Social–environmental drivers inform strategic management of coral reefs in the Anthropocene

Without drastic efforts to reduce carbon emissions and mitigate globalized stressors, tropical coral reefs are in jeopardy. Strategic conservation and management requires identification of the environmental and socioeconomic factors driving the persistence of scleractinian coral assemblages—the foundation species of coral reef ecosystems. Here, we compiled coral abundance data from 2,584 Indo-Pacific reefs to evaluate the influence of 21 climate, social and environmental drivers on the ecology of reef coral assemblages. Higher abundances of framework-building corals were typically associated with: weaker thermal disturbances and longer intervals for potential recovery; slower human population growth; reduced access by human settlements and markets; and less nearby agriculture. We therefore propose a framework of three management strategies (protect, recover or transform) by considering: (1) if reefs were above or below a proposed threshold of >10% cover of the coral taxa important for structural complexity and carbonate production; and (2) reef exposure to severe thermal stress during the 2014–2017 global coral bleaching event. Our findings can guide urgent management efforts for coral reefs, by identifying key threats across multiple scales and strategic policy priorities that might sustain a network of functioning reefs in the Indo-Pacific to avoid ecosystem collapse

Changes in life history and ecological characteristics of coral reef fish catch composition with increasing fishery management

Abstract  Length, life history and ecological characteristics of landed fish communities were studied over a 10-year period to test theories of fishing disturbance during a time of increased gear and closure management in heavily utilised fisheries. It was predicted that with greater management restrictions: (1) the earliest and fastest responses in the fishery will be seen in those species with faster turnovers, or relatively lower vulnerabilities to fishing; (2) the fishery would transition to a landed catch with higher mean trophic levels, and greater mean body lengths. In addition, the removal of a non-selective, small-mesh seine nets should benefit the catch of gears that previously had the greatest species selectivity overlap with the seine net. Many predictions were supported, although maximum lengths and lengths at maturity responded more rapidly than anticipated. The response to eliminating the non-selective seine net was a more rapid increase in sizes caught by gears with a larger overlap in size (hook and lines) than species selectivity (gill nets). The simultaneous comparison of management systems over time indicates that open-access fishing grounds can benefit from restrictions imposed in adjacent fishing grounds. The study indicated that multi-species coral reef fisheries management objectives of maximising yields, as well as maintaining the fish community's life-history diversity, require management trade-offs that balance local socio-economic and biodiversity needs

Socioeconomic factors that lead to overfishing in small-scale coral reef fisheries of Papua New Guinea

The coral reefs of Papua New Guinea are among the most species diverse in the world, support an important artisanal fishery, but lack an effective national conservation programme. Increased commercialization, population growth, promotion of fisheries development projects, and the live reef food fish trade are expected to increase demand for the country's reef fish. This paper examines how socioeconomic factors affect the condition of the artisanal multi-species coral reef fishery in six sites in Papua New Guinea. Catch characteristics such as diversity, trophic level and body size by landing site were examined along a fishing pressure gradient. Both exogenous factors such as markets and endogenous factors such as fishing pressure were related to the condition of fish catch. In general, the trophic level and lengths of fish captured in Papua New Guinea were relatively high, but were reduced on reefs with high fishing effort near fish markets. Fisheries showed signs of depletion above c. 25 fishing trips per km2 per day and the proximity of markets was a better indicator of overfishing than human population size. A cross-scale approach to fisheries management is required in Papua New Guinea to coordinate decentralized local management, limit the intrusion of extractive enterprises, and develop policies that seek to minimize exogenous pressures on marine resources