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Evaluation of rockfish conservation area networks in the United States and Canada relative to the dispersal distance for black rockfish (Sebastes melanops).

Lotterhos KE, Dick SJ, Haggarty DR - Evol Appl (2013)

Bottom Line: We used isolation-by-distance theory to estimate the scale of dispersal from microsatellite data in the black rockfish, Sebastes melanops, and compared this estimate with the distance between RCAs that would protect this species.Within each country, we found that the distance between RCAs was generally within the confidence intervals of mean dispersal per generation.The distance between these two RCA networks, however, was greater than the average dispersal per generation.

View Article: PubMed Central - PubMed

Affiliation: Department of Zoology, University of British Columbia Vancouver, BC, Canada.

ABSTRACT
Marine reserves networks are implemented as a way to mitigate the impact of fishing on marine ecosystems. Theory suggests that a reserve network will function synergistically when connected by dispersal, but the scale of dispersal is often unknown. On the Pacific coast of the United States and Canada, both countries have recently implemented a number of rockfish conservation areas (RCAs) to protect exploited rockfish species, but no study has evaluated the connectivity within networks in each country or between the two countries. We used isolation-by-distance theory to estimate the scale of dispersal from microsatellite data in the black rockfish, Sebastes melanops, and compared this estimate with the distance between RCAs that would protect this species. Within each country, we found that the distance between RCAs was generally within the confidence intervals of mean dispersal per generation. The distance between these two RCA networks, however, was greater than the average dispersal per generation. The data were also consistent with a genetic break between southern Oregon and central Oregon. We discuss whether additional nearshore RCAs in southern Oregon and Washington would help promote connectivity between RCA's for shallow-water rockfishes.

No MeSH data available.


Distances between rockfish conservation areas (RCAs) that would protect black rockfish in Canada (top) and the United States (bottom); distances are in blue font inside black circles. RCAs with habitat <50 m in depth were included for analysis. Insets show detail for Haida Gwaii and Prince Rupert (upper right), Barkley Sound (center right) and central OR (bottom right). The distance between Cape Falcon MR (the northernmost nearshore reserve in the US) and Carmanah RCA (the southernmost outer-coast RCA in Canada) is 314 km.
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fig05: Distances between rockfish conservation areas (RCAs) that would protect black rockfish in Canada (top) and the United States (bottom); distances are in blue font inside black circles. RCAs with habitat <50 m in depth were included for analysis. Insets show detail for Haida Gwaii and Prince Rupert (upper right), Barkley Sound (center right) and central OR (bottom right). The distance between Cape Falcon MR (the northernmost nearshore reserve in the US) and Carmanah RCA (the southernmost outer-coast RCA in Canada) is 314 km.

Mentions: We found that RCAs in BC are potentially connected by demographically relevant dispersal within a generation, because the distance among reserves was generally <100 km (Fig. 5, top). Likewise, RCAs in Oregon would generally be connected by dispersal within a generation because the distance among reserves was generally <100 km (Fig. 5, bottom). These two networks are unlikely to be connected by demographically relevant dispersal within a generation, however, because of a lack of RCAs along the Washington coast that would protect shallow-water rockfish species (Fig. 5, bottom). The northernmost RCA <50 m deep in the United States is the Cape Falcon Marine Reserve, and it is 314 km to the southernmost RCA in Canada at Carmanah. While dispersal is still possible through long tails on the dispersal kernel, it is unlikely to be demographically relevant, and we return to this point in the discussion.


Evaluation of rockfish conservation area networks in the United States and Canada relative to the dispersal distance for black rockfish (Sebastes melanops).

Lotterhos KE, Dick SJ, Haggarty DR - Evol Appl (2013)

Distances between rockfish conservation areas (RCAs) that would protect black rockfish in Canada (top) and the United States (bottom); distances are in blue font inside black circles. RCAs with habitat <50 m in depth were included for analysis. Insets show detail for Haida Gwaii and Prince Rupert (upper right), Barkley Sound (center right) and central OR (bottom right). The distance between Cape Falcon MR (the northernmost nearshore reserve in the US) and Carmanah RCA (the southernmost outer-coast RCA in Canada) is 314 km.
© Copyright Policy - open-access
Related In: Results  -  Collection

License
Show All Figures
getmorefigures.php?uid=PMC3927886&req=5

fig05: Distances between rockfish conservation areas (RCAs) that would protect black rockfish in Canada (top) and the United States (bottom); distances are in blue font inside black circles. RCAs with habitat <50 m in depth were included for analysis. Insets show detail for Haida Gwaii and Prince Rupert (upper right), Barkley Sound (center right) and central OR (bottom right). The distance between Cape Falcon MR (the northernmost nearshore reserve in the US) and Carmanah RCA (the southernmost outer-coast RCA in Canada) is 314 km.
Mentions: We found that RCAs in BC are potentially connected by demographically relevant dispersal within a generation, because the distance among reserves was generally <100 km (Fig. 5, top). Likewise, RCAs in Oregon would generally be connected by dispersal within a generation because the distance among reserves was generally <100 km (Fig. 5, bottom). These two networks are unlikely to be connected by demographically relevant dispersal within a generation, however, because of a lack of RCAs along the Washington coast that would protect shallow-water rockfish species (Fig. 5, bottom). The northernmost RCA <50 m deep in the United States is the Cape Falcon Marine Reserve, and it is 314 km to the southernmost RCA in Canada at Carmanah. While dispersal is still possible through long tails on the dispersal kernel, it is unlikely to be demographically relevant, and we return to this point in the discussion.

Bottom Line: We used isolation-by-distance theory to estimate the scale of dispersal from microsatellite data in the black rockfish, Sebastes melanops, and compared this estimate with the distance between RCAs that would protect this species.Within each country, we found that the distance between RCAs was generally within the confidence intervals of mean dispersal per generation.The distance between these two RCA networks, however, was greater than the average dispersal per generation.

View Article: PubMed Central - PubMed

Affiliation: Department of Zoology, University of British Columbia Vancouver, BC, Canada.

ABSTRACT
Marine reserves networks are implemented as a way to mitigate the impact of fishing on marine ecosystems. Theory suggests that a reserve network will function synergistically when connected by dispersal, but the scale of dispersal is often unknown. On the Pacific coast of the United States and Canada, both countries have recently implemented a number of rockfish conservation areas (RCAs) to protect exploited rockfish species, but no study has evaluated the connectivity within networks in each country or between the two countries. We used isolation-by-distance theory to estimate the scale of dispersal from microsatellite data in the black rockfish, Sebastes melanops, and compared this estimate with the distance between RCAs that would protect this species. Within each country, we found that the distance between RCAs was generally within the confidence intervals of mean dispersal per generation. The distance between these two RCA networks, however, was greater than the average dispersal per generation. The data were also consistent with a genetic break between southern Oregon and central Oregon. We discuss whether additional nearshore RCAs in southern Oregon and Washington would help promote connectivity between RCA's for shallow-water rockfishes.

No MeSH data available.