Biophysical modeling of larval Baltic cod (Gadus morhua) growth and survival

Authored by HH Hinrichsen, C Mollmann, R Voss, FW Koster, G Kornilovs

Date Published: 2002

DOI: 10.1139/f02-149

Sponsors: European Union

Platforms: No platforms listed

Model Documentation: Other Narrative Mathematical description

Model Code URLs: Model code not found

Abstract

A coupled hydrodynamic-trophodynamic individual-based model of drift and feeding was utilized to analyze the intra- and inter-annual variability in growth and survival of cod (Gadus morhua) larvae in the central Baltic Sea. Highly temporally and spatially resolved simulated flow fields were used to investigate the potential drift of larval cod from the centre of spawning effort in the Bornholm Basin towards their nursery areas through temporally resolved three-dimensional idealized prey fields. Stomach content analyses of larval cod from the Bornholm Basin revealed calanoid copepod nauplii and early copepodite stages to be the preferred prey organisms. The results of the model runs indicate that larval cod changed from a nonlimited to a food-limited stage because of the strong decrease in abundance of the calanoid copepod Pseudocalanus elongatus during the last two decades. The modeling study revealed retention and dispersal from the main spawning ground to be a key process influencing larval survival. When P. elongatus was available in the prey fields, high cod larval survival rates occurred in spring and early summer. In contrast, when P. elongatus was not available, hatched larvae had only high survival probabilities later in the year or if they were transported into shallower coastal regions.
Tags
Individual-based model Spatially explicit Population-dynamics Georges bank Ingestion rates Haddock melanogrammus-aeglefinus Theragra-chalcogramma Walleye pollock Shelikof-strait Early-life stages