear to be no very extensive areas of hard bottom in the region observed, ex- cepting on the extinct natural beds, but there are many places where the bottom, while soft, would support deposits of shells or seed oysters, and there is usually a narrow fringe of hard bottom arosnd the shores of the bays. The experiments in this parish were carried on at two places, Sea- breeze and Pelican Lake, but in neither case were satisfactory results attained from the planting of shells. Undoubtedly more favorable places could be found, but the general inaccessibility of the region and the lack of living accommodations operated to restrict the choice of localities. 38 OYSTER CULTURE EXPERIMENTS IN LOUISIANA. SEABREEZE. Seabreeze is the name given to an oyster house, no longer operated, situated on Bayou Terrebonne where it is intersected by Bayou La Graisse and the cut-off to Lake Barre. Below this point Terrebonne Bayou is very shallow and its discharge is mainly through Bayou La Graisse and the cut-off into Terrebonne Bay and Lake Barre, respectively. There are a number of leases located in this vicinity in Terrebonne Bayou, Bayou La Graisse, and Lake Barre, but they are all or nearly all on extinct oyster reefs and are planted with seed oysters obtained from the natural beds. Experiments were under- taken at this place for the purpose of determining whether a method could be devised for using the exceedingly soft bottom common at many places in the parish, and whether the physical and biological conditions were such as to permit the set and development of young oysters on planted materials. The site selected was a small cove on ihe north side of Bayou La Graisse, where the water has a depth of about 2 feet and the mud is so soft that a man wading will at once sink above his knees, a consistency which any experienced oyster grower would at once pronounce prohibitive. The currents in this cove are sluggish, but a strong circulation is maintained in the ad- joining bayou. The salinity of the water at this station is compara- tively high, the specific gravity during the two years in which records were made ranging between 1.0138 and 1.0206, few observations de- parting materially from the general average of 1.0163. The waters of this vicinity are but moderately productive in oyster food, the observations made in Lake Felicity, Lake Barre, Terrebonne Bayou, and on the experimental beds yielding approximately the same average results. The following table gives the record on the experimental beds: Foop CoNTENT, SPECIFIC GRAVITY, AND TEMPERATURE OF WATER ON EXPERI- MENTAL OYSTER BEDS AT SEABREEZE. Food organisms per : liter of water. Dat Specifie | Temper- UC gravity. ature. Number.| Volume. 1906. ris Cu.mm. Aspril30. 1335225 .anc2 sess sake oe ties area eee aera 1.0174 78.8 13, 500 0. 297 Mav Oi. ir SE a aR oe A eee ee eae eee 1.0158 80.6 9,000 .193 ie: | Maa eee etE SA SAE INS SOY EAS Gun pace 1.0171 83.3 8, 000 . 286 On eee Se eee nA Se Oe aoa S Tose 1.0165 86 oc ees eee 4 bho Ts) CGO. Ae ree Cah ee Mine Sei Sao ao 5 5el 1.0162 83.3 6, 000 . 190 i fot hs ee ee Se ee OORT AE Ho sisc bse Blea e ica IAS | 1.0164 78.8 1,000 016 ct SL Oe ee ee anda ope a QS Soe | 1.0184 78.8 2, 000 «152 1907 JANA Os. cree eles no saee eee BE ERE area 8 BSE 1.0205 2 5, 400 . 144 Artal 20 joa rcieiaie eicintets yate =n) =jnon eStart ete pen eee == 1.0158 66.5 1,800 . 097 Ri ohals\e eee 4 eee Cae ee Sei nee ee aia a he anes 1.0146 87 2, 500 . 149 PC eee or enon Ge nee eee ee ee eemecat: Detic 445A sabe 1 OLGS | PSatee sae 5, 355 . 169 OYSTER CULTURE EXPERIMENTS IN LOUISIANA. 39 No actual observations of oyster enemies were made at this station, but the conditions are such as to make it probable that the borer may occur in sufficient numbers to prevent the successful application of the methods of planting shells and other materials for the purpose of securing a strike of spat. At this station no brood oysters were planted, the supply of floating fry originating on the natural and planted beds in contiguous waters being amply sufficient to fill all requirements. In all 16 plantings were made, the methods being more varied than at any other station. The first cultch was planted about the end of April, 1906, and additional sections of the bottom were planted on the last of May and early in July of the same year. The results were such as to discourage further work, and after a final examination of the beds in April, 1907, the experiment was abandoned. Oyster shells were deposited both broadcast and in small piles in proportions varying from 400 to 600 bushels to the acre, and after the lapse of about one month were found to be so densely covered with spat as to defy count, in many cases the small oysters being superimposed in several layers. At the end of two months many of the shells spread broadcast had become engulfed in the mud, but those still unburied bore large numbers of young oysters measuring between three-fourths and 14 inches in length, with many smaller ones. The shells deposited in piles were still unburied in larger proportions, and all not covered by the mud, whether they were on the surface of the piles or in the interior, bore an average of about 35 young oysters, each ranging from one-half inch to over 14 inches long. In April, 1907, practically all of these shells, both those spread broadcast and those planted in piles, were buried in the mud. Only 4 or 5 shells, of those planted in piles, were recovered, and these bore 7 oysters, the largest of which was 23 inches