Suspended sediment grain size and mineralogy across the continental shelf of the Great Barrier Reef: Impacts on the physiology of a coral reef sponge

Rapid respiratory responses of the deep-water sponge Geodia barretti exposed to suspended sediments

“…The reduction in metabolic activity of Geodia barretti contradicts the results of Bannister et al (2012), who clearly demonstrated that the respiration activity of the tropical demosponge Rhopaloeides odorabile increased slightly during a 7 h exposure period to elevated suspended sediment concentrations (64 mg l −1 ), and significantly (+ 43%) during a longer exposure period (24 h) to the same concentration. A study by Murray (2009) demonstrated that exposing the temperate sponge Tethya bergquistae to a very high sediment concentration of 2.5 g l −1 does not initiate any respiratory response, while exposure to 8.5 and 16.5 g l −1 resulted in an 80% reduction in respiration.…”

“…The rapid response of G. barretti was also seen during recovery, when respiration rates returned quickly to baseline levels. Both Tompkins-MacDonald & Leys (2008) and Bannister et al (2012) measured recovery after exposure to suspended sediment, and these studies demonstrated that sponges returned to their initial respiration and pumping rates respectively, between 3 and 25 h after exposure ended.…”

“…data), and in some areas of the Barents Sea biomasses of up to 6 kg m −2 have been observed (Zenkevitch 1963). Studies show that at least some sponges are sensitive to turbid water (Reiswig 1971, Genin et al 1992, Tompkins-Mac Donald & Leys 2008, Bannister et al 2012. This is demonstrated by the redu ced distribution, abundance and species richness of sponges in shallow reef environments (Carballo 2006, Maldonado et al 2008, Bannister et al 2010.…”

“…This is demonstrated by the redu ced distribution, abundance and species richness of sponges in shallow reef environments (Carballo 2006, Maldonado et al 2008, Bannister et al 2010. The effects of suspended and deposited sediment include increased metabolic stress (Bannister et al 2012), reduced pumping and filtration rate (Gerrodette & Flechsig 1979, Lohrer et al 2006, Tompkins-MacDonald & Leys 2008, reduced growth (Wilkinson & Vacelet 1979), decreased reproduction (Roberts et al 2006, Whalan et al 2007), re duced larval settlement (Moran 1991, Whalan et al 2007) and reduced survival (Mal donado et al 2008). However, a number of other studies in shallow water systems demonstrate that some sponge species favour areas with high sedimentation rates (Carballo et al 1996, Bell & Smith 2004, presumably a function of the morpho logical/ physio logical adaptation to such conditions.…”

“…However, a number of other studies in shallow water systems demonstrate that some sponge species favour areas with high sedimentation rates (Carballo et al 1996, Bell & Smith 2004, presumably a function of the morpho logical/ physio logical adaptation to such conditions. The effects can also depend on the composition of the sediment such as organic content and mineralogical composition (Maldonado et al 2008, Bannister et al 2012. It is noteworthy that human activities in deep water ecosystems are currently increasing (Glover & Smith 2003, Puig et al 2012.…”