Science & Data

Biophysical data were collected along a primary marine migration corridor of juvenile Pacific salmon (Oncorhynchus spp.) in the northern region of southeastern Alaska. Data were collected at 13 stations in four sampling intervals (25 d total) from May to August 2002. This survey marks the sixth consecutive year of systematic monitoring, and was implemented to identify the relationships among biophysical parameters that influence the habitat use, marine growth, predation, stock interactions, year-class strength, and ocean carrying capacity of juvenile salmon. Habitats were classified as inshore (Auke Bay), strait (four stations each in Chatham Strait and Icy Strait), and coastal (four stations off Icy Point), and were sampled from the National Oceanic and Atmospheric Administration ship John N. Cobb. At each station, fish, zooplankton, surface water samples, and physical profile data were collected using a surface rope trawl (fish), conical and bongo nets (zooplankton), and a conductivity-temperature-depth profiler (physical profile), usually during daylight. Surface (2-m) temperatures and salinities ranged from 6.1 to 13.9EC and 17.4 to 32.2 PSU from May to August. A total of 8,665 fish and squid, representing 21 taxa, were captured in 75 rope trawl hauls from June to August. Juvenile salmon comprised 61% of the total catch and occurred frequently in the trawl hauls, with coho (O. kisutch) occurring in 65% of the trawls, pink (O. gorbuscha) in 57%, chum (O. keta) in 55%, sockeye (O. nerka) in 47%, and chinook salmon (O. tshawytscha) in 21%. Of the 5,336 salmonids caught, more that 98% were juveniles. Walleye pollock (Theragra chalcogramma) and crested sculpin (Blepsias bilobus) were the only non-salmonid species that comprised more than 1% of the total catch. Temporal and spatial differences were observed in the catch rates, size, condition, and stock of origin of juvenile salmon species, and in predation rates on them. Catches of juvenile chum, pink, sockeye, and coho salmon were generally highest in July, whereas catches of juvenile chinook salmon were highest in June. By habitat type, juvenile salmon catches were highest in straits. In the coastal habitat, catches were highest within 40 km of shore. Size of juvenile salmon increased steadily throughout the season; mean fork lengths in June and August were respectively: 86 and 143 mm for pink, 96 and 145 mm for chum, 121 and 139 mm for sockeye, 153 and 235 mm for coho, and 201 and 235 mm for chinook salmon. Coded-wire tags were recovered from 20 juvenile and immature salmon; most were from hatchery and wild stocks of southeastern Alaska origin; however, juvenile chinook and coho salmon from the Columbia River Basin were also recovered. In addition, otoliths were examined from four species of juvenile salmon: 1,525 from chum, 248 from sockeye, 363 from coho, and 18 from chinook salmon. Alaska hatchery stocks were identified by thermal marks from 44% of the chum, 17% of the sockeye, 5% of the coho, and 61% of the chinook salmon. Onboard stomach analysis of 135 potential predators, representing nine species, indicated five predation instances on juvenile salmon in August, including both of the age 1+ sablefish (Anoplopoma fimbria) and 3 of 12 (25%) adult coho salmon. Our results suggest that, in southeastern Alaska, juvenile salmon exhibit seasonal patterns of habitat use synchronous with environmental change, and display species- and stock-dependent migration patterns. Long-term monitoring of key stocks of juvenile salmon, both on an intra- and interannual basis, will enable researchers to understand how growth, abundance, and ecological interactions affect year-class strength and ocean carrying capacity for salmon.

Since 1995, the North Pacific Fishery Management Councils (NPFMC) Groundfish Plan Teams have prepared a separate Ecosystem Considerations section to the annual SAFE report. The intent of the Ecosystems Considerations section is to provide the Council with information about the effects of fishing from an ecosystem perspective, and the effects of environmental change on fish stocks. The effects of fishing on ecosystems have not been incorporated into most stock assessments, in part due to data limitations. Most single species models cannot directly incorporate the breadth and complexity of much of this information. ABC recommendations may or may not reflect discussion regarding ecosystem considerations. This information is useful for effective fishery management and maintaining sustainability of marine ecosystems. The Ecosystems Considerations chapter attempts to bridge this gap by identifying specific ecosystem concerns that should be considered by fishery managers, particularly during the annual process of setting catch limits on groundfish.

The annual stock assessment and fishery evaluation (SAFE) report is a requirement of the North Pacific Fishery Management Council's Fishery Management Plan for Bering Sea/Aleutian Islands King and Tanner Crabs (FMP), and a federal requirement [50 CFR Section 602.12(e)]. The SAFE summarizes the current biological and economic status of fisheries, guideline harvest levels (GHL), and analytical information used for management decisions or changes in harvest strategies. The report is assembled by the Crab Plan Team with contributions from the State of Alaska, Department of Fish and Game (ADF&G) and the National Marine Fisheries Service (NMFS), and is available to the public and presented to the North Pacific Fishery Management Council (NPFMC) on an annual basis.

The domestic groundfish fishery off Alaska is an important segment of the U.S. fishing industry. This report contains figures and tables which summarize various aspects of the economic performance of the fishery. Generally, data are presented for the domestic groundfish fishery for 1997 through 2001. Limited catch and ex-vessel value data are reported for earlier years in order to depict the rapid development of the domestic groundfish fishery in the 1980s and to provide a more complete historical perspective on catch. Pacific halibut (Hippoglossus stenolepis) is not included in data for the groundfish fishery in this report because for management purposes halibut is not part of the groundfish complex.

This document summarizes data on salmon collected by SECM scientists on biophysical parameters from May-September 2001 in southeastern Alaska.

