Geographic variation among age-0 walleye pollock (Theragra chalcogramma): evidence of mesoscale variation in nursery quality?
Nurseries play an important part in the production of marinef ishes. Determining the relative importance of different nurseries in maintaining the parental population, however, can be difficult. In the western Gulf of Alaska, the Kodiak Island vicinity may be particularly well suited as a pollock nu...
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ftoceandocs:oai:aquadocs.org:1834/26261 2023-05-15T17:04:41+02:00 Geographic variation among age-0 walleye pollock (Theragra chalcogramma): evidence of mesoscale variation in nursery quality? Wilson, Matthew T. Brown, Annette L. Mier, Kathryn L. 2005 application/pdf 207-218 http://hdl.handle.net/1834/26261 en eng http://fishbull.noaa.gov/1031/wils.pdf 0090-0656 http://hdl.handle.net/1834/26261 http://aquaticcommons.org/id/eprint/9653 403 2012-08-14 12:22:47 9653 United States National Marine Fisheries Service Biology Ecology Fisheries article TRUE 2005 ftoceandocs 2023-04-06T17:03:09Z Nurseries play an important part in the production of marinef ishes. Determining the relative importance of different nurseries in maintaining the parental population, however, can be difficult. In the western Gulf of Alaska, the Kodiak Island vicinity may be particularly well suited as a pollock nursery because of a prey-rich nearshore environment. Our objectives were 1) to examine age-0 pollock body condition, growth, and diet for evidence of a nearshore-shelf effect, and 2) to determine if variationin the potential prey field of zooplankton was associated with this effect. This was a pilot study that occurredin three bays and over the adjacent shelf off east Kodiak Island during 5−18 September 1993. Sampling occurred only during night at locations where echo sign indicated thepresence of age-0 pollock. Echo sign was targeted to increase the chance of collecting fish given the limited vessel time. Fish condition was indicated by length-specific body weight. Growth rate indices were estimated for three different periods by using fish lengthage data and daily otolith increment widths: 1) from hatching date to capture, 2) 1−5 d before capture, and 3) 6−10 d before capture. Fish diet was determined from gut content analysis.Considerable variation among areas was evident in zooplankton composition, and fish condition, growth, anddiet. However, relatively high prey densities, as well as fish condition and growth rates indicated that ChiniakBay was particularly well suited as a pollock nursery. Hatching-date distributions indicated that most of the age-0 walleye pollock from bays were spawned earlier than were those from the shelf. The benefit of being reared in nearshore areas is therefore realized more by individuals that were spawned early than by individuals spawned relatively late. Article in Journal/Newspaper Kodiak Theragra chalcogramma Alaska IODE-UNESCO: OceanDocs - E-Repository of Ocean Publications Gulf of Alaska |
institution |
Open Polar |
collection |
IODE-UNESCO: OceanDocs - E-Repository of Ocean Publications |
op_collection_id |
ftoceandocs |
language |
English |
topic |
Biology Ecology Fisheries |
spellingShingle |
Biology Ecology Fisheries Wilson, Matthew T. Brown, Annette L. Mier, Kathryn L. Geographic variation among age-0 walleye pollock (Theragra chalcogramma): evidence of mesoscale variation in nursery quality? |
topic_facet |
Biology Ecology Fisheries |
description |
Nurseries play an important part in the production of marinef ishes. Determining the relative importance of different nurseries in maintaining the parental population, however, can be difficult. In the western Gulf of Alaska, the Kodiak Island vicinity may be particularly well suited as a pollock nursery because of a prey-rich nearshore environment. Our objectives were 1) to examine age-0 pollock body condition, growth, and diet for evidence of a nearshore-shelf effect, and 2) to determine if variationin the potential prey field of zooplankton was associated with this effect. This was a pilot study that occurredin three bays and over the adjacent shelf off east Kodiak Island during 5−18 September 1993. Sampling occurred only during night at locations where echo sign indicated thepresence of age-0 pollock. Echo sign was targeted to increase the chance of collecting fish given the limited vessel time. Fish condition was indicated by length-specific body weight. Growth rate indices were estimated for three different periods by using fish lengthage data and daily otolith increment widths: 1) from hatching date to capture, 2) 1−5 d before capture, and 3) 6−10 d before capture. Fish diet was determined from gut content analysis.Considerable variation among areas was evident in zooplankton composition, and fish condition, growth, anddiet. However, relatively high prey densities, as well as fish condition and growth rates indicated that ChiniakBay was particularly well suited as a pollock nursery. Hatching-date distributions indicated that most of the age-0 walleye pollock from bays were spawned earlier than were those from the shelf. The benefit of being reared in nearshore areas is therefore realized more by individuals that were spawned early than by individuals spawned relatively late. |
format |
Article in Journal/Newspaper |
author |
Wilson, Matthew T. Brown, Annette L. Mier, Kathryn L. |
author_facet |
Wilson, Matthew T. Brown, Annette L. Mier, Kathryn L. |
author_sort |
Wilson, Matthew T. |
title |
Geographic variation among age-0 walleye pollock (Theragra chalcogramma): evidence of mesoscale variation in nursery quality? |
title_short |
Geographic variation among age-0 walleye pollock (Theragra chalcogramma): evidence of mesoscale variation in nursery quality? |
title_full |
Geographic variation among age-0 walleye pollock (Theragra chalcogramma): evidence of mesoscale variation in nursery quality? |
title_fullStr |
Geographic variation among age-0 walleye pollock (Theragra chalcogramma): evidence of mesoscale variation in nursery quality? |
title_full_unstemmed |
Geographic variation among age-0 walleye pollock (Theragra chalcogramma): evidence of mesoscale variation in nursery quality? |
title_sort |
geographic variation among age-0 walleye pollock (theragra chalcogramma): evidence of mesoscale variation in nursery quality? |
publishDate |
2005 |
url |
http://hdl.handle.net/1834/26261 |
geographic |
Gulf of Alaska |
geographic_facet |
Gulf of Alaska |
genre |
Kodiak Theragra chalcogramma Alaska |
genre_facet |
Kodiak Theragra chalcogramma Alaska |
op_source |
http://aquaticcommons.org/id/eprint/9653 403 2012-08-14 12:22:47 9653 United States National Marine Fisheries Service |
op_relation |
http://fishbull.noaa.gov/1031/wils.pdf 0090-0656 http://hdl.handle.net/1834/26261 |
_version_ |
1766059002155761664 |