Trends and drivers of Macoma balthica L. dynamics in Kandalaksha Bay, the White Sea

Abstract

Long-term population dynamics of marine invertebrates can be shaped by environmental conditions as well as biotic factors, including predation, diseases, interspecific or intraspecific competition. Towards the northern edge of species ranges the role of biotic interactions gradually decreases while the impact of climate oscillations becomes more important. This study examined the long-term changes in abundance, individual growth rates and shell shape characteristics of Macoma balthica, one of the dominant species in White Sea soft-bottom intertidal communities. To test the role of predators in changes in clam abundance, we examined the number of moonsnails Amauropsis islandica. Macoma balthica exhibited spatially synchronous population dynamics at six sites in Kandalaksha Bay, where densities of clams varied between 140 and 8500 ind. m−2 during the 21-year period of observations. Statistical modelling using generalized additive models (GAM) shows that a combination of mild winter and warm summer led to an increase in M. balthica density the following year. Predation by A. islandica had no impact on changes in M. balthica density. Growth rates of M. balthica were higher during a cool decade, but clams that lived in a warmer period were characterized by more globose shells. Our results suggest that the climate oscillations can be regarded as the key factor causing the shift in abundance of M. balthica in the White Sea during the last two decades via recruitment and survival.

Spatiotemporal dynamics of subarctic intertidal macrobenthos: going their own ways

“…Both of these species have relatively long spawning periods and long stages of pelagic larvae. The spatially synchronous population dynamics of these species have previously been reported in several locations in the White Sea intertidal zone (Maximovich and Guerassimova, 2003; Genelt-Yanovskiy et al ., 2018). Spatial synchrony among local populations is often attributed to either dispersal processes (e.g.…”

Genetic Structure of the Limecola Balthica Population in the Gulf of Riga, Baltic Sea

“…According to monitoring data for L. balthica in the White Sea (Genelt-Yanovskiy et al, 2017) for the last 20 years, predators have a smaller influence on mollusks than temperature change. A huge number of studies devoted to bivalve mollusks and their adaptation to a changing environment have revealed serious morphological, histological and cytogenetic changes of these creatures (Sokolowski et al, 2004).…”

“…The L. balthica shell is usually round or oval with triangular tops, but some of them have visible morphological deformations. Parameters like length, height, width, proportions of posterior side and flexure on it, are often used for the analysis of changes in the environment and their impact on marine ecosystem (Sokolowski et al, 2008;Genelt-Yanovskiy et al, 2017). The reasons for the various changes can be a combi-nation of several factors.…”

“…The proportion of modified shells can reach up to 65% of the total population size. Over the past decade, various studies have investigated the possible effects of temperature change and predators (Genelt-Yanovskiy et al, 2017), food availability (Beukema et al, 2014), anoxia and hydrogen sulfide concentration at different depths (Sokolowski et al, 2008), acidification (Jansson et al, 2013;Van Colen et al, 2018) and trace metal and other contaminant concentrations (Sokolowski et al, 2004) on the shell growth. There exist several hypotheses to explain the causes of these changes, but the reason for these modifications is still unclear.…”

Characterizing spatio-temporal changes in benthic communities: Taxonomic and functional trajectories of intertidal assemblages in the bay of Saint-Brieuc (English Channel)

“…Different indicators and numerous species were involved in the definition of assemblages and taxonomic trajectory clusters but the contribution of some species to these descriptions was constant over time, notably P.ulvae, L. balthica, U. (Beukema et al, 2009;Genelt-Yanovskiy et al, 2017;Jansen et al, 2007;Ong et al, 2017;Philippart et al, 2003;Van Colen et al, 2018). The bay of Saint-Brieuc being located in the southern part of L. balthica's distribution, populations are likely to be affected by climate warming.…”