scholarly journals Coral Reef Recovery in the Mexican Caribbean after 2005 Mass Coral Mortality—Potential Drivers

Diversity ◽  
2020 ◽  
Vol 12 (9) ◽  
pp. 338
Author(s):  
Xochitl E. Elías Ilosvay ◽  
Ameris I. Contreras-Silva ◽  
Lorenzo Alvarez-Filip ◽  
Christian Wild
Keyword(s):  
Coral Cover ◽  
Geographical Location ◽  
Relative Effect ◽  
Significant Loss ◽  
Coral Mortality ◽  
Hard Coral ◽  
Mexican Caribbean ◽  
Algae Growth ◽  
Reef Recovery ◽  
Coral Recovery

In 2005, an extreme heatwave hit the Wider Caribbean, followed by 13 hurricanes (including hurricanes Emily and Wilma) that caused significant loss in hard coral cover. However, the drivers of the potential recovery are yet to be fully understood. Based on recent findings in the literature of coral cover recovery in the Mexican Caribbean after the mass bleaching event and associated hurricanes in 2005, this study analyzed, through random-effects meta-analysis, the hard coral and macroalgae benthic development and potential drivers of change between 2005 and 2016 in the Mexican Caribbean. Therefore, we tested the relative effect of sea surface temperature (SST), chlorophyll-a water concentration, coastal human population development, reef distance to shore, and geographical location on both hard coral and macroalgae cover over time. Findings revealed increases of both hard coral (by 6%) and algae cover (by ca. 14%, i.e., almost three times the increase of corals) over 12 years. Although our findings confirm the partial coral recovery after the 2005 Caribbean mass coral mortality event, they also indicate rapid colonization of algae across the region. Surprisingly, only SST correlated negatively with changes in coral cover. Contrary to expectations, there was a significantly greater algae cover increase in the Central section of the Mexican Caribbean, which is characterized by a low population density. However, a constant discharge of nutrient-rich freshwater may have facilitated algae growth there. This study reports partial regional reef recovery, but it also indicates that local factors, particularly eutrophication, facilitate algae growth at a speed that is much faster than coral recovery.

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 PERBANDINGAN TUTUPAN KARANG KERAS SEBELUM, SAAT DAN SESUDAH PEMUTIHAN KARANG DI PERAIRAN KRUENG RAYA, ACEH BESAR

2018 ◽  
Vol 10 (3) ◽  
pp. 739-745
Author(s):  
Maria Ulfah ◽  
Chyndy Yolanda ◽  
Sofyatuddin Karina ◽  
Syahrul Purnawan ◽  
Sri Agustina
Keyword(s):  
Mortality Rate ◽  
Data Collection ◽  
Coral Bleaching ◽  
Coral Cover ◽  
Coral Mortality ◽  
Hard Coral ◽  
Average Percentage ◽  
Mortality Index ◽  
Hard Coral Cover

ABSTRAKPenelitian ini bertujuan untuk mengetahui tutupan karang keras pada waktu sebelum (tahun 2015) saat (2016) dan sesudah pemutihan karang (2017) di Krueng Raya, Aceh Besar. Penelitian ini dilakukan pada bulan April 2017 di Krueng Raya, Aceh Besar. Pengambilan data dilakukan di 3 stasiun pengamatan menggunakan metode PIT (Point Intercept Transect) yang meliputi: Benteng Inong Balee, Ahmad Rhang Manyang, dan Lhok Mee. Hasil penelitian menunjukkan persentase rata - rata tutupan karang keras tahun 2015 sebesar 52,83% berkategori baik, tahun 2016 sebesar 32,43% berkategori sedang dan tahun pada tahun 2017 persentase tutupan karang keras menjadi 22,90% dan masuk ke dalam kategori rusak. Terdapat sebanyak 16 genus karang (2015), 18 genus karang (2016) dan 8 genus karang 8 (2017). Indeks Mortalitas (IM) tahun 2015 berkisar antara 0,02-0,20 (tingkat kematian karang yang rendah), tahun 2016 berkisar antara 0,13-0,49 (kematian karang rendah), tahun 2017 berkisar antara 0,63-0,79 (tingkat kematian karang tinggi). Hasil penelitian ini menunjukkan bahwa persentase tutupan karang keras mengalami penurunan hingga mencapai ±50% yang diakibatkan oleh pemutihan karang pada Perairan Krueng Raya Aceh Besar. ABSTRACTThe aim of this study was to determine hard coral cover at the time before (2015), during (2016) and after coral bleaching (2017) in Krueng Raya, Aceh besar. This study was conducted on April 2017 in Krueng Raya, Aceh Besar. Data collection was carried out at 3 observation stations using the PIT (Point Intercept Transect) method which included : Fort Inong Balee, Ahmad Rhang Manyang, and Lhok Mee. The results showed that the average percentage of hard coral cover in 2017 was 22.90% (bad category), it was lower than in 2016 32.43% (medium category) and in 2015 was 52.83% (good category). There were found 16 genera of coral (2015), 18 genera of coral (2016), and 8 genera of coral (2017). Mortality Index (MI) in 2015 ranged between 0.02-0.20 (low coral mortality rate), in 2016 ranged between 0.13-0.49 (low coral mortality rate), in 2017 ranged between 0.63-0.79 (high coral mortality rate). The results of this study indicate that the percentage of hard coral cover has decreased to reach 50% due to coral bleaching in the waters of Krueng Raya Aceh Besar.

