scholarly journals Sediment suppresses herbivory across a coral reef depth gradient

2012 ◽  
Vol 8 (6) ◽  
pp. 1016-1018 ◽  
Author(s):  
Christopher H. R. Goatley ◽  
David R. Bellwood
Keyword(s):  
Coral Reef ◽  
Coral Reefs ◽  
Reef Fishes ◽  
Reef Crest ◽  
Depth Gradient ◽  
Ecological Processes ◽  
Natural Sediment ◽  
Fish Feeding ◽  
Sediment Loads

Sediments are a ubiquitous feature of all coral reefs, yet our understanding of how they affect complex ecological processes on coral reefs is limited. Sediment in algal turfs has been shown to suppress herbivory by coral reef fishes on high-sediment, low-herbivory reef flats. Here, we investigate the role of sediment in suppressing herbivory across a depth gradient (reef base, crest and flat) by observing fish feeding following benthic sediment reductions. We found that sediment suppresses herbivory across all reef zones. Even slight reductions on the reef crest, which has 35 times less sediment than the reef flat, resulted in over 1800 more herbivore bites (h −1 m −2 ). The Acanthuridae (surgeonfishes) were responsible for over 80 per cent of all bites observed, and on the reef crest and flat took over 1500 more bites (h −1 m −2 ) when sediment load was reduced. These findings highlight the role of natural sediment loads in shaping coral reef herbivory and suggest that changes in benthic sediment loads could directly impair reef resilience.

Prominence of environmental and anthropogenic agents on the occurrence of coral reef bleaching syndrome and coral diseases

2024 ◽  
Vol 74 (10) ◽  
pp. 6139-2024
Author(s):  
MICHAŁ SCHULZ ◽  
ALEKSANDRA ŁOŚ ◽  
PATRYCJA SKOWRONEK ◽  
ANETA STRACHECKA
Keyword(s):  
Coral Reef ◽  
Coral Reefs ◽  
Oil Spills ◽  
Global Scale ◽  
Ecological Processes ◽  
Coral Diseases ◽  
Rapid Changes ◽  
Anthropogenic Threats ◽  
Negative Factors ◽  
Main Relationship

Coral reefs are the most productive ecosystems on Earth. They ensure the conservation of biodiversity and are a live habitat for 25% of all marine organisms. The main relationship on the coral reef is the symbiosis between corals and algae from the genus Symbiodinium (commonly called zooxanthellae). The authors of this publication have characterized and described the factors limiting the occurrence of coral reefs, including: water temperature, salinity, access to sunlight, contamination, physicochemical and hydromechanical parameters of water. Moreover anthropogenic threats to coral reefs have been specified, including diving tourism, ecological disasters (e.g. oil spills) and the development of marine aquaristics. Rapid changes in the basic living conditions are dangerous for corals and their symbionts and may cause the unsuitability of the new environment resulting in diseases such as coral bleaching. Corals bleaching is a disease associated with the break of the coral and algae relationship which results in a coral reef death on a global scale. Awareness of these negative factors, often related to human activity, may allow us to better understand the ecological processes that are the basis of reef functioning and might enable us to prevent and oppose to the changes and ecological recessions of coral reefs.

scholarly journals Assessing the impact of static and fluctuating ocean acidification on the behavior of Amphiprion percula

2021 ◽  
Author(s):  
Matthew A. Vaughan ◽  
Danielle L. Dixson
Keyword(s):  
Coral Reef ◽  
Ocean Acidification ◽  
Reef Fishes ◽  
Amphiprion Percula ◽  
Behavioral Abnormalities ◽  
Negative Impacts ◽  
Ground Truthing ◽  
Chemosensory Behavior ◽  
The Impact

AbstractCoral reef organisms are exposed to both an increasing magnitude of pCO2, and natural fluctuations on a diel scale. For coral reef fishes, one of the most profound effects of ocean acidification is the impact on ecologically important behaviors. Previous behavioral research has primarily been conducted under static pCO2 conditions and have recently come under criticism. Recent studies have provided evidence that the negative impacts on behavior may be reduced under more environmentally realistic, fluctuating conditions. We investigated the impact of both present and future day, static (500 and 1000 μatm) and diel fluctuating (500 ± 200 and 1000 ± 200 μatm) pCO2 on the lateralization and chemosensory behavior of juvenile anemonefish, Amphiprion percula. Our static experimental comparisons support previous findings that under elevated pCO2, fish become un-lateralized and lose the ability to discriminate olfactory cues. Diel-fluctuating pCO2 may aid in mitigating the severity of some behavioral abnormalities such as the chemosensory response, where a preference for predator cues was significantly reduced under a future diel-fluctuating pCO2 regime. This research aids in ground truthing earlier findings and contributes to our growing knowledge of the role of fluctuating conditions.

