Profound ecological changes are occurring on coral reefs throughout the tropics, with marked coral cover losses and concomitant algal increases, particularly in the Caribbean region. Historical declines in the abundance of large Caribbean reef fishes likely reflect centuries of overexploitation. However, effects of drastic recent degradation of reef habitats on reef fish assemblages have yet to be established. By using meta-analysis, we analyzed time series of reef fish density obtained from 48 studies that include 318 reefs across the Caribbean and span the time period 1955-2007. Our analyses show that overall reef fish density has been declining significantly for more than a decade, at rates that are consistent across all subregions of the Caribbean basin (2.7% to 6.0% loss per year) and in three of six trophic groups. Changes in fish density over the past half-century are modest relative to concurrent changes in benthic cover on Caribbean reefs. However, the recent significant decline in overall fish abundance and its consistency across several trophic groups and among both fished and nonfished species indicate that Caribbean fishes have begun to respond negatively to habitat degradation.

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Many fishes, including groupers, produce sounds associated with mating behavior; recording and analyzing the occurrence of these sounds can provide long time-series records of grouper use of spawning habitat. Red hind Epinephelus guttatus sound production was recorded on spawning aggregation sites off the west coast of Puerto Rico and at Mona Island, Puerto Rico. Audiovideo recordings were used to identify a species-specific sound produced by male red hind, most commonly during territorial patrols, and also during interactions with females. This sound is low in frequency (50 to 400 Hz) and consists of a series of pulses repeated at a variable rate. Long-term acoustic recorders were placed off the west coast of Puerto Rico at Abrir La Sierra and at Mona Island to record the timing of red hind sound production from January through March. Red hind sounds were detected at all times of the day, with peaks in sound production just before dusk. Monthly peaks in sound production were evident in each time series, but the monthly peak in sound production at Abrir La Sierra was 6 d later than the peak at Mona Island, suggesting that the timing of spawning of these 2 aggregations, while on a lunar schedule, was not broadly synchronized during this time period. This research lays the groundwork for both long-term monitoring and mapping of red hind spawning sites that will be useful for managing spawning aggregations, especially in remote areas.KEY WORDS: Red hind · Spawning aggregation · Sound production · Mona Island · Puerto Rico Resale or republication not permitted without written consent of the publisherRed hind were recorded by Tavolga (1968) and Fish & Mowbray (1970) as part of a survey of sounds produced by fishes. In their studies, red hind were found to produce low-frequency pulsed sounds with most of the energy below 200 Hz. These sounds were recorded from captive specimens, and were likely defensive sounds associated with being handled. It is possible that the sounds recorded in captivity were not representative of the sounds that might be produced by aggregating red hind, as has been observed for many sciaenids. The goals of the present study were to record and characterize sounds from wild red hind on known spawning aggregation sites and to document long-term patterns of sound production from daily to monthly time scales at 2 sites separated by deep water in Puerto Rico during the red hind spawning season. MATERIALS AND METHODS Underwater video recordings.Underwater audiovideo recordings of red hind behavior were conducted by SCUBA divers at Mona Island, Puerto Rico, using Sony PC-110 and SR80 video cameras. Each camera was housed in an Ocean Images underwater video housing and connected to an HTI 96-min hydrophone (sensitivity 2 Hz to 37 kHz; -164 ± 1 dBV µPa -1 ). Recordings were made from January to March 2007 during dives from 16:00 h through dusk. The video recordings were used to record red hind behavior and associated sound production. The audio portion of the recordings was only used for des...

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