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The Workshop was convened in the auditorium, North HEW Building, Department of Health, Education, and Welfare, Washington, D. C., at 9:40 a.m. After an invocation by Mr. William R. Woodfield, President of the Woodfield Fish and Oyster Co., the Chairman introduced the initial speaker, Harry Hanson, Associate Chief for Environmental Health of the Public Health Service, Bureau of State Services. Mr. Hanson spoke for Dr. Robert J. Anderson, Chief of the Bureau.
Mr. Hanson welcomed the visitors on behalf of the Surgeon General and the Public Health Service to the Workshop and pointed out that the registration had at that time reached 160, and included representatives from Canada and Japan, indicating widespread interest in the program. He mentioned that 1964 is the 40th year of the operation of the Shellfish Sanitation Program, and said that the durability and soundness of the original program concepts were reflected in the long life of the program. Mr. Hanson discussed contemporary problems in shellfish sanitation and emphasized that the shellfish industry, the States, and the Public Health Service all have responsibilities in shellfish sanitation and that a breakdown or lapse on the part of any one of the participants jeopardizes the entire program. He further indicated that the Public Health Service should not be a party to the Voluntary Cooperative Program unless it was confident that there is a sincere and frank exchange of information with each State concerned, and that the exchange is on a fully cooperative basis. He also mentioned that the Department is on record with the Congress as declaring that the Shellfish Sanitation Program currently needs strengthening, and that through the workshop, the technical or administrative changes needed in the program will be determined. The report to the Congress indicated the need for a National Register of Shellfish Growing Areas, he said, and stated that the Public Health Service hoped to have such a register fully operational in fiscal year 1965. In addition, he indicated in the report that there is a need for correlation of shellfish sanitation and pollution prevention abatement objectives, at both the State and the Federal levels, and that more effort is needed to assure that shellfish imported from other countries is equal in sanitary quality to that of the domestic product. (Mr. Harry Hanson's complete statement is included as Appendix A of these Proceedings.)
Industry Report on the Status of the Cooperative Program for the Certification of
Mrs. Elizabeth Wallace, Director of the Oyster Institute of Nor the America reviewed the present Cooperative Program from the standpoint of the shellfish industry. She indicated that industry members were present to deliberate with the various state agencies, and the Public Health Service to discuss current program needs of the molluscan industry, and to re-evaluate, modify, or change existing program to effectively resist program obsolescence. She indicated that the industry was concerned with the long-continuing and the recent precipitous decline in clam and oyster production and because demand exceeds supply the temptation to take these from uncertified waters, or to otherwise short-circuit regulations established to guarantee the safety of this food. Although supplies may be short during the 1964-65 season, she pointed out, advances in molluscan culture are promising, and the industry can here and now resolve to face current difficulties and prepare for a brighter future.
It was pointed out by Mrs. Wallace that the industry, with individual knowledge of the nearby waters and the habits of their neighbors, and as a partner with the State agencies, can forbid the market to the opportunist. She also suggested that the quality of producing waters should improve or the shellfish removed from such waters. It was indicated that the South Jersey Shellfisherman's Association has organized to do just these things through persuasion and political pressure on nearby municipalities so as to rectify local sources of contamination. Mrs. Wallace cited recent pollution problems in Maryland and said they had been resolved through the appointmenć by the Governor of an Expediting Committee made up of members from concerned State agencies and the shellfish industry which assisted in reevaluations leading to the reclaiming of approximately 70% of the aquatic resources. She indicated that the industry would insist that the
needs of shellfisheries be included in comprehensive planning of uses of estuar i ne waters and that the industry would support the upgrading of water pollution control to a position of sufficient stature to insure good results. She pledged the industry to a course of action and responsibilities in cooperating with all official agencies so as to help make the Shellfish Sanitation Program successful. (Mrs. Wallace's complete statement is included as Appendix B of these proceedings.)
PHS Report on the Status of the Cooperative Program for the Certification of Interstate Shellfish Shippers
The current status of the Cooperative Program for Certification of Interstate Shellfish Shippers was reviewed by Mr. James Silva, Chief of the Field Operations Section, Shellfish Sanitation Branch, Public Health Service. He pointed out that although the Program has administrative, financial, technical and legislative problems of varying proportion, it is a revitalized program at both the State and the Federal levels, and has improved Federal research resources, as well as many States carrying out research programs of their own.
