Auke Bay Laboratory  (cont.)

Eastern Bering Sea Coastal Research (August- September 2001) on Juvenile Salmon

An eastern Bering Sea research cruise was conducted by members of the ABL Ocean Carrying Capacity program during August and September 2001 to study the early marine distribution, migration, and growth of juvenile sockeye salmon, Oncorhynchus nerka, from Bristol Bay.  Juvenile sockeye salmon were mainly distributed throughout the middle domain with the greatest catch per unit effort (CPUE) occurring in the southernmost stations (south of 56ºN) along the 164ºW, 163ºW, and 162ºW transects.  The distribution differed slightly from the August – September 2000 survey when large numbers of juvenile salmon were found further north (north of 56ºN) along the 164ºW transect.  The small CPUE of juvenile sockeye salmon west of 165ºW suggests that the westward extent of their migration was east of 166ºW during this period.  Analyses of plankton, stomach contents, freshwater age, size, and growth data, and genetic stock identification are underway to gain additional information on the growth and migration characteristics of juvenile sockeye salmon from Bristol Bay.

By Ed Farley

 
Gulf of Alaska Coastal Research on Juvenile Salmon

Scientists with the OCC program conducted a research cruise during July and August 2001 to study the early marine distribution, migration, and growth of juvenile salmon Oncorhynchus spp. in relation to oceanographic conditions in the coastal waters of the GOA.  Past OCC surveys in this region have focused mainly on broadscale surveys of juvenile salmon in the coastal waters of the GOA with little emphasis on associated oceanographic information. These annual summer surveys have documented that juvenile salmon are found on the continental shelf of the GOA and that juvenile salmon may utilize Shelikof Strait (an area associated with the Alaska Coastal Current) as a westward migration corridor rather than the seaward side of Kodiak Island.  During 2001, the OCC program collaborated with oceanographers from the Pacific Marine Environmental Laboratory in Seattle, Washington and other GLOBEC investigators in a new interdisciplinary focus on the relationships between biological and physical oceanographic processes and juvenile salmon distribution in the coastal GOA. Our objective is to identify specific processes or factors that may be influencing juvenile salmon spatial distribution, migration, growth, condition, and survival in the GOA and juvenile salmon utilization of Shelikof Strait as a primary migration corridor.

By Ed Farley.

 
Chinook Salmon Data Storage Tag Studies in Southeast Alaska, 2001

Chinook salmon were tagged in April and May 2001 with temperature and pressure data storage tags during two surveys in coastal Southeast Alaska conducted by ABL scientists.  Six tags have been recovered to date from the 48 chinook salmon tagged. The duration between tagging and recovery ranged between 4 and 86 days, and the minimum distance traveled by each fish ranged between 0 and 585 nmi. Depth data from the data storage tags indicate that chinook salmon, unlike other species of salmon, migrate to their deepest daily depths during the night.

By Jim Murphy and William Heard.

 
Assessment of Spot Shrimp Abundance in Prince William Sound

The goal of the spot shrimp project is to determine the extent to which spot shrimp abundance has recovered since the population decline which began just prior to 1989.  We estimated the abundance of adult and juvenile spot shrimp at 12 sites in western Prince William Sound (PWS),  determined the sex and size composition of spot shrimp at the study sites, and estimated spot shrimp fecundity and relative number of egg-bearing females in PWS. Statistical comparison with the summarized annual survey data from 1998 to 2000 provided to us by the ADF&G revealed a significantly increasing trend in the number of spot shrimp per station and weight of shrimp catch per station from 1998 to 2000, indicating population recovery may be taking place.  Our estimates of spot shrimp fecundity in 1999 were frequently substantially higher than previously published estimates for the ADF&G traditional sampling sites from 1989 to 1991, suggesting that spot shrimp fecundity may be an important variable to monitor on a periodic basis.

By Mandy Lindeberg.

AFSC Quarterly
Research Reports
July-Sept 2001