Estimation of Fishery Losses from Great Cormorants during the Wintering Period in Greek Lagoons (Ionian Sea, W. Greece)

The present study aims through a modeling approach to quantify fishing losses from the impact of great cormorants (Phalacrocorax carbo sinensis) during their wintering period in Greek lagoons. A number of assumptions were incorporated into the model regarding fish population growth, species distribution, age (or size) of fish caught, and the different fishing strategies that could be applied in the studied lagoons. The results indicated that the mean value of daily economic losses ranged from 0.614 to 1.075 euro & BULL;bird(-1)& BULL;day(-1), whereas the ratios of biomass losses to landings biomass and of economic losses to economic profit ranged from 0.18:1 to 3.80:1 and from 0.14:1 to 4.18:1, respectively, depending on the lagoon. The results supported a strong competitive relationship between great cormorants and fisheries in lagoons of the Amvrakikos Gulf.