It was indicated that for the fiscal years 1962, 1963, and 1964, the Public Health Service had used the program appraisal procedure, entitled Part 111 - "Public Health Service Appraisal of State Shellfish Sanitation Programs" in making State shellfish sanitation program evaluations. These appraisal procedures were given tentative acceptance by the 1961 Workshop. The use of Part 111 has brought about uniformity in State program evaluation procedures and has focussed attention on shellfish program components requiring attention and emphasis. Of the 23 States evaluated in FY 1964, 19 had final ratings greater than 70%. The highest rating was 100% and the lowest was 54.4%. The median value for all States was 84.8%. Eleven States had no program element rating less than 70%, four had one element less than 70%, five had two elements less than 70%, and two had three element ratings less than 70%. Caution in the interpretation of combined final State ratings was recommended as a combined rating greater than 70% could, and has contained within it, individual element ratings of less than 70%. It should be recalled that in a satisfactory program all elements must rate 70% or better. Overall, the appraisal procedure has been effective in describing areas of program need, both on a quantitative and qualitative basis. Tables of individual component values were presented, and are included in the complete paper in Appendix C.
During FY 1964, there were an average of 1,250 shellfish shippers listed each month on the Interstate Shellfish Shippers List. Twenty-two issues of this list were printed and were distributed to approximately 4,000 persons. Approximately 300 shuckerpackers and repackers were inspected with the weighted sanitation ratings computed to be 87.1%. Approximately 100 shell stock shippers were inspected with an overall rating of 93.5%. Of 387 identified growing areas in the United States, approximately 349 were evaluated.
It was noted that since the 1961 Workshop there have been several disease outbreaks associated with the consumption of shellfish. In one of these outbreaks, several persons experienced symptoms resembling paralytic shellfish poisoning after consuming shellfish harvested from a non-polluted Gulf-State growing area. Subsequent investigation revealed that the suspect shellfish became toxic during an occurrence of Red Tide known to local fisherman, and that a new problem had arisen in the sanitary control of shellfish. The 1963-64 winter season saw approximately 250 cases of infectious hepatitis linked with the harvesting of shellfish from polluted waters.
Mr. Silva discussed the development of a National Register of Shellfish Growing Areas, the development of the depuration process, the seriousness of the pesticide contamination problem in shellfish growing areas, the presence of radionuclides in growing waters, the Quarterly Report of the Shellfish Sanitation Branch, program training needs, and Congressional hearings on problems of the shellfish industry. (Mr. Silva's complete paper is included as Appendix C of these proceedings.)
Report on Depuration--The National Posture
Mr. Eugene Jensen, Chief, Shellfish Sanitation Branch, Public Health Service, presented a discussion of the status of the depuration process in the Cooperative Shellfish Sanitation Program. He pointed out that with increasing use of coastal areas the public confidence in preventing disease outbreaks from consumption of raw shellfish decreases.
It was pointed out that the Public Health Service is committed to the principle that shellfish must be as safe to eat as are other foods, and that since shellfish is not an essential food, consumers will not purchase shellfish if they believe there is a hazard. He suggested that if we are to keep on operating as we have in the past, i.e., with no change other than aggressive and coordinated support for pollution-prevention and abatement, we finally get to a point of no return where there will be no more areas to close, little industry, and a low confidence-factor on the part of consumers. Although a few areas might be "reserved" for shellfish culture, it is already too late for this because of the present degree of development as well as public and industry pressure for multiple-use of water areas. The use of a controlled system for shellfish production was not given, by him, much chance of success because of the current pressure for multiple use of estuarine areas.
It was explained that the depuration process seems to offer a partial solution to the problem of pollution of growing areas, since most coastal areas could then continue to be used for shellfish culture. Shellfish could also still be consumed raw; there would be no sweeping changes required in the industry; and the problem of wild or unprecedented growths in marginal restricted areas would be met.
Mr. Jensen recommended in his summary that the Workshop endorse the following concepts:
(1) That a satisfactory confidence factor is necessary to protect the health of
shellfish consumers, and to assure continued acceptance of this food. (2) That in many areas the problems of assuring continuous high sanitary quality
of shellfish areas are such that it is becoming exceedingly difficult to
maintain a satisfactory confidence-factor in shellfish.
will assure a satisfactory confidence-factor in shellfish as a food.
research in other techniques which would help to assure the high sanitary
(Mr. Jensen's complete paper is included in these Proceedings as Appendix D.)
Mr. Jensen also suggested that rather than proceed with a discussion of the various points in his paper, the Workshop proceed to listen to the other papers on depuration and then discuss the entire subject. The chairman indicated this procedure would give the participants a better chance to make judgments on the proposals.
