SynopsisA synthesis of ethnobiological, behavioral and physical oceanographic information leads to the conclusion that temperate zone models of reproductive strategy are inapplicable to many fishes of the coastal tropics. Intense predation appears to exert heavy selection pressure on fishes that spend their adult lives in coral, mangrove or tropical seagrass communities. Many exhibit spawning behaviors and spawn at times and locations that favor the transport of their pelagic eggs and pelagic larvae offshore wherc predation is reduced. This creates a countervailing selection pressurethe need to return the larvae to shallow water once they are ready to colonize their post-larval habitats. Accordingly, spawning is often concentrated at times of the year when prevailing winds or currents are at their weakest, thereby reducing the transport of larvae long distances from where they originated. Spawning is also concentrated in thc vicinity of nearshore gyres which similarly favor the ultimate return of the larvae to their natal area. Among these species, therefore, offshore larval dispersal does not seem to be an adaptation for dispersal of the species, but rather an evolutionary response to intense predation pressure in the adult habitats. Lunar reproductive periodicity is more common among these species than has previously been recognized, and is one of the strategies employed to enhance the offshore flushing of eggs and larvae.* This paper forms part of the proceedings of a mini-symposium convened at
Key Words marine protected areas, customary marine tenure, Pacific Island conservation s Abstract Twenty-five years ago, the centuries-old Pacific Island practice of community-based marine resource management (CBMRM) was in decline, the victim of various impacts of westernization. During the past two decades, however, this decline has reversed in various island countries. Today CBMRM continues to grow, refuting the claim that traditional non-Western attitudes toward nature cannot provide a sound foundation for contemporary natural resource management. Limited entry, marine protected areas, closed areas, closed seasons, and restrictions on damaging or overly efficient fishing methods are some of the methods being used. Factors contributing to the upsurge include a growing perception of scarcity, the restrengthening of traditional village-based authority, and marine tenure by means of legal recognition and government support, better conservation education, and increasingly effective assistance, and advice from regional and national governments and NGOs. Today's CBMRM is thus a form of cooperative management, but one in which the community still makes and acts upon most of the management decisions.
We describe five examples of how, by ignoring fishers’ ecological knowledge (FEK), marine researchers and resource managers may put fishery resources at risk, or unnecessarily compromise the welfare of resource users. Fishers can provide critical information on such things as interannual, seasonal, lunar, diel, tide‐related and habitat‐related differences in behaviour and abundance of target species, and on how these influence fishing strategies. Where long‐term data sets are unavailable, older fishers are also often the only source of information on historical changes in local marine stocks and in marine environmental conditions. FEK can thus help improve management of target stocks and rebuild marine ecosystems. It can play important roles in the siting of marine protected areas and in environmental impact assessment. The fact that studying FEK does not meet criteria for acceptable research advanced by some marine biologists highlights the inadequacy of those criteria.
This study confirms reports by fishermen of a large and predictable aggregation of whale sharks Rhincodon typus along the Belize Barrier Reef. Although whale sharks are rarely sighted at this location during most of the year, we counted as many as 25 whale sharks in a 50 m diameter area on 1 occasion and tagged 6 sharks during a 22 min period on another. The whale shark aggregation coincides seasonally and temporally with a multispecies reef-fish spawning aggregation at a reef promontory, Gladden Spit, at sunset, during the full and last-quarter moon periods of April and May each year. We report here, for the first time, that whale sharks feed on the freshly released spawn of cubera snappers Lutjanus cyanopterus and dog snappers L. jocu (Lutjanidae), and have documented the phenomenon with still and digital video photography of hundreds of feeding events. There is consensus locally that this remarkable interaction is in need of immediate protection from overfishing of snappers and unregulated tourism development. Our continued investigations are providing management recommendations for a new marine reserve at the site.
Per unit weight, marine protozoa excrete dissolved phosphorus one to two orders of magnitude faster than marine microcrustaceans and several orders of magnitude faster than marine macrofauna.Protozoa may therefore be responsible for a major fraction of faunal nutrient excretion even though present only as a minor fraction of the faunal biomass.Regeneration of dissolved inorganic phosphate from organic detritus proceeds faster and more completely in the presence of bacteria and ciliates or colorless flagellates than in the presence of bacteria alone. An increased consumption of organic detritus in the presence of protozoa is performed by bacteria, which are kept in a prolonged state of "physiological youth" by grazing protozoa. Present results indicate that it is the protozoa that produce, via excretion, the greater regeneration of nutrients from organic detritus. By constituting a nutrient source for protozoa, bacteria are indirectly involved in this increased regeneration.
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