Synchronous annual recruitment variation in barnacles and ascidians in the White Sea shallow subtidal 1999–2010

Аннотация

Multiple foundation species in a community may exhibit alternative ecological strategies. Barnacles Balanus crenatus Bruguiere and solitary ascidians Styela spp. often co-dominate on mixed sediments in the White Sea shallow subtidal, supporting numerous dependent organisms. Larvae of B. crenatus stay in plankton for several weeks, while ascidian tadpoles float for 1–2 days. Given this difference in spreading potential, we expected recruitment in barnacles and ascidians to be controlled by the factors operating at different spatial scales. In 1999–2010, we annually sampled the community dominated by barnacles and ascidians to relate their recruitment rates to the substrate space availability, abundance of adults, and climatic variables. Most barnacles recruited to the surfaces of shells, stones, and conspecific adults. Ascidian recruits were chiefly found on barnacles. Annual recruitment rates of barnacles and ascidians were strictly correlated and strongly depended on average temperatures of the preceding fall (positively), winter (negatively), and current summer (negatively). Variation of mean annual recruitment rates was 26-fold for barnacles and 30-fold for ascidians. We found no limitation of recruitment by hard substrate availability. Inconsistent with our original hypothesis, large-scale environmental factors similarly accounted for most annual recruitment variation in both foundation species studied.

Тип публикации
Публикация
Hydrobiologia, 706(1), 69–79.