scholarly journals Condition of Hard Corals and Quality of The Turbid Waters in Spermonde Islands (Case Studies in Kayangan Island, Samalona Island and Kodingareng Keke Island)

2021 ◽  
Vol 921 (1) ◽  
pp. 012060
Author(s):  
D Parenden ◽  
J Jompa ◽  
C Rani

Abstract Coral reefs in Spermonde waters have experienced degradation as a result of the increasing turbidity in these waters. This research was conducted on Kayangan Island, Samalona Island and Kodingareng Keke Island, Spermonde Islands, Makassar City. The purpose of this study was to determine the percentage of coral cover, types and the how much the turbidity of the waters influence the coral. The researcher measured the coral cover using Underwater Photo Transect and processed the data using CPCe software. The levels of turbidity were taken at three locations and examined in the laboratory and the other parameters were measured on site. The correlation between turbidity and coral cover was analysed by regression analysis method. Based on the regression results, the turbidity level has a negative effect on coral cover. The level of turbidity is higher on Kayangan Island with 0.89 NTU with a cover percentage of 4.95 %, Temperature of 30°C, Salinity of 30 ppm, DO of 5.44 mg/l, pH 7.8 and the species found were Porites and Faviidae. Samalona Island is 0.43 NTU with a percentage of coral cover of 14.08 %, Temperature of 30°C, Salinity of 30 ppm, DO of 5.44 mg/l, pH of 7.7 and the most common types are Acropora and Fungiidae. Kodingareng Keke Island has a turbidity value of 0.32 NTU, Temperature of 29°C, Salinity of 30 ppm, DO of 6.08 mg/l, pH 7.3 and the most common coral species, Fungiidae. Higher levels of turbidity in Kayangan Island will result in the death of certain coral species (unable to adapt) and will also have an impact on the percentage of hard coral cover.

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.


Author(s):  
Eghbert Elvan Ampou ◽  
Suciadi Catur Nugroho ◽  
Nuryani Widagti

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


2020 ◽  
Vol 12 (2) ◽  
pp. 263
Author(s):  
Idris Idris ◽  
Neviaty P. Zamani ◽  
Suharsono Suharsono ◽  
Fakhrurrozi Fakhrurrozi

HighlightDamage to coral reefs by ship aground is twice the area of a football fieldFound four zones of damage including runoff, dune, blow and dispersalMortality of live coral and other benthic biota ranges from 75-100% in the affected locationThe form of damaged live coral growth is predominantly slow growing.Eight hard coral species were found on the IUCN-Redlist list with a vulnerable status.AbstractShip grounding on coral reefs often results in physical and biological damage, including dislodging and removal of corals from reefs, destruction of coral skeletons, erosion and removal of sediment deposits, and loss of three-dimensional complexity. Indonesia, as an archipelagic country, is very vulnerable to various pressures; for example, the case of ship grounding is a great concern of scientists, managers, divers, and sailors themselves. Most of the damage is very severe. The purpose of the research conducted is to identify the condition of the live coral cover, mapping the type and extent of coral reef damage, affected coral species, their conservation status, and to quantify the extent of the area of coral reef damage. Measuring the extent of damage to coral reef ecosystems using the fishbone method, while the level of damage and its impact was measured using the Underwater Photo Transect (UPT) and belt transect method. The event of the grounding of the MV Lyric Poet on the Bangka Waters, Bangka-Belitung Province, has caused damage to the coral reef ecosystem. There are four damage zones identified, i.e., trajectory, mound, propeller, and dispersion zone. Corals are damaged with a total area of 13.540m2; equivalent to twice that of an international football field. Diversity of hard coral found as many as 49 species included in the CITES-Appendix II. A total of eight protected species are included in the IUCN Red List with extinction-prone status.


2021 ◽  
Author(s):  
Allan Elnar ◽  
Christianlly Cena ◽  
Christopher Casenas Bernido ◽  
M. Victoria Carpio-Bernido

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 .


Coral Reefs ◽  
2020 ◽  
Vol 39 (6) ◽  
pp. 1605-1618
Author(s):  
Miriam Reverter ◽  
Matthew Jackson ◽  
Nauras Daraghmeh ◽  
Christian von Mach ◽  
Nina Milton

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.


2020 ◽  
Vol 10 (1) ◽  
Author(s):  
Anna Koester ◽  
Valentina Migani ◽  
Nancy Bunbury ◽  
Amanda Ford ◽  
Cheryl Sanchez ◽  
...  

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.


Author(s):  
J.J. Bell ◽  
J. Jompa ◽  
A. Haris ◽  
S. Werorilangi ◽  
M. Shaffer ◽  
...  

