Settlement timing, distribution, and abundance of Dover sole (Microstomus pacificus) on an outer continental shelf nursery area

• Published in: Canadian journal of fisheries and aquatic sciences 1997-03, Vol.54 (3), p.531-542
• Main Authors: TOOLE, C. L, MARKLE, D. F, DONOHOE, C. J
• Format: Article
• Language: English
• Subjects: Agnatha. Pisces; Animal and plant ecology; Animal, plant and microbial ecology; Animals; Biological and medical sciences; Continental shelves; Demecology; Fundamental and applied biological sciences. Psychology; Marine; Microstomus pacificus; Sole (Fish); Vertebrata
• ISSN: 0706-652X; 1205-7533
• DOI: 10.1139/cjfas-54-3-531

Settlement timing, distribution, and abundance of Dover sole (Microstomus pacificus) were compared with depth and environmental variables off Oregon, USA. Surveys were made every 2 months from January to November 1989 on three 50-400 m depth transects and every March from 1990 to 1994 on one transect. Annual March age-1 CPUE estimates did not support Hayman and Tyler's (1980) recruitment hypothesis that strong year-classes are associated with offshore convergence during the settlement season, despite a similar distribution of oceanographic conditions during the 2 studies. High March CPUE was correlated with high bottom temperature in the primary nursery area (100-119 m depth) and an increase in the proportion of larvae in deeper strata. Seasonal and annual observations support Hayman and Tyler's assumption that the primary postsettlement nursery area is bathymetrically restricted. Otolith increments indicated that larvae at 50-159 m had been on the bottom longer than larvae from greater depths, suggesting postsettlement inshore migration. Sediment size and bottom temperature do not explain the high CPUE in the primary nursery area. A negative size-depth relationship and a change in depth distribution with increasing density suggest that biological interactions may influence the spring distribution.