scholarly journals EFFECTIVENESS OF ARTIFICIAL REEF IN INCREASING THE RESILIENCE OF CORAL REEF ECOSYSTEMS OVER CLIMATE VARIABILITY

Jurnal Segara ◽  
2020 ◽  
Vol 16 (2) ◽  
Author(s):  
Reny Puspasari ◽  
Ngurah Nyoman Wiadnyana ◽  
Sri Turni Hartati ◽  
Rita Rachmawati

Some coral bleaching event related to climate variability (ENSO or IOD) lead to coral mortality resulted in ecosystem damage and decreased in ecosystem health.  Artificial reef is one of management efforts adopted by stakeholders to restore coral reef condition.  Successful artificial reef could extend coral coverage and provides a new habitat for several marine organisms and could divert anthropogenic pressure on natural coral ecosystems. The current research aims are to identify the impact of artificial reef installment on ecosystem and fisheries. Three indicators for ecosystem were determined, such as an increase in coral cover, biofouling organism and fish abundance and number of fish species.  The indicator to measure artificial impact on fisheries is fish production after installment.  Data collection were done during 2017 around Bali area, including the occurrence of coral bleaching, the number of artificial reef installed and the case of positive impact of artificial reef.  The list of indicator data was done, then the data were analyzed to measure any changes occurred after artificial reef installment.  Results show that artificial reef installment has a significant impact on increasing coral cover, fouling organism, fish abundance and species richness; however the effect of artificial reef installment could not directly quantify on fish production due to unavailability of monitoring data. 

Hydrobiologia ◽  
2021 ◽  
Author(s):  
L. Saponari ◽  
I. Dehnert ◽  
P. Galli ◽  
S. Montano

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.


2020 ◽  
Vol 6 (1) ◽  
pp. 1
Author(s):  
Mahmudin Mahmudin ◽  
Chair Rani ◽  
Hamzah Hamzah

Dynamite fishing is one of the causes of damage to the coral reef ecosystem in Indonesia. Fishing activities using explosives (dynamite fishing) occur because of the desire of fishermen to get a lot of catch with low cost in a short time. Kapoposang Water Park (WP) is a region rich in marine biological resources. However, dynamite fishing activities which are still found within the area have caused the coral reef ecosystem to be severely damaged. The results showed a lower difference in the percentage of live coral cover at dynamite fishing locations (DF1, DF2) compared to control locations (K1, K2). In addition, the highest average values of coral fish abundance were found at locations K1, DF1, and DF2. Conversely, the results of the analysis found the lowest fish abundance at the K2 location. Different from the average number of reef fish species that were higher at the control location (K1, K2) compared to dynamite fishing locations (DF1, DF2). For the target fish biomass there is no real difference between the control location and dynamite fishing.


2020 ◽  
Vol 100 (7) ◽  
pp. 1093-1106
Author(s):  
Joseph J. Romain ◽  
Dan A. Exton ◽  
David J. Smith ◽  
Amelia Rose ◽  
Clayton Vondriska ◽  
...  

AbstractCleaning mutualisms are important interactions on coral reefs. Intraspecific variation in cleaning rate and behaviour occurs geographically and is often attributed to local processes. However, our understanding of fine-scale variation is limited, but would allow us to control for geography and region-specific behavioural patterns. Here, we compare the cleaning activity of Pederson's cleaner shrimp (Ancylomenes pedersoni) on two neighbouring, yet ecologically dissimilar, reef systems in Honduras: Banco Capiro, an offshore bank close to significant land runoff with high coral cover but a depleted fish population, and an oligotrophic fringing reef around the island of Utila, with lower coral cover but high fish abundance and diversity. The proportion of realized to potential fish clientele was <60% at both sites, and the composition of clientele was neither reflective of the demographics of the resident assemblages at each site nor similar between sites. Parrotfishes represented 13–15% of total fish abundance at both sites yet accounted for >50% (Banco Capiro) and 10% (Utila) of all cleans. Conversely, the schoolmaster snapper (Lutjanus apodus) represented ~1% of total fish abundance at both sites yet accounted for 40% (Utila) and 1% (Banco Capiro) of all cleans. After standardizing our cleaning rate data by clientele abundance, we find that clientele at Banco Capiro engage in over four times as many cleaning encounters per hour with A. pedersoni than at Utila. Our study highlights the variable nature of coral reef cleaning interactions and the need to better understand the ecological and environmental drivers of this biogeographic variation.


