scholarly journals Degraded Coral Reefs are Becoming More Resistant to Hurricanes

Author(s):  
Laura Mudge ◽  
John Bruno

Abstract The frequency and intensity of Atlantic cyclonic storms are projected to increase as climate change warms the ocean 1,2. These changing disturbance dynamics, paired with simultaneous changes in the condition and composition of Caribbean coral reefs, could be altering reef resilience to storms in unexpected ways. For example, the observed decline of fast-growing, disturbance-sensitive species could promote resistance to and decrease recovery from storms3,4, increasingly locking reefs into a state dominated by weedy taxa. To test this hypothesis, we combined data from coral reef monitoring studies and historical hurricane records to develop a regional reef-storm interaction database. We found that as the living cover of Caribbean corals declined over the past 40 years, while resistance to storms increased, despite a concurrent increase in cyclonic storm frequency and intensity. Because storms selectively damaged branching coral species and had no measurable effect on the cover of “weedy” corals, reef composition shifted towards greater weedy dominance and reduced ecological function. Additionally, storms accelerated the loss rate of threatened acroporid corals, already in pre-storm decline, suggesting a worrisome synergism with other climate-related disturbances.

Ecosphere ◽  
2019 ◽  
Vol 10 (11) ◽  
Author(s):  
Bert W. Hoeksema ◽  
Auke‐Florian Hiemstra ◽  
Mark J. A. Vermeij

2018 ◽  
Vol 17 ◽  
pp. 1-14
Author(s):  
Maya Wijsman-Best

In the past, several big expeditions crossed the Indonesian waters. Coral reefs and their amazing structures and inhabitants were always amongst their special interest. Geomorphological reef theories concerning the Sunda shelf in the Pleistocene period and the barrier reefs in the archipelago have been formulated during the first forty years of the present century. Two major areas of research are discussed i.e. the Bay of Jakarta with emphasis on structure and history of one of two coral islands, Nyamuk and Sakit, and the Togian area in Celebes. The rich tertiary coral reefs, east of the Pleistocene Sunda shelf around Celebes, are treated at the hand of the studies of the geologist, J.H.F. UMBGROVE. This author came across several coral reef problems which are still of present day interest e.g. the diversity and variability of the coral species as a result of the complex ecosystem. Two examples are mentioned to give a general idea of the questions arising in different coral species. Nowadays these problems are normally approached from the geological, physiological, ecological or taxonomic point of view. Even so, in the future many field descriptions will have to be carried out along with zoogeographical work in the main centres of taxonomy, before the species of major influence on the structure of the coral reefs can even merely'be listed.


Author(s):  
Zhihua Zhang ◽  
Andy Jones ◽  
M. James C. Crabbe

Purpose Currently, negotiation on global carbon emissions reduction is very difficult owing to lack of international willingness. In response, geoengineering (climate engineering) strategies are proposed to artificially cool the planet. Meanwhile, as the harbor around one-third of all described marine species, coral reefs are the most sensitive ecosystem on the planet to climate change. However, until now, there is no quantitative assessment on the impacts of geoengineering on coral reefs. This study aims to model the impacts of stratospheric aerosol geoengineering on coral reefs. Design/methodology/approach The HadGEM2-ES climate model is used to model and evaluate the impacts of stratospheric aerosol geoengineering on coral reefs. Findings This study shows that (1) stratospheric aerosol geoengineering could significantly mitigate future coral bleaching throughout the Caribbean Sea; (2) Changes in downward solar irradiation, sea level rise and sea surface temperature caused by geoengineering implementation should have very little impacts on coral reefs; (3) Although geoengineering would prolong the return period of future hurricanes, this may still be too short to ensure coral recruitment and survival after hurricane damage. Originality/value This is the first time internationally to quantitatively assess the impacts of geoengineering on coral reefs.


Author(s):  
Mauro Giovanni Zucconi ◽  
Levy D. Obonaga ◽  
Edgardo Londoño-Cruz

Coral reefs are very important and highly biodiverse ecosystems that are exposed to various stressors, including biological ones, such as parasitism and corallivory – the direct consumption of coral tissue by a predator. Knowledge on the effects of corallivory on the coral reefs in the Colombian Pacific is poor. Therefore a study was set up to quantify the abundance of and the corallivory rate by the snail Jenneria pustulata in La Azufrada and Playa Blanca coral reefs (Gorgona Island, Colombia). Snails were manually sampled from the underside of Pocillopora sp. colonies and measured in situ to determine their size structure for each reef. To measure possible damage caused by corallivory, several snails were kept under controlled laboratory conditions for 24 h. Snail sizes and corallivory varied significantly between reefs (P=0.0001; P«0.001). Snails from Playa Blanca were larger than snails from La Azufrada, while corallivory was higher in La Azufrada than in Playa Blanca. Although corallivory rates by J. pustulata are smaller than rates reported for other predators in different coral species, it is recommended to continue this kind of investigations in order to increase the knowledge on biological dynamics of this species and to understand how they affect the reefs at Gorgona Island.


