Dr. Joe Wroblewski
Investigation of local fisheries resources of the Labrador
coast: J. Wroblewski, C. Parrish.
This is a subproject of ‘Coasts Under Stress’ looking at the nutritional value of cultured finfish and shellfish, in comparison to seafood from wild harvest. The goal is to provide scientific information for government policy on aquaculture development in Newfoundland and Labrador. In addition, the living marine resources of coastal Labrador are being studied. These have not been scientifically documented to date because of the remoteness of Labrador. Participatory research is being conducted with fishers to incorporate their ecological knowledge into scientific hypothesis testing, with the objective of improving their involvement with stock assessment science and management of local stocks. The reliability of the colouration of cod as an index of stock structure is being investigated. Fishers recognize bay cod by their reddish-brown colouration, while offshore cod are recognized by their grey-white coloration. Offshore cod are countershaded as an adaptation to their deep water habitat, while the reddish-brown coloration of shallow-water cod arises from a diet rich in carotenoids.
Bio-physical modeling of bay-scale populations of marine
fish: J. Wroblewski, B. deYoung (Physics), Y. Chen (U of
The hypothesis to be tested is that bay-scale populations of marine fish exist where adults display homing-to-spawn behaviour and local oceanographic conditions promote retention of eggs and survival of larvae. Computer models are being used to simulate homing-to-spawn behaviour of cod and physical oceanographic circulation in bays which support local populations of Atlantic cod to seek commonalities. Bays known to support local populations of cod all have major freshwater input during the spring spawning season. Surface stratification may play a role in retention and larval survival. The large volume of runoff in springtime may be important to the spring phytoplankton bloom and production of coastal cod. Simulations will determine the assessment sampling required to detect mixing between coastal populations of fish.