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MESA Archives: Ecosystem Monitoring and Analysis (EMA)

(PLEASE NOTE: These web pages are for archival purposes only and are no longer maintained. For current information on this topic at the AFSC visit the Ecosystem Monitoring and Assessment program. )

ABL Home
Marine Ecology & Stock Assessment:
Ocean Carrying Capacity
Ecosystem Monitoring and Analysis (EMA)
Monitoring Age and Size
Retrospective Studies
Climatological Series
Southeast Alaska Coastal Monitoring
Program Activities:
Data Sets
Reports & Activities
Mean body length of male age 4 chum salmon at Fish Creek near Hyder in Alaska from 1972 to 2006.
Mean body length of male age 4 chum salmon at Fish Creek near Hyder in Alaska from 1972 to 2006.

Ecosystem Monitoring and Analysis research is used to develop indicators for ecosystem dynamics, assessment, and forecasting through monitoring changes in age and size of salmon populations and retrospective studies to assess past changes in Gulf of Alaska and Bering Sea salmon. Age and growth research is focused on constructing and analyzing time series on age, size, growth, survival, and production of salmon stocks and characterizing linkages with climate and abundance.

Monitoring Age and Size

Long-term monitoring of changes in age and size-at-maturity of Pacific salmon has occurred since the late 1950s. Annual stream surveys consist of the field sampling of scales, length, and weights from the carcasses of chum salmon that spawned and died in rivers ranging from southcentral Alaska to Washington. Long-term monitoring of salmon age and size-at-maturity is used to evaluate the influence of marine climate and population abundances on the dynamics of salmon and marine fish populations.

Retrospective Studies

Seasonal and annual growth patterns of scales in relation to climate indices and population abundances provide useful indicators for climate change and carrying capacity limits for salmon in the North Pacific Ocean and Bering Sea. Historic collections of salmon scales are used to reconstruct somatic growth histories of salmon. OCC scientists have developed and analyzed time series of growth for Karluk, Kvichak, Egegik, and Ugashik sockeye salmon stocks.

Auke Bay Climatological Series

Environmental monitoring and assessment requires long term consistent observations of climatological and physical environmental data. Daily environmental records have been maintained at the Auke Bay Marine Station since February 1963 as part of the National Weather Service Cooperative Observer Program. Additional historical records extend back to 1959 prior to the establishment of the U. S. Fish and Wildlife Service Bureau of Commercial Fisheries.

Southeast Alaska Coastal Monitoring (SECM)

The marine water of Southeast Alaska support major fisheries for salmonid and non-salmonid fishes. The Southeast Alaska Coastal Monitoring Program was established in 1997 to study biological and physical environmental conditions along major migratory corridors of juvenile salmon, in particular chum (Oncorhynchus keta) and pink (Oncorhynchus gorbuscha) during their spring and summer migration to the open Gulf of Alaska. Monthly cruises during May through August track the growth and survival of wild and hatchery stocks with particular emphasis on forage conditions.

Population Mixture Analysis (PMA)

Population mixture analysis (PMA) research by OCC is focused on developing and improving statistical approaches for identifying population structure and estimating population composition in fisheries that exploit fish from multiple populations. Software developed and maintained by OCC staff are used for research and management of mixed fisheries.

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