6. Reef fish and other major predators

2014 ◽  
Author(s):  
Charles Sheppard
Keyword(s):  
Coral Reef ◽  
Coral Reefs ◽  
Reef Fish ◽  
Feeding Ecology ◽  
Natural Habitat ◽  
Marine Species ◽  
Reef Fishes ◽  
Symbiotic Relationships ◽  
The Earth ◽  
Reef Communities

Healthy reefs provide a habitat for an immense number of fish that come in a variety of shapes, sizes, and colours. No other natural habitat in the ocean shows this diversity and abundance. About a quarter of all marine species may be found on coral reefs even though this habitat occupies only one or two per cent of the area of the earth. ‘Reef fish and other major predators’ describes the diverse feeding ecology of reef fishes; coral reef predators such as the colourful crown of thorns starfish, Acanthaster plancii; symbiotic relationships between different species of fish or with different invertebrates; and the dangers of overfishing in reef communities.

The scientific issues surrounding remote detection of submerged coral ecosystems

1998 ◽  
Vol 22 (2) ◽  
pp. 190-221 ◽  
Author(s):  
Heather Holden ◽  
Ellsworth LeDrew
Keyword(s):  
Remote Sensing ◽  
Coral Reef ◽  
Coral Reefs ◽  
Large Scale ◽  
Aerial Photographs ◽  
Coastal Zones ◽  
Global Status ◽  
Coral Reef Ecosystems ◽  
Remote Estimation

According to the 1993 colloquium on the ‘Global status of coral reefs', our understanding of the global role of coral reefs is inadequate. To increase our understanding, an accurate large-scale mapping and monitoring programme is necessary. Historically, coastal zones have been mapped using traditional surveying tools such as topographic maps, nautical charts, existing aerial photographs and direct observations. Although less expensive than digital imagery, exclusive use of these traditional tools may not be practical for monitoring large or remote coral reef ecosystems accurately. Researchers are attempting to develop an adequate coral reef mapping system based on digital remote sensing, but are impeded by issues such as effects of the intervening water column and spectral distinction of bottom types. The two variables discussed, which will contribute to our understanding of the global role of coral reefs, are: 1) remote sensing of submerged coral reefs in general; and 2) remote sensing of coral bleaching in particular. A summary of radiative transfer theory is presented and case studies of attempts at mapping remotely the geographic extent and health of submerged ecosystems, as well as a discussion of the remote estimation of water depth and quality. Problems in the translation and delivery of information to the end user are presented, and possible solutions suggested.

scholarly journals Digging for DNA at depth: rapid universal metabarcoding surveys (RUMS) as a tool to detect coral reef biodiversity across a depth gradient

PeerJ ◽  
2019 ◽  
Vol 7 ◽  
pp. e6379 ◽  
Author(s):  
Joseph D. DiBattista ◽  
James D. Reimer ◽  
Michael Stat ◽  
Giovanni D. Masucci ◽  
Piera Biondi ◽  
...  
Keyword(s):  
Coral Reef ◽  
Coral Reefs ◽  
Indicator Species ◽  
18S Rrna ◽  
Spatial Scales ◽  
Environmental Dna ◽  
Marine Biodiversity ◽  
Depth Gradient ◽  
Coral Reef Ecosystems ◽  
Eukaryotic Organisms

