Publication Abstract

Multispecies virtual population analysis of North Sea predators for the years 1963-1987

J.G. Pope and C.T. Macer

A modified version of MSVPA, based on a simple model for deriving predation mortalities, has been used to estimate population numbers and mortality rates for the main predators in the North Sea for years earlier (1963-1973) than those for which appropriate data are available for use in the full MSVPA. The results suggest that predation mortality was higher in the earlier years. Hence, the resultant estimates of population numbers in the young fish diverge increasingly from those derived from single species VPA, as the time series is extended backwards.

Reference:

J.G. Pope and C.T. Macer, 1991. Multispecies virtual population analysis of North Sea predators for the years 1963-1987. ICES Marine Science Symposium, 193, 46-49.