long. Other shells were planted on a flooring of palmetto leaves, on the supposition that the fibrous matter of the latter would resist decay and serve as a mattress to prevent the sinking of the shells. Though this experiment was by no means a success the results were the best attained in this locality, and after the lapse of a year a few oysters measuring 14 to 33 inches long were recovered from the bed. It is possible that in the remote future, when it may be advisable to utilize the very soft bottoms of Terrebonne Parish, some modification of this method may be of value, but it has no present utility. Several plantings were made of palmetto leaves and brush thrust by their stems into the mud. It was hoped that these materials would hold together long enough to yield marketable oysters and that the vege- table fragments and oysters falling to the bottom would eventually stiffen the consistency of the surface mud and make a firm foundation for future operations. The strike on these materials, especially on 40) OYSTER CULTURE EXPERIMENTS IN LOUISIANA. the palmetto, was enormous in quantity. Atthe end of the first month there were over 800 oysters between one-eighth and one-half inch long on each leaf and there were probably over three times that man smaller spat. One month later, however, practically all of these had dropped off and had become lost in the mud, while the few still at- tached fell away at the slightest touch. After the lapse of a year no trace of oysters was to be found, the brush had become covered with slime and more or less rotten, while the palmetto was reduced to a few wisps of fiber still attached to the stem and a small mass of decayed material on the bottom. The foregoing experiments exhausted the list of cultch materials available at this place, and in view of the results the work was abandoned. It is believed that the hopelessness of the attempt to use at present the very soft bottoms in this vicinity has been demon- strated. They undoubtedly can be made available for oyster culture by the use of large quantities of sand or shells to form an artificial firm surface, but such materials would have to be transported long distances and the expense would be at present prohibitive, especially in view of the area of naturally more favorable bottom to be found in adjacent waters. That a prolific strike occurs in this region was shown and it is probable that it can be depended on yearly. It was also demonstrated, by the few surviving oysters, that the conditions are favorable for very rapid growth. PELICAN LAKE. After the abandonment of the plantation at Seabreeze, experi- ments were begun at Pelican Lake, on the recommendation of the state oyster commission. Large operations in planting seed oysters from the natural beds had recently been undertaken by a company at Houma, and it appeared desirable to determine whether the method of cultch planting to catch a strike of young oysters was feasible. The location also appeared to have some advantage from the presence of a watchman to prevent depredations and the destruction of the boundary marks, but the expectations in this respect were not realized. Pelican Lake is a somewhat quadrangular body of water lying northwest of Lake Pelto, with which it communicates through Bay Rond and connecting bayous. At its southwestern corner it is con- nected with Wilson Bay and on its northern and northeastern borders are the mouths of several considerable bayous. The bay has an area of 5 or 6 square miles and a depth, toward the middle, of about 6 or 7 feet, graduaily shoaling to 3 or 4 feet closer to the shores. There are strong currents near the entrances of Wilson Bay and Bayou Go-to-Hell, but in the greater part of the lake they are sluggish. The salinity of the water is rather high, the specific gravity rang- ing, during the three years in which it was under observation, be- tween 1.0136 and 1.0209, the average of all observations, 34 in number, OYSTER CULTURE EXPERIMENTS IN LOUISIANA. 41 being 1.0167. The salinity is least in spring and summer and greatest in December and January. The bottom of the greater part of the lake is composed of soft mud, but there is a fringe of moderately hard bottom extending around most of the rim for a distance of several hundred yards from the shore. Near the entrance to Wilson Bay and at several other places in the southern part of Pelican Lake there are hard areas of limited extent occupying, apparently, the sites of extinct oyster beds. Oyster planting is at present confined to the littoral fringe of moderately hard bottom, and although the soft bottoms of the center of the lake eventually may be utilized, their preparation would involve an expense so considerable as to prevent their occupation until the naturally more suitable bottoms are more fully occupied. In oyster food Pelican Lake is richer than any waters between there and Barataria Bay, with the single exception of Timbalier Bay, with which it is about on a parity. In this respect, however, it is inferior to the sites of the experimental plants at Falsemouth Bay, Bay Tambour, and Bayou St. Denis, but is superior to Three- mile Bay and Seabreeze. The most prolific waters are in the north- ern part of the lake, where the influence of the strong currents in Bayou Go-to-Hell is experienced, the region close to Wilson Pass, also a locality with strong currents, being fair. The fluctuations in the food supply, the specific gravities, and the temperatures of the water, observed at various times during the course of the investiga- tions, are shown in the following table. In most cases the data re- corded are the averages of several observations made practically simultaneously in different parts of the lake. Foop CONTENT, SPECIFIC GRAVITY, AND TEMPERATURE OF WATER AT PELICAN LAKE. Food organisms per Specicel i Permner liter of water. peci e - Date. gravity. | ature. i Number. | Volume. 