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 Mesophotic corals on the subtropical shelves of Lord Howe Island and Balls Pyramid, south-western Pacific Ocean

2019 ◽  
Vol 70 (1) ◽  
pp. 43 ◽  
Author(s):  
Michelle Linklater ◽  
Alan R. Jordan ◽  
Andrew G. Carroll ◽  
Joseph Neilson ◽  
Sallyann Gudge ◽  
...  
Keyword(s):  
Pacific Ocean ◽  
Coral Cover ◽  
Benthic Communities ◽  
Video Data ◽  
Critical Knowledge ◽  
Lord Howe Island ◽  
Marine Park ◽  
The Pacific ◽  
Baseline Information ◽  
The Pacific Ocean

Subtropical reefs are predicted to be dynamic areas of change under increased warming of global sea-surface temperature. A critical knowledge gap exists for deeper, mesophotic corals in these higher-latitude settings, where little is known about their spatial and depth distributions. At the latitudinal limits of coral-reef growth in the Pacific Ocean, abundant mesophotic corals were revealed on the shelf surrounding the subtropical, mid-ocean island of Balls Pyramid, which is a World Heritage-listed and marine park-protected area. Our study extended these findings to the nearby Lord Howe Island shelf to assess mesophotic coral cover and explore spatial patterns in mesophotic benthic communities. Underwater towed-video data collected around Lord Howe Island (24 sites) were combined with existing benthic data from the Balls Pyramid shelf. Results showed that similar habitats occur across both shelves, with communities varying among inner-, mid- and outer-shelf zones. Corals were most prevalent on the Balls Pyramid mid-shelf, with selected locations around the Lord Howe Island mid-shelf reporting similar cover (maximum site-average cover of 24%). The benthic data presented in this study provide important baseline information for monitoring coral cover and detecting potential shifts in community composition under ongoing climate change.

Seasonal variations in the density of and corallivory by Drupella rugosa and Cronia margariticola (Caenogastropoda: Muricidae) from the coastal waters of Hong Kong: ‘plagues’ or ‘aggregations’?

2008 ◽  
Vol 89 (1) ◽  
pp. 147-159 ◽  
Author(s):  
Brian Morton ◽  
Graham Blackmore
Keyword(s):  
Hong Kong ◽  
Coastal Waters ◽  
Feeding Behaviour ◽  
Prey Selection ◽  
Coral Cover ◽  
Feeding Activity ◽  
Hard Coral ◽  
Coral Communities ◽  
Hard Coral Cover ◽  
Muricid Gastropods

Sixteen coral sites in the coastal waters of Hong Kong were examined for the corallivorous muricid gastropods Drupella rugosa and Cronia margariticola. These were recorded from all sites where there was significant hard coral cover and observed feeding upon species of Platygyra, Leptastrea, Stylocoeniella, Porites, Favites, Cyphastrea, Goniastrea, Favia, Acropora, Montipora, Pavona, Lithophyllon, Hydnophora, Echinophyllia and Plesiastrea. One large aggregation (~2000 individuals) of, mainly, D. rugosa was observed but much smaller groups (<20 individuals) were more typical. Five sites were chosen for more detailed study and surveyed during winter and summer. Despite being characterized by different coral communities, inter-site densities of D. rugosa were not significantly different and, usually, ~2 individuals · m2 were recorded. Seasonal differences were, however, significant with numbers greater during the summer, possibly related to reproduction. Feeding activity followed a similar pattern and was also largely confined to summer.Prey selection by Drupella rugosa was complex in the field and changed according to the relative abundance of each coral taxon. Acropora was strongly selected for at all sites where it was present and Montipora, Platygyra and Pavona were usually fed upon in greater proportions than their abundances. Leptastrea, Cyphastrea, Favites, Favia and Goniastrea were fed upon but in proportions lower than suggested by their abundances. Goniopora was never fed upon despite being relatively common. The seasonality of feeding, low density, rarity of large feeding aggregations, prey selection and aspects of the feeding behaviour, that is, generally only consuming the coral's coenenchyme (the polyps surviving), suggest that while D. rugosa is widespread in Hong Kong, and contrary to other views, it poses little, if any, threat to local coral communities. Thus, reported feeding clusters of D. rugosa are probably not ‘plague’ outbreaks but examples of seasonally fostered ‘aggregations’ of feeding (and probably reproducing) individuals. Indeed, no ‘plague-like’ outbreak of any species of Drupella has been reported upon in the literature since 1999.

