Attendance: Steve Boyd, David Bouchard, Hemont Chikarmane, Harlyn Halvorson, Rick Karney, Deirdre Kimball, Alan Kuzirian, Hans Laufer, Dale Leavett, Michael Patrick O'Malley, Jack Pearce, Paul Russell, Scott Soares, Alison Thibodeau, Steve Tucker, Rick York

Greetings Dr. Harlyn Halvorson welcomed the group and thanked the Mass Maritime Academy not only for hosting the meeting, but also for their support of aquaculture. Dr. Kim Harrison called to express her regrets at not being able to attend. She reported that the Blueprint will go to the printers on Friday. This report will have an ISBN which will make it available to the public. He went on to report an article by Stephen Rappaport in the October Commercial Fisheries News "A visit to Japan for technology transfer: Cultured scallop success: A model for Northeast US?". A copy is attached with the minutes.

Update on SEMAC activities Dr. Dale Leavitt reviewed the activities of SEMAC. He reminded everyone that they have a mini grant program. The SSWG was the recipient of one of those mini grants. He anticipates distributing $50,000 this spring. The RFP should be coming out in December or January. They are also in the process of setting up a Bay Scallop project on Cape Cod, funded through Barnstable County. An upwelling demonstration project will be established in a few weeks at Point Marina, near MMA. Later these will be distributed to 5 sites around the Cape to look at mortality for over wintering. The survivors will be distributed to 10 sites on the Cape to start developing a spawning sanctuary program.

Update on Massachusetts Aquaculture Mr. Scott Soares briefly called attention to the upcoming meeting to be held Oct. 13th at MMA. Everyone was invited to this meeting which will review the Mass. Aquaculture Plan and its priorities.

Offshore muscle production and crab parasites Dr. Jack Pearce called attention to an article "The mussel team takes to deep water" by George Hanson and his colleagues which appeared in the new Cape Coder paper. He periodically brings back muscles and gives them to Dr. Pearce to look for pea crabs and other parasites. Contrary to previous experience, Jack Pearce now finds crabs in various stages of development. The incident of infestation in shellfish vary from time to time. This is of practical importance since the amount of muscle in bivalves can be reduced by as much as 50% by infestation. This phenomenon has been long known for oysters. He also called attention to an article by Joseph Hart in a book on "Crabs on the West Coast". The adult West Coast crab lives inside a mussel. On the east coast this crab lives inside Bay Scallops. In late April or May the crabs become oviferous and they produce 9 -10 thousand eggs. When these hatch the larvae will swarm into the water. They go through four molts leading to a megalop stage. These swim in the water through May and June and then go back to a bivalve host. After going through a number of instars, at instar 1 (swarming stage) it return to the water. These small swimming crabs can be seen in August. At this stage the males copulate and inseminate the females (discovery by Dr. Pearce). A hormonal change occurs and the females reinfect a bivalve to repeat this cycle. As we cultivate shellfish in dense situations, the above infestations are too be expected leading to reduced meatiness of the shellfish. Dr. Pearce suggested genetically modifying the bivalve to prevent multiple infestations. Potential targets are the attractants that lead the crabs to their host. In Woods Hole today 70% of the mussels are infected. In response to a question, Jack Pearce stated that after mating, the males stay in the water column and continue copulating. Hans Laufer suggested a biological control rather than a genetic manipulation.

Control of Mollusks by hormones Hans Laufer, in reflecting on Jack Pearce's comments, thought there may be ways of manipulating crustacean hormones so that they stop molting or reproducing. This is an area of his expertise. The work to date on mollusks is mostly on the non commercial forms. By using the information that already exists, one can apply it to commercial forms of mollusks. Comparative endocrinology builds upon the commonalties arising from the evolutionary tree. Most of the living organisms in the world are invertebrates - arthropods. Mollusks represent about 15% of all known species - about equivalent to the vertebrates. Starting with an elementary eucaryotic cell, as yeast, various larval forms emerge. The arthropods (animals with jointed legs) annelids and mollusks are a common branch of the evolutionary tree. The simple yeasts share many common pathways with the vertebrates. Animals on the same branch of the evolutionary tree show more commonalty than others. For example, higher forms use the hormones, or some modification of them from lower forms. One would like to have a complete control of the reproductive cycle. What are the compound, compounds, and glands which are involved? This is what we call signal transduction. Both yeast and worms, for example, devote 11% of their genome effort, a significant amount, to signal transduction. A simple example of signal transduction is vision. We perceive light by the eye, which is then transmitted by nerve impulses to the hind brain which recognizes the light. Through signal transduction, organisms integrate into their environment. In aquaculture we manipulate the life cycle my manipulating environmental conditions. In mollusks chemical signals tell the males that the females are ready to mate. Integration of the environment makes the system go. This can be very precise. Some organisms reproduce only at high tide and at a particular phase of the moon. Most of these signal transductions are done by hormones and the nervous system. Biochemically most of these processes are understood and the hormones identified.

