Utility of continuous light and triploidy to control sexual maturation of Atlantic cod in the Bay of Fundy
Early maturation in pre-market Atlantic cod affects ~100% of fish in sea cages, and this problem is not isolated to the Bay of Fundy. Preliminary results from 24 h light treatment (six 400 W submerged lights) in a 70 m polar circle cage holding 2004 YC cod support the hypothesis that continuous light delays onset of sexual maturity, in this case by ~ 4-5 months, with females subsequently retaining the state of ripeness for another 4 months (ACRDP project MG-04-09-001).
The current proposal will explore two approaches to impede sexual maturation:
- continued experimentation with light level and wavelength and
- induction of sterility by triploidy.
This study has six objectives:
- To further evaluate on-going light treatments and test the use of new light technology to inhibit sexual maturation of Atlantic cod.
- To examine the degree of suppression of maturation in both sexes in 0+ group, pre-market and market fish exposed to 24 h light.
- To develop protocols for the pressure-induced production and early identification of triploid cod.
- To monitor seasonal sex-specific growth of immature and mature cod (derived from light treatments and triploidy) as well as incidence of deformities and mortality.
2007 - 2010
Atlantic: Gulf of Maine, Scotian Shelf
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