A temporal analysis on the dynamics of deep-sea macrofauna: Influence of environmental variability off Catalonia coasts (western Mediterranean)

• Published in: Deep-sea research. Part I, Oceanographic research papers Vol. 58; no. 4; pp. 323 - 337
• Main Authors: Mamouridis, V., Cartes, J.E., Parra, S., Fanelli, E., Saiz Salinas, J.I.
• Format: Journal Article
• Language: English
• Published: Kidlington Elsevier Ltd 01.04.2011; Elsevier; Pergamon Press Inc
• Subjects: Ampharetidae; Animal and plant ecology; Animal, plant and microbial ecology; Annelids; Biological and medical sciences; Biomass; Canyon; Canyons; Capitellidae; Carangoliopsis; Crustaceans; Deposits; Dynamics; Flabelligeridae; Food availability; Foods; Fundamental and applied biological sciences. Psychology; Glyceridae; Habitats; Harmothoe; Harpinia; Macrofauna; Marine; Marine ecology; Onchnesoma; Onuphidae; Paraonidae; Sampling; Sea water ecosystems; Seasonal dynamics; Sediments; Spionidae; Synecology; Temporal logic; Turbidity; Mediterranean Sea; West Mediterranean; Catalonia Spain; Catalan Sea; MED, Spain, Cataluna; MED, Catalan Sea; MED, Spain, Cataluna, Barcelona, Besos; MED, Toulon Canyon; MED, Western Mediterranean; Macrofauna; Food availability; Canyon; Seasonal dynamics; Availability; Fauna; Environmental factor; Deep water; Submarine canyon; Marine environment; Dynamics; Seasonal variation; Invertebrata; Food supply
• ISSN: 0967-0637; 1879-0119
• DOI: 10.1016/j.dsr.2011.01.005

A seasonal analysis of deep-sea infauna (macrobenthos) based on quantitative sampling was conducted over the Catalan Sea slope, within the Besòs canyon (at ∼550–600 m) and on its adjacent slope (at 800 m). Both sites were sampled in February, April, June–July and October 2007. Environmental variables influencing faunal distribution were also recorded in the sediment and sediment/water interface. Dynamics of macrobenthos at the two stations showed differences in biomass/abundance patterns and trophic structures. Biomass was higher inside the Besòs canyon than on the adjacent slope. The community was mostly dominated by surface-deposit feeding polychaetes (Ampharetidae, Paraonidae, Flabelligeridae) and crustaceans (amphipods such as Carangoliopsis spinulosa and Harpinia spp.) inside the canyon, while subsurface deposit feeders (mainly the sipunculan Onchnesoma steenstrupii) were dominant over the adjacent slope. The taxonomic composition in the suprabenthic assemblages of polychaetes, collected on the adjacent slope by a suprabenthic sledge, was clearly different from that collected by the box-corer. The suprabenthic assemblage was dominated by carnivorous forms (mainly Harmothoe sp. and Nephthys spp.) and linked to higher near-bottom turbidity. Inside Besòs a clear temporal succession of species was related to both food availability and quality and the proliferation of opportunistic species was consistent with higher variability in food sources (TOC, C/N, δ 13C) in comparison to adjacent slope. This was likely caused by a greater influence of terrigenous inputs from river discharges. Inside the canyon, Capitellidae, Spionidae and Flabelligeridae, in general considered as deposit feeders, were more abundant in June–July coinciding with a clear signal of terrigenous carbon (depleted δ 13C, high C/N) in the sediments. By contrast, during October and under conditions of high water turbidity and increases of TOM, carnivorous polychaetes (Glyceridae, Onuphidae) increased. Total macrobenthos biomass found over Catalonian slopes were higher than that found in the neighboring Toulon canyon, probably because the two canyons are influenced by different river inputs, connected with distinct terrigenous sources. ► Seasonal analysis of deep-sea infauna (box-core sampling) at canyon and slope sites. ► Results: influence of environmental and trophic variables on faunal dynamics. ► Canyon vs slope: differences in taxonomic composition/biomass/abundance patterns. ► Temporal succession of species inside canyon, related to food availability and quality. ► Suprabenthic assemblages of polychaetes (carnivorous forms) linked to turbidity.