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Long-Term Changes in the Distributions of Larval and Adult Fish in the Northeast U.S. Shelf Ecosystem.

Walsh HJ, Richardson DE, Marancik KE, Hare JA - PLoS ONE (2015)

Bottom Line: Overall, these results demonstrate that larval fish distributions are changing in the ecosystem.The temporal changes are more complex, indicating we need a better understanding of reproductive timing of fishes in the ecosystem.These changes may impact population productivity through changes in life history connectivity and recruitment, and add to the accumulating evidence for changes in the Northeast U.S. Shelf Ecosystem with potential to impact fisheries and other ecosystem services.

View Article: PubMed Central - PubMed

Affiliation: National Oceanic and Atmospheric Administration, National Marine Fisheries Service, Northeast Fisheries Science Center, Narragansett, Rhode Island, United States of America.

ABSTRACT
Many studies have documented long-term changes in adult marine fish distributions and linked these changes to climate change and multi-decadal climate variability. Most marine fish, however, have complex life histories with morphologically distinct stages, which use different habitats. Shifts in distribution of one stage may affect the connectivity between life stages and thereby impact population processes including spawning and recruitment. Specifically, many marine fish species have a planktonic larval stage, which lasts from weeks to months. We compared the spatial distribution and seasonal occurrence of larval fish in the Northeast U.S. Shelf Ecosystem to test whether spatial and temporal distributions changed between two decades. Two large-scale ichthyoplankton programs sampled using similar methods and spatial domain each decade. Adult distributions from a long-term bottom trawl survey over the same time period and spatial area were also analyzed using the same analytical framework to compare changes in larval and adult distributions between the two decades. Changes in spatial distribution of larvae occurred for 43% of taxa, with shifts predominately northward (i.e., along-shelf). Timing of larval occurrence shifted for 49% of the larval taxa, with shifts evenly split between occurring earlier and later in the season. Where both larvae and adults of the same species were analyzed, 48% exhibited different shifts between larval and adult stages. Overall, these results demonstrate that larval fish distributions are changing in the ecosystem. The spatial changes are largely consistent with expectations from a changing climate. The temporal changes are more complex, indicating we need a better understanding of reproductive timing of fishes in the ecosystem. These changes may impact population productivity through changes in life history connectivity and recruitment, and add to the accumulating evidence for changes in the Northeast U.S. Shelf Ecosystem with potential to impact fisheries and other ecosystem services.

No MeSH data available.


Percent frequency of occurrence of directional shifts in distribution among larval taxa by seasonal occurrence in the Northeast U.S. Shelf Ecosystem.Occurrence of each type of distributional shift for larvae were grouped by season to examine patterns in relation to seasonal occurrence.
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pone.0137382.g007: Percent frequency of occurrence of directional shifts in distribution among larval taxa by seasonal occurrence in the Northeast U.S. Shelf Ecosystem.Occurrence of each type of distributional shift for larvae were grouped by season to examine patterns in relation to seasonal occurrence.

Mentions: Relationships among directional shifts in distribution and seasonal timing of larval occurrence were examined for the larval stage only, and not found to be significant (Table 3). About 55% of summer taxa had a significant change in distribution, and shifted northward and inshore (Fig 7). Slightly fewer winter taxa shifted distributions (46%), and exhibited the most variability (Fig 7). Spring and fall taxa shifted the least (33%). Spring taxa shifted only northward, and fall taxa only shifted offshore (Fig 7).


Long-Term Changes in the Distributions of Larval and Adult Fish in the Northeast U.S. Shelf Ecosystem.

Walsh HJ, Richardson DE, Marancik KE, Hare JA - PLoS ONE (2015)

Percent frequency of occurrence of directional shifts in distribution among larval taxa by seasonal occurrence in the Northeast U.S. Shelf Ecosystem.Occurrence of each type of distributional shift for larvae were grouped by season to examine patterns in relation to seasonal occurrence.
© Copyright Policy
Related In: Results  -  Collection

License
Show All Figures
getmorefigures.php?uid=PMC4580593&req=5

pone.0137382.g007: Percent frequency of occurrence of directional shifts in distribution among larval taxa by seasonal occurrence in the Northeast U.S. Shelf Ecosystem.Occurrence of each type of distributional shift for larvae were grouped by season to examine patterns in relation to seasonal occurrence.
Mentions: Relationships among directional shifts in distribution and seasonal timing of larval occurrence were examined for the larval stage only, and not found to be significant (Table 3). About 55% of summer taxa had a significant change in distribution, and shifted northward and inshore (Fig 7). Slightly fewer winter taxa shifted distributions (46%), and exhibited the most variability (Fig 7). Spring and fall taxa shifted the least (33%). Spring taxa shifted only northward, and fall taxa only shifted offshore (Fig 7).

Bottom Line: Overall, these results demonstrate that larval fish distributions are changing in the ecosystem.The temporal changes are more complex, indicating we need a better understanding of reproductive timing of fishes in the ecosystem.These changes may impact population productivity through changes in life history connectivity and recruitment, and add to the accumulating evidence for changes in the Northeast U.S. Shelf Ecosystem with potential to impact fisheries and other ecosystem services.

View Article: PubMed Central - PubMed

Affiliation: National Oceanic and Atmospheric Administration, National Marine Fisheries Service, Northeast Fisheries Science Center, Narragansett, Rhode Island, United States of America.

ABSTRACT
Many studies have documented long-term changes in adult marine fish distributions and linked these changes to climate change and multi-decadal climate variability. Most marine fish, however, have complex life histories with morphologically distinct stages, which use different habitats. Shifts in distribution of one stage may affect the connectivity between life stages and thereby impact population processes including spawning and recruitment. Specifically, many marine fish species have a planktonic larval stage, which lasts from weeks to months. We compared the spatial distribution and seasonal occurrence of larval fish in the Northeast U.S. Shelf Ecosystem to test whether spatial and temporal distributions changed between two decades. Two large-scale ichthyoplankton programs sampled using similar methods and spatial domain each decade. Adult distributions from a long-term bottom trawl survey over the same time period and spatial area were also analyzed using the same analytical framework to compare changes in larval and adult distributions between the two decades. Changes in spatial distribution of larvae occurred for 43% of taxa, with shifts predominately northward (i.e., along-shelf). Timing of larval occurrence shifted for 49% of the larval taxa, with shifts evenly split between occurring earlier and later in the season. Where both larvae and adults of the same species were analyzed, 48% exhibited different shifts between larval and adult stages. Overall, these results demonstrate that larval fish distributions are changing in the ecosystem. The spatial changes are largely consistent with expectations from a changing climate. The temporal changes are more complex, indicating we need a better understanding of reproductive timing of fishes in the ecosystem. These changes may impact population productivity through changes in life history connectivity and recruitment, and add to the accumulating evidence for changes in the Northeast U.S. Shelf Ecosystem with potential to impact fisheries and other ecosystem services.

No MeSH data available.