Background Effective biodiversity monitoring is fundamental in tracking changes in ecosystems as it relates to commercial, recreational, and conservation interests. Current approaches to survey coral reef ecosystems center on the use of indicator species and repeat surveying at specific sites. However, such approaches are often limited by the narrow snapshot of total marine biodiversity that they describe and are thus hindered in their ability to contribute to holistic ecosystem-based monitoring. In tandem, environmental DNA (eDNA) and next-generation sequencing metabarcoding methods provide a new opportunity to rapidly assess the presence of a broad spectrum of eukaryotic organisms within our oceans, ranging from microbes to macrofauna. Methods We here investigate the potential for rapid universal metabarcoding surveys (RUMS) of eDNA in sediment samples to provide snapshots of eukaryotic subtropical biodiversity along a depth gradient at two coral reefs in Okinawa, Japan based on 18S rRNA. Results Using 18S rRNA metabarcoding, we found that there were significant separations in eukaryotic community assemblages (at the family level) detected in sediments when compared across different depths ranging from 10 to 40 m (p = 0.001). Significant depth zonation was observed across operational taxonomic units assigned to the class Demospongiae (sponges), the most diverse class (contributing 81% of species) within the phylum Porifera; the oldest metazoan phylum on the planet. However, zonation was not observed across the class Anthozoa (i.e., anemones, stony corals, soft corals, and octocorals), suggesting that the former may serve as a better source of indicator species based on sampling over fine spatial scales and using this universal assay. Furthermore, despite their abundance on the examined coral reefs, we did not detect any octocoral DNA, which may be due to low cellular shedding rates, assay sensitivities, or primer biases. Discussion Overall, our pilot study demonstrates the importance of exploring depth effects in eDNA and suggest that RUMS may be applied to provide a baseline of information on eukaryotic marine taxa at coastal sites of economic and conservation importance.

scholarly journals DIVERSITY OF REEF FISH FUNGSIONAL GROUPS IN TERMS OF CORAL REEF RESILIENCES

2017 ◽  
Vol 22 (2) ◽  
pp. 109
Author(s):  
Isa Nagib Edrus ◽  
Muhammad Abrar Abrar
Keyword(s):  
Coral Reef ◽  
Reef Fish ◽  
Functional Groups ◽  
Data Gathering ◽  
Reef Fishes ◽  
Fish Diversity ◽  
Infrastructure Development ◽  
Management Actions ◽  
Resilience Indicators

Infrastructure development in the particular sites of  Seribu Islands as well as those in main land of Jakarta City increased with coastal population this phenomenon is likely to increase the effects to the adjacent coral waters of Seribu Islands.  Chemical pollutants, sedimentation, and domestic wastes are the common impact and threatening, the survival of coral reef ecosystem. Coral reef resiliences naturaly remained on their processes under many influences of supporting factors. One of the major factor is the role of reef fish functional groups on controling algae growth to recolonize coral juveniles. The  aim of this study to obtain data of a herbivory and other fish functional groups of reef fishes in the Pari Islands that are resilience indicators, or that may indicate the effectiveness of management actions. A conventional scientific approach on fish diversity and abundance data gathering was conducted by the underwater visual cencus. Diversity values of the reef fish functional groups, such as the abundance of individual fish including species, were collected and tabulated by classes and weighted as a baseline to understand the resilience of coral reed based on Obura and Grimsditch (2009) techniques. The results succesfully identified several fish functional groups such as harbivores (21 species), carnivores (13 species) and fish indicator (5 species) occurred in the area. Regarding the aspects of fish density and its diversity, especially herbivorous fish functional group, were presumably in the state of rarely available to support the coral reef resiliences. Resilience indices ranged from 1 (low level) to 3 (moderate level) and averages of the quality levels ranged from 227 to 674. These levels were inadequate to support coral reef recolonization.

scholarly journals Warming has a greater effect than elevated CO 2 on predator–prey interactions in coral reef fish

2017 ◽  
Vol 284 (1857) ◽  
pp. 20170784 ◽  
Author(s):  
Bridie J. M. Allan ◽  
Paolo Domenici ◽  
Sue Ann Watson ◽  
Philip L. Munday ◽  
Mark I. McCormick
Keyword(s):  
High Temperature ◽  
Coral Reef ◽  
High Temperatures ◽  
Swimming Performance ◽  
Reef Fishes ◽  
Independent Effect ◽  
Combined Effects ◽  
Ecological Processes ◽  
Predator Prey ◽  
Short Term Exposure

