Rosa M Viejo1, José Luis Acuña2, Pelayo Rico1, Ana Ramirez1, Rosa M Chefaoui1
1Universidad Rey Juan Carlos , Spain - 2Universidad de Oviedo, Spain
Herbivory is a main driver of the structure and dynamics in terrestrial and marine ecosystems. In the marine realm, intensity of herbivory is hypothesized to decrease from tropical to temperate reefs. Large brown algae, mostly fucoids and kelps, are key components of these temperate reefs, providing food and shelter for a diverse array of organisms. However, herbivory by fishes is recently increasing in temperate regions, likely as an indirect consequence of climate change, with evident negative ecological impacts on these macroalgal forests. To date, these shifts in grazing intensity have been mostly reported in subtidal rather than in intertidal forests.
We investigated the effect of fish herbivory on the performance of two intertidal fucoids (Ascophyllum nodosum and Fucus serratus) at the southern range of its distributions in northern Spain. In recent years, these southern populations are in decline also showing signs of grazing damage.
We set up exclusion experiments in marginal populations of both species, where an increased in grazing damage has been observed. Our results indicated that fish marks greatly reduced the performance of both species, in addition to the impact of climate changeon these marginal populations. Our study reveals that the rising and severe impacts of fish species in temperate waters are also reaching the intertidal zone, impairing the resilience capacity of fucoid populations to environmental changes and limiting their potential for habitat generation.
Biography
Rosa M Viejo is a marine ecologist working in coastal intertidal ecosystems, using mainly an experimental approach. Her interests of research include: the impacts of invasive species, the resilience and recovery processes of coastal communities after disturbances, and the mechanisms determining the geographic range edges of species. These studies have often focused on determining the effect of the abiotic context, and more recently, on assessing the ecological impacts of climate change.