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

• Published in: Marine environmental research 2021-02, Vol.164, p.105229-105229, Article 105229
• Main Authors: Domínguez, Rula, Olabarria, Celia, Woodin, Sarah A., Wethey, David S., Peteiro, Laura G., Macho, Gonzalo, Vázquez, Elsa
• Format: Article
• Language: English
• Subjects: Animals; Bivalvia; Burrowing organisms; Burrowing- mortality –thermal refuge; Cardiidae; Coastal ecosystems; Dominant species; Economic impact; Economics; Ecosystem; Ecosystem management; Environmental changes; Exposure; Fisheries; Fisheries management; Fishery management; Heat; Heat wave; Heat waves; Heatwaves; Hot Temperature; Interspecific relationships; Intertidal bivalves; Low tide; Marine molluscs; Mollusks; Predation; Scope for growth; Sedentary species; Sediment; Sediments; Small-scale fisheries; Spain; Sublethal effects; Temperature; Temperature effects; Temperature tolerance; Thermal stress
• ISSN: 0141-1136; 1879-0291
• DOI: 10.1016/j.marenvres.2020.105229

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 are limited to some extent in escapes from sudden temperature changes, rather modifications to their physiology and behaviour are expected. This may lead to strong ecological and economic impacts on commercial bivalve species, such as Venerupis corrugata, Ruditapes decussatus, the introduced Ruditapes philippinarum and Cerastoderma edule, the most relevant in NW Spain. We investigated lethal and sublethal effects of heat during low tide on these species in the laboratory. Summer temperatures experienced within field, shallow sediments at approximately 2 cm depth i.e. 20 °C (control), 27 °C, 32 °C, and 37 °C, were replicated during four consecutive days and the diffusion of heat at the burrowing depth of each species was estimated; temperature exposure was expressed as degree hours above 22 °C. After two days of tidal exposure, C. edule and V. corrugata suffered significant mortalities, and also the most dramatic decrease in scope for growth (SFG) as well as reduction in burrowing activity. After four days under stress, all species had negative SFG. On recovery, species showed compensation at longer exposures, particularly C. edule. These effects of temperature on mortality, growth potential and burrowing ability may increase the time to achieve commercial size and exposure to predation. Particularly, V. corrugata, with a center of distribution lower in the intertidal and subtidal, and C. edule, shallower in the sediment, may be the most affected. Clearly the intensity and frequency of heat waves will affect these key species in the intertidal sediment flats changing ecosystem functioning and fisheries management strategies. [Display omitted] •Effects of sediment thermal stress at low tide on four infaunal bivalves studied.•Heat transfer into sediment was calculated depending on the species burrowing depth.•After 24 h of stress mortality was greater in the most superficial species.•Scope for growth decreased to negative values at higher temperature exposures.•Responses differed depending on preferment habitat and burrowing depth of species.