scholarly journals Coral Communities on Marginal High-Latitude Reefs in West Australian Marine Parks

Diversity ◽  
2021 ◽  
Vol 13 (11) ◽  
pp. 554
Author(s):  
Claire L. Ross ◽  
Ben French ◽  
Emily K. Lester ◽  
Shaun K. Wilson ◽  
Paul B. Day ◽  
...  
Keyword(s):  
High Latitude ◽  
Coral Cover ◽  
Marine Reserve ◽  
Ocean Warming ◽  
Tropical Species ◽  
Marine Park ◽  
Temperate Reefs ◽  
South West ◽  
Coral Communities ◽  
Over Time

Many temperate reefs are experiencing a shift towards a greater abundance of tropical species in response to marine heatwaves and long-term ocean warming worldwide. Baseline data for coral communities growing in high-latitude reefs is required to better understand ecosystem changes over time. In this study, we explore spatial and temporal trends in the distribution of coral communities from 1999 to 2019 at 118 reef sites within the five marine parks located in the south-west of Western Australia (WA) between 30° to 35 °S. Our estimates of coral cover were generally low (< 5%), except for a few sites in Jurien Bay Marine Park and Rottnest Island Marine Reserve where coral cover was 10% to 30%. Interannual changes in genera assemblages were detected but were not consistent over time, whereas significant temporal increases in coral cover estimates were found at the lowest latitude site in Jurien Bay. Coral assemblages were primarily distinguished by Turbinaria spp. at Marmion Marine Park and Ngari Capes Marine Park, and Pocillopora spp. and Dipsastraea spp. at Rottnest Island and Jurien Bay. Our findings suggest that conditions in south-west WA are favorable to the ongoing survival of existing genera and there were minimal signs of expansion in coral cover at most study sites. Coral cover and composition on these reefs may, however, change with ongoing ocean warming and increased occurrence of marine heatwaves. This study provides a valuable benchmark for assessing future changes in coral assemblages and highlights the need for targeted hard-coral surveys to quantify subtle changes in high-latitude coral community assemblages.

Extraordinarily high coral cover on a nearshore, high-latitude reef in south-west Australia

Coral Reefs ◽  
2010 ◽  
Vol 29 (4) ◽  
pp. 923-927 ◽  
Author(s):  
D. P. Thomson ◽  
A. J. Frisch
Keyword(s):  
High Latitude ◽  
Coral Cover ◽  
South West

The coral communities of Lord Howe Island

1995 ◽  
Vol 46 (2) ◽  
pp. 457 ◽  
Author(s):  
VJ Harriott ◽  
PL Harrison ◽  
SA Banks
Keyword(s):  
Coral Cover ◽  
Benthic Communities ◽  
Tropical Species ◽  
Hard Coral ◽  
Lord Howe Island ◽  
The Pacific ◽  
The Status ◽  
Coral Communities ◽  
Apparent Reduction ◽  
Hard Coral Cover

Lord Howe Island (31�33′S, 159�05′E) is surrounded by the southern-most coral reefs in the Pacific Ocean. The status of the benthic communities at Lord Howe Island was quantified in 1992-93 using replicated video-transects at 20 sites in the shallow reefal area (<20 m depth). The cover of hard coral was comparable with coral cover on some tropical reefs, ranging from less than 10% at some reef flat sites to greater than 40% cover at two seaward beach sites. The process of reef formation is apparently slow, and accretion of limestone is localized. A total of 59 scleractinian coral species were recorded during this study (including 19 new records), bringing the total number recorded at Lord Howe Island to 83. The coral communities contain a unique association of tropical species at their southern limits of distribution, and subtropical species which are rare or absent from the Great Barrier Reef. Many of the species that have been recorded from Lord Howe Island are rare, and may have resulted from chance recruitment of only a few larvae. There have been few major changes in the coral communities at Lord Howe Island in the past 16 years. At two inshore sites there was an apparent reduction in hard coral cover in the 1980s.

scholarly journals Coral distribution and bleaching vulnerability areas in Southwestern Atlantic under ocean warming

