Nutrient and sediment loading affect multiple facets of functionality in a tropical branching coral

ABSTRACTCoral reefs, one of the most diverse ecosystems in the world, face increasing pressures from global and local anthropogenic stressors. Therefore, a better understanding of the ecological ramifications of warming and land-based inputs (e.g. sedimentation and nutrient loading) on coral reef ecosystems is necessary. In this study, we measured how a natural nutrient and sedimentation gradient affected multiple facets of coral functionality, including endosymbiont and coral host response variables, holobiont metabolic responses and percent cover of Pocillopora acuta colonies in Mo′orea, French Polynesia. We used thermal performance curves to quantify the relationship between metabolic rates and temperature along the environmental gradient. We found that algal endosymbiont percent nitrogen content, endosymbiont densities and total chlorophyll a content increased with nutrient input, while endosymbiont nitrogen content per cell decreased, likely representing competition among the algal endosymbionts. Nutrient and sediment loading decreased coral metabolic responses to thermal stress in terms of their thermal performance and metabolic rate processes. The acute thermal optimum for dark respiration decreased, along with the maximal performance for gross photosynthetic and calcification rates. Gross photosynthetic and calcification rates normalized to a reference temperature (26.8°C) decreased along the gradient. Lastly, percent cover of P. acuta colonies decreased by nearly two orders of magnitude along the nutrient gradient. These findings illustrate that nutrient and sediment loading affect multiple levels of coral functionality. Understanding how local-scale anthropogenic stressors influence the responses of corals to temperature can inform coral reef management, particularly in relation to the mediation of land-based inputs into coastal coral reef ecosystems.

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Kajian Kondisi dan Nilai Ekonomi Manfaat Ekosistem Terumbu Karang di Pantai Wediombo, Kabupaten Gunung Kidul, Daerah Istimewa Yogyakarta

Jurnal Ilmu Lingkungan ◽

10.14710/jil.14.2.82-87 ◽

2016 ◽

Vol 14 (2) ◽

pp. 82

Author(s):

Heriawan Maulana ◽

Sutrisno Anggoro ◽

Bambang Yulianto

Keyword(s):

Coral Reef ◽

Coral Reefs ◽

Common Property ◽

Economic Valuation ◽

Economic Value ◽

Survey Method ◽

Economic Losses ◽

Percent Cover ◽

Coral Reef Ecosystems ◽

Line Intercept

ABSTRAKPerairan Wediombo Kabupaten Gunung Kidul yang telah ditetapkan sebagai Pencadangan Kawasan Konservasi Perairan Daerah pada tahun 2013. Pemanfaatan wilayah Pantai Wediombo oleh masyarakat sebagai lokasi pendaratan ikan dan pariwisata mengakibatkan peningkatan tekanan terhadap ekosistem perairan khususnya terumbu karang. Sebagai common property, kerusakan ekosistem terumbu karang tidak dirasakan sebagai kerugian ekonomi sehingga eksploitasi dari manfaat ekosistem terumbu karang menjadi tidak terkendali. Pengelolaan Pantai Wediombo menjadi tantangan bagi stakeholder untuk dapat mengoptimalkan pemanfaatan jasa lingkungan bagi kesejahteraan masyarakat. Salah satu komponen upaya pengelolaannya yaitu dengan melakukan pemantauan kondisi terumbu karang di Pantai Wediombo. Valuasi ekonomi ekosistem termbu karang merupakan instrumen untuk menilai produk dan jasa yang dihasilkan oleh ekosistem terumbu karang. Tujuan dari penelitian ini adalah untuk mengetahui kondisi ekosistem terumbu karang yang diwakili oleh persen tutupan terumbu karang dan nilai manfaat ekosistem terumbu karang yang diwakili oleh produk perikanan yang dihasilkan dari ekosistem terumbu karang di Pantai Wediombo. Metode yang digunakan adalah metode survei. Metode pengumpulan data kondisi terumbu karang mengacu pada metode Line Intercept Transect (LIT). sedangkan nilai ekonomi manfaat ekosistem terumbu karang dihitung menggunakan metode Effect on Productivity. Pada penelitian diperoleh hasil prosentase tutupan terumbu karang di Pantai Wediombo sebesar 25,29% dengan status kondisi rusak sedang. nilai ekonomi aktual ekosistem terumbu karang di Pantai Wediombo sebesar Rp. 634.553.504,-, sedangkan nilai manfaat sekarang dari ekosistem terumbu karang di Pantai Wediombo sebesar Rp. 20.304.872,-.Kata kunci: Ekosistem Terumbu Karang, Valuasi Ekonomi, Pantai Wediombo ABSTRACTBodies Wediombo Gunung Kidul regency which has been designated as a Local Backup Water Conservation Area in 2013. Utilization Wediombo Turkish territory by the public as a fish landing site and tourism resulted in increased pressure on aquatic ecosystems, especially coral reefs. As common property, damage to coral reefs is not perceived as economic losses so that the exploitation of the benefits of coral reef ecosystems had become unmanageable. Wediombo Coastal management is a challenge for stakeholders to be able to optimize the use of environmental services for the welfare of society. One component management efforts is by monitoring the condition of coral reefs in Wediombo Beach. Economic valuation of coral ecosystems termbu is an instrument to assess the products and services produced by a coral reef ecosystems. The purpose of this study was to determine the condition of coral reef ecosystems are represented by percent cover of coral reefs and coral reef ecosystems benefit value represented by the fishery products produced from coral reef ecosystems Wediombo Beach. The method used is a survey method. Methods of data collection coral reef condition refers to a method Line Intercept Transect (LIT). while the economic value of coral reef ecosystem benefits are calculated using methods Effect on Productivity. In the research results the percentage of coral reef cover in Turkish Wediombo of 25.29% with a damaged condition status. the true economic value of coral reef ecosystems Wediombo Coast of Rp. 634 553 504, -, while the value of current benefits of coral reef ecosystems Wediombo Coast of Rp. 20,304,872, -.Keywords: Coral Reef Ecosystems, Economic Valuation, Turkish WediomboCara sitasi: Maulana, H., Anggoro, S., Yulianto, B. (2016). Kajian Kondisi dan Nilai Ekonomi Manfaat Ekosistem Terumbu Karang di Pantai Wediombo, Kabupaten Gunung Kidul, Daerah Istimewa Yogyakarta. Jurnal Ilmu Lingkungan,14(2),82-87, doi:10.14710/jil.14.2.82-87

