Science & Data

The Chukchi Offshore Monitoring in Drilling Area (COMIDA) aerial survey component was initiated in 2008, via an Interagency Agreement (No. M08PG20023) between the Minerals Management Service (MMS) [Department of the Interior; currently the Bureau of Ocean Energy Management, Regulation and Enforcement] and the National Marine Mammal Laboratory (NMML) [Alaska Fisheries Science Center, National Marine Fisheries Service, National Oceanic and Atmospheric Administration, Department of Commerce]. These surveys are a continuation of aerial surveys that were conducted by MMS-sponsored contractors from 1982-1991 (Ljungblad et al., 1987; Moore and Clarke, 1992) and use similar methodology. Aerial surveys remain the only practical means of assessing marine mammal distribution, population density, and habitat use in large study areas. The goal of this study is to investigate the distribution and relative abundance of marine mammals in the Chukchi Sea Planning Area (CSPA) during the open water (ice-free) months of June-October, when various species are undertaking seasonal migrations through the area. The COMIDA study area encompasses the northeastern Chukchi Sea from shore seaward, latitude 68°N to 72°N and longitude 157°W to 169°W, and overlays Lease Sale 193 (offered in February 2008). Species of interest include the bowhead whale (Balaena mysticetus), gray whale (Eschrichtius robustus), beluga (Delphinapterus leucas), polar bear (Ursus maritimus), walrus (Odobenus rosmarus), and ice seals. Increasing the understanding of marine mammal distribution, abundance and migration timing in this region will assist in decision-making to minimize impacts from petroleum exploration, development and production activities and other anthropogenic impacts.

Underwater noise survey

Juvenile Pacific salmon (Oncorhynchus spp.), ecologically-related species, and associated biophysical data were collected along primary marine migration corridors in the northern and southern regions of southeastern Alaska in 2007. Up to 17 stations were sampled in epipelagic waters over four time periods (27 sampling days) from May to August. This survey marks 11 consecutive years of systematically monitoring how juvenile salmon interact in marine ecosystems, and was implemented to identify the relationships among biophysical parameters that influence the habitat use, marine growth, predation, stock interactions, and year-class strength of salmon. Typically, at each station, fish, zooplankton, surface water samples, and physical profile data were collected using a surface rope trawl, conical and bongo nets, water sampler, and a conductivity-temperature-depth profiler during daylight. Surface (3-m) temperatures and salinities ranged from 7.7 to 15.3 ºC and 12.3 to 30.6 PSU from May to August. A total of 48,170 fish and squid, representing 17 taxa, were captured in 97 rope trawl hauls from June to August. Juvenile salmon comprised about 7% of the total fish and squid 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 51-92% of the trawls in the southern and northern regions, whereas juvenile Chinook salmon (O. tshawytscha) occurred in about 23% of the hauls. Of the 3,412 salmonids caught, over 97% were juveniles. Only two non-salmonid species represented catches of >30 individuals in either region: Pacific herring (Clupea pallasi) in the southern region (n = 44,637) and crested sculpin (Blepsias bilobus) in the northern region (n = 34). Catch rates of juvenile salmon in both regions were generally highest in June for all species except pink salmon. However, in the more extended, 11-yr time series in the northern region, juvenile pink salmon catches were among the lowest observed in June and July 2007, suggesting a poor adult return in the subsequent year. Mean size of juvenile salmon generally increased from June to July; however, condition residuals were lower than the longterm average for most species. Coded-wire tags were recovered from 14 juvenile coho salmon and five Chinook salmon (1 juvenile and 4 immature). All but one fish were from hatchery and wild stocks originating in southeastern Alaska. The non-Alaskan stock was a Chinook salmon that originated from the Upper Columbia River. Alaska enhanced stocks were also identified by thermal otolith marks from 67% of the chum and 4% of the sockeye salmon examined. Onboard stomach analysis of 95 potential predators, representing 8 species, did not provide evidence of predation on juvenile salmon. This research suggests that in southeastern Alaska, juvenile salmon exhibit seasonal patterns of habitat use and display species- and stock-dependent migration patterns. This third season of comparing biophysical parameters between the northern and southern regions of southeastern Alaska suggests that summer conditions differ between the regions. 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 role in North Pacific marine ecosystems.

