Estimates of Particulate Organic Carbon Flowing from the Pelagic Environment to the Benthos through Sponge Assemblages

Abstract

Despite the importance of trophic interactions between organisms, and the relationship between primary production and benthic diversity, there have been few studies that have quantified the carbon flow from pelagic to benthic environments as a result of the assemblage level activity of suspension-feeding organisms. In this study, we examine the feeding activity of seven common sponge species from the Taputeranga marine reserve on the south coast of Wellington in New Zealand. We analysed the diet composition, feeding efficiency, pumping rates, and the number of food particles (specifically picoplanktonic prokaryotic cells) retained by sponges. We used this information, combined with abundance estimates of the sponges and estimations of the total amount of food available to sponges in a known volume of water (89,821 m3), to estimate: (1) particulate organic carbon (POC) fluxes through sponges as a result of their suspension-feeding activities on picoplankton; and (2) the proportion of the available POC from picoplankton that sponges consume. The most POC acquired by the sponges was from non-photosynthetic bacterial cells (ranging from 0.09 to 4.69 g C d−1 with varying sponge percentage cover from 0.5 to 5%), followed by Prochlorococcus (0.07 to 3.47 g C d−1) and then Synechococcus (0.05 to 2.34 g C d−1) cells. Depending on sponge abundance, the amount of POC that sponges consumed as a proportion of the total POC available was 0.2–12.1% for Bac, 0.4–21.3% for Prochlo, and 0.3–15.8% for Synecho. The flux of POC for the whole sponge assemblage, based on the consumption of prokaryotic picoplankton, ranged from 0.07–3.50 g C m2 d−1. This study is the first to estimate the contribution of a sponge assemblage (rather than focusing on individual sponge species) to POC flow from three groups of picoplankton in a temperate rocky reef through the feeding activity of sponges and demonstrates the importance of sponges to energy flow in rocky reef environments.

Nitrogen Biogeochemistry in the Caribbean Sponge, Xestospongia muta: A Source or Sink of Dissolved Inorganic Nitrogen?

“…2), may differentially influence N cycling on the surrounding coral reef relative to FL or LSI sponges. We do not know the extent to which sponge-derived DIN influences the biogeochemistry and ecology of the surrounding habitat, but studies on multi-species sponge assemblages, and coral reef communities dominated by active suspension feeding sponges, have shown the significant role of active suspension feeding and the coupling of POC and PON from the water column to the benthos [71], [72]. The composition of DIN released into the water column by sponges would influence how it might be utilized, and who utilizes it in the surrounding environment, as NH 4 + is more readily incorporated into biomass than NO 3 − which can then potentially support local increases in planktonic community production [73].…”

Single-cell genomics reveals complex carbohydrate degradation patterns in poribacterial symbionts of marine sponges

“…Sponges feed on dissolved and particulate organic matter (Yahel et al, 2003;De Goeij et al, 2008) as well as heterotrophic bacteria and eukaryotes (Maldonado et al, 2012;Perea-Blázquez et al, 2012). It has further been shown that sponge feeding on dissolved and particulate organic matter from bacterial and algal sources can be mediated by bacterial symbionts (De Goeij et al, 2008).…”

Demography alters carbon flux for a dominant benthic suspension feeder, the giant barrel sponge, on Conch Reef, Florida Keys

“…There is increasing evidence that sponges are particularly important benthic suspension feeders in aquatic systems and especially on Caribbean coral reefs (Colman, ; Maldonado, Ribes, & van Duyl, ; Pawlik, Burkepile, & Thurber, ), where their biomass surpasses that of any other benthic group (Diaz & Rützler, ). Sponge populations efficiently process large volumes of seawater (McMurray, Pawlik, & Finelli, ; Reiswig, ) and represent an important trophic link between pelagic and benthic systems (Perea‐Blázquez, Davy, & Bell, ; Pile, Patterson, Savarese, Chernykh, & Fialkov, ). Sponges significantly influence the cycling of phosphorous and nitrogen and thus may influence levels of primary production on coral reefs (Southwell et al., ; Zhang et al., ).…”