Climate change impacts on potential recruitment in an ecosystem engineer

Abstract

Climate variability and the rapid warming of seas undoubtedly have huge ramifications for biological processes such as reproduction. As such, gametogenesis and spawning were investigated at two sites over 200 km apart on the south coast of Ireland in an ecosystem engineer, the common cockle, Cerastoderma edule. Both sites are classed as Special Areas of Conservation (SACs), but are of different water quality. Cerastoderma edule plays a significant biological role by recycling nutrients and affecting sediment structure, with impacts upon assemblage biomass and functional diversity. It plays a key role in food webs, being a common foodstuff for a number of marine birds including the oystercatcher. Both before and during the study (early 2010–mid 2011), Ireland experienced its two coldest winters for 50 years. As the research demonstrated only slight variation in the spawning period between sites, despite site differences in water and environmental quality, temperature and variable climatic conditions were the dominant factor controlling gametogenesis. The most significant finding was that the spawning period in the cockle extended over a greater number of months compared with previous studies and that gametogenesis commenced over winter rather than in spring. Extremely cold winters may impact on the cockle by accelerating and extending the onset and development of gametogenesis. Whether this impact is positive or negative would depend on the associated events occurring on which the cockle depends, that is, presence of primary producers and spring blooms, which would facilitate conversion of this extended gametogenesis into successful recruitment.

Neoplastic diseases of marine bivalves

“…3(B)) and C. edule (Fig. 3(C)) shows a distribution of the decline and minimal prevalence compatible with the spawning seasons described in the literature for these species (Seed, 1976;Brousseau, 1987b;Guillou et al, 1990;Martínez-Castro and Vázquez, 2012;Morgan et al, 2013). Moreover, Leavitt et al (1990) reported the seasonal cycle of DN prevalence and condition indices in two softshell clam populations; interestingly, though not highlighted in that paper, the minimal values of prevalence detected in late spring/early summer of their second year of study coincided with declines in the condition indices in both studied populations; those declines in condition indices could be indicative of spawning and, thus, it would support the hypothesis of the role played by spawning in the seasonal pattern of DN through its influence over mortality of diseased individuals.…”

Reproduction and size at first maturity in a Mediterranean exploited <em>Callista chione</em> bivalve bed

“…The gametogenic cycle of C. chione described in Portugal reported three spawning peaks and the release of the gametes lasted from January to October. Water temperature and nutrient supply are known to directly affect the physiological status of bivalves, regulating gametogenic cycles and spawning, among other physiological processes (Wilson and Hodgkin 1967, Hilbish and Zimmerman 1988, Gosling 2003, Morgan et al 2013). In agreement with these studies, we found a very strong relationship between the amount of ripe individuals and the water temperature.…”

Fine‐scale seascape genomics of an exploited marine species, the common cockle Cerastoderma edule, using a multimodelling approach

“…Furthermore, cockles have been shown to undergo boom and bust years (Morgan, O'Riordan, & Culloty, 2013) with the dispersal of cockle larvae and recruitment altering between years (Miller, Versace, Matthews, Montgomery, & Bowie, 2013;Morgan et al, 2013). Another explanation of positive F IS could be the Wahlund effect, caused by the presence of substructure within populations.…”