1906. Or Cu. mm. ibe (053.5 Be oR aeO Coe BoeeRE aD He OSCE BEE ME OBE RTO ace arodoc 1.0180 83.5 10, 900 0.119 auily, CES i a TI aN SR ee SOLS Sire eae a nie Bee TOSS Sse. aescee 4,125 .077 SUID TISGO EES: CoE ee cee eee tet aaa eat ce draenei sab eee ia\= 1. 0204 84 9,000 . 128 ISPRAATEL DY OS co BOR se EA as ee eRe orea > 1.0205 70. 7 12,875 . 302 nee 1. 0209 73 1, 800 082 a cUTUELAT Vathig aatela niet mtalel sei ate miseb octet aiaiciatarsiajalejetectafnyse\e mi aje'n aisere ln \ate . 02 3 : ‘April 20. Fe Se Pe cys eretat one RPE ote emi cteoue eee cele tele aia ietel= simi ote 1.0180 68 3, 600 . 193 Mir MRL: crores re aerate coer nee tee eta sagen enw iilaiga aie as 1.0170 7.9 10, 250 - 409 AL) Seapets Reena aes nee Sex GOT MM oni te: Soscics awate cemane 1.0156 73.4 8, 500 .312 20) pa Ree as Bek Meee OR LS OE eo o0 ro canctase aap aitaiars 1.0150 77 7, 325 BLS RING SOs cme See ee ene Sar RncCreME EGE pacisine = Steed cae vs kets 1.0168 86. 6 2, 850 .077 BULL 325 Scr eiel ees ee Se et spam fac attics hala tascim clniar a alais, shataieisjaies a 1.0145 87.3 2, 650 B64) HD ECEINDCL iis cere cet antes wets ales aisismetarsetioe c wcleclistde cle aeaaanns 1.0169 58 19, 500 - 943 e 4 1.0154 79.5 | 36,000 561 Eso S el ig IS AS aaa SS RIE ee ee, Sa Bon ee eS er 7 I ), 5 Tae ihhas 56 sega sete enc SHbr ee Bod Gh ie SSS SERRE ERE oA boo a Se 1.0171 83 5,000 . 235 INCOME O ocist ae cjeie< os ERE EEC Mewidiia cin ciel cle sicko riaateimets T0172) See eee 9, 598 277 42 OYSTER CULTURE EXPERIMENTS IN LOUISIANA. The drumfish is reputed to cause some damage in these waters and it is said that 5 per cent of the seed oysters planted are killed by it. There were formerly several natural oyster beds, but they are now wholly extinct, and it is stated that they have been unproductive for about twenty years. It is believed that the extinction of these beds is due largely to the great numbers of borers found in the lake. Dur- ing the progress of the experiments hereafter recounted practically all of the young oysters were killed by these industrious enemies, and it may be fairly assumed that the same conditions obtained on the original natural beds. With the majority of the spat being killed in this manner and the adults being taken by the oystermen, the utter extermination of the beds was practically inevitable. It is possible, also, that the water has increased in salinity, and, therefore, has be- come more favorable to the borers, through the improvement of the levee system and the consequent changes in drainage. We have no evidence that this is the case in the region under discussion, but it is undoubtedly true in certain localities to the eastward already men- tioned. The experiments in Pelican Lake were conducted on five sites, three in the northern part of the bay and two in the southern half. The characteristics of the several localities planted are as follows: Bed A.—North of the mouth of California Pass. Bottom soft. Currents moderately strong. Bed B.—West of the mouth of Bayou Go-to-Hell. Bottom moder- ately hard. Currents strong. Bed C.—On the west side of the lake about halfway between the preceding and Wilson Pass. Bottom moderately hard. Currents not noted. Bed D.—East of the mouth of Wilson Pass. Bottom hard, on edge of extinct reef. Currents of moderate strength. 5 Bed E.—South of the mouth of California Pass. Bottom soft. Currents moderate. On all of these the mud, as shown by mechanical tests with the mud-sounding machine, was sufficiently firm to warrant planting without previous preparation of the bottom. Planting of oyster shells spread broadcast were made on each of these beds in May and June, 1907, and, in addition, on bed E in April, 1908, in quantities varying from 600 to 900 bushels per acre. No experiments were made in planting seed oysters, as that method was already under trial on a large commercial scale. On May 9, 1907, a single planting was made on bed B, and on June 30 every shell was found to bear spat about one-half inch long, while on the same date sections of this bed and bed A, planted on May 27 and 29, had spat on from 25 to 45 per cent of the shells. Sections on beds C and D, in the southern part of the lake, planted on the same OYSTER CULTURE EXPERIMENTS IN LOUISIANA. 43 dates, were practically devoid of living spat, although there were a few dead ones bearing evidence of having been killed by borers. In April, 1908, when the beds were examined all sections of bed A were devoid of young oysters. On bed B every shell tonged bore numerous spat killed by borers, but there were among them a few young live oysters from 1 to 14 inches long. Bed D was entirely exterminated so far as living oysters were concerned, and the shells were much corroded by the yellow boring sponge, which produces the condition which the oystermen term “ worm-eaten.” On the section of bed E planted June 30, 1907, about 40 per cent of the shells bore, each, one or two oysters about 1 to 2 inches long in the following year, but an adjoining section planted in April, 1908, had a heavy set of spat entirely killed by borers when exam- ined in June. On the seed oysters which-had