Advantages of using crest nets to sample presettlement larvae of reef fishes in the Caribbean Sea

Identifying the spatial and temporal patterns of larval fish supply and settlement is a key step in understanding the connectivity of meta-populations (Sale et al., 2005). Because of the potentially dispersive nature of the pelagic larval phase of most reef fishes, tracking cohorts from hatching to settlement is extremely difficult (but see Jones et al., 1999). However, for many studies it is sufficient to sample larvae immediately before settlement. Many coral reef fish species use mangrove and seagrass beds as nursery habitats (Nagelkerken et al., 2001; Mumby et al., 2004) and larvae of these species must pass over the reef crest in order to arrive at their preferred settlement habitats. The ability to sample this new cohort of larval fishes provides opportunities for researchers to explore the intricacies of the transition from larva to juvenile (Searcy and Sponaugle, 2001). Quantifying the potential settlers also provides valuable information about the spatial and temporal supply of presettlement larvae (Victor, 1986). Therefore a number of larval sampling methods were developed, one of which is the use of crest nets (Dufour and Galzin, 1993).

Spillover of commercially valuable reef fishes from marine protected areas in Guam, Micronesia

Does adult spillover (movement out of marine protected areas [MPAs]) of fish create a net export of fish biomass from MPAs to adjacent fished reefs? Biomass of five commercial reef fish species was estimated by visual census within and outside three MPAs in Guam, Micronesia. For most species and sites, biomass was significantly higher within the MPAs than in adjacent fished sites. Movement of fishes into and out of the MPAs was determined by markrecapture experiments, in which fishes were tagged both inside and outside of MPAs. Four out of five species studied showed little or no net movement out of MPAs. However, the orangespine surgeonfish (Naso lituratus) showed a net spillover of biomass from all three MPAs; 21.5% of tagged individuals and 29% of the tagged biomass emigrated from MPAs. Patterns of spillover were strongly influenced by physical habitat barriers, such as channels, headlands, or other topographic features. MPAs that are physically connected by contiguous reef structures will likely provide more spillover to adjacent fished sites than those that are separated by habitat barriers. This study demonstrates that MPAs can enhance export of fish biomass to fished areas, but spillover is species-specific and depends on factors such as species size and mobility.

Reference area as a factor affecting potential yield estimates of coral reef fishes

A compilation of 48 estimates of Caribbean and Pacific coral reef fish catches, ranging from 0.1 to 23.7 t km super(-2) year super(-1), obtained from coral reef areas ranging from 0.1 to nearly 4-10 super(5) km super(2), are used to show that observed catches, and hence potential yield estimates, depend strongly on the reference area. The implications for coral reef fisheries assessments are discussed.

Growth and mortality of Ctenochaetus striatus, Stegastes nigricans and Sargocentron microstoma in Tiahura Reef, Moorea Island, French Polynesia

Growth parameters and mortality rates were estimated from length-frequency data sampled in 1982, using the FiSAT software, for three coral reef fish species, the surgeon fish (Ctenochaetus striatus), the damselfish (Stegastes nigricans) and the squirrel fish (Sargocentron microstoma) in Tiahura Reef, Moorea Island, French Polynesia.

How fresh is too fresh?: the live reef food fish trade in eastern Indonesia

Although the live reef food fish trade has become an increasingly "hot" topic in the environmental press in recent months, many of the sources reporting on this practice have tended to focus on issues related to the rampant use of sodium cyanide in the trade, rather than the more pressing matter of the looming potential for overexploitation engendered by this practice. Presented in this article is a brief overview of the live reef food fish trade as it is practiced in eastern Indonesia covering the methods used and economics, geographic extent and numerous deleterious effects of the fishery.

An ABC guide to coral reef fisheries in southwest Sulawesi, Indonesia

The article serves as anecdotal directory to the major fisheries, techniques and problems faced by the fishers in the coral reef area of Spermonde Archipelago, Southwest Sulawesi, Indonesia.

Length-weight relationships of coral reef fishes from the Alacran Reef, Yucatan, Mexico

Length-weight relationships were computed for 42 species of coral reef fishes from 14 families from the Alacran Reef (Yucatan, Mexico). A total of 1 892 individuals was used for this purpose. The fish species were caught by different fishing techniques such as fishhooks, harpoons, gill and trawl nets. The sampling period was from March 1998 to January 2000.

Coral reef resources of East Africa, Kenya, Tanzania and the Seychelles

Coral reefs are widespread along the east African coast and Seychelle islands. Their roles in island building and coastal protection are often underestimated, they are also important fishery habitats and major tourist attractions. The east African marine fishery production, estimated at 1.4-4.9 tonnes per km super(2), is principally a result of artisanal fishing. Siltation, trampling, and destructive fishing methods are the main cause of coral reef degradation along the east African coast and associated islands. Legislation has been implemented to protect coral reefs by establishing marine parks and reserves. However, poaching and anchor damage are widespread on these protected reefs. Legislative provision to increase the benefit to fishing communities may reduce poaching. The establishment of exclusive nature reserves may be one way to ensure preservation of some coral reefs in the region.

A taste for live fish: Hong Kong's live reef fish market

This paper provides an overview of the live reef fish market in Hong Kong, which accounted for about 15,000 t/yr (US$345 million) of live fish imports in the mid-1990s. The live fish trade has spawned a number of management concerns, including overfishing of highly-valued species, use of destructive fishing techniques and human health risks. Recent actions by the Hong Kong government in response to these concerns are reported and possible region-wide initiatives are briefly discussed in this paper.