Chronic overfishing continues throughout most of the Caribbean and fish stocks

Chronic overfishing continues throughout most of the

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densities or extend to its former depth range. Chronic overfishing continues throughout most of the Caribbean, and fish stocks remain severely depleted in most regions. 5.7.2. The Great Barrier Reef Australia’s Great Barrier Reef system is in relatively good condition, due in part to its large size, relative isolation, and a long-term investment by governments in reef science and management. Unusually among coral reef nations, Australia has a low population density and is relatively very wealthy. However, the Great Barrier Reef is showing symptoms of change and increased vulnerability that warrant concern. Fisheries that flourished following European colonization (e.g., sea cucumbers, pearl shell, Trochus snails, dugongs, whales, and turtles) have collapsed or are no longer commercially viable. Runoff of sediment and nutrients from land has increased greatly since the mid-1800s, affecting nearshore reefs and sea grass beds. In the past 40 years, large-scale outbreaks of crown-of-thorns starfish, Acanthaster planci , have occurred three times, reducing coral cover on roughly 200 reefs (out of the total number of 2,900 comprising the Great Barrier Reef system). Major bleaching events from climate change struck the Great Barrier Reef 20
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in 1998 (during the same El Nino event that damaged reefs elsewhere in the western Pacific and Indian Ocean) and again in 2002, damaging close to 600 individual reefs. Coral cover remains low on reefs affected by runoff, crown-of-thorn starfish, and coral bleaching. Rapid growth in recreational and commercial fishing has reduced the biomass of targeted fish species by more than 80% in heavily fished inshore areas, compared to adjacent no-take reserves (Williamson, Russ, and Ayling 2004). Herbivorous fishes remain abundant and are protected by regulations on fishing gear. From July 1, 2004, the proportion of the Great Barrier Reef Marine Park closed to fishing (i.e., no-take fishing reserves) was increased from 5% to 33%, encompassing at least 20% of all major habitat types (Fernandes et al. 2005). Simultaneously, a new ten-year program, the Reef Water Quality Protection Plan, was formulated in an attempt to curb future nutrient and sediment runoff. These management changes exemplify a new ecosystem-based approach that arose from a shift in perceptions about the increasing risks to the “once pristine” Great Barrier Reef. The changes in zoning were undertaken to build ecological resilience and to cope proactively with the risk associated with human population growth, rising fishing pressure, future bleaching events, and other uncertainties. Australia belatedly ratified the Kyoto Protocol in 2008, following a change of national government. 5. 8. Future Prospects 21
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Building the resilience of coral reefs to avoid phase shifts provides a new framework for preserving and managing these important ecosystems. There is growing awareness among reef managers of the functional role of fishes, the effects of overfishing on the dynamics of foodwebs, and the bottom-up influence of pollution. In particular, preserving
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