Between 1911 and 1984, northern fur seal (Callorhinus ursinus) research was conducted by Canada, Japan, Russia, and the United States under the Treaty for the Preservation and Protection of Fur Seals and Sea Otters. Since 1984, studies have been carried out independently by former member nations.

Since 1995, the North Pacific Fishery Management Councils (NPFMC) Groundfish Plan Teams have prepared a separate Ecosystem Considerations section to the annual SAFE report. The intent of the Ecosystems Considerations section is to provide the Council with information about the effects of fishing from an ecosystem perspective, and the effects of environmental change on fish stocks. The effects of fishing on ecosystems have not been incorporated into most stock assessments, in part due to data limitations. Most single species models cannot directly incorporate the breadth and complexity of much of this information. ABC recommendations may or may not reflect discussion regarding ecosystem considerations. This information is useful for effective fishery management and maintaining sustainability of marine ecosystems. The Ecosystems Considerations chapter attempts to bridge this gap by identifying specific ecosystem concerns that should be considered by fishery managers, particularly during the annual process of setting catch limits on groundfish.

The annual stock assessment and fishery evaluation (SAFE) report is a requirement of the North Pacific Fishery Management Council's Fishery Management Plan for Bering Sea/Aleutian Islands King and Tanner Crabs (FMP), and a federal requirement [50 CFR Section 602.12(e)]. The SAFE summarizes the current biological and economic status of fisheries, guideline harvest levels (GHL), and analytical information used for management decisions or changes in harvest strategies. The report is assembled by the Crab Plan Team with contributions from the State of Alaska, Department of Fish and Game (ADF&G) and the National Marine Fisheries Service (NMFS), and is available to the public and presented to the North Pacific Fishery Management Council (NPFMC) on an annual basis.

The domestic groundfish fishery off Alaska is an important segment of the U.S. fishing industry. This report contains figures and tables which summarize various aspects of the economic performance of the fishery. Generally, data are presented for the domestic groundfish fishery for 1996 through 2000. Limited catch and ex-vessel value data are reported for earlier years in order to depict the rapid development of the domestic groundfish fishery in the 1980s and to provide a more complete historical perspective on catch. Pacific halibut (Hippoglossus stenolepis) is not included in data for the groundfish fishery in this report because for management purposes halibut is not part of the groundfish complex.

Biophysical data were collected along a primary marine migration corridor of juvenile Pacific salmon (Oncorhynchus spp.) in the northern region of southeastern Alaska at 20 stations in five, six-day sampling intervals from May to September 2000. This survey marks the fourth consecutive year of systematic monitoring, and was implemented to identify the relationships among biophysical parameters that influence the habitat use, marine growth, predation, stock interactions, year-class strength, and ocean carrying capacity of salmon. Habitats were classified as inshore (Taku Inlet and Auke Bay), strait (Chatham Strait and Icy Strait), and coastal (Cross Sound and Icy Point), and were sampled from the National Oceanic and Atmospheric Administration ship John N. Cobb. At each station, fish, zooplankton, surface water samples, and physical profile data were collected during daylight using a surface rope trawl, conical and bongo nets, and a conductivity-temperature-depth profiler. Surface (2-m) temperatures and salinities during the survey ranged from 6.6 to 14.1°C and 11.5 to 32.0 PSU. A total of 7,920 fish and squid, representing 30 taxa, were captured in 89 rope trawl hauls from June to September. Juvenile Pacific salmon comprised 86% of the total catch and were the most frequently occurring species: pink (O. gorbuscha; 60%), chum (O. keta; 55%), coho (O. kisutch; 49%), sockeye (O. nerka; 47%), and chinook salmon. Of the 6,846 salmonids caught, > 99% were juveniles. Non-salmonid species making up > 2% of total catch included walleye pollock (Theragra chalcogramma), Pacific herring (Clupea pallasi), and soft sculpin (Psychrolutes sigalutes). Temporal and spatial differences were observed in the catch rates, size, condition, stock of origin, and predation rates of juvenile salmon species. Catches of juvenile chum, pink, and coho salmon were highest in July, whereas catches of juvenile sockeye and chinook salmon were highest in June and September, respectively. By habitat type, juvenile salmon except chinook were most abundant in straits; juvenile chinook salmon were most abundant in inshore habitat. In the coastal habitat, catches along the Icy Point transect were highest within 40 km of shore. Size of juvenile salmon increased steadily throughout the season; mean fork lengths (mm) in June and September were: pink (95 and 198), chum (106 and 218), sockeye (114 and 196), coho (166 and 285), and chinook salmon (157 and 264). Coded-wire tags (CWTs) were recovered from seven juvenile and one immature chinook; only one was of non-Alaska origin, a juvenile chinook from the Columbia River Basin recovered in September. CWTs were recovered from seven juvenile and two adult coho; all were of Alaska origin. In addition, otoliths of 1,260 juvenile chum and 401 juvenile sockeye salmon revealed that 59% and 27% of these fish were Alaska hatchery stocks represented by thermal marks. Onboard stomach analysis of 214 potential predators, representing eleven species, indicated that 11% of adult coho salmon, 4.5% of spiny dogfish (Squalus acanthias), and 1% of adult walleye pollock preyed on juvenile salmon. Our results suggest that, in southeastern Alaska, juvenile salmon exhibit seasonal patterns of habitat use synchronous with environmental change, and display species- and stock-dependent migration patterns. Long term monitoring of key stocks of juvenile salmon, both on intra- and interannual bases, will enable researchers to understand how growth, abundance, and ecological interactions affect year-class strength and ocean carrying capacity for salmon.