2020 ◽  
Vol 9 (1) ◽  
pp. 72-80
Author(s):  
Ary Hendri Pribadi ◽  
Suryanti Suryanti ◽  
Churun Ain

ABSTRAK Pulau Karimunjawa adalah salah satu objek destinasi wisata keindahan ekosistem terumbu karang. Kunjungan wisatawan di Karimunjawa dapat berdampak pada terumbu karang dan nilai ekonomi pariwisata. Penelitian ini dilaksanakan pada April-Mei 2019 di Kepulauan Karimunjawa, Kabupaten Jepara. Tujuan dari penelitian ini untuk mengetahui dampak pariwisata terhadap nilai status tutupan terumbu karang dengan menggunakan metode Line Intercept Transect (LIT) di Pulau Tanjung Gelam, Pulau Menjangan Besar dan Pulau Cemara Kecil serta nilai valuasi ekonomi pariwisata dengan menggunakan metode biaya perjalanan atau Travel Cost Method (TCM). Hasil yang didapatkan dari penelitian ini yaitu jumlah kunjungan wisatawan yang datang ke Pulau Karimunjawa meningkat sejak tahun 2016 hingga tahun 2018. Kondisi status tutupan terumbu karang yang diperoleh dalam kondisi baik dengan nilai karang hidup yang didapatkan pada Pulau Tanjung Gelam 61,6%, Pulau Menjangan Besar 70,8% dan Pulau Cemara Kecil 57,3%. Luasan terumbu karang pada tahun 2016 hingga tahun 2018 di Pulau Mejangan Besar dan Cemara Kecil mengalami penurunan. Sedangkan nilai valuasi ekonomi tahun 2016 sejumlah Rp.125.426.860,- 2017 dan 2018 sejumlah Rp.135.437.480,- dan Rp.156.932.039,-. Dampak wisatawan yang berkunjung tahun 2016-2018 pada valuasi ekonominya tiap tahunnya mengalami peningkatan. Hasil nilai valuasi ekonomi yang didapatkan pada penelitian ini,nilai rata-rata TCM pada wilayah Kabupaten Jepara Rp.1.111.023,- dan nilai ekonomi pertahunnya Rp.3.369.031.988,-. Rata-rata biaya perjalanan luar wilayah Kabupaten Jepara Rp.1.146.314,- dan nilai biaya pertahunnya Rp.12.324.171.938,-. Nilai total valuasi ekonomi dari dalam wilayah Kabupaten Jepara dan luar wilayah Kabupaten Jepara yaitu Rp.156.693.203.925,-. ABSTRACT Karimunjawa Island is one of the tourist destinations of the beauty of the coral reef ecosystem. Tourist visits in Karimunjawa can have an impact on coral reefs and the economic value of tourism. This research was conducted in April-May 2019 in the Karimunjawa Islands, Jepara Regency. The purpose of this study was to determine the impact of tourism on the status of coral cover status using the Line Intercept Transect (LIT) method on Tanjung Gelam Island, Menjangan Besar Island and Cemara Kecil Island and the economic valuation value of tourism using the travel cost method or the Travel Cost Method ( TCM). The results obtained from this study are the number of tourist arrivals to Karimunjawa Island increased from 2016 to 2018. The status of coral cover status obtained in good condition with the value of live coral obtained on Pulau Tanjung Gelam 61.6%; Pulau Menjangan Besar 70.8% and Pulau Cemara Kecil 57.3%. The extent of coral reefs in 2016 to 2018 on Pulau Mejangan Besar and Pulau Cemara Kecil declined. While the value of economic valuations in 2016 amounted to Idr.125,426,860,- 2017 and 2018 amounted to Idr.135,437,480,- and Idr.156,932,039,-. The impact of tourists visiting 2016-2018 on their economic valuations has increased each year. The results of the economic valuation obtained in this study, the average value of TCM in the Jepara Regency region is Idr.1,111,023, and the annual economic value is Idr.3,369,031,988. The average cost of trips outside the area of Jepara Regency is Idr.1,146,314, and the annual cost is Idr.12,321,171,938. The total value of economic valuations from within the Jepara Regency and outside the Jepara Regency is Idr.156,693,203,925. 


