Search

Peaks in the reproduction of coral reef fish in equatorial regions are hypothesised to usually coincide with periods of the year when winds are weaker, presumably to minimise larval transport and maximise recruitment. The annual patterns of spawning of four species of reef fish in the central Philippines (9.201355°N, 123.327421°E) were investigated over 11-22 months. On an annual basis, the study area experiences two windy monsoon seasons and two monsoon transition periods when winds are weaker. Protracted breeding seasons were evident, but the timing of inferred spawning peaks varied among species. Spawning peaks of Pterocaesio pisang (Caesionidae) coincided with the first monsoon transition period of the year (April-June) and the north-east monsoon (November-March). Caesio caerulaurea (Caesionidae) showed a spawning peak during the south-west monsoon (July-September) extending to the following monsoon transition period (October). In Naso minor (Acanthuridae), an annual pattern was difficult to discern due to insufficient data, but there was some suggestion of higher spawning activity during the northeast monsoon. Spawning in Pomacentrus moluccensis (Pomacentridae) was inferred to occur year-round except during the north-east monsoon. These results suggest that conditions favourable to the survival of pelagic larvae are not restricted to monsoon transition periods. Alternatively, the results indicate direct or indirect effects of temperature, rainfall, wind or wave action on the reproduction of adults. Variable annual patterns of reproduction in reef fish pose a further challenge to fisheries management interventions in the region. This variability is possibly being influenced in complex ways by environmental factors that change with the monsoons., Introduction Patterns of reproduction in coral reef fish are remarkably diverse and highly variable at several temporal scales (Munro et al. 1973; Thresher 1984; Robertson 1991; Sadovy 1996; Claydon et [...]

It has become almost paradigmatic in the coral reef literature that fishing-induced reductions of parrotfish abundance cause benthic phase shifts from coral to macroalgal dominance. This study examined the alternatives of top-down control of the benthos by parrotfish density and bottom-up control of parrotfish density by the benthos at four Philippine islands in a long-term (7.5-30 years) 'natural experiment'. No-take marine reserves (NTMRs) demonstrated that fishing reduced parrotfish density significantly at two islands (Sumilon, Mantigue), but not significantly at two other islands (Apo, Selinog). There was no evidence that cover of hard coral decreased, nor macroalgal cover increased, in fished areas relative to NTMRs, no evidence that parrotfish density affected hard coral cover significantly, and thus no evidence of top-down, fishing-induced benthic phase shifts at all four islands. There was, however, compelling evidence that benthos (cover of dead substrata and hard coral) exerted strong bottom-up control on parrotfish density. This bottom-up control was demonstrated most clearly by major environmental disturbances (e.g. typhoons, coral bleaching) that changed benthic habitat and, subsequently, parrotfish density. As hard coral cover declined (and cover of dead substratum increased), parrotfish density increased and vice versa. This response occurred in both major parrotfish feeding guilds (scrapers and excavators). This long-term study on heavily fished coral reefs suggests that the benthos drives the parrotfish, not the other way around. The paradigm of fishing-induced benthic phase shifts may not apply to all coral reefs at all times. Multiple drivers of benthic change on coral reefs should always be considered. Electronic supplementary material The online version of this article (doi:10.1007/s00227-015-2728-3) contains supplementary material, which is available to authorized users., Author(s): Garry R. Russ[sup.1] [sup.2] , Sarah-Lee A. Questel[sup.1] [sup.2] , Justin R. Rizzari[sup.1] [sup.2] , Angel C. Alcala[sup.3] Author Affiliations: (1) College of Marine and Environmental Sciences, James Cook [...]

Abstract--The contribution of the no-take marine reserve at Apo Island, Philippines, to local fishery yield through 'spillover' (net export of adult fish) was estimated. Spatial patterns of fishing effort, yield, [...]

Abstract--Spatial variation in demographic parameters of the red throat emperor (Lethrinus miniatus) was examined among 12 coral reefs in three geographic regions (Townsville, Mackay, and Storm Cay) spanning over 3° [...]