AbstractMesophotic ecosystems have been relatively poorly studied in the Indo-Pacific and in particular within the Coral Triangle region. Here we used a mini-ROV to explore the changes in major benthic groups at two sites (~200 m apart) in the Wakatobi Marine National Park, SE Sulawesi, Indonesia spanning shallow water coral reefs (5 m) to deeper water mesophotic ecosystems (80 m). We found very similar patterns at both sites where coral cover peaked at 15 m, declined rapidly by 30 m, and was virtually absent at 50 m. As coral declined there was a marked increase in sponges, soft corals and other encrusting organisms (including ascidians, bryozoans, tubeworms, gorgonians and molluscs). Importantly, our results differ from most previous studies in other geographic locations where hard corals extend much deeper. It is unclear what drives this difference but it may be related to higher levels of turbidity and therefore reduced light penetration in the Wakatobi compared with other areas, which limits the vertical extent of coral development.


Diversity ◽  
2019 ◽  
Vol 11 (2) ◽  
pp. 23 ◽  
Author(s):  
Eva McClure ◽  
Laura Richardson ◽  
Alexia Graba-Landry ◽  
Zoe Loffler ◽  
Garry Russ ◽  
...  

Cross-shelf differences in coral reef benthic and fish assemblages are common, yet it is unknown whether these assemblages respond uniformly to environmental disturbances or whether local conditions result in differential responses of assemblages at different shelf positions. Here, we compare changes in the taxonomic and functional composition, and associated traits, of herbivorous reef fish assemblages across a continental shelf, five years before and six months after two severe cyclones and a thermal bleaching event that resulted in substantial and widespread loss of live hard coral cover. Each shelf position maintained a distinct taxonomic assemblage of fishes after disturbances, but the assemblages shared fewer species among shelf positions. There was a substantial loss of species richness following disturbances within each shelf position. Total biomass of the herbivorous fish assemblage increased after disturbances on mid- and outer-shelf reefs, but not on inner-shelf reefs. Using trait-based analyses, we found there was a loss of trait richness at each shelf position, but trait specialisation and originality increased on inner-shelf reefs. This study highlights the pervasiveness of extreme environmental disturbances on ecological assemblages. Whilst distinct cross-shelf assemblages can remain following environmental disturbances, assemblages have reduced richness and are potentially more vulnerable to chronic localised stresses.


1995 ◽  
Vol 46 (2) ◽  
pp. 457 ◽  
Author(s):  
VJ Harriott ◽  
PL Harrison ◽  
SA Banks

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.


2003 ◽  
Vol 30 (4) ◽  
pp. 388-407 ◽  
Author(s):  
S.F. Walmsley ◽  
A.T. White

Marine sanctuaries are increasingly being promoted as tools for conservation and fisheries management. This study investigates the effects of protection over 19 years on substrate composition and fish communities in four marine sanctuaries and corresponding non-sanctuary areas in the Philippines and examines the importance of community support, management measures and enforcement of regulations on these ecological effects. Between 1981 and 2000, substrate cover variables were measured using line transects with scuba and snorkel surveys, and fish censuses (identification to family level) were conducted using scuba within a 500 m2 area. Semi-structured interviews collected data on community support for the sanctuaries, and observations and interviews established management and enforcement aspects of the sanctuaries. Over time, all sanctuaries showed improvements, or maintenance of, ecological variables compared with pre-enforcement times, with maintenance of hard coral cover and average increases of 8.3% in fish species richness and 54.9% in fish abundance. In comparison, non-sanctuary areas showed maintenance of the status quo or declines in ecological variables. However hard coral cover, fish abundances and fish species richness showed significant declines as well as increases in sanctuary areas. Community, management and enforcement factors were significantly related to positive ecological trends in sanctuary areas; management and enforcement were related to a wider variety of ecological factors than community score. Community support was significantly related to an increase in hard coral cover in deep areas. Enforcement of regulations was significantly related to an increase in abundance of fishery target fish species in sanctuary areas, and simple management measures were significantly related to an increase in abundance of large predators. Supportive communities that voluntarily implemented sanctuary regulations, improved enforcement, and small discrete cohesive communities may have facilitated the process of building this community support. Well-enforced sanctuaries that showed an increase in abundance of target species may have contributed to the maintenance of fish yields in adjacent non-sanctuary areas. The effects of sanctuary implementation varied on a case-by-case basis, influenced by environmental, biological, physical and human factors. However, a combination of community support, management measures and enforcement of regulations contributed towards positive ecological trends in sanctuary areas.


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