2021 ◽  
Author(s):  
Mohit Arora ◽  
Kalyan De ◽  
Nandini Ray Chaudhury ◽  
Mandar Nanajkar ◽  
Prakash Chauhan ◽  
...  

Coral reefs are one of the most sensitive, productive, and invaluable biological resources on the earth. However, coral reefs are facing unprecedented stress due to ongoing climate changes and intensified anthropogenic disturbances globally. Elevated Sea Surface Temperature (SST) has emerged as the most imminent threat to the thermos-sensitive reef-building corals. The 2010–2014-2016 El Niño Southern Oscillation (ENSO) caused prolonged marine heat waves (MHWs) that led to the most widespread coral bleaching and mortality in the tropical Indi-Pacific regions. Coral bleaching prediction is vital for the management of the reef biodiversity, ecosystem functioning, and services. Recent decades, satellite remote sensing has emerged as a convenient tool for large-scale coral reef monitoring programs. As thermal stress is a critical physical attribute for coral bleaching hence, the present study examines the effectiveness of the elevated SSTs as a proxy to predict coral bleaching in shallow water marginal reefs. Advanced Very High-Resolution Radiometer (AVHRR) satellite data from the NOAA Coral Reef Watch’s (CRW) platform has been used for this study. Coral bleaching indices like Bleaching Threshold (BT), Positive SST Anomaly (PA), and Degree Heating Weeks (DHW) are computed to analyze the thermal stress on the coral reefs. The computed thermal stress from satellite-derived SST data over regions concurrence with the mass coral bleaching (MCB) events. This study concludes that in the last decades (2010 to 2019) the coral cover around these regions has dramatically declined due to higher SST, which indicates that the thermal stress induced recurrent bleaching events attributed to the coral loss.


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.


PeerJ ◽  
2016 ◽  
Vol 4 ◽  
pp. e2084 ◽  
Author(s):  
Adam Suchley ◽  
Melanie D. McField ◽  
Lorenzo Alvarez-Filip

Long-term phase shifts from coral to macroalgal dominated reef systems are well documented in the Caribbean. Although the impact of coral diseases, climate change and other factors is acknowledged, major herbivore loss through disease and overfishing is often assigned a primary role. However, direct evidence for the link between herbivore abundance, macroalgal and coral cover is sparse, particularly over broad spatial scales. In this study we use a database of coral reef surveys performed at 85 sites along the Mesoamerican Reef of Mexico, Belize, Guatemala and Honduras, to examine potential ecological links by tracking site trajectories over the period 2005–2014. Despite the long-term reduction of herbivory capacity reported across the Caribbean, the Mesoamerican Reef region displayed relatively low macroalgal cover at the onset of the study. Subsequently, increasing fleshy macroalgal cover was pervasive. Herbivorous fish populations were not responsible for this trend as fleshy macroalgal cover change was not correlated with initial herbivorous fish biomass or change, and the majority of sites experienced increases in macroalgae browser biomass. This contrasts the coral reef top-down herbivore control paradigm and suggests the role of external factors in making environmental conditions more favourable for algae. Increasing macroalgal cover typically suppresses ecosystem services and leads to degraded reef systems. Consequently, policy makers and local coral reef managers should reassess the focus on herbivorous fish protection and consider complementary measures such as watershed management in order to arrest this trend.


