Modeled larval fish prey fields and growth rates help predict recruitment success of cod and anchovy in the North Sea
Authored by Klaus B Huebert, Myron A Peck, Marc Hufnagl, Johannes Paetsch, Markus Kreus
Date Published: 2018
DOI: 10.3354/meps12615
Sponsors:
No sponsors listed
Platforms:
R
Model Documentation:
Other Narrative
Model Code URLs:
Model code not found
Abstract
We introduce a new, coupled modeling approach for simulating
ecosystem-wide patterns in larval fish foraging and growth. An
application of the method reveals how interplay between temperature and
plankton dynamics during 1970-2009 impacted a cold-water species
(Atlantic cod Gadus morhua) and a warm-water species (European anchovy
Engraulis encrasicolus) in the North Sea. Larval fish growth rates were
estimated by coupling models depicting traitbased foraging and
bioenergetics of individuals, spatiotemporal changes in their prey
field, and the biogeochemistry and hydrodynamics of the region. The
biomass composition of modeled prey fields varied from 89\% nano-, 10\%
micro-, and 1\% mesoplankton to 15\% nano-, 20\% micro-, and 65\%
mesoplankton. The mean slope of the normalized biomass size spectrum was
near -1.2, consistent with theoretical and empirical estimates. Median
larval fish growth rates peaked in June for cod (24\% d(-1)) and in July
for anchovy (17\% d(-1)). Insufficient prey resources played a
substantial role in limiting the growth rates of cod larvae. Anchovy
were consistently limited by cold temperatures. Faster median larval
growth during specific months was significantly (p < 0.05) positively
associated with detrended (i.e. higher than expected) juvenile
recruitment indices in cod (rank correlation Kendall's tau = 22\%) and
anchovy (tau = 42\%). For cod, the most predictive month was February,
which was also when food limitation was most prevalent. The continued
development of modeling tools based on first principles can help further
a mechanistic understanding of how changes in the environment affect the
productivity of living marine resources.
Tags
individual-based models
Model
carbon
plankton
growth
Recruitment
Climate-change
Atlantic cod
Fish larvae
Gadus-morhua
Continental-shelf
German bight
Marine fishes
Early-life history
Cod
Spawning stock
Anchovy
Prey availability
Bottom-up processes
North sea
Plankton communities
Pelagic
ecosystem