Spisula Solidissima): a Step Towards Diversifying the New Jersey Shellfish Aquaculture Sector
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THERMAL TOLERANCE OF JUVENILE ATLANTIC SURFCLAMS (SPISULA SOLIDISSIMA): A STEP TOWARDS DIVERSIFYING THE NEW JERSEY SHELLFISH AQUACULTURE SECTOR Michael P. Acquafredda*, Daphne Munroe, Lisa M. Calvo, Michael P. De Luca Rutgers, The State University of New Jersey, Haskin Shellfish Research Laboratory, 6959 Miller Avenue, Port Norris, New Jersey 08349 [email protected] New Jersey shellfish aquaculture is currently limited to two species: the northern quahog (=hard clam) (Mercenaria mercenaria) and the eastern oyster (Crassostrea virginica); however, shellfish farmers eager to diversify have expressed interest in culturing new species. The Atlantic surfclam (Spisula solidissima) represents an ideal target species for diversification because it is native, grows rapidly, and fits into the established farming framework. To optimize the husbandry techniques required for sustainable and profitable farming, it is necessary to gain a thorough understanding of how temperature impacts the performance of the surfclam throughout its different developmental stages. This study examined the effects of five different temperatures (≈18˚C, 20˚C, 23˚C, 24˚C, and 26˚C) on the growth and survival of juvenile surfclams (shell length = 0.69–3.00 mm). Three independent cohorts were tracked for several weeks and cultured using downweller and upweller systems. Shell length and survival estimates were collected 2–3 times per week. Results suggest that colder temperatures reduce clam mortality, while temperatures between 20 and 24˚C promote the greatest growth. The parentage of each cohort also had a significant impact on growth and survival, suggesting there is a genetic component to surf clam thermal tolerance. These findings and the results from our on-going surfclam aquaculture optimization studies will be incorporated into a manual of best practices. This manual will be made accessible to the state’s local shellfish farmers. Moreover, these results can be incorporated into species distribution models, and further refine the management of the lucrative wild surfclam fishery. SEASONAL FEEDING AND GROWTH OF THE EASTERN OYSTER (CRASSOSTREA VIRGINICA) IN THE DAMARISCOTTA RIVER ESTUARY, MAINE Cheyenne Adams1*, Lawrence Mayer1, Paul Rawson2, Carter Newell3 1University of Maine School of Marine Sciences, Darling Marine Center, 193 Clarks Cove Road, Walpole, ME 04573 2University of Maine School of Marine Sciences, Orono, ME 04469 3Pemaquid Oyster Co., Pemaquid Mussel Farms, and University of Maine School of Marine Sciences, 7 Creek Lane, Damariscotta, Maine 04543 [email protected] Production on oyster farms depends on the quantity and quality of the planktonic food, including phytoplankton and detritus, available at the site. This research, part of the Sustainable Ecological Aquaculture Network (SEANET) program, is investigating seasonal variation in the nutritional quality of suspended particulates and associated feeding and growth responses of eastern oysters (Crassostrea virginica). From May through October 2016, bi-weekly water sampling was conducted in an intensively farmed segment of the Damariscotta River Estuary. Multiple water quality parameters were measured, including temperature, salinity, turbidity, chlorophyll α, pheophytin, total particulate matter, particulate organic matter, particulate inorganic matter, phytoplankton community composition, phytodetritus, and enzymatically hydrolysable amino acids (EHAA, which quantifies bioavailable protein). Seasonal variation in food quantity and quality data were compared to water clearance, filtration, ingestion, and absorption rates in C. virginica; these, in turn, were compared to seasonal variation in growth of individual oysters. Preliminary results show that clearance rate scales with temperature, and absorption efficiency and growth are lower when there is an increase in particulate inorganic matter and pheophytin concentrations. Although absorption efficiency and growth were expected to be highest at times of increased chlorophyll α concentrations, they remained low when high chlorophyll α concentrations coincided with high concentrations of inorganic matter and pheophytin. These results will be used to improve oyster growth modelling and site selection for oyster farms in Maine. DEVELOPMENT OF A QPCR ASSAY TO DETECT PROCTOECES MACULATUS IN THE WATER COLUMN M. Victoria Agnew*, Chris Materna, Abigail Scro, Roxanna Smolowitz Roger Williams University, 1 Old Ferry Road, Bristol RI 02809 [email protected] The digenetic trematode Proctoeces maculatus is known to infect the blue mussel Mytilus edulis. Although little is known about the overall health effects these pathogens have on the blue mussel, it