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Comparative thermal performance ofOrbicella franksiat its latitudinal range limits

10.1101/583294 ◽

2019 ◽

Author(s):

Nyssa J. Silbiger ◽

Gretchen Goodbody-Gringley ◽

John F. Bruno ◽

Hollie M. Putnam

Keyword(s):

Coral Reef ◽

Thermal Performance ◽

Thermal Sensitivity ◽

Thermal Adaptation ◽

Geographic Range ◽

Gross Photosynthesis ◽

Biological Responses ◽

Thermal Performance Curve ◽

Coral Reef Ecosystems ◽

A Site

AbstractTemperature drives biological responses that scale from the cellular to ecosystem levels and thermal sensitivity will shape organismal functions and population dynamics as the world warms. Reef building corals are sensitive to temperature due to their endosymbiotic relationship with single celled dinoflagellates, with mass mortality events increasing in frequency and magnitude. The purpose of this study was to quantify the thermal sensitivity of important physiological functions of a Caribbean reef-building coral,Orbicella franksithrough the measurement of thermal performance curves (TPCs). We compared TPC metrics (thermal optimum, critical maximum, activation energy, deactivation energy, and rate at a standardized temperature) between two populations at the northern and southern extent of the geographic range of this species. We further compared essential coral organismal processes (gross photosynthesis, respiration, and calcification) within a site to determine which function is most sensitive to thermal stress using a hierarchical Bayesian modeling approach. We found evidence for differences in thermal performance, which could be due to thermal adaptation or acclimatization, with higher TPC metrics (thermal optimum and critical maximum) in warmer Panama, compared to cooler Bermuda. We also documented the hierarchy in thermal sensitivity of essential organismal functions within a population, with respiration less sensitive than photosynthesis, which was less sensitive than calcification. Understanding thermal performance of corals is essential for projecting coral reef futures, given that key biological functions necessary to sustain coral reef ecosystems are thermally-mediated.Summary statementWe apply a thermal performance curve approach to a variety of fitness related parameters in a reef building coral across its geographic range and various functions to improve our understanding of the inherent variability in thermal tolerance.

