title: Restriction of sponges to an atoll lagoon as a result of reduced environmental quality.
abstract: The lagoon at Palmyra Atoll in the central Pacific was subject to major military modifications during WWII and now the dominant fauna on the lagoon's hard substrate are sponges, not corals. In this study, we quantified the physical and biological factors explaining the variation in sponge distribution patterns across 11 sites to determine the potential for the sponges in the lagoon at Palmyra to invade the surrounding reef systems. Significant differences in sponge assemblages were found among all but three sites. For all the models we examined the strongest environmental relationships were found for variables related to sedimentation/turbidity and food/habitat availability. Our findings suggest that the sponges in Palmyra's lagoon are likely to be restricted to this habitat type where they are associated with conditions resulting from the earlier heavy disturbance and are unlikely to spread to the outer reef environments unless there is a dramatic decline in environmental quality.
authors.affiliation: CMEER, School of Biological Sciences, Victoria University of Wellington, P.O. Box 600, Wellington, New Zealand.
authors.forename: Ingrid S S
authors.initials: IS
authors.lastname: Knapp
authors.forename: Gareth J
authors.initials: GJ
authors.lastname: Williams
authors.forename: José Luis
authors.initials: JL
authors.lastname: Carballo
authors.forename: José Antonio
authors.initials: JA
authors.lastname: Cruz-Barraza
authors.forename: Jonathan P A
authors.initials: JP
authors.lastname: Gardner
authors.forename: James J
authors.initials: JJ
authors.lastname: Bell
mesh_terms: D000818:Animals; D017753:Ecosystem; D004784:Environmental Monitoring; D010139:Pacific Islands; D011161:Porifera / Q000502:physiology*; D014876:Water Pollution / Q000032:analysis* / Q000706:statistics & numerical data