2021 ◽  
Vol 11 (1) ◽  
Author(s):  
Jessica Bleuel ◽  
Maria Grazia Pennino ◽  
Guilherme O. Longo
Keyword(s):  
Climate Change ◽  
Coral Cover ◽  
Global Climate ◽  
Ocean Warming ◽  
Southwestern Atlantic ◽  
Tropical Regions ◽  
Coral Communities ◽  
Conservation Actions ◽  
High Emission ◽  
High Emission Scenario

AbstractGlobal climate change is a major threat to reefs by increasing the frequency and severity of coral bleaching events over time, reducing coral cover and diversity. Ocean warming may cause shifts in coral communities by increasing temperatures above coral’s upper thermal limits in tropical regions, and by making extratropical regions (marginal reefs) more suitable and potential refugia. We used Bayesian models to project coral occurrence, cover and bleaching probabilities in Southwestern Atlantic and predicted how these probabilities will change under a high-emission scenario (RCP8.5). By overlapping these projections, we categorized areas that combine high probabilities of coral occurrence, cover and bleaching as vulnerability-hotspots. Current coral occurrence and cover probabilities were higher in the tropics (1°S–20°S) but both will decrease and shift to new suitable extratropical reefs (20°S–27°S; tropicalization) with ocean warming. Over 90% of the area present low and mild vulnerability, while the vulnerability-hotspots represent ~ 3% under current and future scenarios, but include the most biodiverse reef complex in South Atlantic (13°S–18°S; Abrolhos Bank). As bleaching probabilities increase with warming, the least vulnerable areas that could act as potential refugia are predicted to reduce by 50%. Predicting potential refugia and highly vulnerable areas can inform conservation actions to face climate change.

scholarly journals Spatial distribution of coral communities on fringing reefs at Tioman Island Marine Park, Malaysia

2021 ◽  
Author(s):  
Khodzori Fikri Akmal ◽  
Saad Shahbudin
Keyword(s):  
Scleractinian Coral ◽  
Coral Cover ◽  
Peninsular Malaysia ◽  
Current Data ◽  
Coastal Development ◽  
Live Coral ◽  
Point Count ◽  
Marine Park ◽  
Coral Communities ◽  
Coral Health

Monitoring coral health status is important for effective reef ecosystem management. The present study aimed to determine the coral condition and distribution at twenty sites around Tioman Island Marine Park (TIMP), Malaysia. The Coral Video Transect (CVT) method was used to survey coral, and the Coral Point Count with Excel extension (CPCe) software was used to analyse images for identification and coral coverage measurement. The findings indicate that TIMP reefs had a mean live coral cover of 48.0% ± 0.7, suggesting they were in ‘fair’ coral condition. A total of 254 species, spanning 61 genera and 15 families of scleractinian coral were identified across all reef sites. Following the recent taxonomic classification, coral surveys and past studies revealed 355 species from 67 genera and 15 families of scleractinian coral with additional 30 new species records for TIMP, and 15 for the east coast of Peninsular Malaysia. Overall, 29 identified scleractinian species are considered rare, 86 vulnerable, and 3 are endangered. Current data also recorded 77 genera from 24 families of hard and soft corals with Acropora, Montipora and Porites predominantly found in reef assemblages. Overall, it can be concluded that the extensive coastal development and widespread tourism activities may have influenced the variations in coral condition and distribution in this Marine Park.

Differences between protected and unprotected reefs of the western Caribbean in attributes preferred by dive tourists

2000 ◽  
Vol 27 (4) ◽  
pp. 382-391 ◽  
Author(s):  
Ivor D. Williams ◽  
Nicholas V.C. Polunin
Keyword(s):  
Protected Areas ◽  
Marine Protected Areas ◽  
Coral Cover ◽  
Marine Reserve ◽  
Grand Cayman ◽  
Reef Structure ◽  
Marine Park ◽  
Western Caribbean ◽  
Large Animals ◽  
Reference Areas