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Status Terkini Tutupan Terumbu Karang di Perairan Dangkal Pulau Bedil, Desa Labuan Bajo, Kabupaten Sumbawa, NTB

Jurnal Sains Teknologi & Lingkungan ◽

10.29303/jstl.v0i0.277 ◽

2021 ◽

pp. 243-253

Author(s):

Mahardika Rizqi Himawan ◽

Eni Hidayati ◽

Nurliah Buhari ◽

Sitti Hilyana ◽

Maulita Syahdina

Keyword(s):

Coral Reef ◽

Coral Reefs ◽

Small Island ◽

Percent Cover ◽

Coral Mortality ◽

Dead Coral ◽

The North ◽

Mortality Index ◽

Coral Reef Ecosystems ◽

Index Value

Bedil Island is included in the Keramat, Bedil, and Temudong Small Island Park (TPK), which was approved by the Regent of Sumbawa. Administratively, this island is included in the Labuan Bajo Village area, Sumbawa, NTB. There is the existence of coral reef ecosystems in these waters that form a reef flat and reef slope profile, that stretches to the southwest and northeast. By its designation as a small island park, the coral reefs in Bedil Island are used as an underwater tourism object. This study aims to determine the current condition of coral reef cover in the waters around Bedil Island, especially in the eastern and southern parts of the island. Coral reefs in the north and west area are limited and there is the existence of seagrass beds. The line intercept transect method is carried out by spreading the roll meter as far as 50 meters on the east and south sides of the island with a depth of 2-3 meters. The coral lifeform that is tangent with the roll meter is then recorded and then analyzed for the average percent cover, clustering status, and coral mortality index. Coral reefs in the eastern and southern parts of Bedil Island are classified as very good/excellent because they have a percent cover value above 75%. In addition, the coral mortality index value is also relatively small which indicates that the corals are living well. Clearwater conditions and locations far from human settlements are thought to be factors that support coral survival. However, the presence of dead coral algae and rubble still indicates a threat of damage even though the value is small. Algae life on the surface of dead coral also indicates that the coral has been dead for a long time.

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Thermal Stress and Resilience of Corals in a Climate-Changing World

Journal of Marine Science and Engineering ◽

10.3390/jmse8010015 ◽

2019 ◽

Vol 8 (1) ◽

pp. 15

Author(s):

Rodrigo Carballo-Bolaños ◽

Derek Soto ◽

Chaolun Allen Chen

Keyword(s):

Thermal Stress ◽

Coral Reef ◽

Fossil Fuels ◽

High Temperature Stress ◽

Coral Host ◽

Physiological Diversity ◽

Coral Reef Ecosystems ◽

Adaptation Processes ◽

Symbiotic Organisms ◽

Ecological Functioning

Coral reef ecosystems are under the direct threat of increasing atmospheric greenhouse gases, which increase seawater temperatures in the oceans and lead to bleaching events. Global bleaching events are becoming more frequent and stronger, and understanding how corals can tolerate and survive high-temperature stress should be accorded paramount priority. Here, we review evidence of the different mechanisms that corals employ to mitigate thermal stress, which include association with thermally tolerant endosymbionts, acclimatisation, and adaptation processes. These differences highlight the physiological diversity and complexity of symbiotic organisms, such as scleractinian corals, where each species (coral host and microbial endosymbionts) responds differently to thermal stress. We conclude by offering some insights into the future of coral reefs and examining the strategies scientists are leveraging to ensure the survival of this valuable ecosystem. Without a reduction in greenhouse gas emissions and a divergence from our societal dependence on fossil fuels, natural mechanisms possessed by corals might be insufficient towards ensuring the ecological functioning of coral reef ecosystems.

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Light-harvesting in mesophotic corals is powered by a spatially efficient photosymbiotic system between coral host and microalgae

10.1101/2020.12.04.411496 ◽

2020 ◽

Author(s):

Netanel Kramer ◽

Raz Tamir ◽

Or Ben-Zvi ◽

Steven L. Jacques ◽

Yossi Loya ◽

...

Keyword(s):

Coral Reef ◽

Light Harvesting ◽

Optical Scattering ◽

Light Transport ◽

Coral Host ◽

Light Conditions ◽

Plastic Response ◽

Coral Reef Ecosystems ◽

Fundamental Insight ◽

Insight Into

SummaryThe coral-algal photosymbiosis fuels global coral-reef primary productivity, extending from sea level to as deep as 150 m (i.e., mesophotic). Currently, it is largely unknown how such mesophotic reefs thrive despite extremely limited light conditions. Here, we show that corals exhibit a plastic response to mesophotic conditions that involves a spatially optimized regulation of the bio-optical properties by coral host and symbiont. In contrast to shallow corals, mesophotic corals absorbed up to three-fold more light, resulting in excellent photosynthetic response under light conditions of only ~3% of the incident surface irradiance. The enhanced light harvesting capacity of mesophotic corals is regulated by average refractive index fluctuations in the coral skeleton that give rise to optical scattering and facilitate light transport and absorption by densely pigmented host tissue. The results of this study provide fundamental insight into the energy efficiency and light-harvesting mechanisms underlying the productivity of mesophotic coral reef ecosystems, yet also raise concerns regarding their ability to withstand prolonged environmental disturbances.

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