T.S. Kristiansen, K.E. Jorstad, H. Ottera, O.I. Paulsen, T. Svasand-1997
Journal of Fish Biology, 51 Suppl. A : 264-283 (from Current Contents)
Abstract:
In the spring of 1995, 18 million generically marked yolk-sac cod larvae Gadus morhua were released into a 2.9-km(2), nearly land-locked fjord in western Norway. Four quantitative surveys were conducted, 11, 33, and 63 days, and 1 year after the first release. Almost 100% of the collected cod larvae were successfully identified to GPI-1* genotype. The marked cod larvae constituted 18% of all sampled cod larvae in the first survey and 9% in the two next. The average rate of mortality was estimated to be 23%/day for the first 10 days after release and 12%/day during the next month after release. After 1 year (April 1996), the number genetically marked I-group cod in the fjord was estimated to be <120. The effect of the historical programme of large-scale releases of yolk-sac larvae on recruitment were evaluated and found to be small.
(POB 1870, N-5024 Bergen, Norway)