Ocean acidification and warming, driven by anthropogenic CO 2 emissions, are considered to be among the greatest threats facing marine organisms. While each stressor in isolation has been studied extensively, there has been less focus on their combined effects, which could impact key ecological processes. We tested the independent and combined effects of short-term exposure to elevated CO 2 and temperature on the predator–prey interactions of a common pair of coral reef fishes ( Pomacentrus wardi and its predator, Pseudochromis fuscus ). We found that predator success increased following independent exposure to high temperature and elevated CO 2 . Overall, high temperature had an overwhelming effect on the escape behaviour of the prey compared with the combined exposure to elevated CO 2 and high temperature or the independent effect of elevated CO 2 . Exposure to high temperatures led to an increase in attack and predation rates. By contrast, we observed little influence of elevated CO 2 on the behaviour of the predator, suggesting that the attack behaviour of P. fuscus was robust to this environmental change. This is the first study to address how the kinematics and swimming performance at the basis of predator–prey interactions may change in response to concurrent exposure to elevated CO 2 and high temperatures and represents an important step to forecasting the responses of interacting species to climate change.

scholarly journals Tutupan makroalga pada terumbu karang di kawasan konservasi perairan (KKP) Nusa Penida, Bali

DEPIK ◽  
2018 ◽  
Vol 7 (1) ◽  
pp. 69-75
Author(s):  
Muhammad Akhyar Maududi ◽  
Oktiyas Muzaky Luthfi
Keyword(s):  
Coral Reef ◽  
Coral Reefs ◽  
Regional Planning ◽  
Water Mass ◽  
Initial Study ◽  
Food Sources ◽  
Marine Resources ◽  
Ecological Processes ◽  
Algae Growth ◽  
Coral Reef Ecosystems

The interaction between algae and coral is one of the most important of ecological processes in coral reef ecosystems. They are one of the main food sources in a large number of herbivorous animals in coral reef ecosystems. Makroalgae is also a major competitor in degrading coral reefs at a time when macroalgae gains dominate the coral reefs. Algae growth is relatively very fast, so it can be used as an indicator in the initial study to determine the processes that affect populations and coral reef communities. The purpose of this study is to determine the distribution of macroalgae cover on coral reefs in the Nusa Penida, Bali using the transect quadrant (1x1m2)x 100m method. This study shows that the lowest macroalgae cover at Crystal Bay and the highest in Buyuk can be concluded that the high macroalgae cover is made possible by the large supply of nutrients from the land which becomes the supplier of organic materials that increases the fertility of waters, meanwhile in the waters close to the high seas obtain additional nutrients derived from the lifting of the water mass (upwelling). Data and information are needed for the interest of regional planning towards the future related to the management and utilization of marine resources potential in the coastal area in Nusa Penida, Bali.Interaksi antara alga dan karang merupakan hal terpenting dari proses ekologi pada ekosistem terumbu karang. Mereka merupakan salah satu sumber produsen primer pada sejumlah besar hewan herbivora pada ekosistem terumbu karang. Makroalga juga menjadi pesaing utama dalam mendegradasi terumbu karang pada saat kelimpahaan makroalga mendominasi terhadap terumbu karang. Pertumbuhan alga tergolong sangat cepat, sehingga dapat digunakan sebagai indikator dalam studi awal untuk mengetahui proses yang mempengaruhi populasi dan komunitas terumbu karang. Tujuan dari penelitian ini adalah mengetahui sebaran tutupan makroalga pada terumbu karang di daerah utama wisata penyelaman Nusa Penida, Bali dengan menggunakan metode transek kuadran dengan ukuran (1x1m2) x 100 m. Penelitian ini menunjukan bahwa tutupan makroalga terendah pada Crystal Bay dan tertinggi di Buyuk dapat ditarik kesimpulan jika tingginya tutupan makroalga dimungkinkan oleh besarnya suplai nutrien daratan yang menjadi pensuplai bahan organik yang meningkatkan kesuburan perairan. Sedangkan pada  perairan yang dekat dengan laut lepas mendapat tambahan nutrien yang berasal dari pengangkatan massa air (upwelling). Data dan informasi ini diperlukan untuk kepentingan perencanaan pengembangan wilayah ke depannya yang terkait dengan pengelolaan dan pemanfaatan potensi sumberdaya laut di wilayah pesisir di Nusa Penida, Bali.

