Coral Reef Ecology Research Papers (original) (raw)
Growth rates and longevities were estimated for five major fishery species of parrotfishes (“uhu”) at Oahu, Hawai’i. All species grew rapidly with von Bertalanffy growth formula k values ≥0.4·year−1. Longevities were found to range... more
Growth rates and longevities were estimated for five major fishery species of parrotfishes (“uhu”) at Oahu, Hawai’i. All species grew rapidly with von Bertalanffy growth formula k values ≥0.4·year−1. Longevities were found to range broadly among the three small species, 4 years in Calotomus carolinus and 6 and 11 years in Scarus psittacus and Chlorurus spilurus, and to 15–20 years in Scarus rubroviolaceus and Chlorurus perspicillatus for the two large species. Age reading and growth curves for the latter two large species were validated using bomb radiocarbon dating. Median ages at sexual maturity as females (AM50) and at sex change (from female to terminal phase male, AΔ50) were estimated using logistic models. Sexual maturation occurred at 1–2 years for the small species and at 3–3.5 years in the large species. AΔ50 estimates ranged from 2 to 4 years in the small species and were about 5 and 7 years in S. rubroviolaceus and C. perspicillatus, respectively. Estimated milestones poo...
Veracruz coral reefs are located on the continental shelf of the Gulf of Mexico. There are 17 well developed reef structures and 4 fringing reefs, even though this area is affected by the winter "nortes" and by heavy rain causing run-off.... more
Veracruz coral reefs are located on the
continental shelf of the Gulf of Mexico. There are
17 well developed reef structures and 4 fringing
reefs, even though this area is affected by the winter
"nortes" and by heavy rain causing run-off. An intensive
survey was camed out on all the structures
from August 1986 to October 1989. Coral species,
benthic community composition and substrate
morphology were recorded. A detailed description
of reef habitats and communities is given by means
of a zonation model consisting of four zones and
ten subzones. The main structural features of these
reefs are: a well developed leeward slope in the offshore
group, and a buttress zone in the windward
slope. Three reef growing zones are described, characterized
by three different scleractinian species
associations.
Dimensional analysis and scaling are related, semi-formal procedures for capturing the essential process(es) controlling the behaviour of a complex system, and for describing the functional relationships between them. The techniques... more
Dimensional analysis and scaling are related, semi-formal procedures for capturing the essential process(es) controlling the behaviour of a complex system, and for describing the functional relationships between them. The techniques involve the parameterization of natural processes, the identification of the temporal and spatial scales of variation of processes, and the evaluation of potential interactions between processes referenced to those scales using non-dimensional (scaled) parameters. Scaling approaches are increasingly being applied to a broad range of marine ecological problems, with the aims of assessing the relative importance of physical and biological parameters in controlling variation in process rates, and placing limits on the ability of one process to affect another. The value of the approach to coral reef research lies in the conceptualization of relationships between discipline-specific processes, and the evaluation of scale-dependent processes across the large range of spatial and temporal scales which pertain to coral reefs. Characteristic scales of physical, geological and biological processes exhibit different patterns of distribution along the temporal dimension. Scaling arguments based on examples from reef systems indicate that a large group of biological and biogeochemical processes are strongly influenced by hydrodynamic processe occuring at similar time scales within the range from about on hour to one year. We argue that scaling approaches to process-related problems are pre-requisite to interdisciplinary research on coral reefs.