Hans Laufer gave examples of juvenile hormones, well identified in insects, that control the form of an animal. The gonadotrophin hormones control reproduction. Using the principal of comparative endocrinology his lab has searched out the hormones for crustaceans and found them nearly identical to those in insects - on the same branch of the evolutionary tree. The same reproductive hormone found in insects is identical to that found in crustaceans. Laufer's lab found hormonal activities in mollusks that were active on annelids. The juvenile hormone from insects also works to increase the gonad index-in crayfish a commercial aquaculture species. The development of metamorphosis of abalone is stimulated by metabolites from cyanobacteria. Red algae tend to be attractants for settlement. He cited a number of examples in which the food organisms were attractants for marine organisms. The mollusks tend thus to settle near each other in response to food organisms. For example an annelid worm in Woods Hole has a larval stage like the intermediate larval stages of mollusks. That animal metamorphoses into a worm If the swimming stage is given a juvenile hormone it settles into the substrate (mud) with an hour rather than 2 - 3 days! Prostaglandin , a derivative of the juvenile hormone, is the spawning factor for a number of organisms (oysters, clams, scallops) and as well in human reproduction. This is another example of evolutionary conservation.

The actions of juvenoides are now beginning to be understood. These work through protein kinases. Certain ions are involved - calcium and potassium. He gave us examples in which settlement can be induced by calcium or in another case by potassium. Another example of initiating metamorphosis was by adjusting the pH. There are a number of these examples in the literature. This is summarized in a book "Endocrinology of Selected Invertebrate Types" by Hans Laufer and others. One chapter is designated to mollusks. Most of the literature is on the non commercial mollusks, based on interests in medical problems or basic research. Since the location of the organs producing these hormones is known, cutting them out or destroying them with lasers, and replacing them have served to identify them and define their function. The molecules which exercise these controls are well known in a few cases and the genes coding for these are characterized at the molecular level. These will vary between species by 20 - 30%. They collectively represent a family of very similar genes. In summary the interactions which a mollusk undertakes is controlled by a light and food stimulus which is expressed on the brain and the nervous system and it produces a number of endocrine substances mostly in the brain which are tightly regulated.

Larval development Alan Kuzirian discussed larval development and what controls this process. He focused on the planktrophic larvae which are obligate feeders in the water column. The bivalves, including sea scallops, have to feed on phytoplankton or zooplankton in order to grow and develop. Fertilization takes place in the water column. The meeting of the sperm and the egg open a calcium channel. The burst of calcium into the cell initiates cell division leading ultimately to a planktonic larvae. The developing cilia provide locomotion and feeding currents. In one or two days they form shells. After they reach sufficient size they undergo metamorphosis and settlement. There is a stage just before this when they develop competency. The competency factors, in the hormones and the signal transducton, makes the black box hard to open. The appropriate chemical signals will not work for metamorphosis and settling unless the animals are competent. The big question is what are the steps involving competency? This is an active area for academic research. Some years ago his lab found that the element strontium has to be present for any mineralization to occur. You need a minimum of 4 parts per million of strontium and at a very specific time. In the hard shell clam this exposure only has to take place between hour 15 and 30. If strontium is not present you will not get shell formation. These bivalves release their eggs on the incoming tide when the strontium levels (from seawater) are highest.

To extend this to sea scallops, Alan Kuzirian showed some of the data from Scott Gallager who could not be with us today. Sea Scallop larvae are concentrated in specific water masses. If you can find that water mass you can collect large amounts of spat. The larvae are entrained within a given water mass determined by temperature. If you are going to sample off Georgias Bank you would look for preference areas within a given temperature range (around 100C) Tidal mixing fronts are extremely important in entrapping or entraining larvae, based on temperature and density. Larvae are simply not able to swim out of this current. Food also gets entrained. These convention currents are very stable and entrap the larvae throughout their entire development period. When it gets time to settle they simply settle to the bottom. The depth is about 60 - 65 meters. This is the depth along the shelf to look for larvae. Richard Taylor has reported finding phytopectin at this depth on the ocean floor. Gallager reproduced thermoclines in the laboratory to verify the above findings. They also found that sea scallops were concentrated at the thermocline during the day but moved towards the surface at night. They are so concentrated that they create minicells. Gallager further confirmed the larvae distribution by putting spat collectors at various depths in the laboratory They further experimented to show that the larvae were concentrated by temperature not by food supply. Thus the thermocline is the most important factor in entraining the larvae.