been planted in this lake there are a very small growth of spat, much boring sponge, and many borers. This seed was obtained largely from Pointe au Fer Reef at the mouth of the Atchafalaya River; it was very rough and mixed with débris, and no effort appears to have been made to cull it or even to break up the larger bunches. In consequence the oysters now on the beds are badly clustered and crowded, to the detriment of both shape and condition. When last examined in January, 1909, they were of large size, averaging, as taken from the beds, about 150 per bushel, and they were plump but watery in appearance. It is probable that Pelican Lake would prove an excellent place for growing oysters if clean, properly culled seed were used, and if it were not planted too densely. The margin only of the lake is fit to use in its unimproved condition, but the soft mud in the middle should serve as a good nursery for oyster food, the supply of which, in the lake at large, is good. On the other hand, as shown by the ex- periments just recounted, it would be futile to attempt to raise oysters from spat caught on planted shells or other cultch, owing to the favorable environment which the high salinity of the water furnishes to the borer. It is probable that the numbers of this destructive pest have been greatly augmented by the accessions to those naturally present brought in with the rough seed from the natural reefs, although, both from its location and its repute, it is not believed that Pointe au Fer is especially pernicious in this respect. OYSTER FOOD. In certain parts of the Louisiana coast oystermen and planters have encountered the difficulty frequent in all oyster-producing waters, the constant or occasional failure of the oysters to fatten. In Three- mile Bay and some of the adjacent waters, in Bay Adam and vicinity, 44 OYSTER CULTURE EXPERIMENTS IN LOUISIANA. and at various places in Terrebonne Parish, this difficulty has become a serious impediment to oyster culture. In some cases the trouble is undoubtedly due to the overcrowding of oysters on the planted beds or to the planting of such extensive areas that the total oyster population of the region affected is in ex- cess of the number for which the waters are able to furnish an ample food supply. In any given body of water, under fixed conditions of drainage and tidal flow, there is probably a more or less fixed limit to the production of the minute plants on which oysters feed, and a correlated limit to the number of oysters that can be produced for the market. Where this limit is exceeded either by planting densely over a small area or more sparsely over an extensive one, especially in an inclosed body of water, the result 1s manifested in the poor con- dition of the product. This is not a theory, but a demonstrated fact, analogous to overgrazing of cattle on pasture lands, and must be given consideration by the successful oyster culturist. The same condition is induced by a heavy growth of mussels and other organ- isms whose food is the same as the oysters. There are, however, other cases of failure of oysters to fatten which are not so well understood. Regions formerly favorable sometimes entirely cease to produce marketable oysters, even where there has occurred no material change in the density and distribution of the oyster population. In such instances it often happens that there has been some coincident sudden or gradual change in the drainage or in the tidal flows. Something of this nature seems to have occurred in the vicinity of Bay Adam, where practically no fat oysters are now produced, though we were informed that in former years good oysters were grown regularly. Coincidently with this change in conditions, the rice fields draining into the bay went out of production. It is the opinion of some of the oyster planters that the two occurrences were causally related, and the authors concur as to the probable truth of this explanation. Undoubtedly the drainage from the rice fields carried with it considerable quantities of the fertilizing salts required for the production of the microscopic plant food of the oyster, and since these enriching materials have been largely or entirely cut off the waters have become less fertile and productive. It has been proposed to correct this deficiency in several places by conducting fresh water to the oyster grounds from the Mississippi River through siphons such as were used in the irrigation of the rice fields. Whether or not this measure would afford effective relief is a matter of some doubt. It can hardly be questioned that much of the fertility of the waters formerly came from the organic and mineral matter carried from the rice fields themselves, and it is doubtful whether the river water itself carries organic matter in sufficient quantity to afford material OYSTER CULTURE EXPERIMENTS IN LOUISIANA. 