NAFO Sci. Coun. Studies, 29: 13–21 Fleming Survey of Demersal Juvenile Cod in Coastal Areas of Eastern Newfoundland
The primary objective during the 1995 study of Fleming survey area was to test for any possible enhanced density of first year demersal juvenile cod resulting from a well docu-mented spawning aggregation in Smith Sound area in April and May of 1995. Enhanced density of juveniles settling to the bott...
| Main Authors: | , , , , |
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| Format: | Text |
| Language: | English |
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| Online Access: | http://citeseerx.ist.psu.edu/viewdoc/summary?doi=10.1.1.603.3809 http://archive.nafo.int/open/studies/s29/schneid1.pdf |
| Summary: | The primary objective during the 1995 study of Fleming survey area was to test for any possible enhanced density of first year demersal juvenile cod resulting from a well docu-mented spawning aggregation in Smith Sound area in April and May of 1995. Enhanced density of juveniles settling to the bottom in suitable coastal habitat was expected about 3– 4 months later, in August and September. The second objective was to compare the abun-dance of identifiable length groups corresponding to ages 0+ 1+ and 2+ cod to the abun-dance of the same length groups in previous years. The survey revisited sites sampled in 1959–64 and 1992–94. The density of first year (0+) demersal juvenile cod (length group 0) did not exceed the average for 1992–94 for the entire survey area (St. Mary's Bay north to Notre Dame Bay). Within this area the density of length group 0 in Trinity and Conception Bay did not exceed that in previous years. The density of second year (1+) juveniles was expected to be higher in 1995 than 1994, based on higher density of the 0-group in 1994 than in 1993. Instead, the numbers of length group 1 fish were the lowest in the 10 year record of comparable counts. Third year (2+) juveniles were expected to be more abundant in 1995 than 1994, again based on strength of that cohort in previous years. Contrary to expectation the density of length group 2 fish was lower in 1995 than 1994. The expected density calculated from cohort strength the prior year assumed no change in performance of gear, and no greater shift of juvenile length group 1 cod into deep water than in previous years. Potential sources of mortality include incidental catch, predation by seals or large cod moving into shallow water. |
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