Choice No. 2, if I understand it correctly, is a partial plan to cover by depuration shellfish taken from unsafe areas. The only desirable aspect of this, aside from the possibility that it takes the pressure off producers of shellfish from approved areas, is that it might reclaim resources which are not now safe. The question here is whether or not it is worth the effort, and whether it would not introduce a competition of a poor product against a good product. Our information on the state of development of the depuration process at present is that it has been applied to soft-shell clams with some success, to oysters with limited success, but not yet with any success to hard clams. This means that we have no evidence at present that the entire depuration plan is feasible at all for hard clams. We have heard that the New York State Conservation Department is preparing to set up a depuration plant for hard clams to see what can be done, but until there is some indication that such a process is feasible, we stand opposed to committing ourselves to moving in that direction at all. As for more effective implementation of the present setup, may we present the following two suggestions. Since the problem of contaminated clams arises through the ignorance or greed of a very small minority, would it not be well for the presently established organizations such as the Long Island Shellfish Farmers, local baymen's associations, et.al, to conduct an educational campaign which would strike at the grass roots. I have in mind the mailing of literature to every holder of a shellfish permit which would alert him and impress upon him the threat which exists to the entire industry because some foolish individuals cannot resist the temptation of forbidden fruit. Emphasis might better be placed upon the penalty to the entire enterprise if the culprit is successful in making a few dollars, than the penalty to be paid if he is caught. Having come up from the ranks of the lowly clam digger, and now having received the information from our contacts with other shellfish farmers as to the actual health hazards and threats to the entire industry, we believe the need exists for enlightenment of every possible taker of shellfish. Our second suggestion is probably far out. This is for on-the-spot analysis of every batch of clams taken from the water. It's a tremendous thought because it is now already so difficult to police the restricted areas; what would it be for all areas? And it is now such a large job for the Conservation Department to make spot-checks and analyses; what a large job it would be for such a thorough certification. This suggestion seems ridiculous even to us, but it seems to be on a scale with depuration itself, so we insert it. Trusting we have not misunderstood the problems, nor muddied the solution, we are Sincerely yours, FIRE ISLAND FISHERIES, INC. /s/ Nelson Slager, Secretary APPENDIX BB INDUSTRY VIEWPOINT OF THE USE OF CHEMICALS By George H. Vanderborgh, Jr. G. Vanderborgh & Son West Sayville, New York The need for chemicals is evident when we realize that 99% of oyster set is destroyed by natural enemies. With the high cost of seed from ponds $12.50 per bushel - we cannot afford to lose seed to drills. For years land farmers have used chemicals to control natural enemies. In order for marine farmers to succeed, we will have to do the same. For the past twenty years, we have been trying in a similar way to control starfish with chemicals. Five years ago, the chemical "Drillex" was discovered to have a controlling effect on drills by research conducted at the Bureau of Commercial Fisheries Laboratory in Milford, Connecticut. Our company, under the rigid supervision of the New York State Conservation Department and the Fish and Wildlife Service, has worked with Drillex for the past three years on a commercial scale. The results have been gratifying. Controlled tests showed 80% mortality in hatchery set on natural growing grounds, but only 10% mortality in set on chemically treated areas, with 50 samples being taken from each area. Two years after having been treated, one lot showed only 5% reinvasion of oyster drills. The clam set on these same areas was 50% less on the treated area than on the control area. This would point out that this chemical should only be used on grounds on which seed oysters are to be planted. Since most of the drill damage is done in the first year of the oyster's life, oysters should be removed from the treated area after one year and placed in other growing beds. This would mean that oysters would grow another three years on untreated ground. Chemicals should only be used with scientific farming methods and constant observation by skin divers. Drillex, while controlling drills, also controls other snails which normally serve as de-silters. As a result, silting accumulates more readily on the bottom. A four-point program is recommended: 1. Continued field research on Drillex as to its effect on all marine 2. Rigid State controls and surveillance should continue. 3. Chemicals should only be used with scientific farming methods. 