45 relief, heavily charged though it may be with suspended mineral particles and salts in solution. More common phenomena of the oyster beds are the seasonal and irregularly periodical fluctuations in the condition of the oysters. In some years the oysters in certain regions may be fat and in other places poor, while at another time the conditions will be wholly reversed. Again seasons will occur when the oysters are poor almost everywhere without apparent reasons. That these fluctuations are immediately due to the relative abundance or scarcity of available food admits of but little doubt, but granting that the assumption be true the difficulty instead of being solved is merely shifted to a more remote cause. Is there an actual deficiency in the quantity of food organisms and if so, what are the chemical, physical, and biological causes producing it? Or is there an abundance of food merely un- available on account of some peculiarity of its distribution ? The feeding of oysters has been studied for many years, both in this country and in Europe, but we still know very little concerning the subject, other than the mere nature of the food and the general anatomical means by which it is ingested. It is only within three years that it has been possible even approximately to estimate the comparative volumes of the food carried by the waters of different localities, and such data are available for but a few places, all previous results being too indefinite to be of any material value. Even with the methods at present employed the results are not justly comparable between various localities unless large numbers of obser- vations are made embracing all average weather conditions; though in the case of neighboring localities, where the weather conditions may be assumed to be approximately the same, simultaneous or approximately simultaneous observations may be accepted as com- parable. It may be observed in the preceding tables, presented in the dis- cussion of the experiments in oyster culture, that there is wide diver- gence in the number and volume of the food organisms present in the water at different times. In Pelican Lake, for instance, the number of diatoms and other food organisms varied between 1,800 and 36,000, while their volume ranged between 0.077 and 0.943 cubic millimeter per liter of water (a cubic millimeter is about equal to the volume of a cube measuring one twenty-fifth of an inch in diameter, and a liter is about 14 quarts). This divergence is due very largely to the varying state of the weather, the smaller results being as a rule obtained after and during periods of calm, while the higher ones were invariably observed at times when strong winds prevailed. The reason for this is readily understood. The water specimens for the determination of the food content are taken from the stratum lying between 2 and 12 inches of the bottom. Many of the or- ° 46 OYSTER CULTURE EXPERIMENTS IN LOUISIANA. ganisms, especially the minute plants known as “ diatoms,” on aie the oyster feeds, live habitually on or close to the bottom, from which they are lifted and transported mainly through the agency of waves and currents. Many of them possess feeble powers of locomotion, but these are practically negligible in most of the bottom- dwelling species. It is therefore obvious that when the water is agitated by heavy winds and the bottom is stirred, the food organ- isms which in calm weather lie more or less quiescent on the mud will become mingled with other sedimentary matter in suspension in the water and the quantity taken in the specimen will be vastly augmented. This accords with field observation and is confirmed by the correlation existing between the volume of the food and that of the sand and other sedimentary matter in the precipitate from the water specimens. When the food is much in excess of the average, ordinary sediment is likewise large in volume, and when it is at the minimum, inorganic matter is comparatively lacking. At present there appears to be no accurate method by which these fluctuations in the sedimentary condition of the water may be taken into account in the study of the comparative values of different locali- ties for purposes of oyster culture, the most that can be done being to indicate more or less indefinitely the general state of the weather at and immediately preceding the time at which the observations are made. If observations could be taken at each locality daily or at frequent intervals throughout the year, the average results at- tained in different places would be strictly comparable, for the methods employed show the quantity of food which is actually avail- able to the oysters at the time of observation. When the diatoms and other food organisms are lifted from the bottom through the mechanical effect of the waves it is almost cer- tain that the oysters should profit. Therefore, although we have as yet no experimental data which would render the statement positive, it is extremely probable that the matter of wave action must be added to the numerous other factors entering into the food supply of oys- ters, and that a certain amount of agitation of the bottom favors fattening. A region subject to this phenomenon should accordingly be preferable to one not so subject, and a season of strong winds should be more favorable than one of prevailing calms or breezes so light as to leave the bottom wholly undisturbed. When we have accumulated more data on the subject it is not improbable that in some cases seasons in which oysters fail to fatten may be found to be characterized by the prevalence of light winds. During the course of the experiments in oyster culture previously described an attempt was made to study the distribution of oyster food on the coast of Louisiana in the hope that facts could be gar- nered which would throw some light on the reasons for local and OYSTER CULTURE EXPERIMENTS IN LOUISIANA. 