2021 ◽  
Vol 10 (2) ◽  
pp. 151-161
Author(s):  
Insafitri Insafitri ◽  
Eka Nurahemma Ning Asih ◽  
Wahyu Andy Nugraha

Wisata snorkeling terumbu karang di perairan pulau Gili Labak merupakan salah satu sektor wisata bahari yang sedang dikembangkan oleh pemerintah kebupaten Sumenep Madura sejak tahun 2014 hingga saat ini. Peningkatan jumlah wisatawan yang terjadi pada beberapa tahun terakhir dapat menimbulkan resiko tekanan dan kerusakan ekosistem terumbu karang di area snorkeling secara berkala. Penelitian ini bertujuan untuk mengetahui dampak kegiatan wisatawan sebelum, selama dan sesudah snorkeling terhadap ekosistem terumbu karang yang dikaji dengan mengetahui jenis karang yang mendominasi, status persentase tutupan terumbu karang serta potensi Dampak Wisata Bahari (DWB) snorkeling di lokasi wisata snorkeling pulau Gili Labak Sumenep. Persentase penutupan lifeform karang pulau Gili Labak khususnya di area snorkelling didominasi oleh karang hidup sebanyak 74% dan unsur abiotik sebesar 22%. Jenis karang yang mendominasi pulau Gili Labak adalah Acropora Branching sebesar 19,88% dan Coral Foliose sebesar 10,25%. Selama waktu 6 minggu pengamatan terjadi penurunan total karang sebesar 0,64% yang termasuk kategori rusak ringan, dimana sebagian besar kerusakan terjadi pada karang dengan bentuk pertumbahan branching misalnya Acropora Submassive dan Coral Submassive. Penurunan persen tutupan karang yang tinggi terjadi setelah kegiatan snorkeling (after) yang dilakukan oleh wisatawan. Analisa potensi Dampak Wisata Bahari (DWB) snorkeling pada terumbu karang di perairan Gili Labak selama 6 minggu pengamatan masuk dalam kategori rendah yaitu berkisar 0,052% hingga 0,085%. Faktor penyebab kecilnya nilai presentase Dampak Wisata Bahari (DWB) ini diduga karena waktu pengamatan cenderung pendek dan jenis karang yang mendominasi yaitu Acropora. Acropora memiliki kemampuan regenerasi lebih cepat dibandingkan jenis lainnya.  The snorkeling activity around coral reefs in the waters of Gili Labak is one of the marine tourism sectors that is being developed by the Sumenep Madura district government since 2014. Increasing number of tourists that occurs in recent years pose a risk of pressure and damage to coral reef ecosystems in the snorkeling area. This study aims to determine the impact of tourist activities before, during and after snorkeling on coral reef ecosystems that are studied by knowing the type of dominated coral, the percentage status of coral cover and the potential Impact of snorkeling at the snorkeling sites of the island of Gili Labak Sumenep. The percentage of coral cover in the island of Gili Labak especially in the snorkelling area is dominated by live coral ( 74%) and abiotic elements by 22%. Coral species that dominate the island of Gili Labak are Acropora Branching at 19.88% and Coral Foliose at 10.25%. During the 6-week observation there was a decrease in live coral cover by 0.64% which was categorized as minor damage, most of the damage occurred to branching   Acropora, sub-massive Acropora and Coral Sub-massive. The high percent decrease in coral cover occurred after snorkeling conducted by tourists. Analysis of the potential impact of snorkeling on coral reefs in the waters of Gili Labak for 6 weeks of observation is in the low category, ranging from 0.052% to 0.085%. The factor causing the small impact of Marine Tourism is presumably because the observation time tends to be short and the dominant coral species is Acropora. Acropora has the ability to regenerate faster than other types.


