Science & Data

Steller sea lion survey data and memos completed in the Aleutian Islands of Alaska.

In 1953, the Outer Continental Shelf Lands Act (OCSLA) (43 USC 1331-1356) charged the U.S. Secretary of the Interior with the responsibility for administering minerals exploration within and development of the Outer Continental Shelf (OCS). The Act empowered the Secretary to formulate regulations so that its provisions could be met. The OCSLA Amendments of 1978 (43 USC 1802) established a policy for the management of oil and natural gas in the OCS and for protection of the marine and coastal environments. The amended OCSLA states that the Secretary of the Interior shall conduct studies in areas or regions of sales to ascertain the “environmental impacts on the marine and coastal environments of the Outer Continental Shelf and the coastal areas which may be affected by oil and gas development” (43 USC 1346).

Aerial survey to assess western DPS Steller sea lion pup production.

Juvenile Pacific salmon (Oncorhynchus spp.), ecologically-related species, and associated biophysical data were collected from the marine waters of the northern region of southeastern Alaska (SEAK) in 2011. This annual survey, conducted by the Southeast Coastal Monitoring (SECM) project, marks 15 consecutive years of systematically monitoring how juvenile salmon utilize marine ecosystems during a period of climate change. The survey was implemented to identify the relationships between year-class strength of juvenile salmon and biophysical parameters that influence their habitat use, marine growth, prey fields, predation, and stock interactions. This report also contrasts the 2011 findings with selected biophysical factors from the prior 14 sampling years. Thirteen stations were sampled monthly in epipelagic waters from May to August (total of 21 sampling days). Fish, zooplankton, surface water samples, and physical profile data were typically collected during daylight at each station using a surface rope trawl, Norpac and bongo nets, a water sampler, and a conductivity-temperature-depth profiler. Surface (3-m) temperatures and salinities ranged from approximately 6 to 14 ºC and 15 to 32 PSU, respectively, from May to August across inshore, strait, and coastal habitats. A total of 6,640 fish and squid, representing 27 taxa, were captured in 96 rope trawl hauls fished from June to August. Juvenile salmon comprised approximately 78% of the total fish catch. Juvenile pink (O. gorbuscha), chum (O. keta), sockeye (O. nerka), and coho (O. kisutch) salmon occurred in 42-80% of the hauls by month and habitat, while juvenile Chinook salmon (O. tshawytscha) occurred in ≤ 17% of the hauls. Abundance of juvenile salmon was relatively low in 2011; peak catch-per-unit-effort (CPUE) in strait habitat occurred in August for all species except chum salmon (June). Coded-wire tags were recovered from 10 coho salmon and 6 Chinook salmon from hatchery and wild stocks originating in SEAK and Washington. Alaska enhanced stocks were also identified by thermal otolith marks from 60%, 21%, and 5% of chum, sockeye, and coho salmon examined, respectively. Predation on juvenile salmon was observed in 3 of 9 species examined. Biophysical measures from 2011 differed from prior years, in many respects. Compared to the 15-yr longterm mean values, temperature anomalies were negative, salinity anomalies were positive, zooplankton density was low, and condition residuals were negative for juvenile pink, chum, and sockeye salmon. The SECM juvenile salmon stock assessment and biophysical data are used in conjunction with basin-scale biophysical data to forecast pink salmon harvest in SEAK. Longterm seasonal monitoring of key stocks of juvenile salmon and associated ecologically-related species, including fish predators and prey, permits researchers to understand how growth, abundance, and interactions affect year-class strength of salmon during climate change in marine ecosystems.

In 1953, the Outer Continental Shelf Lands Act (OCSLA) (43 USC 1331-1356) charged the U.S. Secretary of the Interior with the responsibility for administering minerals exploration within and development of the Outer Continental Shelf (OCS). The Act empowered the Secretary to formulate regulations so that its provisions could be met. The OCSLA Amendments of 1978 (43 USC 1802) established a policy for the management of oil and natural gas in the OCS and for protection of the marine and coastal environments. The amended OCSLA states that the Secretary of the Interior shall conduct studies in areas or regions of sales to ascertain the “environmental impacts on the marine and coastal environments of the Outer Continental Shelf and the coastal areas which may be affected by oil and gas development” (43 USC 1346).

