The growth of larval cod and haddock in the Irish Sea: a model with temperature, prey size and turbulence forcing
Authored by Sophie G Pitois, Mike Armstrong
Date Published: 2014
DOI: 10.1111/fog.12078
Sponsors:
Department for Environment Food & Rural Affairs (DEFRA)
Platforms:
No platforms listed
Model Documentation:
Other Narrative
Flow charts
Mathematical description
Model Code URLs:
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Abstract
We applied a physiological individual-based model for the foraging and
growth of cod (Gadus morhua) and haddock (Melanogrammus aeglefinus)
larvae, using observed temperature and prey fields data from the Irish
Sea, collected during the 2006 spawning season. We used the model to
estimate larval growth and survival and explore the different
productivities of the cod and haddock stocks encountered in the Irish
Sea. The larvae of both species showed similar responses to changes in
environmental conditions (temperature, wind, prey availability, daylight
hours) and better survival was predicted in the western Irish Sea, covering the spawning ground for haddock and about half of that for cod.
Larval growth was predicted to be mostly prey-limited, but exploration
of stock recruitment data suggests that other factors are important to
ensure successful recruitment. We suggest that the presence of a
cyclonic gyre in the western Irish Sea, influencing the retention and/or
dispersal of larvae from their spawning grounds, and the increasing
abundance of clupeids adding predatory pressure on the eggs and larvae;
both may play a key role. These two processes deserve more attention if
we want to understand the mechanisms behind the recruitment of cod and
haddock in the Irish Sea. For the ecosystem-based management approach, there is a need to achieve a greater understanding of the interactions
between species on the scale a fish stock is managed, and to work toward
integrated fisheries management in particular when considering the
effects of advection from spawning grounds and prey-predator reversal on
the recovery of depleted stocks.
Tags
Marine fish
Atlantic cod
North-sea
Small-scale turbulence
Georges-bank
Early-life stages
Melanogrammus-aeglefinus
Whiting merlangius-merlangus
Gadus-morhua growth
Encounter rates