2021 ◽  
Vol 17 (1) ◽  
pp. 35-45
Author(s):  
Dicky Sahetapy ◽  
Laura Siahainenia ◽  
Debby A J Selanno ◽  
Johannes M S Tetelepta ◽  
Novianty C Tuhumury

Coral reef is one of the important coastal ecosystems that have high biodiversity. This study aims to analyze the composition of the taxa and the distribution of coral species, the ecological index of coral communities and the status of coral reefs. The research was conducted from April-May 2019 in the coastal waters of Hukurila Village, South Leitimur District, Ambon City. Collecting coral data by using the Line Intercept Transect (LIT) method. Determination of coral reef condition based on percent data (value) of coral reef cover. During the study, 116 species of stony coral from 49 genera and 16 families were found, which 50 species of them are protected and 23 species of ornamental coral. The similarity index of stony coral species between coral reef locations ranges from 0.52-0.76 or there is the similarity of stony coral species between locations coral reef in the amount of 52-76%. The coral reefs of Hukurila Village have high diversity of coral species, with a low dominance of coral species in the community, and the compatibility of coral species in the community is classified as stable. Acropora corals contributed a low covering percent value (9.98%), while Non-Acropora corals contributed a relatively high percent of covering value (43.56%). The status of coral reefs between locations in the coastal waters of Hukurila Village is in the criteria of good (healthy).   ABSTRAK Terumbu karang merupakan salah satu ekosistem pesisir penting yang emiliki kenanekaragaman hayati tinggi. Penelitian ini bertujuan untuk menganalisis komposisi taksa dan sebaran spesies karang, indeks ekologi kominitas karang dan status terumbu karang. Penelitian dilakukan dari April-Mei 2019 di perairan pesisir Negeri Hukurila Kecamatan Leitimur Selatan Kota Ambon. Pengumpulan data karang menggunakan metode Line Intercept Transect (LIT). Penentuan kondisi terumbu karang berdasarkan data (nilai) persen penutupan karang batu. Selama penelitian ditemukan 116 spesies karang batu dari 49 genera dan 16 famili, dimana 50 spesies diantaranya dilindungi dan 23 spesies karang hias. Indeks similaritas spesies karang batu antar stasiun terumbu karang berkisar antara 0,52-0,76 atau terdapat kesamaan spesies karang batu antar lokasi terumbu karang sebesar 52-76%. Terumbu karang Negeri Hukurila memiliki diversitas spesies karang tinggi, dengan dominansi spesies karang rendah dalam komunitas, dan keserasian spesies karang dalam komunitas tergolong stabil. Karang Acropora memberi kontribusi nilai persen penutupan rendah (9,98%), sementara karang Non-Acropora memberi kontribusi nilai persen penutupan karang batu relatif tinggi (43,56%). Status terumbu karang antar stasiun terumbu perairan pesisir Negeri Hukurila berada dalam kriteria baik (sehat).   Kata kunci: terumbu, karang batu, keragaman spesies, kesamaan, persen penutupan


2021 ◽  
Vol 8 ◽  
Author(s):  
Juan L. Torres-Pérez ◽  
Carlos E. Ramos-Scharrón ◽  
William J. Hernández ◽  
Roy A. Armstrong ◽  
Maritza Barreto-Orta ◽  
...  

Land-based sediment stress represents a threat to many coral reefs in Puerto Rico primarily as a result of unrestricted land cover/land use changes and poor best management practices. The effects of such stresses have been documented along most coasts around the island. However, little attention has been paid to reefs located on the north coast, and very little is known about their composition and current state. Here, we present a study characterizing riverine inputs, water quality conditions, and benthic composition of two previously undescribed coral reefs (Tómbolo and Machuca reefs) located just eastward of the Río Grande de Manatí outlet in north-central Puerto Rico. This study utilizes a time series of remotely sensed ocean color products [diffuse vertical attenuation coefficient at 490 nm (Kd490) and chlorophyll-a concentration (Chl-a) estimated with data from the Visible Infrared Imaging Radiometer Suite (VIIRS)] to characterize water quality in this coastal region. In general, the months with relatively high mean daily river streamflow also coincide with months having the highest proportion of eastward wave direction, which can promote the eastward influence of river waters toward the two coral reefs sites. Kd490 and Chl-a showed a higher riverine influence closer to the watershed outlet. Kd490 and Chl-a monthly peaks also coincide with river streamflow highs, particularly at those pixels closer to shore. Tómbolo Reef, located farther eastward of the river outlet, shows a well-developed primary reef framework mainly composed of threatened reef-building species (Acropora palmata, Pseudodiploria) and high coral cover (19–51%). The benthos of Machuca Reef, located closer to the river outlet, is dominated by macroalgae with a significantly lower coral cover (0.2–2.7%) mainly composed of “weedy” coral species (Porites astreoides and Siderastrea radians). Cover of major benthic components correlates with distance from the river outlet, and with gradients in Kd490 and Chl-a, with higher coral cover and lower macroalgal cover farther from the river outlet. Coral cover at Tómbolo Reef is higher than what has been reported for similar sites around Puerto Rico and other Caribbean islands showing its ecological importance, and as up until now, an unrecognized potential refuge of reef-building threatened coral species.


2015 ◽  
Vol 520 ◽  
pp. 1-20 ◽  
Author(s):  
TC Adam ◽  
DE Burkepile ◽  
BI Ruttenberg ◽  
MJ Paddack

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