Cod Broodstock Development Programme
Joint DFO and Industry
The federal Department of Fisheries & Oceans (DFO Newfoundland & Labrador Region), in conjunction with an industry partner, Newfoundland Aquaventures Ltd. (NAV), and in collaboration with the Ocean Science Center (OSC) of Memorial University, are engaged in a cod broodstock research & development project at the Aquaculture Research and Development Facility (ARDF). Funded by DFO's new Aquaculture Collaborative Research and Development Program (ACRDP) in October 2001, the four-year project is designed to further advance cod aquaculture in Newfoundland. Research is focused on photo manipulation of broodstock to promote production of high quality eggs beyond the natural spawning season, and the improvement of husbandry techniques to develop a top condition broodstock. Research results from the project will contribute to broodstock management protocols intended for use by the industry partner at their new commercial hatchery presently under construction at Bay Roberts, Newfoundland.
Results from the first year of the project have been very encouraging. Three-month advanced spawning occurred through photo manipulation of the previous years captive broodstock with 45 liters of eggs produced in 41 batches. Egg quality was excellent based on high fertilization rate (96%), low cell division abnormalities (4.9%) and mean egg diameter values (1.31mm). Two groups of ambient photoperiod broodstock were brought to the OSC in the late winter and early spring of 2002 and both spawned under captive conditions that spring. The data collected from the photo-advanced spawning was comparable to the ambient spawning in all parameters measured, demonstrating no adverse effect of photo-advancement on egg quality. The cod broodstock project is continuing with photo manipulation experiments through 2003. Continuous light experiments are also being investigated with anticipated spawning of this group slated for late December 2002.
The project has also begun experiments on broodstock husbandry practices as a means to optimize future broodstock management procedures and condition of resulting eggs and larvae. Previously, the husbandry practice has been to discontinue feeding broodstock during the spawning period as a means to reduce the potential for fecal and bacterial contamination of the eggs. In the 2001 season, broodstock were fed throughout spawning, 1-2 times per week. Egg quality was not detrimentally affected by feeding during the spawning season. Post-spawning survivorship and broodstock re-conditioning results were very good. The high post-spawning broodstock survival, not observed in past years, may be indicative of the benefit of feeding broodstock during spawning.
Beginning in 2003, the cod broodstock development project will include pedigree/ spawner identification research in collaboration with Dr. Jeff Hutchings of Dalhousie University, and experiments to test the efficacy of various egg disinfectants to reduce the chance of vertical transmission of potential diseases. Diet trials to examine the nutritional effectiveness of a cod broodstock moist pellet formulated by Dr Santosh Lall of the National Research Council will also be examined with the intention to improve overall broodstock condition, and reduce reliance on trash fish feeding (and its attendant risk as a potential disease vector).