Coral recovery at Aldabra Atoll, Seychelles: five years after the 1998 bleaching event

2005 ◽  
Vol 363 (1826) ◽  
pp. 251-255 ◽  
Author(s):  
Ben Stobart ◽  
Kristian Teleki ◽  
Raymond Buckley ◽  
Nigel Downing ◽  
Martin Callow
Keyword(s):  
Large Scale ◽  
Considerable Increase ◽  
Coral Cover ◽  
Method Comparison ◽  
Research Programme ◽  
Coralline Algae ◽  
Maximum Diameter ◽  
Bleaching Event ◽  
Hard Coral ◽  
Coral Recovery

Changes in reef benthos were assessed at Aldabra Atoll following the mass coral bleaching event of 1998. Video transects were used to survey the benthos and analysed using the Australian Institute of Marine Science five–dot method. Comparison of coral cover data collected by the Cambridge Southern Seychelles Atoll Research Programme with data collected during this study revealed that mortality of coral at Aldabra following the bleaching event was approximately 66% at 10 m depth and 38% at 20 m depth. Five years on, there are signs of hard coral recovery at some locations, but in spite of several years of high coral recruitment (7–9 recruits per m 2 at 10 m depth, 4–6 recruits per m 2 at 20 m depth, where recruits are defined as any colony under 5 cm maximum diameter), recovery of hard coral has not occurred at a significant level. There has been a considerable increase in soft coral cover at some locations, which was dominated by the genus Rhytisma . Macro algal cover did not increase following the bleaching event, although, as would be expected, dead corals have been colonized by coralline algae. There have been no further events leading to large–scale coral mortality at Aldabra since 1998.

Size-structure patterns of juvenile hard corals in the Maldives

2011 ◽  
Vol 92 (6) ◽  
pp. 1335-1339 ◽  
Author(s):  
Ulisse Cardini ◽  
Mariachiara Chiantore ◽  
Roberta Lasagna ◽  
Carla Morri ◽  
Carlo Nike Bianchi
Keyword(s):  
Size Structure ◽  
Coral Cover ◽  
Hard Coral ◽  
Abundance Data ◽  
Settlement Success ◽  
Structure Index ◽  
Reef Recovery ◽  
Different Depths ◽  
Hard Coral Cover ◽  
Structure Patterns

In April 2006 and May 2007 abundance data of small coral colonies were collected in the central atolls of the Maldives (N3°35.9–4°26.6 E72°47.3–73°57.5) in order to evaluate variability in hard coral recruitment and post-settlement success. Visual quadrats were randomly placed in two reef typologies (oceanic reef and lagoonal reef) at three different depths. Colonies were conventionally defined as ‘recruits’ when smaller than 5 cm in diameter, whereas the term ‘juveniles’ was reserved for colonies ranging between 5 and 15 cm. Clear differences in the relative importance of the two size-classes across the three different depths and the two reef typologies were found. A size-structure index (SsI%), based on abundance data, was calculated in order to evaluate the percentage of ‘recruits’ out of the total juvenile hard corals. SsI% values differed between reef typologies and according to depth zones with a higher percentage of ‘recruits’ found in shallow oceanic reefs. Physical and ecological differences between the two reef typologies according to depth are presumed to cause different success in the settlement of new colonies and their survival during growth. Coupled with the usual estimates of hard coral cover, SsI% may represent a useful tool for monitoring, and be effective for the quick assessment of coral reef recovery after disturbances.

scholarly journals Differential impacts of 2016 coral bleaching on coral reef benthic communities at Sekotong Bay, Lombok Barat, Indonesia

2019 ◽  
Vol 20 (2) ◽  
pp. 570-575 ◽  
Author(s):  
IMAM BACHTIAR ◽  
TRI ARYONO HADI
Keyword(s):  
Coral Reef ◽  
Coral Bleaching ◽  
Soft Coral ◽  
Coral Cover ◽  
Benthic Communities ◽  
Coral Community ◽  
Coral Mortality ◽  
Reef Recovery ◽  
The Individual ◽  
Cascade Effects

