Benthic-Pelagic Coupling: New Perspectives in the Animal Forests

Abstract

Animal forests all over the world play an essential role in benthic-pelagic coupling processes. These processes can change according to the feeding strategies of benthic species, as well as their extension and biomass. From the oligotrophic coral reefs to the highly seasonal productive Antarctic ecosystems, suspension feeders (the main eco-engineers of the animal forest) have evolved feeding strategies depending on the environmental constraints, which shape their survivorship and partly explain their high biodiversity. In the process of benthic-pelagic coupling, these organisms also have the ability to retain part of the organic and inorganic matter in their long-lived structures. In this chapter, hypotheses related to benthic-pelagic coupling processes will be presented, along with the newest methodology used to quantify the capacity of animal forests to function as carbon sinks. Although the role of animal forests as carbon sinks is an essential ecosystem service, it has been largely neglected in the conservation models for the majority of marine environments. The importance of food availability (quantity and quality) in suspension feeding animals will be discussed with a new approach based on random pulses of energy input. This approach will help to better understand their nutritional condition and the health status of their populations. Finally, to allow making key evaluations of the influence of animal forests in benthic-pelagic coupling processes and as carbon sinks, this approach will be overlapped with the distribution, density, and population size structure of benthic suspension feeders, obtained through the analysis of video or photo recorded via remotely operated vehicles (ROV). This new approach will be an essential tool for coastal, continental shelves and deep water coral area management and conservation, where animal forests are threatened synergistically by several direct and indirect impacts.