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

The Lessepsian bivalve Brachidontes pharaonis is considered as one of 100 worstinvasive species in the Mediterranean rapidly colonizing the most part of the Basin. Itscurrent distribution seems primarily due to ship transport of carrying larvae by ballastwaters and/or in the fouling attached beneath the ship-keels. Although humanmediatedtransport seems to potentially in!uence dispersal of invasive species, habitatsuitability, temperature, salinity and food availability (i.e. in terms of quality and quantityof organic matter) seem to represent decisive factors in determining survivorshipand distribution of this species. Physiological tolerance of B. pharaonis to temperatureand salinity changes has been demonstrated to be very large, while scant informationavailable about its physiological response to food availability changes. In this paper, wereport 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 – 4.0μg l-1. B. pharaonis’s SFG varied from negative values at 0.1 μg l-1 [CHL-a] to positivevalues at > 0.9 μg l-1 [CHL-a]. In addition, by interpolating , SFG data and large satellitedataset 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 anddistribution of this specie along Sicilian coastlines.