The FISHSCALE Action reveals how biodiverse and ecologically complex reef fish communities are organised by their environment and impacted by humans. The research catalogues the trophic, behavioural, or morphological characteristics of reef fish species observed across the Pacific (to consider their ecological niches), investigates the natural bounds in how these fishes are distributed across reefs (and ecoregions), and describes how natural ecological patterns are disrupted by local human impacts. For species-rich but data-poor coral reef fisheries, ecosystem-based management is the dominant paradigm. However, its operationalisation is hindered by a lack of information on how environmental processes determine the natural organisation of coral reefs across scales in space and time, and then how that organisation is affected by human impacts. Understanding how natural and human drivers interact to determine ecological organisation on the reef is critical to the local, context specific and spatially explicit application of ecosystem assessments for management. For example, identifying and prioritizing management areas based on recovery potential and degree of depletion from an unimpacted baseline state.
Using long-term coral reef monitoring data across 35 central western Pacific islands, the research used Bayesian methods to model ecological patterns relating to biophysical forcing across scales. It quantified how the presence of local human impacts disrupt those biophysical relationships. The research revealed how a classic theory of ecological depth zonation — recognized more than six decades ago as a fundamental structuring force of coral reef communities – is limited for predicting ecological dynamics where human impacts are present on contemporary reefs. The Action identifies contemporary ecological baselines on reefs, defined from remote reefs considered to be among the most intact and near-pristine remaining and least exposed to local human impacts. Climate change and local human impacts are worsening and increasing ecological uncertainty. This uncertainty limits our capacity to make effective ecological predictions from which to base decisions of risk-control management, conservation, policy, and governance. To better deal with this uncertainty, we can measure change from revised contemporary baselines as now more pragmatic points of reference. So, the research explored the ecological impacts of contemporary marine heatwave conditions at one of the last remaining ‘pristine’ coral reef systems on earth. It examines the effects of extreme heat stress on reef fish assemblages at a historically highly productive island in the Pacific Ocean to quantify the ecological effects of climate change in the absence of confounding local human impacts.
The broad objectives: 1) Collate a trait database for reef-fishes observed in NOAA’s long-term coral reef monitoring program across the Pacific; 2) Understand how cross-scale biophysical processes determine the distribution of reef-fish assemblages (across reefs, islands and ecoregions); 3) Determine how local human populations disrupt natural patterns governing the ecological organisation of reef fishes; 4) Identify ‘contemporary ecological baselines’ from remote reefs without local human impacts but exposed to climate change.