Abstract Recovery of the threatened staghorn coral (Acropora cervicornis) is posited to play a key role in Caribbean reef resilience. At four Caribbean locations (including one restored and three extant populations), we quantified... more
Abstract Recovery of the threatened staghorn coral (Acropora
cervicornis) is posited to play a key role in Caribbean
reef resilience. At four Caribbean locations (including one
restored and three extant populations), we quantified characteristics
of contemporary staghorn coral across increasing
conspecific densities, and investigated a hypothesis of
facilitation between staghorn coral and reef fishes. High
staghorn densities in the Dry Tortugas exhibited significantly
less partial mortality, higher branch growth, and supported
greater fish abundances compared to lower densities
within the same population. In contrast, partial mortality,
branch growth, and fish community composition did not
vary with staghorn density at the three other study locations
where staghorn densities were lower overall. This
suggests that density-dependent effects between the coral
and fish community may only manifest at high staghorn
densities. We then evaluated one facilitative mechanism for
such density-dependence, whereby abundant fishes sheltering
in dense staghorn aggregations deliver nutrients back to
the coral, fueling faster coral growth, thereby creating more
fish habitat. Indeed, dense staghorn aggregations within the Dry Tortugas exhibited significantly higher growth rates,
tissue nitrogen, and zooxanthellae densities than sparse
aggregations. Similarly, higher tissue nitrogen was induced
in a macroalgae bioassay outplanted into the same dense
and sparse aggregations, confirming greater bioavailability
of nutrients at high staghorn densities. Our findings inform
staghorn restoration efforts, suggesting that the most effective
targets may be higher coral densities than previously
thought. These coral-dense aggregations may reap the benefits
of positive facilitation between the staghorn and fish
community, favoring the growth and survivorship of this
threatened species.
Tourist activity in coral reefs of the Natural National Park Corals of Rosario and San Bernardo, Colombia. Islas del Rosario and San Bernardo is a National Nature Park that protects coral reefs and mangroves but is increasingly affected... more
Tourist activity in coral reefs of the Natural National Park Corals of Rosario and San Bernardo, Colombia. Islas del Rosario and San Bernardo is a National Nature Park that protects coral reefs and mangroves but is increasingly affected by tourism. Between April 2011 and January 2013 we interviewed users of the 16 main submarine trails. The most frequented trail was Ministerio / Acuario mío (23,7 ± 5,7 %); Open Water scuba diving was the main diving certificate among tourists (63,5 ± 4,5 %); 58.6% lacked basic diving experience, and 74% had some type of contact with the corals (mostly hard coral: 0,9 ± 0,05). An average there were 5,39 contacts per diver (scuba). For basic diving there was an average of 0.18 contacts/ min/ diver. Diving causes direct and indirect damages to these ecosystems. Most coral contacts are from inexperienced divers: training the tourists is fundamental.
Global climate change is altering community composition across many ecosystems due to nonrandom species turnover, typically characterized by the loss of specialist species and increasing similarity of biological communities across spatial... more
Global climate change is altering community composition across many ecosystems due to nonrandom species turnover, typically characterized by the loss of specialist species and increasing similarity of biological communities across spatial scales. As anthropogenic disturbances continue to alter species composition globally, there is a growing need to identify how species responses influence the establishment of distinct assemblages, such that management actions may be appropriately assigned. Here, we use trait-based analyses to compare temporal changes in five complementary indices of reef fish assemblage structure among six taxonomically distinct coral reef habitats exposed to a system-wide thermal stress event. Our results revealed increased taxonomic and functional similarity of previously distinct reef fish assemblages following mass coral bleaching, with changes characterized by subtle, but significant , shifts toward predominance of small-bodied, algal-farming habitat generalists. Furthermore, while the taxonomic or functional richness of fish assemblages did not change across all habitats, an increase in functional originality indicated an overall loss of functional redundancy. We also found that prebleaching coral composition better predicted changes in fish assemblage structure than the magnitude of coral loss. These results emphasize how measures of alpha diversity can mask important changes in the structure and functioning of ecosystems as assemblages reorganize. Our findings also highlight the role of coral species composition in structuring communities and influencing the diversity of responses of reef fishes to disturbance. As new coral species configurations emerge, their desirability will hinge upon the composition of associated species and their capacity to maintain key ecological processes in spite of ongoing disturbances. K E Y W O R D S assemblage structure, beta diversity,
Clipperton Atoll, one of the most isolated coral reefs worldwide, is of great scientific interest due to its geomor-phology and high levels of endemism. This study explored the reef fish assemblage structure of Clipperton Atoll and its... more
Clipperton Atoll, one of the most isolated coral reefs worldwide, is of great scientific interest due to its geomor-phology and high levels of endemism. This study explored the reef fish assemblage structure of Clipperton Atoll and its relationship with live coral cover. Nine stations were sampled at three sites and three depths (6, 12 and 20 m) around the reef, measuring fish species richness and biomass and hermatypic coral cover (at genus level). We evaluated variation in species richness, biomass and diversity of fish assemblages among sites and depths, as well as the relationship between the entire fish assemblage composition and live coral cover. The results showed that species richness and biomass were similar among sites, but differed across depths, increasing with depth. In contrast, diversity differed among sites but not among depths. Multivariate analyses indicated that fish assemblage composition differed among sites and depths in relation to changes in cover of coral of the genera Pocillopora, Porites, Pavona and Leptoseris, which dominate at different depths. The results showed that fish species richness and diversity were low at Clipperton Atoll and that, in isolated coral reefs with a low habitat heterogeneity and low human disturbance, live coral cover has a significant influence on the spatial variation of the reef fish assemblages. This study highlights the importance of coral habitat structure in shaping coral reef fish assemblages.
