Time filter

Source Type

Townsville, Australia

Chollett I.,University of Exeter | Chollett I.,University of Queensland | Muller-Karger F.E.,University of South Florida | Heron S.F.,NOAA Coral Reef Watch | And 4 more authors.
Marine Pollution Bulletin | Year: 2012

Recent changes in ocean temperature have impacted marine ecosystem function globally. Nevertheless, the responses have depended upon the rate of change of temperature and the season when the changes occur, which are spatially variable. A rigorous statistical analysis of sea surface temperature observations over 25. years was used to examine spatial variability in overall and seasonal temperature trends within the wider Caribbean. The basin has experienced high spatial variability in rates of change of temperature. Most of the warming has been due to increases in summer rather than winter temperatures. However, warming was faster in winter in the Loop Current area and the south-eastern Caribbean, where the annual temperature ranges have contracted. Waters off Florida, Cuba and the Bahamas had a tendency towards cooling in winter, increasing the amplitude of annual temperature ranges. These detailed patterns can be used to elucidate ecological responses to climatic change in the region. © 2012 Elsevier Ltd.

Bauman A.G.,James Cook University | Feary D.A.,University of Technology, Sydney | Heron S.F.,NOAA Coral Reef Watch | Heron S.F.,James Cook University | And 2 more authors.
Marine Pollution Bulletin | Year: 2013

Multivariate analysis revealed distinct sub-regional coral communities among the southern Persian Gulf, Strait of Hormuz, and Gulf of Oman. Differences in community structure among locations were associated with considerable spatial heterogeneity in oceanic conditions, and strong directional environmental gradients. Despite clear community differences, considerable changes to coral community structure have occurred throughout the northeastern Arabian Peninsula as compared with previous studies. The most dramatic of these are the apparent changes from Acropora dominated to poritid and faviid dominated communities, particularly in the southern Persian Gulf and Strait of Hormuz. Although temperature and salinity have previously been cited as the major environmental factors structuring coral communities around the region, additional environmental parameters, including chlorophyll- a, surface currents and winds are shown to be important in structuring reef communities throughout the northeastern Arabian Peninsula. © 2012 Elsevier Ltd.

Welch H.,James Cook University | Pressey R.L.,James Cook University | Heron S.F.,NOAA Coral Reef Watch | Heron S.F.,James Cook University | And 2 more authors.
Ecography | Year: 2016

Spatial management of the highly dynamic pelagic realm, and the highly mobile species it supports, requires dynamic processes to be incorporated into reserve design. To achieve this, planners need information on how these processes vary across space and time, and how this variation relates to species of conservation interest. This study presents a new method of quantifying variability that captures both between- and within-year changes in variables of interest. We applied this method to remotely-sensed chlorophyll-a in the Coral Sea to find five distinct regimes of variation that serve as surrogates for assemblages of species of conservation interest. We performed a gap analysis to determine protection of the regimes both internationally and nationally within Australia's network of marine reserves in the Coral Sea. We also identified key areas for protection within each regime, in terms of chlorophyll-a variability and species associations, and examined their protection status. Depending on conservation objectives, reserve systems that span multiple national jurisdictions and a rezoning of Australian national waters might be necessary to meet protection requirements for the regimes and for key areas within them. The current suspension and review of the Coral Sea Commonwealth Marine Reserve management plans and the recent proclamation of New Caledonia's as yet unzoned Coral Sea Nature Park offer planners an opportunity to incorporate dynamic processes into conservation planning for the Coral Sea. The method we present can be applied at other locations for time-series of any variable/s of interest, aiding the spatial management of dynamic features in both marine and terrestrial contexts. Ecography © 2016 Nordic Society Oikos

Anderson K.D.,James Cook University | Heron S.F.,NOAA Coral Reef Watch | Heron S.F.,James Cook University | Pratchett M.S.,James Cook University
Coral Reefs | Year: 2015

Reef-building corals are extremely sensitive to changing temperature regimes, such that sustained increases in ocean temperatures are generally expected to have negative effects on coral growth and survivorship. At high-latitude reefs, however, projected increases in ocean temperature may actually increase coral growth (relaxing constraints imposed by cool winter temperatures), though this will depend upon on the rate and extent of declines in aragonite saturation, which is already much lower at high latitudes. This study quantified linear extension rates of six scleractinian corals, Acropora yongei, Isopora cuneata, Pocillopora damicornis, Porites heronensis, Seriatoporahystrix, and Stylophora pistillata, at Lord Howe Island in 2010/11. Contemporary growth rates were compared to equivalent data collected in 1994/95. There was marked interspecific variation in growth rates, with A. yongei growing almost twice the rate of all other species. Temporal changes in annual growth also varied among species. Growth rates of both A. yongei and Pocillopora damicornis were 30 % of that recorded in 1994/95. However, growth rates of Porites heronensis had not changed. Declines in the growth rates of these branching species may be attributable to declines in aragonite saturation or increases in summertime temperatures above limits for optimal growth, but either way it appears that climate change is having negative effects on corals, even at subtropical locations. © 2014, Springer-Verlag Berlin Heidelberg.

Pollock F.J.,James Cook University | Pollock F.J.,Australian Institute of Marine Science | Lamb J.B.,James Cook University | Lamb J.B.,Australian Institute of Marine Science | And 9 more authors.
PLoS ONE | Year: 2014

In recent decades, coral reef ecosystems have declined to the extent that reefs are now threatened globally. While many water quality parameters have been proposed to contribute to reef declines, little evidence exists conclusively linking specific water quality parameters with increased disease prevalence in situ. Here we report evidence from in situ coral health surveys confirming that chronic exposure to dredging-associated sediment plumes significantly increase the prevalence of white syndromes, a devastating group of globally important coral diseases. Coral health surveys were conducted along a dredging-associated sediment plume gradient to assess the relationship between sedimentation, turbidity and coral health. Reefs exposed to the highest number of days under the sediment plume (296 to 347 days) had two-fold higher levels of disease, largely driven by a 2.5-fold increase in white syndromes, and a six-fold increase in other signs of compromised coral health relative to reefs with little or no plume exposure (0 to 9 days). Multivariate modeling and ordination incorporating sediment exposure level, coral community composition and cover, predation and multiple thermal stress indices provided further confirmation that sediment plume exposure level was the main driver of elevated disease and other compromised coral health indicators. This study provides the first evidence linking dredging-associated sedimentation and turbidity with elevated coral disease prevalence in situ. Our results may help to explain observed increases in global coral disease prevalence in recent decades and suggest that minimizing sedimentation and turbidity associated with coastal development will provide an important management tool for controlling coral disease epizootics.

Discover hidden collaborations