The spread of Lessepsian fish does not track native temperature conditions
Manuela D‘Amen, Sonia Smeraldo, Antonio Franco, Ernesto Azzurro
Abstract
Abstract Global warming is enabling tropical invaders to expand into regions, where unsuitable climate conditions used to prevent the survival or reproduction. Here, using the occurrence data of 22 Lessepsian fish in the Mediterranean Sea, we aimed at (1) gaining a deeper understanding of temperature match dynamics over the spatio-temporal spread of each invasion event and (2) testing the hypothesis that successful invasions require a temperature match, as assumed in several bioinvasion risk assessments. For each species, we identified the areas of the Mediterranean lacking a temperature match with native ranges over the past six decades. We found that some species, particularly recent invaders, have spread far beyond temperature matching conditions. The populations at the expanding edge of the range are often found in sites that have experienced increases in temperature. Temperature match positively correlates with species spread rate and after 1990, higher temperatures in the Mediterranean provided analogous conditions for a growing number of non-indigenous species. Our results warn against the general use of temperature-based climate matching in bioinvasion risk and provide guidance for the application of species distribution models that incorporate temperature to marine bioinvasion research.