Present Status of Depuration in Florida
A paper on 'The Present Status of Depuration in Florida' was presented by Mr. Larry Gillespie, Salt Water Fisheries Division, Florida State Board of Conservation, Marine Laboratory, St. Petersburg, Florida. He indicated Florida has 8,000 miles of shoreline, a shellfish industry with an approximate economic production valued at from 1.5 to 2.0 million dollars annually, with the industry largely centered at Apalachicola. It was suggested that depuration could be a possible solution to the pollution problem in Florida. Mr. Gillespie described the depuration methods being tested by the Florida Board of Conservation Marine Laboratory in cooperation with Bay Seafoods, Inc., of Palmetto, Florida, on Crassos trea virginica and Rangia cuneate. It was reported that results were erratic and inconsistent due to problems of maintaining proper circulation and rate of water flow; removal of feces and was te products, temperature control, sanitizing the system before addition of shellfish, etc. It was indicated that tests are continuing with a small experimental pilot system. With this latter system, on two tests, water is coliform free after 4 hours, and oyster meats were below 800 coliform MPN per gram, after 12 hours on one test, and below 1,300 in 4 hours on another test. Future plans call for continuation of testing using the small pilot plant. It is further planned to build a commercial-size unit to continue testing. (Mr. Gillespie's complete statement is included in these Proceedings as Appendix E.)
Progress Report on Depuration in Maine
A "Progress Report on Depuration in Maine" was given by Mr. Phillip L. Goggins, Maine Department of Sea and Shore Fisheries. Mr. Goggins reported that in 1960,
46,958 acres of shellfish growing waters in Maine were closed because of pollution, and that further closures since have been catastrophic in effect to a number of coastal communities. It was indicated that although pollution abatement programs have been recently accelerated in Maine, such actions themselves can not provide conditions allowing the unrestricted taking of shellfish. However, these programs tied in with a controlled depuration scheme, would permit the use of a major part of currently restricted areas. Accordingly, studies were undertaken to determine the effect of environmental factors on depuration of soft shell clams.
Laboratory results, at temperatures between 16°c. and 20°c., indicate that purification was adversely affected with water flow rates less than 1.5 liter per bushel per minute probably because of oxygen-depletion which ranged between 70 and 90%. However, at a flow rate of 1.6-3.0 liter per bushel per minute, purification was not adversely affected, as oxygen depletion ranged between 35% and 70%. The cleansing of clams in single layers was compared with the cleansing of clams in multiple layers, with no adverse effect being demonstrated on the process on clams at various depths. No differences in purification rates (90% coliform and E. coli reduction) were demonstrated during 24 hour periods of depuration between a closed water system (water recirculated through the sterilizer) and an open water system (fresh estuary water passing through sterilizer). However, during the second 24-hour exposure period a 10-fold increase in coliform MPN, but not in E. coli MPN, developed in 43% of the runs in the closed system. However, temperature in the open system varied between 11°c. and 11.5°c. while the temperature in the closed system remained at a room temperature of 18°c. It is postulated that the higher temperature accelerated the breakdown of the mucus of the feces releasing either previously immobilized bacteria, or caused bacterial growth in the slime formation on the tanks.
Mr. Goggins indicated that their experience in two commercial plants demonstrated MPN levels in soft clams can be much lower than the inter im 78-230 fecal coliform standards for oysters, but that the initial load is very important. Clams with high initial loads do not reduce to the interim oyster standard in 24 hours. It is suggested that safe initial levels for 24-hour cleansing cycles and 48-hour cleansing cycles should be determined. It is pointed out that the pilot plant at Biddeford Pool was successful in cleansing clams and that a commercial operation at Sebasco Estates has been operating since August 1964.. Mr. Goggins used photographic slides in demonstrating the equipment and techniques used in the pilot plant. (Mr. Goggins complete report is included in these Proceedings as Appendix F.)
Status of Shellfish Depuration in Massachusetts
A statement, entitled ''Status of Shellfish Depuration in Massachusetts" was presented by Mr. Mario Boschetti, Massachusetts Department of Public Health. Mr. Boschetti pointed out that depuration has been practiced in Massachusetts since the early 1930's in that a shellfish treatment plant for soft shell clams in Newburyport has been operating since that time. Soft clams treated at Newburyport are taken from moderately polluted areas in which the waters have a median coliform MPN of 700 or less. Chlorine has been used as the water sterilizing agent with the concentration kept below 0.5 parts per million. Recent work at Newburyport during 1962 and 1963 indicated that ultraviolet light was effective in reducing the coliform count of sea water to virtually zero even when starting with a water containing several thousand coli forms per hundred ml. It further indicated that soft clams allowed to feed in ultraviolet treated water showed a marked coliform decrease over that achieved with the use of chlorinated water.