scholarly journals New Scales to Guide the Assessment of Hard Coral Cover and Diversity in the Philippines

2020 ◽  
pp. 121-126
Keyword(s):  
Ecosystem Services ◽  
Coral Reefs ◽  
Coral Cover ◽  
Rapid Identification ◽  
The Philippines ◽  
Hard Coral ◽  
Hard Coral Cover ◽  
Assessment Scales

Coral reefs supply vital ecosystem services to the Philippines. Safeguarding these services requires the rapid identification of reefs that provide most services, and identification is best made by measuring hard coral cover and diversity and using updated and locally relevant assessment scales on these measurements. The use of these assessment scales has advantages and is recommended to update and improve Philippine laws.

scholarly journals Cross-Shelf Variation Among Juvenile and Adult Coral Assemblages on Australia’s Great Barrier Reef

Diversity ◽  
2019 ◽  
Vol 11 (6) ◽  
pp. 85 ◽  
Author(s):  
Michelle J. Jonker ◽  
Angus A. Thompson ◽  
Patricia Menéndez ◽  
Kate Osborne
Keyword(s):  
Great Barrier Reef ◽  
Coral Cover ◽  
Synergistic Effects ◽  
Outer Shelf ◽  
Lower Latitude ◽  
Barrier Reef ◽  
Hard Coral ◽  
Coral Abundance ◽  
The Status ◽  
Community Types

Coral reefs are under increasing pressure from a variety of stressors, highlighting the need for information about the status of coral reef communities including the distribution, abundance and composition of juvenile and adult coral assemblages. This information is currently limited for the Great Barrier Reef (GBR) and is necessary for understanding the impacts of disturbances and the system’s potential for recovery. This study reports juvenile and adult hard coral abundance and composition from 122 reefs on the GBR during a period of limited acute disturbance. The data represent baseline observations for juvenile hard coral assemblages spanning the longitudinal cross-shelf gradient of the GBR and 12 degrees of latitude and augment reported distribution of adult coral assemblages over the same scale with inclusion of additional reefs. Juvenile and adult coral assemblages reflected broad differences imposed by the gradient of environmental conditions across the GBR. The mean density of juvenile hard corals was lower in the inshore reefs (5.51 m2) than at either the mid-shelf (11.8 m2) or outer shelf reefs (11.2 m2). The composition of juvenile and adult coral assemblages covaried overall, although there were different relationships between these two life stages across the continental shelf and among community types. Dissimilarity between juvenile and adult coral assemblages was greater on inshore and outer shelf reefs than on reefs in the mid-shelf, although, there were differences in community types both within these shelf positions and those that spanned mid- and outer shelf reefs. Dissimilarity was greatest for Inshore branching Acropora and high for Southern Acropora communities, although very high coral cover and very low juvenile densities at these reefs precluded interpretation beyond the clear competitive dominance of Acropora on those reefs. Dissimilarity was also high between juvenile and adult coral assemblages of Turbid inshore communities suggesting water quality pressures, along with synergistic effects of other stressors, pose ongoing selective pressures beyond the juvenile stage. Conversely, relatively low dissimilarity between juvenile and adult coral assemblages on mid-shelf and lower latitude outer shelf reefs suggests pressures beyond those influencing settlement and early post-settlement survival were having less influence on the composition of adult coral assemblages.

scholarly journals Reports of Cubiceps baxteri McCulloch 1923 from Indian Ocean are probably misidentifications of Cubiceps whiteleggii (Waite 1894)

Zootaxa ◽  
2021 ◽  
Vol 4985 (1) ◽  
pp. 142-144
Author(s):  
V. VIJI ◽  
K.C. HARISH ◽  
B. MADHUSOODANA KURUP
Keyword(s):  
Pacific Ocean ◽  
Indian Ocean ◽  
Baja California ◽  
New South ◽  
Tropical Species ◽  
Lord Howe Island ◽  
South Wales ◽  
The Pacific ◽  
Tasman Sea ◽  
The Pacific Ocean

