Predicting future thermal habitat suitability of competing native and invasive fish species: from metabolic scope to oceanographic modelling.
Global increase in sea temperatures has been suggested to facilitate the incoming and spread of tropical invaders. The increasing success of these species may be related to their higher physiological performance compared with indigenous ones. Here, we determined the effect of temperature on the aerobic metabolic scope (MS) of two herbivorous fish species that occupy a similar ecological niche in the Mediterranean Sea: the native salema (Sarpa salpa) and the invasive marbled spinefoot (Siganus rivulatus). Our results demonstrate a large difference in the optimal temperature for aerobic scope between the salema (21.8°C) and the marbled spinefoot (29.1°C), highlighting the importance of temperature in determining the energy availability and, potentially, the distribution patterns of the two species. A modelling approach based on a present-day projection and a future scenario for oceanographic conditions was used to make predictions about the thermal habitat suitability (THS, an index based on the relationship between MS and temperature) of the two species, both at the basin level (the whole Mediterranean Sea) and at the regional level (the Sicilian Channel, a key area for the inflow of invasive species from the Eastern to the Western Mediterranean Sea). For the present-day projection, our basin-scale model shows higher THS of the marbled spinefoot than the salema in the Eastern compared with the Western Mediterranean Sea. However, by 2050, the THS of the marbled spinefoot is predicted to increase throughout the whole Mediterranean Sea, causing its westward expansion. Nevertheless, the regional-scale model suggests that the future thermal conditions of Western Sicily will remain relatively unsuitable for the invasive species and could act as a barrier for its spread westward. We suggest that metabolic scope can be used as a tool to evaluate the potential invasiveness of alien species and the resilience to global warming of native species.
IAMC-CNR, Institute for the Coastal Marine Environment, National Research Council, Localitá Sa Mardini, Torregrande, OR 09170, Italy.
Stefano
S
Marras
IAMC-CNR, Institute for the Coastal Marine Environment, National Research Council, Localitá Sa Mardini, Torregrande, OR 09170, Italy.
Andrea
A
Cucco
IAMC-CNR, Institute for the Coastal Marine Environment, National Research Council, Localitá Sa Mardini, Torregrande, OR 09170, Italy.
Fabio
F
Antognarelli
Institute for Environmental Protection and Research (ISPRA), Piazzale dei Marmi 2, Livorno 57123, Italy.
Ernesto
E
Azzurro
Dipartimento di Scienze Della Terra e del Mare, University of Palermo, via Archirafi 28, Palermo 90123, Italy.
Marco
M
Milazzo
Department of Biology, FAS, American University of Beirut, Riad El-Solh, Beirut 1107 2020, Lebanon.
Michel
M
Bariche
Plymouth Marine Laboratory, Prospect Place, The Hoe, Plymouth PL1 3DH, UK.
Momme
M
Butenschön
Plymouth Marine Laboratory, Prospect Place, The Hoe, Plymouth PL1 3DH, UK.
Susan
S
Kay
Central Management for Programming and Infrastructures, National Research Council, Piazzale Aldo Moro 7, Roma 00185, Italy.
Massimiliano
M
Di Bitetto
IAMC-CNR, Institute for the Coastal Marine Environment, National Research Council, Localitá Sa Mardini, Torregrande, OR 09170, Italy.
Giovanni
G
Quattrocchi
IAMC-CNR, Institute for the Coastal Marine Environment, National Research Council, Localitá Sa Mardini, Torregrande, OR 09170, Italy.
Matteo
M
Sinerchia
IAMC-CNR, Institute for the Coastal Marine Environment, National Research Council, Localitá Sa Mardini, Torregrande, OR 09170, Italy.
Paolo
P
Domenici
Conservation physiology; distribution modelling; fish physiology; global warming; invasive species; thermal habitat suitability