Pelagic Subsidies Underpin Fish Productivity on a Degraded Coral Reef

Abstract

Highlightsd Pelagic subsidies account for 41% of fish productivity on a windward coral reef d Subsidies were higher in forereef zones and drove increased total fish productivity d Topographic complexity underpins pelagic subsidies, but not internal production d Even degraded reefs may benefit from pelagic subsidies if complexity is maintained

Fishing restrictions and remoteness deliver conservation outcomes for Indonesia's coral reef fisheries

“…The dominance of planktivores at high biomass suggests very high levels of productivity may be subsidized by pelagic processes and access to plankton‐rich oceanic waters (Morais & Bellwood, ). Indonesian reefs therefore could be described as “middle‐driven or convex” systems where trophic structure is predicted by energy into the middle of the food web (Heenan et al., ).…”

“…They contrast with bottom‐driven, high‐biomass Western Indian Ocean (WIO) reefs characterized by greater herbivore biomass (Graham et al., ), perhaps because the fringing and platform reefs typical of the WIO are associated with reef‐based productivity of turf algae and herbivores. Indonesia's reef slopes likely have greater access to pelagic subsidies from oceanographic transport through currents, tidal waves, or deep‐water upwelling, which may subsidize reef productivity when planktivores move off the reef to access and bring back oceanic primary productivity into reef food webs (Morais & Bellwood, ). Surprisingly, we found no relationship between planktivore biomass with modeled estimates of primary productivity, suggesting that remotely sensed global models may not be detecting effects of local currents or other biophysical processes that we believe are driving plankton enrichment at the surveyed sites.…”

Human exploitation shapes productivity–biomass relationships on coral reefs

“…The GBR dataset encompassed fish counts from Lizard Island, northern GBR (Morais & Bellwood, ), distributed between the outer slope, crest, flat and back reef. The Coral Triangle dataset was collected in the southern Raja Ampat, Indonesia, and encompassed counts from the crest/slope of fringing reefs (Supporting Information).…”

Natural variation in coral reef trophic structure across environmental gradients

“…). A recent multi‐method study emphasized the importance of both pelagic and cryptobenthic energy pathways in supporting coral reef fish assemblage productivity (Morais and Bellwood ). It has also become clear that small‐bodied cryptic fishes, such as blennies and gobies, are key energetic resources sustaining overall reef fish production (Brandl et al .…”

“…Inputs of energy from outside the defined ecosystem appear to facilitate increased biomass in upper TLs (McCauley et al 2018), as coral reef planktivore and piscivore biomass is positively related to nearshore oceanic production (Williams et al 2015). A recent multi-method study emphasized the importance of both pelagic and cryptobenthic energy pathways in supporting coral reef fish assemblage productivity (Morais and Bellwood 2019). It has also become clear that small-bodied cryptic fishes, such as blennies and gobies, are key energetic resources sustaining overall reef fish production (Brandl et al 2019).…”