Less common and more controversial artificial

habitats

Less common and more controversial artificial

habitats TSA HDAC mw include worn tires, coal-power waste, and other components (Woodhead et al., 1982 and Collins et al., 2002). The potential toxicity of such structures is as variable as the materials used in their construction. Such installations are also known to affect the surrounding benthos in soft sediments, due to changes in predator forays around the new refugium (Broughton 2012). Little is known about the effects of artificial reefs and other structures installed at depths >100 m (Macreadie et al., 2011). Once considered to be constant, spatially homogeneous, and isolated, deep-sea sediments are now recognized as a dynamic, diverse habitat that is intricately linked to the global biosphere (Levin et al., 2001). Deep-sea biodiversity has been shown to correlate positively with ecosystem function (Danovaro et al., 2008), and therefore is an important consideration when evaluating the impact of an introduced structure. Potential negative impacts of human-introduced structures in marine ecosystems include physical damage to the seabed, undesirable changes in marine food webs, colonization of invasive species, and release of contaminants (Macreadie

et al., 2011). Furthermore, efficiently dispersing, fast-growing, highly fecund (i.e., “weedy”, typically see more non-native) species can create additional oxygen demand in marine ecosystems. In already hypoxic environments such as those in and adjacent to the Oxygen Minimum

Zone (a layer of oxygen-deplete water ranging from approx. 500–1000 m depth), additional oxygen demand may promote declines in ecosystem richness and evenness due to physiological stress (Levin et al., 2001). In this study we evaluate the hypothesis that the diversity, distribution, and abundance of benthic organisms near the lost intermodal container vary spatially in association with the container. The shipping container is located on a mildly sloping, sediment-covered seabed (1281 m depth) on the upper continental slope in the MBNMS (Fig. 1). A megafaunal assemblage of soft corals, crustaceans, and echinoderms dominates the sea floor in this location, all while benthic macrofauna (infauna) is comprised largely of polychaete worms, nematodes, and harpactacoid copepods. Scientists from the MBNMS and MBARI inspected and sampled the container and nearby benthic faunal assemblages during March 2011 using the ROV Doc Ricketts (dive D219), operated by MBARI from the R/V Western Flyer. ROV pilots flew the vehicle up to a 500 m radius from the intermodal container to record high resolution video along 12 transects up to 480 m long (with total video survey area in excess of 3000 m2). In addition, benthic macrofaunal organisms were analyzed from sediments collected in 31 sediment cores (7 cm diameter, 192.4 cm3 of sediment in the top 5 cm analyzed; Fig. 2).

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