TY - JOUR
T1 - Ocean-scale modelling of the distribution, abundance, and seasonal dynamics of the copepod Calanus finmarchicus
AU - Speirs, D.
AU - Gurney, W.S.C.
AU - Heath, M.R.
AU - Horbelt, W.
AU - Wood, S.N.
AU - de Cuevas, B.
PY - 2006
Y1 - 2006
N2 - The copepod Calanus finmarchicus is widely distributed over the sub-polar Atlantic and dominates the mesozooplanktonic biomass in that region. Despite this, all previous C. finmarchicus population modelling studies have been spatially and temporally limited. In this paper we present results from a fully stage-resolved model in a domain spanning the entire geographic range of the species (30 to 80°N and 80°W to 90° E. The model was driven by temperature and transport from the Ocean Circulation and Climate Advanced Modelling project (OCCAM) and phytoplankton food derived from satellite (SeaWiFS) sea-surface colour observations. The resulting quasi-stationary yearly cycle was assessed against seasonally resolved maps of continuous plankton recorder observations, winter cruise data on the distribution of diapausers, and time series from locations distributed over the North Atlantic. The model's high computational efficiency permitted its free parameters to be selected to yield a good correspondence with the field data. We were also able to explore the effects of changing the assumptions regarding diapause and mortality. By falsifying alternative models we conclude that (1) a fixed fraction of each surface generation enters diapause, (2) overwintering individuals enter diapause at the end of the fifth copepodite stage, and (3) mortality is an increasing function of temperature. Finally, we demonstrate that the demographic impact of transport is limited, except in shelf seas and at the edges of the distribution; nevertheless, there is a very high level of population connectivity over the whole domain.
AB - The copepod Calanus finmarchicus is widely distributed over the sub-polar Atlantic and dominates the mesozooplanktonic biomass in that region. Despite this, all previous C. finmarchicus population modelling studies have been spatially and temporally limited. In this paper we present results from a fully stage-resolved model in a domain spanning the entire geographic range of the species (30 to 80°N and 80°W to 90° E. The model was driven by temperature and transport from the Ocean Circulation and Climate Advanced Modelling project (OCCAM) and phytoplankton food derived from satellite (SeaWiFS) sea-surface colour observations. The resulting quasi-stationary yearly cycle was assessed against seasonally resolved maps of continuous plankton recorder observations, winter cruise data on the distribution of diapausers, and time series from locations distributed over the North Atlantic. The model's high computational efficiency permitted its free parameters to be selected to yield a good correspondence with the field data. We were also able to explore the effects of changing the assumptions regarding diapause and mortality. By falsifying alternative models we conclude that (1) a fixed fraction of each surface generation enters diapause, (2) overwintering individuals enter diapause at the end of the fifth copepodite stage, and (3) mortality is an increasing function of temperature. Finally, we demonstrate that the demographic impact of transport is limited, except in shelf seas and at the edges of the distribution; nevertheless, there is a very high level of population connectivity over the whole domain.
KW - calanus finmarchicus
KW - structured population model
KW - diapause
KW - temperature dependent mortality
KW - CPR
KW - OCCAM
KW - SeaWiFS
UR - http://www.int-res.com/abstracts/meps/v313/p173-192/
UR - http://dx.doi.org/10.3354/meps313173
U2 - 10.3354/meps313173
DO - 10.3354/meps313173
M3 - Article
SN - 0171-8630
VL - 313
SP - 173
EP - 192
JO - Marine Ecology Progress Series
JF - Marine Ecology Progress Series
ER -