Environmental factors shaping boring sponge assemblages at Mexican Pacific coral reefs

Abstract

Recent studies suggest a future increase in sponge bioerosion as an outcome of coral reef decline around the world. However, the factors that shape boring sponge assemblages in coral reefs are not currently well understood. This work presents the results of a 17-month assessment of the presence and species richness of boring sponges in fragments collected from living corals, dead coral reef matrix and coral rubble from Punta de Mita and Isabel Island, two coral reefs from the central coast of the Mexican Pacific Ocean. Both localities have a high cover of dead corals generated by past El Niño Southern Oscillation events, but Punta de Mita was also highly exposed to anthropogenic impacts. Additionally, environmental factors (water transparency, water movement, temperature, sediment deposition, SST, and chlorophyll concentration) were assessed to test the hypothesis that environmental conditions which are potentially harmful for corals can enhance sponge bioerosion. Isabel Island and Punta de Mita showed a similar species richness (13 and 11 species, respectively) but boring sponge presence in both live and dead corals was higher at Isabel Island (57.6%) than at Punta de Mita (35.7%). The same result was obtained when each type of substrate was analysed separately: dead coral reef matrix (81.3% versus 55.5%), coral rubble (47.7% versus 20.0%) and living corals (43.7% versus 31.7%). A principal components analysis showed a higher environmental heterogeneity at Punta de Mita, as well as important environmental differences between Punta de Mita and Isabel Island, due to sediment deposition (2.0 versus 0.2 kgÁm À2 Ád À1 ) and water movement (24.5% versus 20.5% plaster dissolution day À1 ), that were also negatively correlated with boring sponge presence (r = À0.7). By analysing the boring sponge assemblage, we found that environmental settings, together with habitat availability (i.e., dead coral substrate) differentiated assemblage structure at both localities. Major structural differences were largely due to species such as Cliona vermifera, Cliona tropicalis and Aka cryptica. In conclusion, factors such as habitat availability favored the presence of boring sponges but some environmental factors such as abrasion resulting from moving sediment acted restrictively, and exerted a major role in structuring boring sponge assemblages in the Mexican Pacific.

Temporal and small‐scale spatial variations in abundance and biomass of seagrass‐dwelling sponges in a tropical estuarine system

“…In general, the average abundance and biomass in the three species was relatively higher at the most distant sites (>150 m) from the shore, where the proportion of coarser particles, water movement and sediment/resuspension rate were also relatively higher. These findings agree with those of previous studies indicating that substrate availability, water movement and sedimentation rates are among the major environmental factors contributing to sponge distribution patterns (Pansini & Pronzato ; Wilkinson & Evans ; Nava & Carballo ). In seagrass bed ecosystems it has been suggested that in addition to sedimentation, light and water movement, the distribution of sponges in certain areas of the meadow may also depend on the density of bundles and rhizomes (Pansini & Pronzato ).…”

The coral killing spongeChalinula nematifera(Porifera: Haplosclerida) along the eastern coast of Sulawesi Island (Indonesia)

“…If C. nematifera had a preference for dead corals, these unfavourable conditions could increase the substratum available for sponge spreading and growth. However, at Isla Isabel National Park (Mexico), where a considerable coral reef deterioration was recorded after the El Niño event of 1982 (Nava & Carballo 2013), this sponge occurred in low percentages on rock, and was not found on coral rubble or mollusc shells (Ávila & Carballo 2009). …”

The effects of coastal development on sponge abundance, diversity, and community composition on Jamaican coral reefs

“…The positively skewed sponge distribution and wide range of sponge sizes at Dairy Bull indicates a healthy population with high recruitment, which has been shown in coral and sponge populations (Meesters et al, 2001;Duckworth et al, 2009). Sediment deposition was found to negatively affect the overall sponge community assemblages in several studies (Carballo, 2006;Nava and Carballo, 2013;Bell and Smith, 2004). This study found differences in the multivariate community composition among locations and depths (Supp.…”