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We investigated spatial patterns of synchrony among coral reef fish populations and environmental variables over an eight-year period on the Great Barrier Reef, Australia. Our aims were to determine the spatial scale of intra- and interspecific synchrony of fluctuations in abundance of nine damselfish species (genus Pomacentrus) and assess whether environmental factors could have influenced population synchrony. All species showed intraspecific synchrony among populations on reefs separated by ≤100 km, and interspecific synchrony was also common at this scale. At greater spatial scales, only four species showed intraspecific synchrony, over distances ranging from 100–300 km to 500–800 km, and no cases of interspecific synchrony were recorded. The two mechanisms most likely to cause population synchrony are dispersal and environmental forcing through regionally correlated climate (the Moran effect). Dispersal may have influenced population synchrony over distances up to 100 km as this is the expected spatial range for ecologically significant reef fish dispersal. Environmental factors are also likely to have synchronized population fluctuations via the Moran effect for three reasons: (1) dispersal could not have caused interspecific synchrony that was common over distances ≤100 km because dispersal cannot link populations of different species, (2) variations in both sea surface temperature and wind speed were synchronized over greater spatial scales (>800 km) than fluctuations in damselfish abundance (≤800 kin) and were correlated with an index of global climate variability, the El Niño-Southern Oscillation (ENSO), and (3) synchronous population fluctuations of most damselfish species were correlated with ENSO; large population increases often followed ENSO events. We recorded regional variations in the strength of population synchrony that we suspect are due to spatial differences in geophysical, oceanographic, and population characteristics, which act to dilute or enhance the effects of synchronizing mechanisms. We conclude that synchrony is common among Pomacentrus populations separated by tens of kilometers but less prevalent at greater spatial scales, and that environmental variation linked to global climate is likely to be a driving force behind damselfish population synchrony at all spatial scales on the Great Barrier Reef. [ABSTRACT FROM AUTHOR]

Assesses the changes in reef assemblages of corals and fishes following a tropical cyclone in the Great Barrier Reef, Queensland. Decrease of mean coral cover due to the cyclone; Abundance and species richness of adult damselfish assemblages; Magnitude and spatial extent of cyclonic storm damage to coral reefs.

The dose-response relationship for hepatic 7-ethoxyresorufin-O-deethylase (EROD) induction in barramundi (Lates calcarifer) was examined under controlled laboratory conditions for 15 d using farm-reared barramundi. These results were compared with EROD activity measured in barramundi collected from two rivers catchments (impacted and nonimpacted) in northern Queensland, Australia. Barramundi were dosed by intraperitoneal injection with a known cytochrome P4501A (CYP1A) inducer, beta-naphthoflavone (beta-NF), at 5, 10, and 50 mg kg(-1) using two controls: A vehicle control (corn-oil injected) and an experimental control (no injection). The EROD induction occurred within 4 h in the 5, 10, and 50 mg beta-NF kg(-1) exposures, reaching mean maximum activities of 88.6 (+/-51.9), 85.5 (+/-91.7), and 149.1 (+/-106.4) pmol min(-1) mg protein(-1), respectively. Mean EROD activities remained low in the corn-oil controls (2.1+/-1.8 pmol min(-1) mg protein(-1)) and experimental controls (5.3+/-4.4 pmol min(-1) mg protein(-1)) throughout the study. Barramundi demonstrated a rapid response curve, which was dose dependent (50 > 10 > 5 mg beta-NF kg(-1)) and decreased progressively over time from induction. Measurement of total cytochrome P450 content (nmol mg protein(-1)) was not dose dependent. The EROD activities from field-collected barramundi from the Johnstone River (impacted) and Olive River (nonimpacted) suggest exposure to low-level contaminants in the Johnstone River fish only. With more controlled laboratory and field studies, barramundi have the potential to become a major indicator species in assessing exposure to environmental contaminants in coastal areas throughout northern Queensland, Australia.