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SPATIAL ANATOMY OF SPECIES SURVIVAL: EFFECTS OF PREDATION AND CLIMATE‐DRIVEN ENVIRONMENTAL VARIABILITY
Author(s) -
Ciannelli Lorenzo,
Dingsør Gjert E.,
Bogstad Bjarte,
Ottersen Geir,
Chan Kung-sik,
Gjøsæter Harald,
Stiansen Jan Erik,
Stenseth Nils Chr.
Publication year - 2007
Publication title -
ecology
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 2.144
H-Index - 294
eISSN - 1939-9170
pISSN - 0012-9658
DOI - 10.1890/05-2035
Subject(s) - gadus , predation , abiotic component , abundance (ecology) , juvenile , ecology , spatial distribution , biology , biotic component , spatial variability , spatial ecology , atlantic cod , spatial heterogeneity , environmental science , geography , fishery , fish <actinopterygii> , statistics , remote sensing , mathematics
The majority of survival analyses focus on temporal scales. Consequently, there is a limited understanding of how species survival varies over space and, ultimately, how spatial variability in the environment affects the temporal dynamics of species abundance. Using data from the Barents Sea, we study the spatiotemporal variability of the juvenile Atlantic cod ( Gadus morhua ) survival. We develop an index of spatial survival based on changes of juvenile cod distribution through their first winter of life (from age‐0 to age‐1) and study its variability in relation to biotic and abiotic factors. Over the 25 years analyzed (1980–2004), we found that, once the effect of passive drift due to dominant currents is accounted for, the area where age‐0 cod survival was lowest coincided with the area of highest abundance of older cod. Within this critical region, the survival of age‐0 cod was negatively affected by its own abundance, by that of older cod, and by bottom depth. Furthermore, during cold years, age‐0 cod survival increased in the eastern and coldest portion of the examined area, which was typically avoided by older conspecifics. Based on these results we propose that within the examined area top‐down mechanisms and predation‐driven density dependence can strongly affect the spatial pattern of age‐0 cod survival. Climate‐related variables can also influence the spatial survival of age‐0 cod by affecting their distribution and that of their predators. Results from these and similar studies, focusing on the spatial variability of survival rates, can be used to characterize species habitat quality of marine renewable resources.