47 seasonal differences in its quantity. It may be confessed at once that the results lead to no satisfactory conclusions, owing to the neces- sarily limited number of observations in most places and the acci- dental fluctuations introduced by the factor just discussed, though the data gathered will probably assist to a solution of the problem when considered in relation to experimental work now being carried on at other places. The accumulation of data is probably the most that can be attempted for several years to come. During a period of thirty-three months 498 food determinations were made at 61 different stations. At most places observations were made but once or twice in each year, but at the experimental plants they were made more frequently. In the case of the latter there is perhaps some basis for comparison, but in most other places the num- ber of observations was too small to be assumed to represent anything approaching average conditions. The following table shows the average quantity of food and the salinity of the water at all places in which five or more observations were made: AVERAGE QUANTITY OF OYSTER FooD IN VARIOUS LOUISIANA LOCALITIES, BASED ON FIVE oR MORE DETERMINATIONS. Food organisms per Nae meets liter of ae Locality. observa- | gravity of tions. water. Number. | Volume. Cu. mm PRT EOsMIMION SAY is atefaiaisisis,ajaisiayeimiara Serie vein ioaeen ese ctce se raece < 14 1. 0064 5, 675 0.177 Halkemouthp bays s. b232 eh oes a eke jaseiwezeees oe 13 1.0056 9,000 - 342 Nine miler bay. Soutmendteron 2 os eon seek saan ones canoe eas 8 1.0076 7, 200 217 PULCASUITERBAV st see ag de be 5 she Se /S2ie yom Da ne ee hy 7 1.0102 6, 630 . 169 BipaMussel Mayas esther ee eee ry fC mae MO et Teen ce 7 1.0119 7,000 - 185 SENG USN / SACS OE Ons LO eee See. Sale ee ah me teres Spee oree 2h am 7 1.0162 5, 230 . 192 BS Tid EB ays = ene rs tes Wk ah he mE mera n LS 6 1.0174 4, 270 S72 Calizo sb aise ives id Paved en Meee a Deiat teas se 8 1.0181 10, 160 . 252 TEE) ie TS hain a Guia Beane ON Os ik LLU iy 1 ai amen el ao 7 1.0160 7,900 . 237 HON eBay cee a 278 ey ee VEN oe bot: io te ee Lae 6 1.0160 6, 725 . 219 Cock Bay es area: Fc fe ye epepe teat Siem aA 2 fafa 8 1.0176 6, 350 . 166 PAU CTICSLTINES Ae eee accep ae Pe Irs AM LENS a 7 1.0184 6, 900 - 248 @alitormia Baytecs.22 te sess. Fates an ae eee ee ane S Been 7 1.0195 5, 540 . 189 Qnarantine’Bay- 242-22 aoe. eee ee ee PT aE es iu 1.0190 8, 640 . 329 IBSSTICHYD Aya. case coe et cae eee ae ee ele ee ae 9 1.0117 4, 890 2155 IBEVOUNCOO kaa Bie 5 A REE ee) Nia a a ae 5 1.0112 7,060 . 222 IBAyEN GAIN As Le Re RET EE a Ee ee ee 26 1.0115 6, 000 . 120 Gran Gea ¥ OUn Si. See me noeeiee es oac mise oes dai ae ae eo ductocuns Boece 11 1.0123 4,275 - 126 IDB YAPANS-DOIS: = eer. 328. see Ona ee aE tS eee NS 9 1.0095 12, 522 . 320 IBY BID) O) 1S Ree eye ae See oe ae ee Ee 10 1.0107 7, 525 . 230 IBAYVOURS leEDCHIS fee fos ce byt eee Ae PE Ee OSG Ae: 19 1.0090 10, 460 . 337 Barataniaebays(Quartelle)) o& 208 5 elke ae ae 11 1.0151 17,363 580 IBayOulbb renter. saan asee ee fae lk oe Lee ROME See) 10 1.0120 9,675 241 ay OUMpIPAl lier ee sie. ae ee) ee ee le 19 1.0157 9, 250 235 Giendsisicwmen se corse eee hte Pie Pe Nes Fees 2 48 . 1.0127 5, 690 195 AV MATA DOT ae See et ME A a) Mle cee he a etait omansinlue 19 1.0147 10, 200 295 Gece RR ACCOISILY ara eerie Lee? SOT Ce he 9 1.0148 17, 500 211 Migr Ler BES ives ee cee wee i tee Bie set a eae 7 | 1.0160 7,000 264 WakevWelicitiyaecs cer es oe dak een eee PR ee ae 5 | 1.0169 6, 600 193 Seabreeze: Wactonyremon ye se tee lees 2 Ae oo lcigoaeee 18 | 1.0164 5, 675 169 Pa RG ECILOp SS. eee eet EPS Oe Ls Ty 5 | 1.0182 5, 600 188 pelican. Wakes titan 8 wee tee ae 38 | 1.0167 12, 600 252 As the salinity depends upon the relative proportions of the ad- mixture of fresh and salt waters, the specific gravity may be taken as an index of the degree to which a locality is influenced by the 48 OYSTER CULTURE EXPERIMENTS IN LOUISIANA, discharge of fresh water from the land. A low specific gravity, such as obtains in Three-mile Bay and vicinity, indicates a close relation to land drainage, as compared with another locality, such as Caligo Bay, in which the specific gravity is high. If land drainage and its contained fertilizing salts are highly important, as we generally sup- pose, in stimulating the growth of oyster food, it would be expected, other things being equal, that a low specific gravity would be cor- related with a high food content as compared with a high specific gravity in the same system of waters. An examination of the fore- going table exhibits no such relation between the salinities and the food contents of the waters, when the various connected waters are compared with others in the same system or chain. The authors have prepared tables showing the specific gravity and food content of the waters at various times in each of the localities enumerated in the foregoing table of averages, and these show the same apparent lack of correlation, a high food content occurring sometimes with a low and at other times with a high specific gravity in the same locality. It is probable that these results are to be regarded as nonconclusive rather than as showing that a relationship does not exist. The un- controlled factors, particularly the stirring up of the bottom by wave action, are too important to be disregarded and their influence can be overcome only, apparently, by making many more observations than were possible under the conditions of the present investigation. Deductions from work of this character, unless the observations can be carried on systematically almost daily throughout the year, are likely to be misleading, and the investigations of the oyster food of Louisiana waters can be regarded as shedding no light