The following paper is now available:
Piroddi, C., Bearzi, G.,
Christensen, V. Effects of local fisheries and ocean productivity on the
northeastern Ionian Sea ecosystem. Ecol.
Model. (2010), doi:10.1016/j.ecolmodel.2010.03.002
Abstract: To better understand the effects
of fisheries and ocean productivity on the northeastern Ionian
Sea we constructed an Ecopath
with Ecosim model with 22
functional groups. Data on biomass, production/biomass, consumption/biomass,
and diet for each group were estimated or extrapolated from the literature.
Fisheries landings and discards were also included. Temporal trajectories were
simulated using Ecosim. The model
was fitted with time-series data for the most important groups from 1964 to
2006. Simulations highlighted a decline of top predators and of most of the
commercial species since the late 1970s. The model shows that the decline of
fish resources was mainly caused by an intensive fishing pressure that occurred
in the area until the end of the 1990s and also by changes in primary
production that impacted the trajectories of the main functional groups. In
particular, simulated changes through time in PP
impacted the abundance trends of all the commercial species, showing a
cascade-up effect through the ecosystem. The application of Ecopath with Ecosim was a useful tool for understanding the trends of the
main functional groups of the northeastern Ionian Sea.
The model underlined that management actions are needed to restore and protect
target species including marine mammals, pelagic and demersal fishes. In
particular, measures to reduce overfishing, illegal fishing activities and to
respect existing legislations are in need. Moreover, the adoption of marine
protected areas could be an effective management measure to guarantee prey
survival and to sustain marine predators.
Keywords:
Ionian Sea; Food web model; Ecopath with Ecosim; Fishing impact;
Primary production
It can be downloaded from
the following link http://dx.doi.org/10.1016/j.ecolmodel.2010.03.002
or a pdf can be obtained from the author (email: c.piroddi@fisheries.ubc.ca).
All the best,
Chiara