Local food availability affects invasion ability of alien bivalves: an experimental and simulation integrated approach

Abstract

The Lessepsian bivalve Brachidontes pharaonis is considered as one of 100 worst invasive species in the Mediterranean rapidly colonizing the most part of the Basin. Its current distribution seems primarily due to ship transport of carrying larvae by ballast waters and/or in the fouling attached beneath the ship-keels. Although humanmediated transport seems to potentially in!uence dispersal of invasive species, habitat suitability, temperature, salinity and food availability (i.e. in terms of quality and quantity of organic matter) seem to represent decisive factors in determining survivorship and distribution of this species. Physiological tolerance of B. pharaonis to temperature and salinity changes has been demonstrated to be very large, while scant information available about its physiological response to food availability changes. In this paper, we report the #rst experimental mesocosmal dataset on B. pharaonis’s scope for growth (SFG) as a function of di"erent concentrations of chlorophyll-a from 0.9 – 1.0 to 3.9 – 4.0 μg l-1. B. pharaonis’s SFG varied from negative values at 0.1 μg l-1 [CHL-a] to positive values at > 0.9 μg l-1 [CHL-a]. In addition, by interpolating , SFG data and large satellite dataset of CHL-a values obtained from the Environmental Marine Information System (EMIS), we estimated on a very small spatial scale (8.1 nmi) the potential dispersal and distribution of this specie along Sicilian coastlines.