Is there a link between the type of habitat and the patterns of abundance of holothurians in shallow rocky reefs?

Abstract

This paper has not been submitted elsewhere in identical or similar form, nor will be during the first three months after its submission to Hydrobiologia. 2 AbstractThe presence of a mosaic of habitats, largely determined by sea urchin grazing, across shallow rocky reefs may potentially influence in differences in the distribution patterns of invertebrates. The aim of this paper was to assess, using a correlative approach, whether the type of habitat influences the abundance patterns of holothurians in the eastern Atlantic. We hypothesized that abundances of large (> 10 cm) holothurians varied among four types of habitat (3 vegetated habitats with low abundances of the sea urchin D. antillarum versus 'barrens' with hyperabundances of sea urchins), and that these differences were consistent at a hierarchy of spatial scales, including two islands and several replicated sites within each type of habitat and island. Three species of large holothurians were found, accounting for a total of 300 specimens. We found remarkable differences in abundances of holothurians between the 'barrens' and the three vegetated habitats. This pattern was strongest for the numerically dominant species, Holothuria sanctorii. Total abundances of holothurians were between 5 -46 times more abundant in 'barrens' compared with the vegetated habitats. Inter-habitat differences were species-specific with some inconsistent patterns from one island to the other. The total abundances of holothurians tended to increase with the abundance of sea urchins within 'barrens'. Our study suggests that there may be a link, at least for the dominant species Holothuria sanctorii, between the distribution and abundances of large holothurians and the habitat across shallow-waters of the eastern Atlantic.3

Localised coastal habitats have distinct underwater sound signatures

“…This suggests that habitat type is important in determining the abundance of resident snapping shrimp. In contrast, previous studies have shown that macroalgal habitats are more diverse and complex than sea urchin barren habitats (Simenstad et al 1978, Behrens & Lafferty 2004, Graham 2004, Tuya et al 2006. Watanabe et al (2002) used the numbers of snaps produced by snapping shrimp as an environmental monitoring tool and showed that the number of snaps produced in an unpolluted habitat was significantly greater than at a polluted site.…”

Comanaging small-scale sea cucumber fisheries in New Caledonia and Vanuatu using stock biomass estimates to set spatial catch quotas

“…We determined suitable habitats for each species based on literature (Conand 1998; Tuya et al . 2006; Bellchambers et al . 2011), and in situ habitat description and species occurrence during the surveys.…”

“…If appropriate, we used these observations to adjust the habitat zone borders in the GIS. We determined suitable habitats for each species based on literature (Conand 1998;Tuya et al 2006;Bellchambers et al 2011), and in situ habitat description and species occurrence during the surveys. The length-weight relationships for each species were taken from Conand (1989).…”

Sea cucumber (Aspidochirotida) community, distribution and habitat utilization on the reefs of Mayotte, Western Indian Ocean

“…Some species' tend to occur in aggregations, and their distribution may be influenced by biotic relationships or sediment characteristics (e.g. grain size, organic content) (Conand 1989, Conand & Chardy 1985, Uthicke & Karez 1999, Tuya et al 2006, Shiell & Knott 2010, Slater & Jeffs 2010, Dissanyake & Stefansson 2012. Distribution can also be influenced by other habitat variables such as shelter (Shiell & Knott 2008).…”