TY - JOUR
T1 - The importance of predator–prey overlap: predicting North Sea cod recovery with a multispecies assessment model
AU - Kempf, Alexander
AU - Dingsør, Gjert Endre
AU - Huse, Geir
AU - Vinther, Morten
AU - Floeter, Jens
AU - Temming, Axel
PY - 2010
Y1 - 2010
N2 - The overlap between predator and prey is known as a sensitive parameter in multispecies assessment models for fish, and its parameterization is notoriously difficult. Overlap indices were derived from trawl surveys and used to parametrize the North Sea stochastic multispecies model. The effect of time-invariant and year- and quarter-specific overlap estimates on the historical (1991–2007) and predicted trophic interactions, as well as the development of predator and prey stocks, was investigated. The focus was set on a general comparison between single-species and multispecies forecasts and the sensitivity of the predicted development of North Sea cod for the two types of overlap implementation. The spatial–temporal overlap between cod and its predators increased with increasing temperature, indicating that foodweb processes might reduce the recovery potential of cod during warm periods. Multispecies scenarios were highly influenced by assumptions on future spatial overlap, but they predicted a considerably lower recovery potential than single-species predictions did. In addition, a recovery of North Sea cod had strong negative effects on its prey stocks. The consequences of these findings for management are discussed.
AB - The overlap between predator and prey is known as a sensitive parameter in multispecies assessment models for fish, and its parameterization is notoriously difficult. Overlap indices were derived from trawl surveys and used to parametrize the North Sea stochastic multispecies model. The effect of time-invariant and year- and quarter-specific overlap estimates on the historical (1991–2007) and predicted trophic interactions, as well as the development of predator and prey stocks, was investigated. The focus was set on a general comparison between single-species and multispecies forecasts and the sensitivity of the predicted development of North Sea cod for the two types of overlap implementation. The spatial–temporal overlap between cod and its predators increased with increasing temperature, indicating that foodweb processes might reduce the recovery potential of cod during warm periods. Multispecies scenarios were highly influenced by assumptions on future spatial overlap, but they predicted a considerably lower recovery potential than single-species predictions did. In addition, a recovery of North Sea cod had strong negative effects on its prey stocks. The consequences of these findings for management are discussed.
U2 - 10.1093/icesjms/fsq114
DO - 10.1093/icesjms/fsq114
M3 - Journal article
SN - 1054-3139
VL - 67
SP - 1989
EP - 1997
JO - ICES Journal of Marine Science
JF - ICES Journal of Marine Science
IS - 9
ER -