Tropical marine protected areas (MPAs) may promote conditions that are attractive to dive tourists, but a systematic basis for assessing their effectiveness in this regard is currently lacking. We therefore interviewed 195 dive tourists in Jamaica to determine which reef attributes they most preferred to see on dives. Attributes relating to fishes and other large animals (‘big fishes’, ‘other large animals’, ‘variety of fishes’, ‘abundance of fishes’, and ‘unusual fishes’) were more appreciated than those relating to reef structure and benthos (‘reef structure e.g., drop-offs’, ‘variety of corals’, ‘large corals’, ‘coral cover’, ‘unusual corals’, ‘sponges’, ‘unusual algae’, ‘lobsters, crabs etc.’). We then surveyed reef condition with regard to those aspects (abundance and variety of fishes, number of ‘unusual’, and number of ‘large’ fish) at four Caribbean MPAs and reference areas. In two cases, Hol Chan Marine Reserve in Belize and Parque Nacional Punta Frances in Cuba, these fish attributes were more pronounced in the MPAs than in the reference areas. Differences between the Montego Bay Marine Park in Jamaica (MBMP) and adjacent reference areas were mainly restricted to shallow sites (<6m), while at Grand Cayman no differences between fully protected and partially protected areas were detected. Management had not been fully effective in the MBMP in the preceding months, while fishing pressure in the partially protected areas on Grand Cayman was very light. We conclude that, if fishing restrictions are well enforced, western Caribbean MPAs can be expected to be effective in ways appreciated by dive tourists.

Changing Places: Rock Art and Holocene Landscapes in the Wadi al-Ajal, South-West Libya

2014 ◽  
Vol 12 (2) ◽  
pp. 165-182 ◽  
Author(s):  
Tertia Barnett ◽  
Maria Guagnin
Keyword(s):  
Spatial Analysis ◽  
Surface Water ◽  
Rock Art ◽  
Human Settlement ◽  
Gis Model ◽  
South West ◽  
Settlement Location ◽  
Central Sahara ◽  
The Relationship ◽  
Over Time

This article examines the relationship between rock art and landscape use by pastoral groups and early settled communities in the central Sahara from around 6000 BC to 1000 AD. During this period the region experienced significant climatic and environmental fluctuations. Using new results from a systematic survey in the Wadi al-Ajal, south-west Libya, our research combines data from over 2000 engraved rock art panels with local archaeological and palaeoenvironmental evidence within a GIS model. Spatial analysis of these data indicates a correspondence between the frequency of rock art sites and human settlement over time. However, while changes in settlement location were guided primarily by the constraints on accessibility imposed by surface water, the distribution of rock art relates to the availability of pasture and patterns of movement through the landscape. Although the reasons for these movements undoubtedly altered over time, natural routes that connected the Wadi al-Ajal and areas to the south continued to be a focus for carvings over several thousand years.

scholarly journals Environmental Variation and How its Spatial Structure Influences the Cross-Shelf Distribution of High-Latitude Coral Communities in South Africa

Diversity ◽  
2019 ◽  
Vol 11 (4) ◽  
pp. 57 ◽  
Author(s):  
Sean N. Porter ◽  
Michael H. Schleyer
Keyword(s):  
South Africa ◽  
Continental Shelf ◽  
High Latitude ◽  
Environmental Variables ◽  
Environmental Gradients ◽  
High Tide ◽  
Environmental Variation ◽  
Shelf Edge ◽  
Spatial Differences ◽  
Coral Communities

Coral communities display spatial patterns. These patterns can manifest along a coastline as well as across the continental shelf due to ecological interactions and environmental gradients. Several abiotic surrogates for environmental variables are hypothesised to structure high-latitude coral communities in South Africa along and across its narrow shelf and were investigated using a correlative approach that considered spatial autocorrelation. Surveys of sessile communities were conducted on 17 reefs and related to depth, distance to high tide, distance to the continental shelf edge and to submarine canyons. All four environmental variables were found to correlate significantly with community composition, even after the effects of space were removed. The environmental variables accounted for 13% of the variation in communities; 77% of this variation was spatially structured. Spatially structured environmental variation unrelated to the environmental variables accounted for 39% of the community variation. The Northern Reef Complex appears to be less affected by oceanic factors and may undergo less temperature variability than the Central and Southern Complexes; the first is mentioned because it had the lowest canyon effect and was furthest from the continental shelf, whilst the latter complexes had the highest canyon effects and were closest to the shelf edge. These characteristics may be responsible for the spatial differences in the coral communities.

