Dear colleagues,
The following article has just been published in this month's issue of
Marine Ecology Progress Series (MEPS):
Ecosystem models clarify the trophic role of whales off Northwest Africa
ABSTRACT: There is global concern about the interaction between whales
and fisheries, and in some countries, great whales are viewed as a
threat to fisheries by potentially eating fish species that could be
exploited for human consumption. We developed an ecosystem model to
explore the trophic interactions between cetaceans and fisheries off
Northwest Africa and to examine the potential impact of a reduction in
the abundance of baleen whales on fishery yields. This allowed us to
characterize the structure and function of the ecosystem in terms of
biomass, mortalities, consumption rates, food habits, and fisheries.
Faced with sparse data for our study area, we explicitly accounted for
uncertainty in ecosystem structure, model accuracy, and input data and
conducted an extensive sensitivity analysis. We tested model
performance with time series of biomass and catches for important
species of the system. Our results indicate that the overlap between
prey species consumed by cetaceans and species targeted in fisheries
is low. Furthermore, for a wide range of assumptions about whale
abundances, diet composition, and food consumption in breeding areas,
we found that whale consumption is several orders of magnitude lower
than total fishery catches and 2 orders of magnitude lower than the
amounts taken by other trophic groups. Finally, simulations of
substantial reductions of whale populations did not influence the
biomass of commercially important fish, nor any other species of the
foodweb. These results suggest that fisheries yields would not benefit
from the removal of whales in this area.
The article can be downloaded from MEPS website (http://www.int-res.com/abstracts/meps/v404/p289-302/
) or you can contact the first author for PDF copies (lyne.morisse...@globetrotter.net
)
Lyne Morissette, Ph.D.
Institut des Sciences de la Mer de Rimouski (UQAR-ISMER)
email: lyne.morisse...@globetrotter.net
Tél. 418-723-1986 #1981 | Sans-fil 418-750-5685