- by Fabian A Rodríguez-Zaragoza and +2
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- Marine Ecology, Community Ecology, Coral Reefs, Ecology
Juvenile coral abundance and community composition depend on the spatial scale studied. To investigate this, an evaluation was made of juvenile coral density with hierarchical spatial analysis in the northern Mesoamerican Barrier Reef... more
Juvenile coral abundance and community composition depend on the spatial scale studied. To investigate this, an evaluation was made of juvenile coral density with hierarchical spatial analysis in the northern Mesoamerican Barrier Reef System (MBRS) at ~10 m depth. Study scope included semi-protected and unprotected areas located in this region. A total of 19 juvenile coral taxa were found, including 10 scleractinian species, 8 scleractinian coral genera not identified to species, and 1 Millepora species (Hydrozoa-Milleporidae). In terms of relative abundance, Agaricia spp., Siderastrea spp., and Porites spp. were the main juvenile taxa in the coral community at the surveyed sites, reefs, and regions levels. Greater variance was seen at smaller scales, at site level for taxa richness, and at the transect level for juvenile density, and lower variance was seen at larger scales (reefs and regions). The variance component contribution from each scale likely differed from other studies because of the different factors affecting the community and the different extensions of each scale used in each study. Densities (1–6.4 juvenile corals/m2) and dominant taxa found in this study agree with other studies from the Western Atlantic. Detected variability was explained by different causal agents, such as low grazing rates by herbivorous organisms, turbidity, and/or sediment suffocation and some nearby or distant localized disturbance (human settlement and a hurricane).
The present study describes corals translocation initiated in response to the Environmental Impact Assessment study (EIA) conducted for the new South Port project in Aqaba. A galvanized steel structure painted with anti-fouling and... more
The present study describes corals translocation initiated in response to the Environmental Impact Assessment study (EIA) conducted for the new South Port project in Aqaba. A galvanized steel structure painted with anti-fouling and anti-rust paints for the establishment of nursery structures was used. Concrete pipes and fossil reef rocks were utilized for the creation of a new cave-shape dive site. Marine cement was used to fix the colonies at the designated sites. About 7000 coral colonies were translocated from the new port site to selected locations within the Aqaba Marine Park showed a survival rate of 89.8% during the first year. The study indicated that coral translocation is a good tool for conservation if well designed and controlled. It would help in mitigating any potential adverse impacts resulted from development activities in coastal areas.