Cubiceps baxteri McCulloch 1923 was described based on a single, imperfect (devoid of a tail) stranded specimen collected from a beach in Lord Howe Island, Tasman Sea. Though C. baxteri was reported as a widely distributed tropical species (Butler 1979), it was mainly a result of its incorrect identification (see Agafonova 1994; Stewart and Last 2015). The distribution of C. baxteri is reported to be restricted to the Pacific Ocean, from Japan and eastwards to Baja California (Mexico), southwards to the Hawaiian Islands, New South Wales (Australia), and Lord Howe Island (Tasman Sea) to the Southern parts of Chile (Eschmeyer et al. 2017; Mundy 2005; Agafonova 1994). 

scholarly journals STATUS TERUMBU KARANG DAN IKAN KARANG DI GILI MATRA, NUSA TENGGARA BARAT

2020 ◽  
Vol 14 (1) ◽  
pp. 14
Author(s):  
Eghbert Elvan Ampou ◽  
Suciadi Catur Nugroho ◽  
Nuryani Widagti
Keyword(s):  
Water Quality ◽  
Coral Reef ◽  
Coral Cover ◽  
Reef Fishes ◽  
Coral Mortality ◽  
Hard Coral ◽  
Mortality Index ◽  
Fish Group ◽  
Hard Coral Cover ◽  
Reef Condition

This study aims to identify the status of reef fishes and coral reefs in Gili Meno, Air, and Trawangan or Gili Matra waters. This area is part of the North Lombok Regency, West Nusa Tenggara Province. Field observation was conducted on September 2011 at 11 (eleven) diving points. The video-transect method was used for observing the coral reef condition, while reef fishes abundance was observed by using visual-census method. The parameter that used to determine the condition of coral reef in study location are the percentage of live hard coral cover and index of coral mortality. In general, the result shows that percentage of live hard coral cover in each diving point ranged from 4.4% - 37.2% and the Coral Mortality Index (IMK) ranged form 0.40-0.92. The values describe that the condition of coral reef at eleven diving points vary from fair until poor condition. Current status of coral reef condition showed an insignificant increase from bad to moderate during the period 2011 -2018. There were 23 families of reef fishes from 46 genera were found during the study consisting of 16 genera of target fish groups, 5 genera of indicator fish group, and 25 genera of major fish group. The water quality is still within the limits of environmental quality standards.   Keywords: Reef fish, coral reef, Mortality Index, water quality, Gili Matra

scholarly journals Great Barrier Reef Degradation, Sea Surface Temperatures, and Atmospheric CO2 Levels Collectively Exhibit a Stochastic Process with Memory

2021 ◽  
Author(s):  
Allan Elnar ◽  
Christianlly Cena ◽  
Christopher Casenas Bernido ◽  
M. Victoria Carpio-Bernido
Keyword(s):  
Stochastic Process ◽  
Great Barrier Reef ◽  
Coral Cover ◽  
Sea Surface ◽  
Atmospheric Co2 ◽  
Sea Surface Temperatures ◽  
Barrier Reef ◽  
Hard Coral ◽  
Co2 Levels ◽  
Hard Coral Cover

Abstract Quantifying ecological memory could be done at several levels from the rate of physiological changes in an ecosystem all the way down to responses at the genetic level. One way of unlocking the information encoded in a collective environmental memory is to examine the recorded time-series data generated by different components of an ecosystem. In this paper, we probe into the case of the Great Barrier Reef (GBR) which is threatened by elevated sea surface temperatures (SST) and ocean acidification attributed to rising atmospheric CO 2 levels. Specifically, we investigate the interrelated dynamics between the degradation of the GBR, SST, and rising atmospheric CO 2 levels, by considering three datasets: (a) the mean percentage hard coral cover of the GBR from the archives of the Australian Institute of Marine Science; (b) SST close to the GBR from the National Oceanic and Atmospheric Administration; and (c) the Keeling curve for atmospheric CO 2 levels measured by the Mauna Loa Observatory. We show that fluctuating observables in these datasets have the same memory behavior described by a non-Markovian stochastic process. All three datasets show a good match between empirical and analytical mean square deviation. An explicit analytical form for the corresponding probability density function is obtained which obeys a modified diffusion equation with a time dependent diffusion coefficient. This study provides a new perspective on the similarities of and interaction between the GBR’s declining hard coral cover, SST, and rising atmospheric CO2 levels by putting all three systems into one unified framework indexed by a memory parameter μ and a characteristic frequency ν . The short-time dynamics of CO2 levels and SST fall in the superdiffusive regime, while the GBR exhibits hyperballistic fluctuation in percent coral cover with the highest values for μ and ν .

