scholarly journals Recurrent coral bleaching in north-western Australia and associated declines in coral cover

2020 ◽  
Author(s):  
R. C. Babcock ◽  
D. P. Thomson ◽  
M. D. E. Haywood ◽  
M. A. Vanderklift ◽  
R. Pillans ◽  
...  
Keyword(s):  
Western Australia ◽  
Coral Bleaching ◽  
Coral Cover ◽  
North Western

scholarly journals Rapid increase in coral cover on an isolated coral reef, the Ashmore Reef National Nature Reserve, north-western Australia

2011 ◽  
Vol 62 (10) ◽  
pp. 1214 ◽  
Author(s):  
D. M. Ceccarelli ◽  
Z. T. Richards ◽  
M. S. Pratchett ◽  
C. Cvitanovic
Keyword(s):  
Coral Reef ◽  
Western Australia ◽  
Coral Cover ◽  
Taxonomic Composition ◽  
Coastal Pollution ◽  
Percent Cover ◽  
Community Recovery ◽  
Coral Communities ◽  
Coral Recovery ◽  
North Western

Against a background of coral reef ecosystem decline, understanding the propensity for coral communities to recover after acute disturbances is fundamental to forecasting and maintaining resilience. It may be expected that offshore reef ecosystems are less affected by anthropogenic disturbances compared with reefs closer to population centres, but that recovery may be slower on isolated reefs following disturbances. To test the hypothesis that community recovery is slow in isolated locations, we measured changes in coral cover and relative abundance of coral genera over a 4 year period (2005–09) at Ashmore Reef, north Western Australia, following severe bleaching. The percent cover of hard coral tripled, from 10.2% (±1.46 s.e.) in 2005 to 29.4% (±1.83 s.e.) in 2009 in all habitats (exposed and lagoonal) and depth zones (2–5 and 8–10 m), and the percent cover of soft corals doubled, from 4.5% (+0.63 s.e.) in 2005 to 8.3% (+1.4 s.e.) in 2009. Significant shifts in the taxonomic composition of hard corals were detected. Our results imply that coral recovery in isolated locations can occur rapidly after an initial delay in recruitment, presumably through the interacting effects of self-recruitment and reduced exposure to additive impacts such as coastal pollution.

Coral bleaching in turbid waters of north-western Australia

2017 ◽  
Vol 68 (1) ◽  
pp. 65 ◽  
Author(s):  
A. Lafratta ◽  
J. Fromont ◽  
P. Speare ◽  
C. H. L. Schönberg
Keyword(s):  
Thermal Stress ◽  
Western Australia ◽  
Large Scale ◽  
Coral Cover ◽  
Coral Community ◽  
Soft Corals ◽  
Hard Coral ◽  
Turbid Waters ◽  
Benthic Survey ◽  
North Western

We report severe bleaching in a turbid water coral community in north-western Australia. Towed still imagery was used for a benthic survey near Onslow in March 2013 to assess thermal stress in hard and soft corals, finding 51–68% of all corals fully bleached in 10–15-m water depth. Tabulate or foliaceous Turbinaria was the locally most abundant hard coral (46%), followed by massives such as faviids and poritids (25%) and encrusting coral (12%), thus over 80% of the local corals could be considered to be bleaching resistant. All coral groups were bleached in similar proportions (massive hard corals 51%<soft corals 60%<encrusting hard corals 62%<Turbinaria 62%<‘others’ 68%). NOAA data and environmental assessments suggest previous recurrent thermal stress throughout the last 10 years in the study area. On the basis of these records this stress apparently changed the community structure from bleaching vulnerable species such as Acropora, leaving more tolerant species, and reduced coral cover. We could see no evidence for adaptation or acclimation of corals in this area. Towed still imagery was found to be a suitable means for rapid and large-scale bleaching studies in shallow, turbid areas where diving can be difficult or impossible.

scholarly journals Assessing population collapse of Drupella spp. (Mollusca: Gastropoda) 2 years after a coral bleaching event in the Republic of Maldives

Hydrobiologia ◽  
2021 ◽  
Author(s):  
L. Saponari ◽  
I. Dehnert ◽  
P. Galli ◽  
S. Montano
Keyword(s):  
Coral Bleaching ◽  
Prey Availability ◽  
Coral Cover ◽  
Environmental Data ◽  
High Plasticity ◽  
Bleaching Event ◽  
Coral Recovery ◽  
The Republic ◽  
The Impact ◽  
Line Intercept