on the effects of introducing river water in such localities as Bay Adam with the purpose of improving the conditions for fattening oysters. SUMMARY AND CONCLUSION. The following epitomizes the results of the experiments and in- vestigations of the oyster regions of Louisiana, east of the Atchafa- laya River, between April, 1906, and January, 1909, and the deduc- tions which the authors draw from their observations: 1. It is believed that the future of both the natural beds and oyster culture in Louisiana will be benefited by greater restrictions on the issuance of permits to take unculled oysters from the natural beds. A too general practice in this respect tends to the depletion of the natural beds of not only oysters, but the shells that are essen- tial for their future prosperity, and at the same time has the effect of discouraging the planting of shells on leased bottoms. 2. A limited issuance of such permits to take unculled stock from designated beds which are known to be overcrowded or which are OYSTER CULTURE EXPERIMENTS IN LOUISIANA. 49 subject to disaster from freshets would prove of benefit to the beds designated and to oyster culture in general. It would result in saving many thousand barrels of oysters which would otherwise die from the effects of fresh water and crowding or which would never reach a good marketable condition owing to starvation and suffocation from an overpopulation of the reefs. 3. Beds known to produce few or no marketable oysters on ac- count of overcrowding should be temporarily set apart as seed beds, from which the planters may secure culled oysters for bedding pur- poses under the provisions of the present law permitting such oysters to be taken after the close of the regular season. The provision of the law permitting this practice in the waters east of the western boundary of Plaquemines Parish could be advantageously extended, under the restriction just stated, to other parts of the state. 4. It will prove of great advantage in the future and will avoid ultimate embarrassment and expense to both the state and the lessees of oyster bottom if some measure can be adopted to insure the refer- ence of leasehold corners to permanent landmarks in such manner that disputed boundaries can be accurately redetermined. This sug- gestion may appear to be of but little present importance, but the experience of other states shows that ultimately it must be followed. 5. The results of the foregoing investigations, and observations made during their course, indicate that as a potential oyster-produc- ing state Louisiana is not excelled, if equalled, by any other section of the country. Wherever experiments were conducted it was shown that there was an abundant strike of spat, and the indications are that this can be depended upon to occur yearly without fail, though in some cases it is often destroyed by the borer. This danger, how- ever, is not to be feared in any place where the specific gravity of the water is less than 1.012—that is, where there is an admixture of about equal parts of salt and fresh water—and the seed-producing area of the state is therefore ample to support an immense planting industry. The Louisiana planter has consequently little to fear from the bugbear of his northern confrere, the occasional or frequent scarcity of seed. 6. The depth of water over most of the oyster-producing area of the state is so small as to minimize the cost of taking up the oysters, and the comparatively sheltered situation of much of the bottom suitable for oyster culture, and the mildness of the weather as com- pared with that encountered in more northern localities during the oyster season, allow the work to be prosecuted with less frequent interruptions and therefore more economically. The warmer tem- perature in spring and fall, however, tends somewhat to reduce the length of the season. 50 OYSTER CULTURE EXPERIMENTS IN LOUISIANA, 7. The configuration of the Louisiana coast, with its broad front- age of salt marshes, which will probably always preclude its occupa- tion by a considerable population, renders the oyster grounds prac- tically immune from dangerous sewage pollution, a consideration of vital importance to the consumer and of corresponding advantage to the producer of oysters. 8. The greater distance of the Louisiana coast from most of the larger centers of population is its chief disadvantage as compared with the oyster regions of the Middle Atlantic States. In respect to the growing population of the West, however, it labors under no such impediment to development, as is shown by the vast increase in the quantity of Louisiana oysters marketed since the enactment of the laws now in force. 9. The oyster food supply in the waters of Louisiana is generally good and the growth of oysters is rapid. As shown by the experi- ments previously described, good marketable oysters can be produced within two years of the time at which they attach to cultch, and a corresponding growth occurs in seed oysters. The oyster planter therefore reaps a quicker and larger return on his investment than he would in places where the growth is slower. 10. The results of the experiments show that a larger quantity of oysters can be grown per acre than can be produced in most places. On the small experimental beds at Falsemouth Bay, Three-mile Bay, and Bayou St. Denis there were, at least, upward of 1,000 standard bushels per acre at the end of two years from the time of planting the cultch, and it is understood that this quantity per acre is grown on planted beds in other parts of the state. 