Kathryn L. Mier

Regional variation in springtime ichthyoplankton assemblages in the northeast Pacific Ocean

The coastal regions of the northeast Pacific support large, economically valuable fishery resources and provide nursery areas for many fish species. Over the last few decades, there have been dramatic shifts in species abundance and composition in this area. In this paper, we examine the springtime spatial patterns in the ichthyoplankton of three oceanographically different regions, the Southeast Bering Sea, the Gulf of Alaska and the U.S. West Coast. The data examined are a subset of a larger database (comprising data from cruises conducted from 1972 to 1997) that is being used to investigate spatial, seasonal and interannual patterns in ichthyoplankton of the northeast Pacific in relation to environmental conditions. Ichthyoplankton were collected during seven cruises using 60-cm bongo nets. Spatial patterns of ichthyoplankton were examined using both classification and ordination techniques. Relative Bray-Curtis dissimilarity coefficients calculated from the log 10 (n+1) of abundance data were used as input to the numerical classification of species and stations. Nonmetric multidimensional scaling was also applied to the abundance data to examine geometric patterns in the data. The numerical analyses of the species abundance data sets for each cruise revealed spatial patterns in the ichthyoplankton that suggest the occurrence of geographically distinct assemblages of fish larvae in each region. For all three sampling regions, the assemblage structure is primarily related to bathymetry, and Shelf, Slope, and DeepWater assemblages are described. This shallow to deep-water gradient in species occurrence and abundance reflects the habitat preference and spawning location of the adult fish. Another degree of complexity is superimposed on this primary assemblage structure in each region and seems to be related to local topography and the prevailing current patterns. The patterns in ichthyoplankton assemblages of the three regions in the northeast Pacific Ocean described here form the basis for future investigations of spatial and temporal patterns in the ichthyoplankton of the subarctic Pacific. Regional Index Terms: Northeast Pacific Ocean, Southeast Bering Sea, Gulf of Alaska, U.S. West Coast.  2002 Published by Elsevier Science Ltd.

Seasonal, interannual, and spatial patterns of community composition over the eastern Bering Sea shelf in cold years. Part II: ichthyoplankton and juvenile fish

Elizabeth C. Siddon*, Janet T. Duffy-Anderson, Kathryn L. Mier, Morgan S. Busby, and Lisa B. Eisner National Oceanic and Atmospheric Administration, National Marine Fisheries Service, Alaska Fisheries Science Center, Ted Stevens Marine Research Institute, Ecosystem Monitoring and Assessment Program, 17109 Pt. Lena Loop Road, Juneau, AK 99801, USA National Oceanic and Atmospheric Administration, National Marine Fisheries Service, Alaska Fisheries Science Center, Resource Assessment and Conservation Engineering Division, Fisheries-Oceanography Coordinated Investigations Program, 7600 Sand Point Way NE, Seattle, WA 98115-6349, USA

Seasonal, interannual, and spatial patterns of community composition over the eastern Bering Sea shelf in cold years. Part I: zooplankton

Seasonal, interannual, and spatial patterns of community composition over the eastern Bering Sea shelf in cold years. Part I: zooplankton Lisa B. Eisner,* Alexei I. Pinchuk, David G. Kimmel, Kathryn L. Mier, Colleen E. Harpold, and Elizabeth C. Siddon National Oceanic and Atmospheric Administration, National Marine Fisheries Service, Alaska Fisheries Science Center, 7600 Sand Point Way NE, Seattle, WA 98115-6349, USA College of Fisheries and Ocean Sciences, Fisheries Division, University of Alaska, 17101 Pt. Lena Loop Road, Juneau, AK 99801, USA National Oceanic and Atmospheric Administration, National Marine Fisheries Service, Alaska Fisheries Science Center, 17109 Pt. Lena Loop Road, Juneau, AK 99801, USA