Recent Region-wide Declines in Caribbean Reef Fish Abundance

Abstract

Profound ecological changes are occurring on coral reefs throughout the tropics, with marked coral cover losses and concomitant algal increases, particularly in the Caribbean region. Historical declines in the abundance of large Caribbean reef fishes likely reflect centuries of overexploitation. However, effects of drastic recent degradation of reef habitats on reef fish assemblages have yet to be established. By using meta-analysis, we analyzed time series of reef fish density obtained from 48 studies that include 318 reefs across the Caribbean and span the time period 1955-2007. Our analyses show that overall reef fish density has been declining significantly for more than a decade, at rates that are consistent across all subregions of the Caribbean basin (2.7% to 6.0% loss per year) and in three of six trophic groups. Changes in fish density over the past half-century are modest relative to concurrent changes in benthic cover on Caribbean reefs. However, the recent significant decline in overall fish abundance and its consistency across several trophic groups and among both fished and nonfished species indicate that Caribbean fishes have begun to respond negatively to habitat degradation.

Rapid Effects of Marine Reserves via Larval Dispersal

“…Worldwide degradation of coral reefs has been well documented [33][34][35], and although the effects of global climate change (and associated effects of bleaching, acidification, and disease) are thought to be the major drivers, local effects related to human population density (e.g., destructive fishing, pollution) exacerbate the destruction to coral habitats [36][37][38][39][40][41]. Decreased coral cover can result in declines to the abundance, biomass, and diversity of coral reef fishes [42][43][44][45][46], but most evidence is for small fishes occupying lower trophic levels, while that for predatory fishes is less clear. For example, Wormald [47] found varying relationships (positive and negative) of coral volume on two snappers (schoolmaster and lane snapper, respectively) while Graham et al [43] was unable to detect a relationship between coral loss and fishes larger than 20 cm.…”

Patrones a gran escala del reclutamiento de coral en Isla Mona, Puerto Rico: evidencia de una trayectoria transitoria de comunidad después del blanqueamiento y mortalidad coralino masivo

“…Mona's isolated reef systems have followed a transitional trajectory leading to a major phase shift favoring macroalgae and non-reef building, ephemeral coral taxa. Lack of coral reef recovery following major disturbances, including climate change, has been a concerning phenomenon across the Caribbean (McClanahan & Muthiga, 1998; Aronson et al., 2002;Gardner et al, 2003;Rogers, 2013), and might have significant long-term ecological and socio-economic consequences (Buddemeier et al, 2008;Paddack et al, 2009;Lane et al, 2013), including regionalscale declines in coral cover and reef complexity (Alvarez-Flip et al, 2011). We suggest that lack of net recovery in remote Mona Island's reefs could be the combined result of several mechanisms involving climate change-related post-bleaching mass coral mortality, chronic YBD disease outbreaks, rapid substrate dominance and out-competition of remnant corals by brown unpalatable macroalgae, declining herbivory due to long-term fishing impacts, lack of D. antillarum population recovery, altered microbial communities associated with crustose coralline algae (CCA) that may negatively affect coral larval settlement cues, and Mona Island's reefs limited connectivity to other reef systems which highly limits potential successful larval recruitment from other locations.…”

Transitional states in marine fisheries: adapting to predicted global change

“…These losses were substantial, affecting both small species and small size classes of larger fishery target species . Because reef fish can be exceptionally long-lived (Choat & Robertson 2002), considerable time lags are expected between the loss of live coral, collapse of the reef structure and declines in remnant fish biomass Paddack et al 2009). We hypothesize that a positive feedback between losses of coral and losses of fish will generate a higher risk of species extinction among reef-fish communities than elsewhere.…”