Pasture production under a series of Pinus radiata-pasture agroforestry systems in South-West Victoria, Australia

1995 ◽  
Vol 46 (6) ◽  
pp. 1285 ◽  
Author(s):  
JD Kellas ◽  
PR Bird ◽  
KN Cumming ◽  
GA Kearney ◽  
AK Ashton
Keyword(s):  
Pinus Radiata ◽  
Agroforestry Systems ◽  
Tree Line ◽  
Pasture Production ◽  
South West ◽  
Tree Edge ◽  
Belt System ◽  
Over Time

Net pasture production has been monitored over time on an on-going Pinus radiata-pasture agroforestry experiment located at Carngham, Victoria. Established in 1983 by thinning a 2-year-old plantation, the study contains five treatments (systems): open pasture (no trees), 60 trees/ha, 200 trees/ha wide-spaced, 200 trees/ha 5-row belt and 1360 trees/ha. Net pasture production was only weakly affected by the proximity of trees in the 60 trees/ha and 200 trees/ha wide-spaced systems. However, in the 200 trees/ha 5-row belt system, pasture production was often significantly less within the tree zone and at 1.5 m from the tree edge compared with production at 10.5 m from the tree edge. While there was a trend for greater pasture production at 10.5 m and 18 m from the tree line than occurred in the open pasture system, the width of pasture adjacent to the 5-row belts was too narrow (36 m) to demonstrate any shelter benefit on pasture production. From 1990 to 1992, pasture production (kg ha-1) for each system was similar, although production tended to decrease with increasing tree stocking. Following the cessation of pruning (1992), pasture production was significantly reduced by increased tree stocking, such that pasture production in the 200 trees/ha wide-spaced and 200 trees/ha 5-row belt systems was 60% and 69% and 23% and 67% of open pasture in 1993 and 1994 respectively.

Acanthaster planci impact on coral communities at permanent transect sites on Bruneian reefs, with a regional overview and a critique on outbreak causes

2011 ◽  
Vol 92 (4) ◽  
pp. 803-809 ◽  
Author(s):  
David J.W. Lane
Keyword(s):  
Coral Cover ◽  
Food Limitation ◽  
Past Century ◽  
Live Coral ◽  
Sea Star ◽  
Acanthaster Planci ◽  
The Past ◽  
Live Coral Cover ◽  
Coral Communities ◽  
High Precipitation

The submerged coral reefs of Brunei, little-impacted by human activity and characterized by high live coral cover, have no recorded history in recent decades of the presence of the crown-of-thorns (COT), Acanthaster planci. This sea star, first recorded on Brunei reefs in 2008, attained outbreak densities in 2010. At Littledale Shoal its impact on corals at permanent transect sites has been quantified; mean live coral cover reduced by half from 2006 to 2010 due predominantly to predation. Line intersect transect data confirm a predisposition for tabular Acropora species, a prominent feature at this site, although other scleractinian taxa were also predated. Other regional outbreaks are reviewed, including episodes, and their timing, within the neighbouring Coral Triangle (CT). Mounting evidence implicates nutrient-enhanced increases in primary production as a primary cause of COT outbreaks. However, this stands in contrast with a report of global oceanic phytoplankton decline in the past century, and there is little evidence of such a link in the CT, even though this region is characterized by high precipitation, erosional plumes and seasonal upwelling-associated phytoplankton blooms. Furthermore, until survivorship and competency for a wider spectrum of mass-spawned invertebrate planktotrophs in relation to elevated phytoplankton densities is better understood, such evidence, suggesting release from food limitation as the principal cause of enhanced COT recruitment, should be interpreted with caution.

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