title: Spatial and temporal variation in sponge spicule patches at Station M, northeast Pacific.
abstract: Changes in habitat-forming organisms can have complex consequences for associated species. Sessile epibenthic glass "plate" sponges (Porifera: Hexactinellida) are conspicuous inhabitants of soft-sediment abyssal areas and their siliceous spicules create persistent spicule patches on the seafloor. Sponge spicule patch density, spatial dispersion, and percent cover were examined over a seven-year period (2006-2013) using remotely operated vehicle videos from Station M in the abyssal northeast Pacific (50˚00N, 123˚00W, ~4,000 m depth). There was an apparent large increase in newly dead plate sponges in February 2007 compared with December 2006, with this trend continuing through June 2007 (mean 0.03 % cover increasing to 0.33 %). A second increase in mean percent cover of dead plate sponges occurred from May 2011 (0.24 %) through June 2012 (0.60 %). Among the 28 megafaunal taxa occurring in association with the patches, the distributions of three taxa [two sponge taxa (Porifera) and brittle stars (Ophiuroidea)] suggested selectivity for the sponge spicule patches. The community structure of visible megafauna within sponge spicule patches was different when compared with that outside the patches suggesting that the sponges, after death, provide preferred habitat patches for certain benthic megafauna. These findings indicate that sponge spicule patches contribute to habitat heterogeneity in space and time.
authors.affiliation: Ocean and Earth Science, University of Southampton, National Oceanography Centre, Southampton, European Way, Southampton, SO14 3HZ UK ; Department of Zoology (Polychaete Group), Natural History Museum, London, SW7 5BD UK.
authors.forename: C
authors.initials: C
authors.lastname: Laguionie-Marchais
authors.affiliation: Monterey Bay Aquarium Research Institute, 7700 Sandholdt Road, Moss Landing, CA 95039 USA.
authors.forename: L A
authors.initials: LA
authors.lastname: Kuhnz
authors.affiliation: Monterey Bay Aquarium Research Institute, 7700 Sandholdt Road, Moss Landing, CA 95039 USA.
authors.forename: C L
authors.initials: CL
authors.lastname: Huffard
authors.affiliation: National Oceanography Centre, University of Southampton Waterfront Campus, European Way, Southampton, SO14 3HZ UK.
authors.forename: H A
authors.initials: HA
authors.lastname: Ruhl
authors.affiliation: Monterey Bay Aquarium Research Institute, 7700 Sandholdt Road, Moss Landing, CA 95039 USA.
authors.forename: K L
authors.initials: KL
authors.lastname: Smith