Responses in growth rate of larval northern anchovy (Engraulis mordax) to anomalous upwelling in the northern California Current
We examined variability in growth rate during the larval stage of northern anchovy (Engraulis mordax) in response to physical and biological environmental factors in 2005 and 2006. The onset of spring upwelling was anomalously delayed by 2–3 months until mid-July in 2005; in contrast, spring upwelli...
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ftoregonstate:ir.library.oregonstate.edu:p5547r987 2024-09-15T18:38:04+00:00 Responses in growth rate of larval northern anchovy (Engraulis mordax) to anomalous upwelling in the northern California Current Takahashi, Motomitsu Checkley, David M., Jr. Litz, Marisa N. C. Brodeur, Richard D. Peterson, William T. Hatfield Marine Science Center https://ir.library.oregonstate.edu/concern/articles/p5547r987 English [eng] eng unknown Blackwell Publishing Ltd. https://ir.library.oregonstate.edu/concern/articles/p5547r987 Copyright Not Evaluated Article ftoregonstate 2024-07-22T18:06:05Z We examined variability in growth rate during the larval stage of northern anchovy (Engraulis mordax) in response to physical and biological environmental factors in 2005 and 2006. The onset of spring upwelling was anomalously delayed by 2–3 months until mid-July in 2005; in contrast, spring upwelling in 2006 began as a normal year in the northern California Current. Larval and early juvenile E. mordax were collected in August, September, and October off the coast of Oregon and Washington. Hatch dates ranged from May to September, with peaks in June and August in 2005 and a peak in July in 2006, based on the number of otolith daily increments. Back-calculated body length-at-age in the June 2005 hatch cohort was significantly smaller than in the August 2005 cohort, which had comparable growth to the July 2006 cohort. Standardized otolith daily increment widths as a proxy for seasonal variability in somatic growth rates in 2005 were negative until late July and then changed to positive with intensification of upwelling. The standardized increment width was a positive function of biomass of chlorophyll a concentration, and neritic cold-water and oceanic subarctic copepod species sampled biweekly off Newport, Oregon. Our results suggest that delayed upwelling in 2005 resulted in low food availability and, consequently, reduced E. mordax larval growth rate in early summer, but once upwelling began in July, high food availability enhanced larval growth rate to that typical of a normal upwelling year (e.g., 2006) in the northern California Current. Keywords: otolith, growth rate, northern anchovy, delayed upwelling, increment width, California Current Keywords: otolith, growth rate, northern anchovy, delayed upwelling, increment width, California Current Article in Journal/Newspaper Subarctic ScholarsArchive@OSU (Oregon State University) |
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Open Polar |
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ScholarsArchive@OSU (Oregon State University) |
op_collection_id |
ftoregonstate |
language |
English unknown |
description |
We examined variability in growth rate during the larval stage of northern anchovy (Engraulis mordax) in response to physical and biological environmental factors in 2005 and 2006. The onset of spring upwelling was anomalously delayed by 2–3 months until mid-July in 2005; in contrast, spring upwelling in 2006 began as a normal year in the northern California Current. Larval and early juvenile E. mordax were collected in August, September, and October off the coast of Oregon and Washington. Hatch dates ranged from May to September, with peaks in June and August in 2005 and a peak in July in 2006, based on the number of otolith daily increments. Back-calculated body length-at-age in the June 2005 hatch cohort was significantly smaller than in the August 2005 cohort, which had comparable growth to the July 2006 cohort. Standardized otolith daily increment widths as a proxy for seasonal variability in somatic growth rates in 2005 were negative until late July and then changed to positive with intensification of upwelling. The standardized increment width was a positive function of biomass of chlorophyll a concentration, and neritic cold-water and oceanic subarctic copepod species sampled biweekly off Newport, Oregon. Our results suggest that delayed upwelling in 2005 resulted in low food availability and, consequently, reduced E. mordax larval growth rate in early summer, but once upwelling began in July, high food availability enhanced larval growth rate to that typical of a normal upwelling year (e.g., 2006) in the northern California Current. Keywords: otolith, growth rate, northern anchovy, delayed upwelling, increment width, California Current Keywords: otolith, growth rate, northern anchovy, delayed upwelling, increment width, California Current |
author2 |
Hatfield Marine Science Center |
format |
Article in Journal/Newspaper |
author |
Takahashi, Motomitsu Checkley, David M., Jr. Litz, Marisa N. C. Brodeur, Richard D. Peterson, William T. |
spellingShingle |
Takahashi, Motomitsu Checkley, David M., Jr. Litz, Marisa N. C. Brodeur, Richard D. Peterson, William T. Responses in growth rate of larval northern anchovy (Engraulis mordax) to anomalous upwelling in the northern California Current |
author_facet |
Takahashi, Motomitsu Checkley, David M., Jr. Litz, Marisa N. C. Brodeur, Richard D. Peterson, William T. |
author_sort |
Takahashi, Motomitsu |
title |
Responses in growth rate of larval northern anchovy (Engraulis mordax) to anomalous upwelling in the northern California Current |
title_short |
Responses in growth rate of larval northern anchovy (Engraulis mordax) to anomalous upwelling in the northern California Current |
title_full |
Responses in growth rate of larval northern anchovy (Engraulis mordax) to anomalous upwelling in the northern California Current |
title_fullStr |
Responses in growth rate of larval northern anchovy (Engraulis mordax) to anomalous upwelling in the northern California Current |
title_full_unstemmed |
Responses in growth rate of larval northern anchovy (Engraulis mordax) to anomalous upwelling in the northern California Current |
title_sort |
responses in growth rate of larval northern anchovy (engraulis mordax) to anomalous upwelling in the northern california current |
publisher |
Blackwell Publishing Ltd. |
url |
https://ir.library.oregonstate.edu/concern/articles/p5547r987 |
genre |
Subarctic |
genre_facet |
Subarctic |
op_relation |
https://ir.library.oregonstate.edu/concern/articles/p5547r987 |
op_rights |
Copyright Not Evaluated |
_version_ |
1810482408405860352 |