is hypothesized that severe infections can be related to mass mortality events. P. maculatus is known to have a multi-host life cycle, starting as miracidia which produce sporocysts that infect their intermediate host M. edulis. The sporocysts produce daughter sporocysts, which progress to the production of cercaria. The cercaria exit the intermediate host and move on to infect their second intermediate host or their definitive host (Stunkard and Uzmann, 1959). Theoretically, at the time when the cercaria leave their intermediate host there should be an increased presence of P. maculatus in the water column due to the migration of the pathogen to its next host. The ability to detect the presence and relative abundance of P. maculatus in the water column could make it possible to identify seasonality trends, and could also be used to relate the departure of these parasites from blue mussels to spawning or mass mortality events within populations. The goal of this research is to create a SybrGreen quantitative polymerase chain reaction (qPCR) assay that is specific and capable of detecting the presence of P. maculaus in the water column. The preliminary research for creating the SybrGreen qPCR will be presented, including the creation of plasmids that form reliable and accurate standard curves, and the specificity and lower detection limit of the assay. A MULTI-OMIC APPROACH TO REVEAL QPX-CLAM INTERACTIONS Bassem Allam*, Sleiman Bassim, Rachel Hartman, Kailai Wang, Emmanuelle Pales Espinosa Stony Brook University, School of Marine and Atmospheric Sciences, Stony Brook, NY 11794 [email protected] QPX is a protistan parasite that infects northern quahogs (=hard clams), Mercenaria mercenaria, often leading to the development of inflammatory masses (nodules) that result from massive hemocyte infiltration to the infection site in an attempt to isolate and encapsulate parasite cells. Inside nodules, active host-pathogen interactions take place leading either to the death of the parasite or invasion of surrounding tissues and infection worsening. This study was designed to investigate host-parasite interactions using a complementary set of in vivo and in vitro approaches in conjunction with transcriptomic and proteomic methods. In vivo, dual gene expression of QPX and clams to characterize molecular host-parasite interactions was studied. This was done via RNA sequencing of nodule biopsies and contrasting these with RNA sequences generated from uninfected tissues from infected clams or from healthy clams, as well as genomic and transcriptomic information generated from cultured parasite cells. Analyses allowed the identification of 900 QPX transcripts that are only produced in clam tissues during infection. These included genes and molecular processes implicated in the secretory pathways of the parasite and secreted proteases which we suspect to play a primary role in QPX virulence towards clams. In parallel, proteomic methods were used to identify host plasma factors that recognize and bind parasite cells in vitro. These included prominent pattern recognition receptors (PRR) such as complement c1q-domain containing proteins and lectins. Results further showed that these PRR are induced upon infection. Altogether, these results provide valuable information on the molecular crosstalk between QPX and its clam host. CARBON MINERALIZATION AND EFFLUX IN CLAM AQUACULTURE Patrick Baker*, Shirley Baker University of Florida, Program in Fisheries and Aquatic Sciences, School of Forest Resources and Conservation, 7922 NW 71st Place, Gainesville, FL 32653 [email protected] Molluscs mineralize carbon as CaCO3 in shells. Shell is a long-term reservoir for carbon but mineralization of dissolved bicarbonate results in an initial efflux of CO2. In Florida, USA, northern hard clams, Mercenaria mercenaria, are cultured in mesh bags in coastal habitats. Carbonate content of shells was quantified by coulometry, and shell production was estimated per harvested clam, and per unit area per year. About 91% of the shell was M. mercenaria and the rest were mostly oysters (Crassostrea virginica and Ostrea equestris) on culture bags, though there were 37 other shelled taxa. Each harvested clam represented a mean of 2.93 g of mineralized carbon, including shell from associated taxa. Clam culture produced about 10,030 kg of mineralized carbon ha-1 y-1, and the Florida clam industry produced about 534 tons of mineralized carbon in 2008. This mineralization resulted in an atmospheric efflux of up to 374 tons (70% of fixed) of carbon as CO2, using a model that predicts 30% dissolution of CO2 back into seawater. Models for CO2 dissolution vary, however, and clams can use metabolic CO2 instead of seawater bicarbonate for up to a third of shell production, reducing net CO2 efflux from shell production. In addition,