11. The area of bottom available for oyster culture is large, but it varies in the character of the oysters produced and consequently in the purposes for which they can be used. It is probable that in practically all places where the fresh water exceeds the salt water and the latter does not fall much below 20 per cent in the admixture, seed oysters can be raised on suitable bottom, either for transplanting to places more favorable for growth or for the production of market oysters in situ. Three-mile Bay and vicinity appears to be of the first sort and Falsemouth Bay and Bayou St. Denis fall in the second category. In places in which the salinity is higher than that de- scribed above, the salt water in the mixture being in excess of the fresh, seed oysters usually can not be produced in considerable quan- tities, not on account of the absence of a strike but because most of the spat is destroyed by drills. Such localities, of which Bay Tam- bour is a type, may often be excellent for producing market oysters from seed raised elsewhere. 12. The experiments at Three-mile Bay demonstrated the possi- bility of producing a heavy growth of oysters on planted shells, but OYSTER CULTURE EXPERIMENTS IN LOUISIANA. 51 the strike was so prolific that they were badly clustered, of bad shape and so poor in quality that they were of small value for market purposes. Oysters planted commercially in contiguous waters were of the same character. To be of much value this growth would require culling, the breaking up of the clusters and replanting less densely, preferably on harder bottom than most of that in the vicin- ity, and where the currents are stronger and food more abundant. It is not certain that this would be commercially profitable under present conditions. The oysters at present raised in this vicinity are suitable for canning purposes only. 13. In Falsemouth Bay a good strike occurred throughout the spring and summer in the three consecutive years of the experiments. The oysters produced exhibited a rapid growth, were in small clusters, and produced 7 pints of perfectly drained meats per standard bushel, an equivalent of over a gallon as measured at the shucking houses. They were nearly all extra selects, and the locality appears to the authors to be especially valuable for the production of oysters for the rawtrade. There is a large area of hard bottom in the bay, and while the quality of the oysters would probably deteriorate if it were all planted, a considerable proportion, especially near the openings of the bayous discharging into Mississippi Sound, could be planted with - confidence of good results. The only drawback to the oysters raised on the experimental beds was that the shells were rather brittle and sometimes broke in shucking. 14. At Bayou St. Denis, in Barataria Bay, the oysters raised on the experimental beds from planted shells were as fine as any that are grown on the Atlantic coast. They grew rapidly, had round, deeply cupped, rather heavy shells, and were very fat. Owing to the thicker shells they produced proportionately less meat than the preceding, but “turned out” about 54 pints, thoroughly drained, per bushel, an equivalent of about 7 pints shucking-house measure- ment. They were equal in quality to the famous “ Lynnhaven Bays” ~ of Virginia, which sell for $3 or more per bushel in the northern markets, and they can be produced in much larger quantity per acre. They are readily salable in the shell as barrel stock. 15. At Bay Tambour, on the contrary, while there is a good set, the young oysters are soon killed by the snail or borer. Seed oysters 2 inches or possibly not less than 14 inches long appear to be immune. The seed oysters planted at this place grew rapidly and attained a condition little if any inferior to those at Bayou St. Denis. A con- siderable area of the southern part of Barataria Bay and the con- tiguous waters has similar characteristics and a number of leases have been taken in that vicinity since the beginning of the experi- ments. Nearly 100,000 standard bushels of excellent oysters were produced on planted beds in Barataria Bay as a whole in the season 52 OYSTER CULTURE EXPERIMENTS IN LOUISIANA. 1908-9, though previous to these experiments the region was totally unproductive. 16. At Seabreeze the attempt to discover a means of using excess- ively soft bottom was unsuccessful. It was demonstrated that a heavy strike occurs, but the salinity of the water is so high that it is probable that trouble with the borer would be encountered. The growth of oysters is rapid and seed planted on hard bottom in the vicinity should flourish. 17. At Pelican Lake a heavy strike occurs, but the spat are soon killed by borers. The region is fairly suitable for growing market oysters from seed, but the latter should be culled at least sufficiently to break up the larger clusters, and the seed should not be planted so densely as to be crowded when it has grown to marketable size. 18. The oyster-food investigations carried on coincidently with the experimental work were inconclusive in demonstrating a relationship between the quantity of surface drainage water on the beds and the production of food organisms. They showed, however, that the latter are abundant in Louisiana as compared with most oyster regions. O { c EL me Wo Roa ae PY or I ; a af a f i 7 * ; ran ne a) . ‘ Tues Pea v1 a n i eo ann eee ea mle te ka eT yi: pin ; ty 1 : IS \ie : : ay | ; a4 y t - 1 a} = w