Mr. Boschetti described the depuration process as presently used at the Newburyport plant and presented data on coliform density of untreated and treated clams. (Mr. Boschetti's complete presentation is included in these proceedings as Appendix G.)
Status of Shellfish Depuration in New York
(Subsequent to the time the Agenda for the Workshop was prepared, the State of New York established a pilot depuration plant for hard clams. Mr. David Wallace, New York Department of Conservation, was therefore asked just prior to the opening of the Workshop if he would make a few remarks about the status of depuration in New York. Mr. Wallace graciously accepted the invitaion and spoke extemporaneously without benefit of the opportunity of prior preparation.)
Mr. Wallace indicated the State of New York with its large population, is one of the largest consumers of shellfish in the United States. Therefore, the State of New York has a very real interest in shellfish in relationship to the health of the consumer. New York also has an interest in that the State produces oysters, mussels, scallops, and clams. (New York State is the largest producer of hard clams.) For the above reasons he said, the State is very much interested in the shellfish sanitation program.
Mr. Wallace indicated that New York State currently has 600,000 acres of shellfish ground, 450,000 acres of which is open and 150,000 acres of which is closed because of pollution. Enforcement efforts to police the restricted areas are being accelerated at the State and county levels. This past year an aggressive program of relaying was launched and it will be greatly expanded in the coming years. New York also has a program in pollution control and abatement such that there may be opened next year a 40-square mile area which has been closed for the past 40 years.
It was stated by Mr. Wallace that it is unknown at the present time where depuration fits into the New York scene as not enough is known about depuration in relation to hard clams. A pilot depuration plant for hard clams is currently being set up in cooperation with local industry. It is currently felt that there are many problems in depuration of hard clams particularly in areas of varying water temperatures and where clams are forced to hibernate during the winter time. It was Mr. Wallace's view that purification is not a panacea for the shellfish industry. He suggested that a balanced program of relaying, pollution abatement, and policing of restricted areas, were still feasible control measures. It was also indicated that bootlogging is still possible around a purification plant and that this would nullify the depuration efforts. Mr. Wallace agreed with the previous speaker, Mr. Boschetti, that the variability of living animals precludes ideas that the depuration process may be compared to the process of pasteurization of milk or the purification of drinking water. (Mr. Wallace's complete statement is included in these Proceedings as Appendix H.)
Progress Report on Rhode Island Depuration Study
Mr. Manuel Canario, Rhode Island Department of Agriculture and Conservation presented a statement, entitled "Progress Report Rhode Island Depuration Study". Mr. Canario indicated the shellfish industry of Rhode Island depends almost entirely upon the supplies of the hard clams, Mercenaria mercenaria, but that since 1955, when 5,020,000 pounds of quahaug meats were harvested, there has been a gradual decline in pounds harvested and diggers employed. Two major areas, the Providence River and Mount Hope Bay, are closed to shellfish harvesting due to pollution. It has been estimated that 600,000 bushels of hard clams are in the Providence River and 400,000 bushels in the Mount Hope Bay area.
Mr. Canario indicated that, in hopes that some of these quahaugs could be harvested and cleansed for market, the Rhode Island Division of Fish and Game has assembled a pilot size quahaug purification plant, and in cooperation with the Public Health Service is working on the development of techniques for the control and processing of depurated hard clams. He described the operation of the system and showed photographic slides. It was noted that at 22°C. Mercenaria mercenaria actively pumps for approximately 90% of the day, but with a drop to 5°C., activity decreases, and below 5°C. hibernation occurs. As water temperature rises above 75°F. quahaugs spawn causing coliform MPN's to increase. This problem was not encountered with the fecal coliform MPN'S. It is postulated that hard clams can be depurated in a 24 hour period since most fecal matter was found to have been expelled by the quahaug between the sixth and twentieth hour after entering the purification tanks. (Mr. Canario's complete report is included in these Proceedings as Appendix 1.)
Industry Report on Depuration
Mr. Richard Loring, Aquaculture Research Corporation, Dennis, Massachusetts, presented a paper on "The Industry Report on Depuration". Mr. Loring indicated he was speaking for the Oyster Institute of North America which was the trade organization for the shellfish producers, processors, and distributors in the United States. It was pointed out that the Institutes membership has knowledge of the Public Health Service's position that there is further need to safeguard the public when they consume raw shellfish, and that this further safeguard should be in the form of depuration. Mr. Loring indicated the industry had been polled on the matter and their ideas had been correlated in his report.