Juvenile Pacific salmon (Oncorhynchus spp.), ecologically-related species, and associated environmental (biophysical) data were collected from the marine waters of the northern region of southeastern Alaska in 2010. This annual survey, conducted by the Southeast Coastal Monitoring (SECM) project, marks 14 consecutive years of systematically monitoring how juvenile salmon utilize in marine ecosystems, and was implemented to identify the relationships among biophysical parameters that influence habitat use, marine growth, predation, stock interactions, and year-class strength of juvenile salmon. This report also contrasts the 2010 findings with selected biophysical parameters from the prior 13 sampling years. Up to 13 stations were sampled in epipelagic waters monthly, totaling 21 sampling days, from May to August. Fish, zooplankton, surface water samples, and physical profile data were typically collected during daylight at each station using a surface rope trawl, conical and bongo nets, a water sampler, and a conductivity-temperature-depth profiler. Surface (3-m) temperatures and salinities ranged from approximately 9 to 14 ºC and 17 to 32 PSU from May to August. More than 39,000 fish, representing 26 taxa, were captured in 67 rope trawl hauls fished from June to August. Juvenile salmon comprised about 97% of the total fish catch. Juvenile pink (O. gorbuscha), chum (O. keta), sockeye (O. nerka), and coho (O. kisutch) salmon occurred in 71-87% of the trawls, while juvenile Chinook salmon (O. tshawytscha) occurred in 9% of the hauls. Unusually high numbers of juvenile salmon were captured in strait habitat in both June and July, although CPUE was greatest in June for all species except sockeye salmon. Coded-wire tags were recovered from 15 juvenile coho salmon and one juvenile Chinook salmon from hatchery and wild stocks originating in southeastern Alaska and Washington. Alaska enhanced stocks were also identified by thermal otolith marks from 67% of the chum and 16% of the sockeye salmon examined. Onboard stomach analysis revealed predation on highly abundant juvenile salmon by adult coho salmon, a common predator, and adult pink salmon, a rare predator. Biophysical measures from 2010 differed from prior years, in many respects. May integrated (20-m) temperature anomalies were generally positive and salinity anomalies were generally negative; in particular, the positive May temperature anomaly was the highest on record. Zooplankton monthly total densities were near longterm averages, reversing the trend for strongly positive anomalies over the past four years. For juvenile pink, chum, and sockeye salmon, low condition residuals in June were followed by small size and low energy density in July. Regional biophysical data from SECM are used in conjunction with basin-scale biophysical parameters to forecast pink salmon harvest in southeastern Alaska. Longterm monitoring of key stocks of juvenile salmon, on seasonal and interannual time scales, will enable researchers to understand how growth, abundance, and ecological interactions affect year-class strength of salmon and to better understand their roles in North Pacific marine ecosystems.

Photographic surveys of adult, juvenile, and pup steller sea lions in Alaska conducted in Summer 2010.

