Population trends of Steller sea lions (Eumetopias jubatus) with respect to remote sensing measures of chlorophyll-a in critical habitat
Lander, M.E.; Fritz, L.W.; Johnson, D.S.; Logsdon, M.G. (2013). Population trends of Steller sea lions (Eumetopias jubatus) with respect to remote sensing measures of chlorophyll-a in critical habitat. Mar. Biol. (Berl.) 160(1): 195-209. http://dx.doi.org/10.1007/s00227-012-2077-4
In: Marine Biology: International Journal on Life in Oceans and Coastal Waters. Springer: Heidelberg; Berlin. ISSN 0025-3162; e-ISSN 1432-1793, more
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Authors | | Top |
- Lander, M.E.
- Fritz, L.W.
- Johnson, D.S.
- Logsdon, M.G.
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Abstract |
The recovery plan for Steller sea lions (SSL; Eumetopias jubatus) suggests critical habitat should be enhanced to incorporate the spatio-temporal variation in dynamic oceanographic features that influence the prey and survival of SSL. It is necessary, therefore, to determine which features affect SSL. Demographics for sub-regions of the endangered, western stock of SSL were examined with respect to corresponding average, maximum, and variance of chlorophyll-a data (SeaWIFS), a proxy for primary productivity. Overall, SSL trends (2000–2008) and pup productivity (1999–2009) were related to maximum values of chl-a in critical habitat. Additionally, conditions in critical habitat appeared worse in areas of decline (i.e., dispersed patterns of chl-a hotspots and greater distances from SSL sites to productive areas). Although there may be a low feasibility of mitigating the effects of dynamic features on the recovery of SSL, the interactive effects of primary productivity and other stressors should be investigated for safeguarding their prey. |
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