Contrasting responsiveness of four ecologically and economically important bivalves to simulated heat waves

Heat waves are expected to increase in duration and frequency, impacting coastal ecosystems, especially intertidal organisms living near their thermal tolerance limits. Sedentary infaunal species limited some extent escapes from sudden temperature changes, rather modifications physiology behaviour expected. This may lead strong ecological economic impacts on commercial bivalve species, such as Venerupis corrugata, Ruditapes decussatus, the introduced philippinarum Cerastoderma edule, most relevant NW Spain. We investigated lethal sublethal effects of heat during low tide these laboratory. Summer temperatures experienced within field, shallow sediments at approximately 2 cm depth i.e. 20 °C (control), 27 °C, 32 37 were replicated four consecutive days diffusion burrowing each was estimated; exposure expressed degree hours above 22 °C. After two tidal exposure, C. edule V. corrugata suffered significant mortalities, also dramatic decrease scope for growth (SFG) well reduction activity. under stress, all had negative SFG. On recovery, showed compensation longer exposures, particularly edule. These mortality, potential ability time achieve size predation. Particularly, with a center distribution lower subtidal, shallower sediment, be affected. Clearly intensity frequency will affect key sediment flats changing ecosystem functioning fisheries management strategies.