bedford institute of oceanography 2001 in review - Région des ...

SCIENCE ACTIVITIES / Biological SciencesShawn Roach and Barry MacDonald assess pedigree mussels in the BIO bivalveculture lab – photo by Dan Jackson.ment of spat collectors can affect farm yield on sites where twosimilar species of mussels, Mytilus edulis and Mytilus trossulus, exist.Other investigations include species identification using geneticmarkers, assessment of inbreeding levels in local European oysterbroodstock using genetic sequence data, and studies of the sex determinationmechanisms in the blue mussel. We are also developinggenetic techniques geared towards identifying disease resistant genesin oyster broodstock.BIO’s scallop triploid project, supported by the federal CanadianBiotechnology Strategy, is designed to produce scallops that grow fasterand have larger, higherquality meats. Our technologyinvolves manipulationof the fertilizationprocess to produce scallopsthat have threecomplete sets of chromosomesinstead of theusual two. These triploidanimals are sterile, and asa result they redirectenergy otherwise allocatedto reproductioninto increasing overallgrowth. Recent efforts inour lab have focussed onA juvenile scallop, approximately two months old –photo by Dan Jackson.the optimum methods of inducing triploidy in sea scallops, and assessmentof the physiological performance (growth and feeding rates) oftriploids and diploids.Our Canadian Biotechnology Strategy-funded genetic biotechnologyprojects examine genetic variability in wild haddock and integratemolecular techniques in attempts to enhance the efficiency of geneticimprovement programs for haddock aquaculture. This work isconducted in collaboration with scientists in the Centre for MarineBiodiversity, Diadromous Fish Division of DFO at BIO, and the St.Andrew’s Biological Station (DFO) in New Brunswick.The BIO facilities (including a phytoplankton production room,shellfish hatchery, nursery, and broodstock rooms, and supportinglabs) are well suited to support our research into the hatcheryproduction of molluscan species. We currently have 13 species ofphytoplankton under production that are used as feed for larval,juvenile, and adult bivalves. Our phytoplankton production labincludes 13 large culture tubes for producing up to 600 litres of algaedaily (at a density of approximately 6 to 7 million cells/ml) forfeeding both juveniles and adults. We also culture algae in 10 litrecarboys, which are used to supply bacteria-free food to the larvalstages. We can produce approximately 50 litres of this higher densityfood (10 to 12 million cells/ml) daily, which is enough to feed up to85 million newly hatched bivalve larvae.Bivalve larvae are usually reared in insulated tanks; we currentlyhave four 1000-litre tanks and fifteen 250-litre tanks, as well as anumber of smaller non-insulated culture vessels. Juvenile and adultanimals are held in a variety of fibreglass and plastic tanks, whichrange in size from six-foot diameter circular tanks to 60-litre plasticcontainers. Larval tanks are changed and cleaned every two daysand the larvae are fed daily, while the adult tanks are supplied witha constant flow of seawater and the juvenile tanks are set up on asemi-recirculating system. These allow for replicated experiments atall life history stages. In addition, BIO has a quarantine facility, withthree lab modules, that is used to support research on diseasedanimals and non-domestic species. These labs offer flexibility withrespect to the size and number of tanks, and have independentlighting and water options. The wastewater is monitored andtreated to ensure that the discharge water will not affect the localenvironment.As an essential part of our aquaculture research, we have developedadvanced laboratory facilities, including the BIO FlowCytometry and Scientific Imaging Laboratory. In this lab we have topgraderesearch microscopes and digital camera equipment that is usedto take high-resolution images of our experimental animals. Using thistechnology we can measure the sizes and other features of the animals,or perform more sophisticated image analysis routines such as fluorescentprobe studies or motion analysis. A flow cytometer is used tomeasure the ploidy level of scallops and mussels in support of ourtriploid research programme. Detailed bivalve feeding studies thatmeasure the type and amount of phytoplankton cells, which areingested by the animals, are also performed using the capabilities ofthe flow cytometer. The affiliated Centre for Marine BiodiversityLaboratory has a new state-of-the-art molecular level biology facility,which features an MJ BaseStation slab gel automated platform andsupporting equipment for performing genotyping and sequencing. Inthis lab, genetic markers are used and developed to address questionsrelated to population genetics or species identification and pedigreeanalysis of broodstock, providing a wide range of molecular biologicalinformation to biologists and researchers at BIO.26 / BIO-2001 IN REVIEW