Document of bibliographic reference 405477

BibliographicReference record

Type

Bibliographic resource

Type of document

Book chapters

BibLvlCode

AMS

Title

The changing focus of coral-macrophyte interactions: A review of four decades of research

Abstract

Coral reefs are one of the world’s most biodiverse ecosystems, yet they are also one of the most threatened. The effects of local anthropogenic stressors are being greatly compounded by those of climate change, leading to widespread declines in coral cover over the past five decades. Declines in coral cover are inevitably accompanied by increases in other benthic taxa, including algae and cyanobacteria, that rapidly colonise the dead coral skeletons. Any recovery of coral assemblages, and the associated communities they support, therefore must generally occur against a backdrop of elevated macrophyte (i.e., algae and cyanobacteria) cover, and in some cases in areas dominated by large fleshy macroalgae. Understanding the mechanisms and outcomes of coral-macrophyte interactions, and how they vary among coral and macrophyte taxa, and among coral life stages is crucial for forecasting future reef configurations. We conducted a systematic review of the evidence on coral-macrophyte interactions to investigate taxonomic, functional and life stage biases in terms of both corals and macrophytes, and how these influence the outcomes of coral-macrophyte interactions. Across 169 studies and >1300 coral-macrophyte interactions, the majority of available data (73%) was based on adult corals, with relatively few studies investigating the potential effects of macrophytes on early life stages of corals (juvenile corals: 10%; larvae and recently settled corals: 17%). This bias towards adult corals is somewhat surprising given the importance of early-life stages to the replenishment of coral assemblages. Indeed, the negative effects of macrophyte interactions on coral health (largely survival and growth) were greatest for early-life stages (i.e., coral larvae, 45%; and juveniles, 38%) and considerably reduced for adult corals (3%). There were also regional differences in the taxonomic and functional identity of the coral and macrophyte taxa investigated, with coral-macrophyte interactions across the tropical Atlantic focusing on Porites, Orbicella and other massive and submassive corals, while those in the Indo-Pacific focused on Acropora and other branching corals. While macrophyte communities on coral reefs are typically diverse, and spatially and temporally variable, the vast majority of studies investigated the effect of a single macrophyte taxon in direct contact with a coral over a relatively short temporal scale. Very few studies considered the potential effects of multiple macrophyte taxa or broader habitat-scale effects of macrophyte assemblages on corals. Given the ongoing effects of climate change on coral reefs, and concerns that reefs may increasingly be overgrown by macroalgae, there is a pressing need to better understand the nature and outcomes of coral-macrophyte interactions to predict the recovery potential of coral assemblages.

Bibliographic citation

Burgo, M.; Hoey, A.S. (2024). The changing focus of coral-macrophyte interactions: A review of four decades of research, in: Todd, P.A. et al. Oceanogr. Mar. Biol. Ann. Rev. 62. Oceanography and Marine Biology: An Annual Review, 62: pp. 267-302. https://dx.doi.org/10.1201/9781003477518-7

Topic

Marine

Is peer reviewed

true