Global biogeography of coral recruitment: tropical decline and subtropical increase

Abstract

Despite widespread climate-driven reductions of coral cover on tropical reefs, little attention has been paid to the possibility that changes in the geographic distribution of coral recruitment could facilitate beneficial responses to the changing climate through latitudinal range shifts. To address this possibility, we compiled a global database of normalized densities of coral recruits on settlement tiles (corals m −2) deployed from 1974 to 2012, and used the data therein to test for latitudinal range shifts in the distribution of coral recruits. In total, 92 studies provided 1253 records of coral recruitment, with 77% origi nating from settlement tiles immersed for 3−24 mo, herein defined as long-immersion tiles (LITs); the limited temporal and geographic coverage of data from short-immersion tiles (SITs; deployed for < 3 mo) made them less suitable for the present purpose. The results from LITs show de clines in coral recruitment, on a global scale (i.e. 82% from 1974 to 2012) and throughout the tropics (85% reduction at < 20°latitude), and in creases in the sub-tropics (78% increase at > 20°latitude). These trends indicate that a global decline in coral recruitment has occurred since 1974, and the persistent reduction in the densities of recruits in equatorial latitudes, coupled with increased densities in subtropical latitudes, suggests that coral recruitment may be shifting poleward.

Vulnerability of global coral reef habitat suitability to ocean warming, acidification and eutrophication

“…An increase in habitat suitability in relation to SST is confirmed, for example, by increasing growth rate of massive Porites along a latitudinal gradient in Western Australia (Cooper, O’Leary, & Lough, 2012) and by previous model studies (Couce et al., 2013; Descombes et al., 2015). This trend is also confirmed by a decline in coral recruitment in tropical waters accompanied by an increase in subtropical waters becoming warmer (Price et al., 2019). However, large‐scale bleaching events that occurred in the GBR and in the Caribbean over the last decades (Berkelmans & Oliver, 1998; Eakin et al., 2010; Hughes, Anderson, et al, 2018; Hughes, Kerry, et al, 2018; Hughes et al., 2017; McWilliams, Côté, Gill, Sutherland, & Watkinson, 2005) indicate that temperature is not the only factor responsible for coral bleaching.…”

Idea Paper: Tracking the distribution of accretive reef communities across the Kuroshio region

“…Paleontological records seem to empirically support the possibility of equatorial decline (Kiessling, Simpson, Beck, Mewis, & Pandolfi, 2012) and poleward expansion (Veron, 1992) of reef corals. Furthermore, and despite a global decline in coral recruitment since 1974 (Price et al, 2019), the persistent reduction in the densities of recruits in equatorial latitudes coupled with increased densities in sub‐tropical latitudes suggest that coral recruitment may also be shifting poleward (Price et al, 2019). In this context, high latitude areas are hypothesized to constitute refuge habitats for endangered tropical taxa as climate changes (Beger, Sommer, Harrison, Smith, & Pandolfi, 2014), especially in areas with strong poleward currents that encourage dispersion like the Kuroshio region (Kumagai et al, 2018).…”

Welcome to the jungle: Algal turf negatively affects recruitment of a Caribbean octocoral

“…Recruitment dynamics play a critical role in structuring and maintaining diversity in communities, and in the resilience of populations to disturbances (Warner and Chesson, 1985;Caley et al, 1996;Wright, 2002). This is especially evident for sessile organisms, such as plants and benthic invertebrates, where variation in recruitment success is essential to recovery from disturbance and impacts adult population dynamics and spatial distributions and (Gaines and Roughgarden, 1985;McGuinness, 1996;Crawley, 2000;Price et al, 2019). On Caribbean coral reefs the abundance of scleractinian corals has been decreasing for decades as a consequence of reduced recruitment in concert with bleaching events, hurricanes, and disease outbreaks (Goreau et al, 1998;Gardner et al, 2005;McWilliams et al, 2005;Price et al, 2019).…”

“…This is especially evident for sessile organisms, such as plants and benthic invertebrates, where variation in recruitment success is essential to recovery from disturbance and impacts adult population dynamics and spatial distributions and (Gaines and Roughgarden, 1985;McGuinness, 1996;Crawley, 2000;Price et al, 2019). On Caribbean coral reefs the abundance of scleractinian corals has been decreasing for decades as a consequence of reduced recruitment in concert with bleaching events, hurricanes, and disease outbreaks (Goreau et al, 1998;Gardner et al, 2005;McWilliams et al, 2005;Price et al, 2019). Just as the decline in scleractinians is an inevitable consequence of failed recruitment, successful recruitment must have been essential to the increased prevalence of other taxa such as sponges and octocorals (Norström et al, 2009;Ruzicka et al, 2013;Lenz et al, 2015;Edmunds and Lasker, 2016;Sánchez et al, 2019).…”