Abstract. Bachtiar I, Hadi TA. 2019. Differential impacts of 2016 coral bleaching on coral reef benthic communities at Sekotong Bay, Lombok Barat, Indonesia. Biodiversitas 20: 570-575. Coral bleaching has been a major causal factor of coral mortality worldwide in the last two decades and it is therefore threaten food security. Understanding post-bleaching recovery is therefore very crucial to formulate strategy in promoting natural coral reef recovery. The present study documented coral reef communities both in pre- and post-bleaching event in early 2016. The results show that coral bleaching variably reduced coral and soft-coral covers. Sponge and other fauna cover considerably fluctuated. Since the individual number of soft-coral, sponge and other fauna were small, there is likely no big impact of coral bleaching. Among 12 study sites, 11 sites showed significant reduction of coral cover but one site showed only little fluctuation. Overall mean reduction of coral cover was about 18%. Consequently, algal cover increased by about 24%. The present study revealed differential coral bleaching impact between outer- and inner- reefs. At outer reefs, coral community suffered more severe mass coral mortality than those at inner reefs. This disparity is likely owing to initial coral cover and species composition of the coral communities. In the second year, there is still no visible coral recruitment from larvae. Cascade effects of land-clearing and overfishing due to increasing tourism development is very likely to be additional major stress that pause post-bleaching coral reef recovery at Sekotong Bay, Lombok Island, Indonesia.

scholarly journals Nitrogen enrichment in macroalgae following mass coral mortality

Coral Reefs ◽  
2021 ◽  
Author(s):  
Eleanor J. Vaughan ◽  
Shaun K. Wilson ◽  
Samantha J. Howlett ◽  
Valeriano Parravicini ◽  
Gareth J. Williams ◽  
...  
Keyword(s):  
Coral Reefs ◽  
Coral Cover ◽  
Strong Association ◽  
French Polynesia ◽  
Mass Mortality ◽  
Transplant Experiment ◽  
Bleaching Event ◽  
Coral Mortality ◽  
Absolute Increase ◽  
Inorganic Matter

AbstractScleractinian corals are engineers on coral reefs that provide both structural complexity as habitat and sustenance for other reef-associated organisms via the release of organic and inorganic matter. However, coral reefs are facing multiple pressures from climate change and other stressors, which can result in mass coral bleaching and mortality events. Mass mortality of corals results in enhanced release of organic matter, which can cause significant alterations to reef biochemical and recycling processes. There is little known about how long these nutrients are retained within the system, for instance, within the tissues of other benthic organisms. We investigated changes in nitrogen isotopic signatures (δ15N) of macroalgal tissues (a) ~ 1 year after a bleaching event in the Seychelles and (b) ~ 3 months after the peak of a bleaching event in Mo’orea, French Polynesia. In the Seychelles, there was a strong association between absolute loss in both total coral cover and branching coral cover and absolute increase in macroalgal δ15N between 2014 and 2017 (adjusted r2 = 0.79, p = 0.004 and adjusted r2 = 0.86, p = 0.002, respectively). In Mo’orea, a short-term transplant experiment found a significant increase in δ15N in Sargassum mangarevense after specimens were deployed on a reef with high coral mortality for ~ 3 weeks (p < 0.05). We suggest that coral-derived nutrients can be retained within reef nutrient cycles, and that this can affect other reef-associated organisms over both short- and long-term periods, especially opportunistic species such as macroalgae. These species could therefore proliferate on reefs that have experienced mass mortality events, because they have been provided with both space and nutrient subsidies by the death and decay of corals.

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 Predicting coral adaptation to global warming in the Indo-West-Pacific

2019 ◽  
Author(s):  
Mikhail V. Matz ◽  
Eric Treml ◽  
Benjamin C. Haller
Keyword(s):  
New Caledonia ◽  
Coral Cover ◽  
First Century ◽  
Genetic Rescue ◽  
West Pacific ◽  
Connectivity Model ◽  
Wide Scale ◽  
Southern Half ◽  
Coral Recovery ◽  
Warming Rate

ABSTRACTThe potential of reef-building corals to adapt to increasing sea surface temperatures is often speculated about but has rarely been comprehensively modeled on a region-wide scale. Here, we used individual-based simulations to model adaptation to warming in a coral metapopulation comprising 680 reefs and representing the whole of the Central Indo-West Pacific. We find that in the first century of warming (approximately from 50 years ago to 50 years in the future) corals adapt rapidly by redistributing pre-existing adaptive alleles among populations (“genetic rescue”). In this way, some coral populations - most notably, Vietnam, Japan, Taiwan, New Caledonia, and the southern half of the Great Barrier Reef - appear to be able to maintain their fitness even under the worst warming scenarios (at least in theory, assuming the rate of evolution is the only limitation to local coral recovery). Still, survival of the majority of reefs in the region critically depends on the warming rate, underscoring the urgent need to curb carbon emissions. Conveniently, corals’ adaptive potential was largely independent of poorly known genetic parameters and could be predicted based on a simple metric derived from the biophysical connectivity model: the proportion of recruits immigrating from warmer locations. We have confirmed that this metric correlates with actual coral cover changes throughout the region, based on published reef survey data from the 1970s to early 2000s. The new metric allows planning assisted gene flow interventions to facilitate adaptation of specific coral populations.

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.

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.

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