4. USE OF CHEMICALS ON OR NEAR SHELLFISH By Herman F. Kraybill, Ph.D. Environmental pollution from agricultural chemicals can result from the unrestrained widespread application of highly toxic, often broad spectrum and stable chemicals in homes, gardens, farms, orchards, range lands and forests. In addition, the promiscuous dumping of industrial, agricultural and domestic pollutants has had its impact on water quality in our major waterways, lakes, bays and ground water supplies. The wide scale use of synthetic organic pesticides causing harmful effects, if not destruction of fish and wildlife, has aroused much interest as to its implications relative to human health. For example, if there is pollution in soil, this may become pollution in water which in turn becomes pollution in fish or domestic animals and ultimately at the end of the food chain results as chemical residues in the adipose tissue and certain target organs of the body of man. Pesticides are as ubiquitous as fallout radionuclides, and there are no environmental media, air, water, milk, soils, and diet, that do not show positive levels of these environmental chemicals. This is particularly true since modern instrumentation and chemical methodology can detect near the molecular level at .001 micrograms (.001 ppm) in some substances and in raw and finished water supplies at parts per billion and parts per trillion level. Undoubtedly, the problem of concentration of pesticides in plankton, fish and shellfish, the last being great concentrators of pesticides, focused attention on the need for corrective measures in application of these chemicals in estuarine waters and near shellfish growing areas. Many illustrations could be given but the observations made in the Willapa Bay area in Washington in 1963 have shown the effect of aerial spraying of DDT for hemlock looper control on the concomitant increase of DDT levels in Pacific Coast oysters. The Federal Pest Control Review Board, now the Federal Committee on Pest Control, recommended that the U.S. Forest Service substitute the less persistent "Sevin" for the highly persistent DDT. Apparently, Sevin does not affect as high a percentage control of the hemlock looper but it does obviate the residue problem in shellfish. (1) Shellfish like other aquatic organisms are quite sensitive to pesticide chemicals, and in Table 1 is shown the effect of the low concentration (0.1 ppm) of various organochlorine insecticides on the growth of mature oysters after seven days of exposure. Endrin which is quite toxic to fish has the lower order of growth retardation than other chlorinated hydrocarbon compounds with the common insecticide DDT being the most toxic to mature oysters. The concentration of these seven pesticides would not have such an acute response on higher forms of animal life including man. (2) Butler et.al. (3) have shown the effect of water quality on the ultimate residues of DDT in oysters and clams (Table 2). By allowing DDT contaminated clams and oysters to remain in clean water up to 90 days, these investigators noted a decrease from 151 ppm of DDT in oysters at zero days to 6.5 ppm of DDT after leaching at the end of 90 days. Clams showed a similar leaching effect and after 20 days in clean water there was a 96 percent reduction in the DDT content. Assays for chlorinated hydrocarbons in shellfish have been made by various laboratories at certain locations and some positive levels of these persistent pesticides have been recorded in oysters, clams and shrimp. In Table 3 some values for heptachlor epoxide, dieldrin, DDE and the ortho para and para para prime isomers of DDT are shown with the isomers of DDT showing the higher residues in oysters and shrimp. The Food Chemistry Laboratory, Milk and Food Research, Sanitary Engineering Center, Cincinnati, Ohio, in cooperation with the Shellfish Sanitation Branch have analyzed a spectrum of shellfish in 1963 and 1964 at various locations. (Table 4) The highest value for DDT plus DDE in shellfish was recorded at Mobile, Alabama at 0.900 ppm and a low value of less than 0.008 ppm at Willapa Bay, Washington. The latter value may reflect a cessation in the aerial spraying of DDT on forests near Willapa Bay through a controlled program. Certainly where the values are high this focuses attention on the need for corrective measures such as restriction of aerial spraying near shellfish growing areas or replacement of less persistent pesticides for the more persistent compounds. Further control measures may be indicated if water pollution surveys show extensive agricultural runoff or excessive dumping of pesticides into waterways. While the data in Table 4 shows some geographical distribution in sampling, there is a much greater degree of sampling and assays made which are not yet summarized. In Table 5, for example, are shown some data on assays of oysters, water, mud, fish and shrimp and canned oysters conducted by the Gulf Coast Shellfish Sanitation Research Center in relation to the Mississippi River Fish Kill Study. At the request of local conservationists, and after consultation with appropriate