Multi‐decadal stability of fish productivity despite increasing coral reef degradation

Abstract

1. Under current trajectories, it is unlikely that the coral reefs of the future will resemble those of the past. As multiple stressors, such as climate change and coastal development, continue to impact coral reefs, understanding the changes in ecosystem functioning is imperative to protect key ecosystem services.2. We used a 26-year dataset of benthic reef fishes (including cryptobenthic fishes) to identify multi-decadal trends in fish biomass production on a degraded coral reef. We converted fish abundances into estimates of community productivity to track the long-term trend of fish biomass production through time.3. Following the first mass coral bleaching event in 1998, the abundance, standing biomass and productivity of fish communities remained remarkably constant through time, despite the occurrence of multiple stressors, including extreme sedimentation, cyclones and mass coral bleaching events. Species richness declined following the 1998 bleaching event, but rebounded to prebleaching levels and also remained relatively stable.4. Although the species composition of the communities changed over time, these new community configurations still maintain a steady level of fish biomass production. While these highly dynamic and increasingly degraded systems can still provide some critical ecosystem functions, it is unclear whether these patterns will remain stable over future decades.

Field collections and environmental DNA surveys reveal topographic complexity of coral reefs as a predictor of cryptobenthic biodiversity across small spatial scales

“…Indeed, many coral reef fish have distinct microhabitat preferences (Ahmadia et al., 2012; Cadena‐Estrada et al., 2019; Munday, 2004; Wilson et al., 2008), and rely on subtle variation in coral reef topography for shelter and/or foraging opportunities (Brandl et al., 2015; Rogers et al., 2014). While the responses of mobile, conspicuous fish communities to coral reef degradation are relatively well documented, potential effects on cryptic fishes and invertebrate communities are poorly resolved (Nelson et al., 2016; Stella et al., 2011; Yan & Bellwood, 2023). Given the tendency of these taxa to be highly associated with specific microhabitats (Kramer et al., 2014), establishing a better understanding of how these communities may react to reef‐wide changes is critical.…”

Rarity mediates species‐specific responses of tropical reef fishes to protection

“…Most studies on the effect of protection focus on individual MPAs and the community level, such as total fish density or biomass of commercial species (Cinner et al, 2018;Giakoumi et al, 2017;Nowakowski et al, 2023). Species-specific responses to protection across MPAs and social-environmental contexts are less clear (Lefcheck et al, 2021;Yan & Bellwood, 2023). On the one hand, fishing can impact the entire food web and body-size spectra (Soler et al, 2018;Zgliczynski & Sandin, 2017) so most species should benefit from MPAs.…”