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Invasions! Galil, B.S. Espècies
invasores de la regió eritrea a la mar Mediterrània.
Senyals de canvi Erythrean alien species in the Mediterranean Sea – Signals of change Nearly 600 alien marine metazoan species have been documented in the Mediterranean Sea. Although the extinction of a native species has not yet been reported, a precipitous decline in population levels, and even local extirpations, concurrent with the proliferation of alien species, had been recorded. The majority of aliens are thermophilic species originating from the Indo-Pacific or Indian Oceans, which have entered the Mediterranean through the Suez Canal. Newly analyzed data, gleaned from a recently assembled database tracing the spread of alien species in the Mediterranean, has facilitated an examination of the possible impacts of climate change. Although thermophilic species were periodically introduced for much of the 20th century, few spread beyond the Levantine Basin until the 1980s. Multiple anthropogenic stressors including pollution, eutrophication, destruction and fragmentation of habitats, fisheries overexploitation, and climate change have been implicated in the overall decline in the richness and diversity of the native Mediterranean littoral ecosystem. However, it is thought that the rising seawater surface temperatures observed during the last two decades has favoured the reproduction, growth, and survival of thermophilic aliens, providing them with a distinct advantage over native temperate Mediterranean taxa. The influx of thermophilic aliens has impacted both tourism and an already teetering fisheries industry by fostering the proliferation of noxious and poisonous species, by displacing commercially important native species, and by altering the food web. |
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