Rekayasa ◽  
2019 ◽  
Vol 12 (1) ◽  
pp. 24
Author(s):  
Elok Faiqoh ◽  
I Wayan Gede Astawa Karang ◽  
Dwi Budi Wiyanto

<p>ABSTRAK<br />Pemutihan karang merupakan salah satu dampak dari perubahan iklim global, kenaikan suhu tersebut memberikan dampak negatif bagi keseimbangan ekosistem terumbu karang. ­Terumbu karang yang memutih dan kehilangan zooxanthella nya akan rentan terkena infeksi dan penyakit. Populasi komunitas ikan karang pemakan hewan karang dan makrozoobenthos juga akan menurun. Tujuan dari penelitian ini adalah untuk mengetahui besar dampak kerusa­kan terumbu karang dan dampaknya bagi populasi ikan dan makrozoobenthos. Survey dilakukan pada 3 titik di wilayah perairan Tejakula dengan metode reefcheck. Hasil penelitian menunjukkan kematian terumbu karang sebesar 5-7.5%, jumlah alga yang menutupi 3.125%. Kondisi ikan kepe-kepe yang merupakan pemakan hewan karang juga sudah ditemukan dalam jumlah cukup banyak. Keberadaan ikan herbivora dan makrozoobenthos herbivore membantu mengurangi jumlah alga yang menutupi. Sedangkan keberadaan ikan pemakan terumbu karang dan ikan predator memperlihatkan bahwa sistem ekologi yang ada di terumbu karang tersebut hampir kembali normal. <br />Kata Kunci: terumbu karang, komunitas ikan karang, makrozoobenthos.</p><p><strong>The Impact of Hard Coral Bleaching in Coral and Macrozoobenthos Fish Communities in Tejakula, Buleleng, Bali Water Areas</strong></p><p>ABSTRACT<br />Coral bleaching is one of the consequences of global climate change, as the rise of temperature negatively impacts the ecological balance of reef ecosystems. Bleached coral reefs lose their zooxanthellae, increasing vulnerability to infection and disease and consequently, causing population decline of macrozoobenthos and reef fish communities which prey on coral-consuming organisms. This research aims to determine the degree of coral reef damage and its impact on fish and macrozoobenthos population. The survey was conducted on 3 stations in Tejakula waters with the reef check method. Results show that coral reef death reaches 5-7.5%, with algal coverage of 3.125%. Kepe-kepe fish which prey on coral-consuming animals were also found in relatively high abundance. The presence of herbivore fish and macrozoobenthos help reduce algal cover. Meanwhile, the presence of coral-consuming and predator fish indicate that the coral reef ecological system has mostly returned to normal. <br />Keywords: coral reef, reef fish community, macrozoobenthos</p>


2020 ◽  
Vol 12 (1) ◽  
pp. 131
Author(s):  
Wahyu Andy Nugraha ◽  
Faizun Mubarak ◽  
Eko Husaini ◽  
Hasyim Evendi

HighlightsCoral cover, rugosity, and reef fish abundance was determinedThe relationship between coral cover and rugosity and fish abundance was analyzed.Coral cover in East Java were categorized as medium – good.The rugosity index and the fish abundance were highest in Bangsring Waters.There are no relationships between coral cover and fish abundance, but there is relationship between rugosity and fish abundance.AbstractA coral reef is one of the most complex and specific ecosystems in a tropical area. It is identified by its high productivity and biodiversity. This research aims to discover the percentage of coral reef cover and rugosity, as well as the fish abundance in several locations in East Java, Indonesia. In addition, this research aims to investigate the correlation of coral reef cover and rugosity with the density of coral reef fish. This research was conducted in three locations, i.e., Bangsring Waters of Wongsorejo District, Banyuwangi Regency; Gili Noko Bawean Island, Gresik Regency; and Kramat Island, Gili Genting District, Sumenep Regency. This research employed the Line Intercept Transect (LIT) method to calculate the percentage of coral reef cover, the Chain Intercept Transect (CIT) method to determine the coral reef rugosity, and the Belt Transect method to estimate the fish abundance. From this research, it was revealed that the highest coral reef cover was in Bawean waters, while the highest rugosity was in Bangring waters. In addition, the highest coral reef fish density was in Bangsring waters. Meanwhile, the coral reef fish density did not correlate with the percentage of coral reef cover. In contrast, it correlated with the coral reef rugosity. 


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