AbstractCorallivory causes considerable damage to coral reefs and can exacerbate other disturbances. Among coral predators, Drupella spp. are considered as delayer of coral recovery in the Republic of Maldives, although little information is available on their ecology. Thus, we aimed to assess their population structure, feeding behaviour and spatial distribution around 2 years after a coral bleaching event in 2016. Biological and environmental data were collected using belt and line intercept transects in six shallow reefs in Maldives. The snails occurred in aggregations with a maximum of 62 individuals and exhibited a preference for branching corals. Yet, the gastropods showed a high plasticity in adapting feeding preferences to prey availability. Drupella spp. were homogenously distributed in the study area with an average of 9.04 ± 19.72 ind/200 m2. However, their occurrence was significantly different at the reef scale with the highest densities found in locations with higher coral cover. The impact of Drupella spp. appeared to be minimal with the population suffering from the loss of coral cover. We suggest that monitoring programs collect temporal- and spatial-scale data on non-outbreaking populations or non-aggregating populations to understand the dynamics of predation related to the co-occurrence of anthropogenic and natural impacts.

scholarly journals Large‐scale eDNA metabarcoding survey reveals marine biogeographic break and transitions over tropical north‐western Australia

2021 ◽  
Author(s):  
Katrina West ◽  
Michael J. Travers ◽  
Michael Stat ◽  
Euan S. Harvey ◽  
Zoe T. Richards ◽  
...  
Keyword(s):  
Western Australia ◽  
Large Scale ◽  
North Western

Bysmatrum teres sp. nov., a new sand-dwelling dinoflagellate from north-western Australia

Phycologia ◽  
2006 ◽  
Vol 45 (2) ◽  
pp. 161-167 ◽  
Author(s):  
Shauna Murray ◽  
Mona Hoppenrath ◽  
Jacob Larsen ◽  
David J. Patterson
Keyword(s):  
Western Australia ◽  
North Western

Recovery of an Isolated Coral Reef System Following Severe Disturbance

Science ◽  
2013 ◽  
Vol 340 (6128) ◽  
pp. 69-71 ◽  
Author(s):  
James P. Gilmour ◽  
Luke D. Smith ◽  
Andrew J. Heyward ◽  
Andrew H. Baird ◽  
Morgan S. Pratchett
Keyword(s):  
Coral Reef ◽  
Coral Cover ◽  
Initial Increase ◽  
Anthropogenic Pressures ◽  
Growth And Survival ◽  
Reef System ◽  
Reef Recovery ◽  
Rates Of Growth ◽  
North Western ◽  
Severe Disturbance

Coral reef recovery from major disturbance is hypothesized to depend on the arrival of propagules from nearby undisturbed reefs. Therefore, reefs isolated by distance or current patterns are thought to be highly vulnerable to catastrophic disturbance. We found that on an isolated reef system in north Western Australia, coral cover increased from 9% to 44% within 12 years of a coral bleaching event, despite a 94% reduction in larval supply for 6 years after the bleaching. The initial increase in coral cover was the result of high rates of growth and survival of remnant colonies, followed by a rapid increase in juvenile recruitment as colonies matured. We show that isolated reefs can recover from major disturbance, and that the benefits of their isolation from chronic anthropogenic pressures can outweigh the costs of limited connectivity.

Feral pigs in north-western Australia: population recovery after 1080 baiting and further control

2006 ◽  
Vol 33 (5) ◽  
pp. 417 ◽  
Author(s):  
Laurie E. Twigg ◽  
Tim Lowe ◽  
Michael Everett ◽  
Gary Martin
Keyword(s):  
Western Australia ◽  
Population Recovery ◽  
Feral Pigs ◽  
Muddy Water ◽  
Good Body Condition ◽  
Bait Station ◽  
Before And After ◽  
Bait Stations ◽  
North Western ◽  
Fitzroy River

The recovery rate of a population of feral pigs (Sus scrofa) in the west Kimberley in north-western Australia was determined 12 months after a 1080 (sodium fluoroacetate)-baiting program. An estimated 56 pigs were present in the 15 000-ha study area in August 2005 compared with the prebaiting levels of 250–275 pigs in 2004 (11 pigs were known to be alive on site after the 2004 baiting). This represents a population recovery of 20–23% of the 2004 prebaiting levels. Although most pigs were in good body condition, environmental conditions were quite different between the two years. In 2005, some waterholes were dry or comprised mainly muddy water with little associated shelter for feral pigs. Consequently, and in contrast to 2004, no pigs were seen, and no bait take could be attributed to feral pigs, at the four resurveyed waterholes. Most pig sightings, and activity, were close to the Fitzroy River. Fermented wheat, with blood and bone, was used to determine areas of pig activity, and also used as prefeed before 1080-baiting commenced in 2005. Using the same bait stations as for 2004, plus additional stations established in new areas of pig activity, 1080-treated wheat and malted barley again proved highly effective in reducing pig numbers. The daily sighting index before and after 1080-baiting indicated that pig numbers had been reduced by ~90% within four days. Estimated pre- and postpoisoning density, with and without an edge effect, was 0.12–1.7 pigs km–2 and 0.05–0.67 pigs km–2. Pig tracks decreased to zero on the six track plots within two days of baiting, but the number of macropod tracks remained constant over the four-day baiting period. Thirty-eight poisoned pigs were found after 1080-baiting, and these were generally in clustered groups within 200 m of an active bait station. Poisoned juvenile pigs were again found closer to the active bait stations than were adult or subadult pigs (P < 0.05).

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