Climate change impedes scleractinian corals as primary reef ecosystem engineers

Abstract

Abstract. Coral reefs are among the most diverse and productive ecosystems on our planet. Scleractinian corals function as the primary reef ecosystem engineers, constructing the framework that serves as a habitat for all other coral reefassociated organisms. However, the coral's engineering role is particularly susceptible to global climate change. Ocean warming can cause extensive mass coral bleaching, which triggers dysfunction of major engineering processes. Sub-lethal bleaching results in the reduction of both primary productivity and coral calcification. This may lead to changes in the release of organic and inorganic products, thereby altering critical biogeochemical and recycling processes in reef ecosystems. Thermal stress-induced bleaching and subsequent coral mortality, along with ocean acidification, further lead to long-term shifts in benthic community structure, changes in topographic reef complexity, and the modification of reef functioning. Such shifts may cause negative feedback loops and further modification of coral-derived inorganic and organic products. This review emphasises the critical role of scleractinian corals as reef ecosystem engineers and highlights the control of corals over key reef ecosystem goods and services, including high biodiversity, coastal protection, fishing, and tourism. Thus, climate change by impeding coral ecosystem engineers will impair the ecosystem functioning of entire reefs.

Evaluating the causal basis of ecological success within the scleractinia: an integral projection model approach

“…OA and elevated temperature are among the most prominent threats to ocean ecosystems (Hughes et al 2003;Hoegh-Guldberg et al 2007), and their interactive effects may represent an evolutionary impasse to the survival of tropical reefs as coral-dominated, calcifying systems (Silverman et al 2009;Wild et al 2011;Anthony et al 2011). While it has rapidly become clear that the responses of corals to OA and thermal stress, individually or interactively, are not uniform among species (Loya et al 2001;Pandolfi et al 2011;Comeau et al 2013), progress in understanding the causal basis of this variability has been slow.…”

Contrasting rates of coral recovery and reassembly in coral communities on the Great Barrier Reef

“…Reassembly ensures that processes and traits that contribute to ecosystem function of a particular coral community are restored (Moberg and Folke 1999;Nystrom et al 2008). For coral reefs, these processes and traits include framework building (Aronson et al 2002;Wild et al 2011), habitat complexity , diversity of food sources (Pratchett 2005), recruitment McClanahan et al 2012), and connectivity (Jones et al 2009). Communities that shift in composition may retain ecological function if the species that are added fulfill the functions of those that are lost.…”

Functional significance of dinitrogen fixation in sustaining coral productivity under oligotrophic conditions

“…They do so by controlling a wide range of biogeochemical processes important to coral reef functioning, and by intensively generating and transforming inorganic and organic materials [2]. These sessile cnidarians owe their evolutionary success to an endosymbiosis with photosynthetic dinoflagellate microalgae of the genus Symbiodinium that contribute a substantial fraction of the total gross primary productivity-that is, the amount of inorganic carbon (CO 2 ) photosynthetically fixed per unit of time-in coral reef ecosystems [3,4].…”