The change of coral cover in Ujong Pancu waters, Peukan Bada Sub-District, Aceh Besar

Coral reef ecosystems are one of the most productive ecosystems on the earth, with large ecological functions. The disruption of coral reef ecosystems has a significant impact on the surrounding biota. This study aims to determine the condition of coral reefs for the last three years in Ujong Pancu waters, Peukan Bada sub-district, Aceh Besar district. This study uses data in 2017, 2018, and 2019 with three observation locations: Lhok Keeutapang, Lhok Mata Ie, and Tuan Island. The method used is Point Intercept Transect (PIT) with a transect length of 20 m with four repetitions. The results showed that the percentage of hard coral cover in the Ujong Pancu waters decreased from the good category (50.31%) in 2017 to moderate (47.81%) in 2019. The percentage with the highest coral cover was at the Lhok Keutapang location at 72, 81% in 2018, while the lowest coral cover at the Tuan Island location was 15.94% in 2017. The composition of the coral genus found also decreased from 12 coral genera (2017) to 9 coral genera (2019).

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

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.

KONDISI TERUMBU KARANG PADA KAWASAN WISATA PANTAI MALALAYANG KOTA MANADO PROVINSI SULAWESI UTARA DENGAN MENGGUNAKAN METODE UNDERWATER PHOTO TRANSECT

Coral reefs are coastal ecosystems with the highest level of diversity with around one million species worldwide. Corals are invertebrates belonging to the Phylum Coelenterate (hollow animals) or Cnidaria. The Underwater Photo Transect (UPT) method is a method that utilizes technological developments, both digital camera technology and computer software technology. Capturing data in the field in the form of underwater photos carried out by shooting using a Canon G-16 camera equipped with a waterproof protector (housing). In this study it can be seen that the percentage of hard corals at point 1 is in the medium category, point 2 is in the medium category, and point 3 is in the bad category with the percentage of hard coral cover as follows: point 1 (one) 29.75%, point 2 (two) 31.16%, and point 3 (three) 24.26%, of the three points can represent the overall condition of the coral reefs in Malalayang Beach which is in moderate condition with a percentage of 28.39%.Keywords: Malalayang Beach, Coral Reef, UPT, CPCe

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

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 .

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

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.

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

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.

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

Corals 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.

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

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

Kelimpahan dan Biomassa Ikan Karang Famili Scaridae pada Ekosistem Terumbu Karang di Perairan Pulau Kembar, Karimunjawa, Jepara

ABSTRAK : Ikan kakatua merupakan salah satu ikan karang yang dapat membantu kehidupan pada ekosistem terumbu karang. Scaridae mengumpulkan berbagai spesies ganggang dengan cara memakan algae pendek yang menutupi substrat karang sehingga dapat mempengaruhi pertumbuhan terumbu karang. Sebaran Scaridae sangat ditentukan oleh kondisi dan variasi habitat terumbu karang. Penelitian ini bertujuan untuk mengetahui kelimpahan dan biomassa dari ikan Famili Scaridae. Penelitian dilaksanakan pada bulan Oktober 2018 di Perairan Pulau Kembar, Karimunjawa, Jepara. Pengambilan data ikan karang menggunakan metode UVC dan data substrat terumbu karang diambil menggunakan metode LIT sepanjang 100 meter sejajar garis pantai dengan pengamatan pada dua kedalaman yaitu 3m dan 10m. Berdasarkan hasil penelitian, didapatkan 11.459 individu yang termasuk dalam 49 spesies ikan karang yang berasal dari 14 famili. Ikan karang dari Famili Scaridae ditemukan sebanyak 1059 individu yang termasuk dalam 4 spesies ikan karang yang berasal dari 2 genus. Nilai kelimpahan ikan karang dari Famili Scaridae berkisar antara 48 hingga 204 ind/500m2, kelimpahan terendah berada pada stasiun 1 dan tertinggi berada di stasiun 3. Nilai biomassa ikan karang dari Famili Scaridae berkisar antara 219,7–2491,7 kg/ha, biomassa terendah berada pada stasiun 1 dan tertinggi berada di stasiun 3. Berdasarkan hasil penelitian dapat disimpulkan bahawa Pengaruh tutupan karang keras hidup sangat berpengaruh terhadap kelimpahan dan biomassa ikan karang dari Famili Scaridae. ABSTRACT : Parrot fish is one of the reef fish that can help life on the coral reef ecosystem. Scaridae collect various species of algae by eating short algae that cover the coral substrate so that it can affect the growth of coral reefs. Scaridae distribution is highly determined by the condition and variety of coral reef habitats. This study aims to examine the abundance and biomass of Scaridae Family fish. The study was conducted in October 2018 in the waters of the Kembar Islands, Karimunjawa, Jepara. Retrieval of reef fish data using UVC method and coral reef substrate data were taken using the LIT method along 100 meters along the coastline with observations at two depths in 3m and 10. Based on the results, 11,459 individuals were included in 49 species of reef fish originating from 14 families. Coral fish from the Family Scaridae were found as many as 1059 individuals included in 4 species of reef fish originating from 2 genera. The value of coral fish abundance from the Scaridae Family ranges from 48 to 204 ind / 500m2, the lowest abundance is at station 1 and the highest is at station 3. The reef fish biomass value of the Scaridae Family ranges from 219.7 - 2491.7 kg / ha, biomass the lowest is at station 1 and the highest is at station 3. Based on the results of the study it can be concluded that the effect of live hard coral cover is very influential on the abundance and biomass of reef fish from the Scaridae Family.

Coral Restoration Effectiveness: Multiregional Snapshots of the Long-Term Responses of Coral Assemblages to Restoration

Coral restoration is rapidly becoming a mainstream strategic reef management response to address dramatic declines in coral cover worldwide. Restoration success can be defined as enhanced reef functions leading to improved ecosystem services, with multiple benefits at socio-ecological scales. However, there is often a mismatch between the objectives of coral restoration programs and the metrics used to assess their effectiveness. In particular, the scales of ecological benefits currently assessed are typically limited in both time and space, often being limited to short-term monitoring of the growth and survival of transplanted corals. In this paper, we explore reef-scale responses of coral assemblages to restoration practices applied in four well-established coral restoration programs. We found that hard coral cover and structural complexity were consistently greater at restored compared to unrestored (degraded) sites. However, patterns in coral diversity, coral recruitment, and coral health among restored, unrestored, and reference sites varied across locations, highlighting differences in methodologies among restoration programs. Altogether, differences in program objectives, methodologies, and the state of nearby coral communities were key drivers of variability in the responses of coral assemblages to restoration. The framework presented here provides guidance to improve qualitative and quantitative assessments of coral restoration efforts and can be applied to further understanding of the role of restoration within resilience-based reef management.