scholarly journals HUBUNGAN PERSENTASE TUTUPAN KARANG DENGAN KELIMPAHAN IKAN KARANG DI PULAU MENJANGAN KECIL, KEPULAUAN KARIMUNJAWA, KABUPATEN JEPARA,JAWA TENGAH (Relationship of Coral Cover Percentage with Reef Fishes Abundance in Menjangan Kecil Island, Karimunjawa Island, Jepara)

2018 ◽  
Vol 6 (4) ◽  
pp. 333-338
Author(s):  
Fahmi Fahmi ◽  
Supriharyono Supriharyono ◽  
Abdul Ghofar
Keyword(s):  
Coral Reef ◽  
Coral Reefs ◽  
Reef Fish ◽  
Coral Cover ◽  
Reef Fishes ◽  
Line Transect ◽  
Live Coral ◽  
East Side ◽  
Visual Census ◽  
West Side

Ekosistem terumbu karang merupakan kekayaan sumberdaya laut yang memiliki peranan penting dalam mendukung kehidupan berbagai organisme perairan. Salah satu organisme yang memiliki ketergantungan hidup pada terumbu karang adalah ikan karang. Hal ini dikarenakan ikan karang melalui fase hidup sebagian atau seluruhnya di terumbu karang, sehingga terumbu karang menjadi tempat tinggal, tempat mencari makan, tempat berlindung dan tempat berkembang biak.  Penelitian dilaksanakan pada bulan Mei 2017, dengan tujuan untuk mengetahui persentase tutupan karang hidup dan kelimpahan ikan. Serta hubungan persentase tutupan karang dengan kelimpahan ikan karang pada sisi Barat dan Timur Pulau Menjangan Kecil kedalaman 1 dan 3 meter. Metode yang digunakan adalah metode observasi lapangan, dengan metode sampling menggunakan transek garis (line transect) pada data karang dan visual census untuk data ikan sepanjang 25m. Hasil dari penelitian ini menunjukkan bahwa Persentase rata-rata tutupan karang yang diperoleh pada kedalaman 1 meter sisi Barat adalah 73,39%, sedangkan pada kedalaman 3 meter adalah 85,97%. Persentase tutupan karang pada kedalaman 1 meter sisi Timur adalah 63,73%, sedangkan pada kedalaman 3 meter adalah 77,61%. Secara keseluruhan kondisi terumbu karang masih tergolong baik. Kelimpahan rata-rata ikan pada sisi Barat kedalaman 1 meter adalah 70 individu/125 m2, sedangkan pada kedalaman 3 meter adalah 232 individu/125 m2. Kelimpahan ikan sisi Timur kedalaman 1 dan 3 meter masing-masing adalah 49 dan 138 individu/125 m2. Hasil perhitungan indeks korelasi secara keseluruhan menghasilkan nilai 0,8415 dengan koefesien determinasi sebesar 0,7081. Hal ini menunjukkan bahwa pola hubungan persentase tutupan karang dengan kelimpahan ikan karang kuat (signifikan) dan positif (searah). Coral reef ecosystem is a wealth of marine resources that have an important role in supporting the life of various aquatic organisms. One of the organisms that has a living dependence on coral reefs is reef fish. This is because coral fish through a partial or complete life phase on the coral reef, so that coral reefs become a place to live, a place to find food, shelter and breeding ground. The study was conducted in May 2017, with the objective of knowing the percentage of live coral cover and fish abundance. And the correlation of percentage of coral cover with abundance of reef fish on West and East side of Menjangan Kecil Island depth of 1 and 3 meters. The method used is field observation method, with sampling method using line transect on coral data and visual census for fish data along 25m. The results of this study indicate that the average percentage of coral cover obtained at a depth of 1 meter west side is 73.39%, while at a depth of 3 meters is 85.97%. The percentage of coral cover at depth of 1 meter East side is 63,73%, while at depth 3 meter is 77,61%. Overall the condition of coral reefs is still quite good. The average abundance of fish on the west side of 1 meter depth is 70 individuals / 125 m2, while at 3 meters depth is 232 individuals / 125 m2. The abundance of fish on Eastern side, depth of 1 and 3 meters respectively were 49 and 138 individu / 125 m2. Result of calculation of correlation index as a whole yield value 0,8415 with coefficient of determination equal to 0,7081. This shows that the pattern of correlation of percentage of coral cover with abundance of reef fish is strong (significant) and positive (unidirectional).

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