If you look at these larvae through polarizing light, you can see the crystalline structure of the calcium carbonate generates birefringence which appears as a recognizable cross pattern (white spot). Gallager used a videoplankton camera and recorder on a tether to find the larvae in the water column. A computer program then counts the number of white spots to determine the concentration. Since all bivalves will birefringe with polarized light, they found that if you add a full lambda wave length plate in the polarizer, rather than seeing bright spots you see patterns of color as you move from the zero order to the first order of refraction. The patterns of the color is species specific as it reflects on the structure of each individual species. By this means it should be possible to identify sea scallop larvae in the water column. The tethered camera, on a programmed basis would move up through the water column and when it reaches the surface send a signal to a satellite on the observations made as it moved up the water column. This would tell you when at what depth to place your spat collectors to collect sea scallop larvae. In response to a question, Alan Kuzirian said that 4 ppm related to a salinity of about 18 parts per thousand. As the bivalves do osmoregulate a bit some can tolerate somewhat lower salinity levels. This explains the normal salinity associated with incoming tides. The 15 hour dependency is about two tidal cycles. After this the animals could settle anywhere.

Environment / Aquaculture workshop Harlyn Halvorson brought the group up to date on the plans thus far for an Aquaculture / Environment workshop in 2000. For the past six months, a group of individuals from a number of local organizations have been developing the concept of a conference, Aquaculture and the Environment: A Meeting of Stakeholders. This conference will examine key issues relating to environmental effects of cultivating marine organisms as viewed by the aquaculture industry, the environmental community, and the scientific community. This conference will provide a neutral setting to assist us in obtaining an open and full discussion of the scientific and technological basis of community concerns. You are cordially invited to join the planning committee or to send us your views to be considered in our next Planning Committee meeting to be held hopefully sometime next month.

The objective of this conference is to identify the following: (1). What are the issues of concern? (2). What is known? (3). Where are the gaps in our knowledge? (4). How do we prioritize and deal with these gaps? (5). How should decision-making about aquaculture development proceed - - given what is known and not known? To achieve this objective, it is our intent to bring the key stakeholders (industry through environmentalists) to "the table" to participate in public discussion where the relevant scientific and technical information, including gaps in our knowledge, is available to all. It is the intent of this "meeting of stakeholders" to have the relevant stakeholders address these decisions collectively and develop a common map and common language relating to the issues that are at stake and the gaps that need to be addressed.

The organizations involved in early planning of this conference are:
Conservation Law Foundation; Ecosystems Center, MBL, Woods Hole, MA; Env., Coastal & Ocean Sci. Dept., UMass Boston; Environmental Defense Fund; Lab. of Marine Animal Health, Univ. Penn.; Mass. Biotech. Ctr of Excel Corp.; Mass. Audubon Society; MIT Sea Grant College Program; N. Regional Aq. Ctr. (USDA), UMass Dartmouth; PCMBT, UMass Boston; Sea Scallop Working Group; SE Mass. Aqu. Ctr. Mass Maritime Acad; Urban Harbors Institute, UMass Boston.

Below are some agenda items for our next planning meeting for the aquaculture workshop.
(1) Clear identification of workshop objectives. Do we want to build a consensus? If so, on what? Research priorities, how to proceed with sustainable aquaculture development? (2) Should we focus on one or several issues? For example we could focus the workshop on the impacts on water quality and marine habitat. (3) Should the workshop focus on specific types of aquaculture in a specific region, for example, pen-raised marine finfish in New England? (4) What should be the meeting format? Small workshop, large open conference, etc. (5) Should we contract and distribute 2-3 white papers in advance of the meeting? If so, suggest names and topics. (6) What individuals of groups do we need to have represented at the workshop? (7) Should the steering committee form subcommittees to work on different aspects of the conference such as list of invitees, venue planning invited. (8) Target a meeting date.

Next Meeting Tuesday December 7th Agenda and Place to follow.