Juvenile Pacific salmon (Oncorhynchus spp.), ecologically-related species, and associated biophysical data were collected from the marine waters of the northern and southern regions of southeastern Alaska in 2009. This annual survey marks 13 consecutive years of systematically monitoring how juvenile salmon interact in marine ecosystems, and was implemented to identify the relationships among biophysical parameters that influence habitat use, marine growth, predation, stock interactions, and year-class strength of juvenile salmon. This report also contrasts the 2009 findings with selected biophysical parameters from the prior 12 sampling years. Up to 17 stations were sampled in epipelagic waters over four time periods (20 sampling days) from May to August. Typically, 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, a water sampler, and a conductivity-temperature-depth profiler. Surface (3-m) temperatures and salinities ranged from approximately 8 to 15 ºC and 19 to 31 PSU from May to August. Nearly 11,000 fish, representing 12 taxa, were captured in 60 rope trawl hauls in July and August in the two regions. No trawling was conducted in June, in contrast to all other years. Juvenile salmon comprised about 97% of the total fish catch. Juvenile pink (O. gorbuscha), chum (O. keta), sockeye (O. nerka), and coho salmon (O. kisutch) occurred in 5698% of the trawls, while juvenile Chinook salmon (O. tshawytscha) occurred in < 13% of the hauls. All juvenile salmon species occurred more frequently in northern region trawls than in southern region trawls in July. In the northern region, catch rates of juvenile pink, chum, and coho salmon were higher in July than in August, whereas catches of sockeye salmon were higher in August. Coded-wire tags were recovered from 18 juvenile coho salmon from hatchery and wild stocks originating in southeastern Alaska. Alaska enhanced stocks were also identified by thermal otolith marks from 47% of the chum and 18% of the sockeye salmon examined. Onboard stomach analysis of 108 potential predators, representing seven species, did not provide evidence of predation on juvenile salmon. Biophysical measures from 2009 differed from prior years, in many respects. Integrated (20-m) temperature anomalies were all positive and salinity anomalies were negative; in particular, the May temperature anomaly was the 2nd highest on record. Anomalies of zooplankton total density were positive each month, a trend which has persisted for four years. In addition, size anomalies for juvenile salmon were positive, a shift from the previous two years. Condition residual anomalies were unusually high for juvenile salmon species in August. These data, in conjunction with basin-scale biophysical parameters, are currently being used to forecast pink salmon harvest in southeastern Alaska. Long-term monitoring of key stocks of juvenile salmon, on seasonal and interannual time scales, will enable researchers to understand how growth, abundance, and ecological interactions affect year-class strength of salmon and to better understand their roles in North Pacific marine ecosystems.

A survey to assess Steller sea lion (Eumetopias jubatus) pup production in Alaska conducted by the Alaska Fisheries Science Center (AFSC) in Summer 2009.

Juvenile Pacific salmon (Oncorhynchus spp.), ecologically-related species, and associated biophysical data were collected from the marine waters of the northern region of southeastern Alaska in 2008. This annual survey marks 12 consecutive years of systematically monitoring how juvenile salmon interact in marine ecosystems, and was implemented to identify the relationships among biophysical parameters that influence habitat use, marine growth, predation, stock interactions, and year-class strength of juvenile salmon. This report summarizes findings from the 2008 survey year, and contrasts these findings to selected biophysical parameters of the prior 11 sampling years. Up to 13 stations were sampled in epipelagic waters over four time periods (20 sampling days) from May to August. Typically, 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, water sampler, and a conductivity-temperature-depth profiler. Surface (3-m) temperatures and salinities ranged from 6.8 to 11.6 ºC and 18.2 to 32.0 PSU from May to August. A total of 5,186 fish, representing 16 taxa, were captured in 56 rope trawl hauls from June to August. Juvenile salmon comprised about 97% of the total fish catch. Juvenile salmon occurred frequently in the trawl hauls, with pink (O. gorbuscha), chum (O. keta), sockeye (O. nerka), and coho salmon (O. kisutch) present in 6686% of the trawls, whereas juvenile Chinook salmon (O. tshawytscha) occurred less commonly, in about 39% of the hauls. Exceptionally few juvenile salmon were captured in June. Peak monthly catch rates of juvenile salmon differed by species: pink, chum, and coho were highest in July, whereas sockeye and Chinook were highest in August. Coded-wire tags were recovered from 11 juvenile coho salmon and three Chinook salmon (one juvenile and two immature). All fish were from hatchery and wild stocks originating in southeastern Alaska. Alaska enhanced stocks were also identified by thermal otolith marks from 39% of the chum and 4% of the sockeye salmon examined. Onboard stomach analysis of 20 potential predators, representing four species, did not provide evidence of predation on juvenile salmon. Biophysical measures from 2008 differed from prior years, in many respects. Integrated (20-m) temperatures and salinities were anomalously low and zooplankton densities were anomalously high in 2008. In addition, for most juvenile salmon species, unusual CPUE patterns, small fish size, and low condition residuals suggested that migration timing shifted to later than average. Long-term monitoring of key stocks of juvenile salmon, on seasonal and interannual time scales, will enable researchers to understand how growth, abundance, and ecological interactions affect year-class strength of salmon and to better understand their roles in North Pacific marine ecosystems.