Juvenile Pacific salmon (Oncorhynchus spp.), ecologically-related species, and associated biophysical data were collected along primary marine migration corridors in the northern and southern regions of southeastern Alaska in 2006. Up to 21 stations were sampled over four time periods (39 sampling days) from May to August. This survey marks 10 consecutive years of systematic monitoring on how juvenile salmon interact in marine ecosystems, and was implemented to identify the relationships among biophysical parameters that influence the habitat use, marine growth, predation, stock interactions, and year-class strength of salmon. Typically, at each station, fish, zooplankton, surface water samples, and physical profile data were collected using a surface rope trawl, conical and bongo nets, water sampler, and a conductivity-temperature-depth profiler during daylight. Surface (3-m) temperatures and salinities ranged from 7.1 to 15.4 ºC and 15.1 to 32.0 PSU from May to August. A total of 10,641 fish and squid, representing 20 taxa, were captured in 94 rope trawl hauls from June to August. Juvenile salmon comprised about 98% of the total fish and squid catch in each region. Juvenile salmon occurred frequently in the trawl hauls, with pink (O. gorbuscha), chum (O. keta), sockeye (O. nerka), and coho salmon (O. kisutch) occurring in 52100% of the trawls in both regions, whereas, juvenile Chinook salmon (O. tshawytscha) occurred in 25% and 28% of the hauls in the southern and northern regions. Of the 10,451 salmonids caught, over 99% were juveniles. In both regions, only two non-salmonid species represented catches of >27 individuals: walleye pollock (Theragra chalcogramma) in the southern region and Pacific herring (Clupea pallasi) in the northern region. Temporal and spatial differences were observed in the catch rates, size, condition, and stock of origin of juvenile salmon species. Catch rates of juvenile salmon in both regions were generally highest in June for all species except Chinook, which had the highest catch rates in July. Size of juvenile salmon increased from June and July; mean fork lengths were: 102 and 121 mm for pink; 112 and 138 mm for chum; 110 and 131 mm for sockeye; 168 and 200 mm for coho; and 202 and 223 mm for Chinook salmon. Coded-wire tags were recovered from 13 juvenile coho salmon, two juvenile and one immature Chinook salmon; all but two were from hatchery and wild stocks of southeastern Alaska origin. The non-Alaska stocks were juvenile Chinook salmon originating from the Similkameen River and the Wells Hatchery within the Columbia River Basin. Alaska enhanced stocks were also identified by thermal otolith marks from 77% of the chum and 7% of the sockeye salmon. Onboard stomach analysis of 95 potential predators, representing 12 species, revealed one predation incident on juvenile salmon by an adult coho salmon. This research suggests that in southeastern Alaska, juvenile salmon exhibit seasonal patterns of habitat use and display species- and stock-dependent migration patterns. Long-term monitoring of key stocks of juvenile salmon, on both intra- and interannual bases, will enable researchers to understand how growth, abundance, and ecological interactions affect year-class strength and to better understand the role salmon play in North Pacific marine ecosystems.

Aerial survey of the beluga population in upper Cook Inlet, Alaska, August 16-17, 2006 to document whale groups via video for an analysis of age structure.

Juvenile Pacific salmon (Oncorhynchus spp.), ecologically-related species, and associated biophysical data were collected by the Southeast Coastal Monitoring Project along primary marine migration corridors in the southern and northern regions of southeastern Alaska. Up to 17 stations were sampled in four time periods (40 sampling days) from May to August 2005. This survey marked the ninth consecutive year of systematic monitoring of how juvenile salmon interact in marine ecosystems, and was implemented to identify the relationships among biophysical parameters that influence the habitat use, marine growth, predation, stock interactions, and year-class strength of salmon. Typically, at each station, fish, zooplankton, physical profile data, and water samples were collected using a surface rope trawl, conical and bongo nets, a conductivity-temperature-depth profiler, and a water sampler during daylight. Surface (3-m) temperatures and salinities ranged from 9.3 to 15.7 ºC and 13.8 to 31.5 PSU over the season. A total of 6,874 fish and squid, representing 19 taxa, were captured in 92 rope trawl hauls from June to August. Juvenile salmon comprised 96% of the total fish and squid catch in each region. Juvenile salmon occurred frequently in both regions, with pink (O. gorbuscha), chum (O. keta), sockeye (O. nerka), and coho (O. kisutch) occurring in 63-86% of the trawl hauls, and juvenile Chinook salmon occurring in 20-25% of the trawl hauls. Of the 6,651 salmonids caught, over 99% were juveniles. In both regions, only two non-salmonid species represented >1% of the catch: market squid (Loligo spp.) in the southern region (2%) and crested sculpin (Blepsias bilobus) in the northern region (2%). Temporal and spatial differences were observed in the catch rates, size, condition, and stock of origin of juvenile salmon species. Catch rates of juvenile salmon were highest in June for all species except pink salmon, which had the highest catch rates in August. Size of juvenile salmon increased steadily throughout the season; mean fork lengths in June, July, and August were, respectively: 92, 127, and 170 mm for pink; 108, 124, and 191 mm for chum; 115, 123, and 180 mm for sockeye; 184, 207, and 239 mm for coho; and 205, 245, and 255 for Chinook salmon. Coded-wire tags were recovered from 17 juvenile coho, 6 juvenile Chinook, and 2 immature Chinook salmon; all but six of these fish were from hatchery and wild stocks of southeastern Alaska origin. The non-Alaska stocks were juvenile coho and Chinook salmon originating from Oregon and Washington. Alaska enhanced stocks were also identified by thermal otolith marks from 53% of the chum, 18% of the sockeye, 9% of the coho, and 50% of the Chinook salmon. Onboard stomach analysis of 63 potential predators, representing eight species, revealed one predation instance on juvenile salmon by a spiny dogfish (Squalus acanthias). Forecasting models using catch-per-unit effort (CPUE) of juvenile pink salmon in strait habitat of the northern region in 2003 and 2004 produced accurate predictions of southeastern Alaska pink salmon harvests in 2004 and 2005. However, the models using 2005 CPUE as a predictor overestimated harvest of pink salmon in 2006, indicating that CPUE alone is not sufficient to consistently predict year class strength. These results suggest that in southeastern Alaska, juvenile salmon exhibit seasonal patterns of habitat use and abundance, and display species- and stock-dependent migration patterns. Long-term monitoring of key stocks of juvenile salmon, on both intra- and interannual bases, will enable researchers to better understand ecological interactions that affect interannual variation in salmon abundance and the role that salmon play in North Pacific marine ecosystems.