State and local authorities, a one year sampling--analysis study was conducted in Rhode Island to determine the movement, uptake, and retention of DDT in shellfish during a community aerial and ground spraying operation for mosquito control. Sixty-five samples of the Soft Shell Clam (Mya arenaria), and thirty-seven samples of the Northern Quahaug (Mercenaria mercenaria), were collected during the period May 9, 1963 to May 22, 1964 from waters in the northern Narragansett Bay areas contiguous with mosquito spray-control areas. The shellfish were shucked, frozen, and analyzed for DDT by gas chrometography by the Food Chemistry Laboratory at the Sanitary Engineering Center, Public Health Service, Cincinnati, Ohio. The maximum increases were from 0.28 to 1.34 ppm total DDT (total of DDT + DDE + TDE) for soft clams and from 0.12 to 0.22 ppm total DDT for hard clams. Measurable levels of dieldrin were found in hard shell clams. (4) Obviously the DDT levels found in shellfish in these studies are below the FDA residue tolerance of 7.0 ppm total DDT on fresh fruits and vegetables. However, one needs to assess these pesticide levels in terms of the additive effect of these shellfish pesticide levels to the total intake from other foods containing pesticides. Various Federal and State agencies are collaborating in environmental surveillance of pesticides to establish residue levels and the trends of this pollution. Many of these compounds remain unaltered, such as the chlorinated hydrocarbons in animal and plant tissue retaining their initial toxicity, and others like the organic phosphorus compounds are rapidly degraded or metabolized in the animal or man and may have less persistence and toxicity at environmental levels. To illustrate the movement of pesticides through the environment, about 5 lbs. of dieldrin applied per acre resulted in 0.10 to 0.13 ppm of this compound in runoff water from a test field. Interestingly enough, this dieldrin level is about one tenth of the lethal dose for some fish and happens to be the level present in adipose tissue of people in the United States. (5) As undesirable as residue levels in shellfish are, they do serve as criteria of water quality and indicate the influence of pesticide control operations and effect of aerial spraying or runoff. As part of the "biological food chain" shellfish concentrate pesticides from the aquatic environment. Similarly animal products concentrate pesticides and serve as reservoirs of persistent pesticides. Meat, eggs and shellfish contribute about 60 percent of the total level of chlorinated hydrocarbons in man's daily diet. Hence, through ingestion of these foods man has a continuous intake of pesticides which ultimately deposit in his body fat and certain target organs. It is difficult to evaluate sublethal effects of pesticides, but the literature is replete with data on the acute toxic responses and lethal effects of high level occupational exposure to pesticides or other environmental chemicals. Of equal public health concern is the potential health hazard from low level exposure or the subthreshold toxic effect of these chemicals which may have a subtle action or latency period in long-term induction of chronic disease. An important concept to keep in mind is that if a substance does not demonstrate a harmful acute toxic effect, it cannot be concluded that such chemicals may not have a harmful effect through their micro insult at the cellular level. The Public Health Service is currently mounting comprehensive epidemiological studies in selected locations in this country to assess the long-term effect of such exposure to pesticides, either of a major or minor stress in terms of induction of disease. Work with experimental animals has demonstrated that environmental chemicals at low concentration can alter cellular constituents such as DNA and it is now recognized that mutagenic, carcinogenic response and other patho-physiological aberrations may be initiated through this basic insult at the cellular level. (6) Increasing testing on shellfish have shown in general that the levels of pesticides in shellfish are low particularly where control procedures have now been implemented. From a public health viewpoint, however, one must reexamine and reevaluate the current practices in the use of pesticides or other environmental chemicals which contribute to chemical residues in the food chain. Certainly, any decision to permit use of various chemicals in shellfish growing areas or other food growing areas must be resolved so that permissible use will involve a low order of risk. This can be achieved by developing at the State level a committee similar to the Federal Committee on Pest Control representing the various State agencies concerned with use and control of pesticides. An important function of this coordinating committee would be to establish constant surveillance of pesticides in the environmental media. Such vigilance in monitoring will help to demonstrate the trends in pesticide levels and establish the movement of these chemicals into the food chain and ultimately to man. |