Growth and Mortality of Fish Larvae in the Northcentral Gulf of Mexico and Implications to Recruitment.
Extensive plankton collections were taken during September for several years along the northcentral Gulf of Mexico's inner continental shelf. Significant differences in growth rates were found for both vermilion snapper and Atlantic bumper larvae collected at stations where hydrographic conditi...
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ftlouisianastuir:oai:repository.lsu.edu:gradschool_disstheses-7473 2024-09-15T18:32:12+00:00 Growth and Mortality of Fish Larvae in the Northcentral Gulf of Mexico and Implications to Recruitment. Comyns, Bruce Henry 1997-01-01T08:00:00Z application/pdf https://repository.lsu.edu/gradschool_disstheses/6474 https://doi.org/10.31390/gradschool_disstheses.6474 https://repository.lsu.edu/context/gradschool_disstheses/article/7473/viewcontent/9808731.pdf English eng LSU Scholarly Repository https://repository.lsu.edu/gradschool_disstheses/6474 doi:10.31390/gradschool_disstheses.6474 https://repository.lsu.edu/context/gradschool_disstheses/article/7473/viewcontent/9808731.pdf LSU Historical Dissertations and Theses Biology oceanography Agriculture fisheries and aquaculture ecology text 1997 ftlouisianastuir https://doi.org/10.31390/gradschool_disstheses.6474 2024-08-08T04:27:14Z Extensive plankton collections were taken during September for several years along the northcentral Gulf of Mexico's inner continental shelf. Significant differences in growth rates were found for both vermilion snapper and Atlantic bumper larvae collected at stations where hydrographic conditions were similar, indicating the probable existence of small-scale patchily-distributed feeding conditions. Such variability in growth rates is probably inevitable given the high variability in the observed spatial and temporal distribution of surface chlorophyll a levels, macrozooplankton biomass, copepod abundance, and dispersion of fish larvae. Cruise estimates of mortality coefficients (Z) for larval vermilion snapper, red drum, and Atlantic bumper were derived from the descending limbs of age-frequency distributions (adjusted for stage duration). Estimates of Z for larval vermilion snapper (n = 2,581, 4 cruises) and Atlantic bumper (n = 39,247, 7 cruises) ranged from 0.18 to 0.29 and 0.20 to 0.39, respectively. Mortality coefficients for red drum larvae (n = 13,658, 15 cruises) were highly variable (Z = 0.17-1.62), which is most likely confounded by the aggregate, synchronous, batch-spawning behavior of red drum which would modulate the relative abundance of age classes. The overall estimate of Z for red drum larvae (0.31), obtained by pooling catch data, was very similar to values found for vermilion snapper and Atlantic bumper. Projections of juvenile recruitment based on these data show that even in a sub-tropical climate, where stage durations of larvae are short, changes in growth rates, particularly when combined with small changes in mortality rates, can cause large differences in cumulative larval survival. Even if the mortality rate is constant, twice as many vermilion snapper and Atlantic bumper larvae potentially survived to a length of 6 mm at stations with the fastest observed growth rates than at stations with the slowest observed growth rates. Accurately predicting recruitment variability may prove to ... Text Red drum LSU Digital Commons (Louisiana State University) |
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LSU Digital Commons (Louisiana State University) |
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English |
topic |
Biology oceanography Agriculture fisheries and aquaculture ecology |
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Biology oceanography Agriculture fisheries and aquaculture ecology Comyns, Bruce Henry Growth and Mortality of Fish Larvae in the Northcentral Gulf of Mexico and Implications to Recruitment. |
topic_facet |
Biology oceanography Agriculture fisheries and aquaculture ecology |
description |
Extensive plankton collections were taken during September for several years along the northcentral Gulf of Mexico's inner continental shelf. Significant differences in growth rates were found for both vermilion snapper and Atlantic bumper larvae collected at stations where hydrographic conditions were similar, indicating the probable existence of small-scale patchily-distributed feeding conditions. Such variability in growth rates is probably inevitable given the high variability in the observed spatial and temporal distribution of surface chlorophyll a levels, macrozooplankton biomass, copepod abundance, and dispersion of fish larvae. Cruise estimates of mortality coefficients (Z) for larval vermilion snapper, red drum, and Atlantic bumper were derived from the descending limbs of age-frequency distributions (adjusted for stage duration). Estimates of Z for larval vermilion snapper (n = 2,581, 4 cruises) and Atlantic bumper (n = 39,247, 7 cruises) ranged from 0.18 to 0.29 and 0.20 to 0.39, respectively. Mortality coefficients for red drum larvae (n = 13,658, 15 cruises) were highly variable (Z = 0.17-1.62), which is most likely confounded by the aggregate, synchronous, batch-spawning behavior of red drum which would modulate the relative abundance of age classes. The overall estimate of Z for red drum larvae (0.31), obtained by pooling catch data, was very similar to values found for vermilion snapper and Atlantic bumper. Projections of juvenile recruitment based on these data show that even in a sub-tropical climate, where stage durations of larvae are short, changes in growth rates, particularly when combined with small changes in mortality rates, can cause large differences in cumulative larval survival. Even if the mortality rate is constant, twice as many vermilion snapper and Atlantic bumper larvae potentially survived to a length of 6 mm at stations with the fastest observed growth rates than at stations with the slowest observed growth rates. Accurately predicting recruitment variability may prove to ... |
format |
Text |
author |
Comyns, Bruce Henry |
author_facet |
Comyns, Bruce Henry |
author_sort |
Comyns, Bruce Henry |
title |
Growth and Mortality of Fish Larvae in the Northcentral Gulf of Mexico and Implications to Recruitment. |
title_short |
Growth and Mortality of Fish Larvae in the Northcentral Gulf of Mexico and Implications to Recruitment. |
title_full |
Growth and Mortality of Fish Larvae in the Northcentral Gulf of Mexico and Implications to Recruitment. |
title_fullStr |
Growth and Mortality of Fish Larvae in the Northcentral Gulf of Mexico and Implications to Recruitment. |
title_full_unstemmed |
Growth and Mortality of Fish Larvae in the Northcentral Gulf of Mexico and Implications to Recruitment. |
title_sort |
growth and mortality of fish larvae in the northcentral gulf of mexico and implications to recruitment. |
publisher |
LSU Scholarly Repository |
publishDate |
1997 |
url |
https://repository.lsu.edu/gradschool_disstheses/6474 https://doi.org/10.31390/gradschool_disstheses.6474 https://repository.lsu.edu/context/gradschool_disstheses/article/7473/viewcontent/9808731.pdf |
genre |
Red drum |
genre_facet |
Red drum |
op_source |
LSU Historical Dissertations and Theses |
op_relation |
https://repository.lsu.edu/gradschool_disstheses/6474 doi:10.31390/gradschool_disstheses.6474 https://repository.lsu.edu/context/gradschool_disstheses/article/7473/viewcontent/9808731.pdf |
op_doi |
https://doi.org/10.31390/gradschool_disstheses.6474 |
_version_ |
1810473953879130112 |