The National Marine Fisheries Service (NMFS) has conducted aerial surveys of the beluga population in Cook Inlet, Alaska, each June and/or July since 1993. Results from 1993 to 2000 were published in Rugh et al. (2000a). The current document is a collection of field reports for the subsequent years, from 2001 to 2004.

NOAA Technical Memorandum NMFS-AFSC-149

Juvenile Pacific salmon (Oncorhynchus spp.), ecologically-related species, and associated biophysical data were collected along a primary marine migration corridor in the northern region of southeastern Alaska. Thirteen stations were sampled over six time periods (31 sampling days) from May to August 2004. This survey marks the eighth consecutive year of systematic monitoring on how juvenile salmon interact in marine ecosystems, and was implemented to identify the relationships among biophysical parameters that influence the habitat use, marine growth, predation, stock interactions, and year-class strength of salmon. Habitats sampled included stations in inshore (Auke Bay and Taku Inlet), strait (four stations each in Chatham Strait and Icy Strait), and coastal (four stations off Icy Point) localities. At each station, fish, zooplankton, surface water samples, and physical profile data were collected using a surface rope trawl, conical and bongo nets, water sampler, and a conductivity-temperature-depth profiler, usually during daylight. Surface (3-m) temperatures and salinities ranged from 6.9 to 17.4 ºC and 9.5 to 31.6 PSU from May to August. A total of 13,460 fish and squid, representing 29 taxa, were captured in 75 rope trawl hauls from June to August. Juvenile salmon comprised 48% of the total catch and occurred frequently in the trawl hauls, with pink (O. gorbuscha) occurring in 75% of the trawls, sockeye (O. nerka) in 73%, chum (O. keta) in 72%, coho (O. kisutch) in 51%, and chinook salmon (O. tshawytscha) in 19%. Of the 6,552 salmonids caught, over 99% were juveniles. Walleye pollock (Theragra chalcogramma) and Pacific herring (Clupea pallasi) 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. Catch rates of juvenile salmon were generally highest in June for all species except coho that had catch rates highest in August. Between habitat types, juvenile salmon catch rates were almost always highest in the strait habitat for each species and in each time period. Size of juvenile salmon increased steadily throughout the season; mean fork lengths in June, July, and August were, respectively: 98, 129, and 163 mm for pink; 104, 139, and 166 mm for chum; 111, 137, and 165 mm for sockeye; 170, 203, and 246 mm for coho; and 199, 228, and 279 for chinook salmon. Coded-wire tags were recovered from 14 juvenile coho, three juvenile and six immature chinook salmon; all but one were from hatchery and wild stocks of southeastern Alaska origin. The non-Alaska stock was a juvenile chinook originating from Oregon. Alaska hatchery stocks were also identified by thermal otolith marks from 74% of the chum, 18% of the sockeye, 9% of the coho, and 45% of the chinook salmon. Onboard stomach analysis of 199 potential predators, representing 10 species, revealed four predation instances on juvenile salmon: three by adult coho salmon and one by an immature chinook salmon. This research suggests 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, on both intra- and interannual bases, will enable researchers to understand how growth, abundance, and ecological interactions affect year-class strength and to better understand the role salmon play in North Pacific marine ecosystems.

The National Marine Fisheries Service (NMFS) conducted aerial surveys of the beluga whale (Delphinapterus leucas) population in Cook Inlet, Alaska, almost monthly between June 2001 and June 2002. The surveys were flown in a twin-engine, high-wing aircraft at an altitude of 244 m (800 ft) and speed of 185 km/hour (100 kt). Tracklines were approximately 1.4 km offshore, and systematic transects were made across the inlet, covering much of upper Cook Inlet. These methods were consistent with NMFS= abundance surveys conducted each June or July since 1993, except that only in June were there multiple surveys (repeat samplings) within a block of days. During the 2001­ 02 monthly surveys, aerial counts of belugas (median counts when more than one observer was counting) generally stayed high from June through October (n = 211 in June, 39 and 152 in July, 205 in August, 185 in September, 162 in October, respectively), but counts dropped from November to April (n = 24 in November, 15 in January, 0 in February, 18 in April, respectively) before rising again the following June (n = 192). Low counts in winter were probably due to ice in the inlet, making it hard to see the white whales. This study provides evidence of the presence of belugas in upper Cook Inlet in nearly every month of the year, but it is not clear what proportion of the population remains in the upper inlet year-round.