Les invasions biològiques en el medi marí: exemples i impactes a la Mediterrània Occidental

Abstract

Biological invasions in marine environment: examples and impacts in the Western Mediterranean. Here, we offer a brief review on the impact invasive species have on coastal marine ecosystems, with particular focus on the Mediterranean Sea. We also provide a list of the main invasive macroalgal species in the Western Mediterranean, indicating the specific invaded habitats and their distribution patterns. Although not yet invasive, we describe certain alien invertebrates known to thrive in several areas of the Spanish Mediterranean. We discuss the main theories on species invasibility and summarize the behaviour of the major Western Mediterranean algal invaders in relation to these theories. We conclude this discussion by explaining the difficulties involved in predicting general patterns of invasion, since the success of a given species is dependent not only upon the existence of predators, competitors and pathogens, nor solely upon resource availability, but also on other unknown factors that might be critical to properly determine invasive capability. Finally, we list several methodologies used for the control and/or eradication of marine invasive species, almost one of which have ever succeeded. It is our belief that prevention remains the most effective measure, as well as the most environmentally friendly and economically viable way to avoid the introduction of alien species.