scholarly journals 11-yr of coral community dynamics in reefs around Dahab (Gulf of Aqaba, Red Sea): the collapse of urchins and rise of macroalgae and cyanobacterial mats

Coral Reefs ◽  
2020 ◽  
Vol 39 (6) ◽  
pp. 1605-1618
Author(s):  
Miriam Reverter ◽  
Matthew Jackson ◽  
Nauras Daraghmeh ◽  
Christian von Mach ◽  
Nina Milton
Keyword(s):  
Coral Reef ◽  
Red Sea ◽  
Coral Cover ◽  
Negative Relationship ◽  
Gulf Of Aqaba ◽  
Benthic Fish ◽  
Hard Coral ◽  
Cyanobacterial Mats ◽  
Invertebrate Assemblages ◽  
Hard Coral Cover

AbstractCorals from the Gulf of Aqaba (northern Red Sea) are resilient to high temperatures and therefore this region is regarded as globally important for reef conservation. However, long-term dynamics of coral reef assemblages from the Gulf of Aqaba remain largely understudied. In this study, we analysed the change in benthic, fish and invertebrate assemblages of reefs around Dahab (South Sinai, Egypt) between 2009 and 2019. We also studied the individual trajectories of coral reef benthic categories, key invertebrate and fish species and their relationship. As site emerged as the main factor explaining the variability in coral reef communities, we identified three clusters of sites with similar assemblages. Both benthic, fish and invertebrate assemblages changed considerably at the three site clusters between 2009 and 2019. We found significant increases in fleshy macroalgae (~ 6 to 15%) and cyanobacterial mats (~ 6 to 12%) in all site clusters. Although not observing a significant reduction of hard coral cover, both macroalgae mat cover and cyanobacterial mat cover were significantly negatively related to hard coral cover and hard coral disease. Soft coral cover (mainly corals from the Xeniidae family) decreased significantly in two of the site clusters, their cover being negatively related to macroalgal and cyanobacterial cover. Significant declines in grazer urchins were observed at all site clusters, and a strong negative relationship was found with macroalgae and cyanobacterial mats cover, suggesting urchin decline as one of the main drivers behind algal increases. Different site clusters had different fish trajectories (butterflyfish, parrotfish, surgeonfish and predators), with only damselfish densities significantly decreasing at all sites. A significant decrease in damselfish densities was related to increases in cyanobacterial mats. These findings suggest that if macroalgae and cyanobacteria continue to increase, Dahab coral reefs could undergo degradation, and therefore, more studies are needed to elucidate the drivers behind these algal increases.

scholarly journals Early trajectories of benthic coral reef communities following the 2015/16 coral bleaching event at remote Aldabra Atoll, Seychelles

2020 ◽  
Vol 10 (1) ◽  
Author(s):  
Anna Koester ◽  
Valentina Migani ◽  
Nancy Bunbury ◽  
Amanda Ford ◽  
Cheryl Sanchez ◽  
...  
Keyword(s):  
Coral Reef ◽  
Water Temperature ◽  
Coral Bleaching ◽  
Coral Cover ◽  
Bleaching Event ◽  
Hard Coral ◽  
Reef Communities ◽  
Remote Sites ◽  
Hard Coral Cover ◽  
Coral Reef Communities

Abstract Documenting post-bleaching trajectories of coral reef communities is crucial to understand their resilience to climate change. We investigated reef community changes following the 2015/16 bleaching event at Aldabra Atoll, where direct human impact is minimal. We combined benthic data collected pre- (2014) and post-bleaching (2016–2019) at 12 sites across three locations (lagoon, 2 m depth; seaward west and east, 5 and 15 m depth) with water temperature measurements. While seaward reefs experienced relative hard coral reductions of 51–62%, lagoonal coral loss was lower (− 34%), probably due to three-fold higher daily water temperature variability there. Between 2016 and 2019, hard coral cover did not change on deep reefs which remained dominated by turf algae and Halimeda, but absolute cover on shallow reefs increased annually by 1.3% (east), 2.3% (west) and 3.0% (lagoon), reaching, respectively, 54%, 68% and 93% of the pre-bleaching cover in 2019. Full recovery at the shallow seaward locations may take at least five more years, but remains uncertain for the deeper reefs. The expected increase in frequency and severity of coral bleaching events is likely to make even rapid recovery as observed in Aldabra’s lagoon too slow to prevent long-term reef degradation, even at remote sites.

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