The coral reefs' crisis is increasing, with the combined effects of natural and anthropogenic disturbances. It is predicted that coral reefs could extinct soon from the world. Bangladesh has only one coral Island named Saint Martin,... more
The coral reefs' crisis is increasing, with the combined effects of natural and anthropogenic disturbances. It is predicted that coral reefs could extinct soon from the world. Bangladesh has only one coral Island named Saint Martin, locally known as 'Narikel Jinjira'. This is one of the most popular tourist spots in Bangladesh, entertaining thousands of tourists per year due to its unique landscape, blue water, and coral colonies' presence. This Island lost most of the coral in recent times. The coral reef ecosystem management needs to focus on the reformation of the legal and institutional frameworks for enhancing the local administration's capabilities to address the adverse effects of the stressors and promote the ecosystem services by improving the resilience. The study aims at analysing the existing institutional and legal frameworks for conserving the coral reefs. To collect data, fieldwork was conducted at Saint Martin Island and Teknaf Upazila. The related literature on legal documents was reviewed critically. It is found that despite having legal mechanisms and institutional frameworks, non-compliances with laws and poor coordination among different sectors are widespread, resulting in severe degradation of coral resources. In most of the laws, robust institutional arrangements were ignored. The study recommends integrating the legal and institutional frameworks governing the environment, tourism, and fisheries sectors. Effective marine governance, increasing coordination among different sectors, amending some existing rules, and activating MCS (monitoring, control, surveillance) system can improve the scenario.
As in the tropical Atlantic, Acropora populations in the southern Persian/Arabian Gulf plummeted within two decades after having been ecosystem engineers on most wave-exposed reefs since the Pleistocene. Since 1996/1998 live coral cover... more
As in the tropical Atlantic, Acropora populations in the southern Persian/Arabian Gulf plummeted within two decades after having been ecosystem engineers on most wave-exposed reefs since the Pleistocene. Since 1996/1998 live coral cover in the Gulf declined by over 90% in many areas, primarily due to bleaching and diseases
caused by rising temperatures. In the formerly dominant table-coral species A. downingi, population dynamics corresponding to disturbance regimes was quantified in three transition matrices (lower disturbance pre-1996; moderate disturbance from 1998 to 2010 and 2013 to 2017, disturbed in 1996/1998, 2010/11/12, 2017). Increased disturbance frequency and severity caused progressive reduction in coral size, cover, and population fecundity. Small size-classes were bolstered more
by partial colony mortality than sexual recruitment. Some large corals had a size refuge and resisted die-back but were also lost with increasing disturbance. Matrix
and biophysical larval flow models suggested one metapopulation. Southern, Arabian, populations could be connected to northern, Iranian, populations but this connectivity was lost under assumptions of pelagic larval duration at rising temperatures shortened to a third. Then, the metapopulation disintegrated into isolated populations. Connectivity required to avoid extinctions increased exponentially with disturbance frequency and correlation of disturbances across the metapopulation.
Populations became unsustainable at eight disturbances in 15 years, when even highest theoretical recruitment no longer compensated mortality. This lethal disturbance frequency was 3-fold that of the moderately disturbed monitoring period and 4-fold of the preceding low-disturbance period—suggesting ongoing shortening of the disturbance-free period. Observed population collapse and environmental changes in the Gulf suggest that A. downingi is heading toward at least functional extinction mainly due to increasingly frequent temperature-induced mortality events, clearly linked to climate change
Populations of Acropora palmata and Orbicella faveolata, two important reef-building corals, have declined precipitously across the Caribbean region since at least the 1970s. Recruitment failure may be limiting population recovery,... more
Populations of Acropora palmata and Orbicella faveolata, two important reef-building corals, have declined precipitously across the Caribbean region since at least the 1970s. Recruitment failure may be limiting population recovery, possibly due to lack of suitable settlement habitat. Here, we examine the effects of algal turfs and algal turfs + sediment, two widely abundant substrate types across the Florida Keys, on the settlement of these two ecologically-important species. We show that sediment significantly impedes coral settlement, reducing settlement 10-and 13-fold for A. palmata and O. faveolata, respectively, compared to turf algae alone. This result is corroborated by our field survey data that showed a strong, negative relationship between the abundance of turf + sediment and the abundance of juvenile corals. Turf algae alone did not reduce coral settlement. Our results suggest that sediment-laden turf algae are detrimental to settling corals, but that turf algae alone may be relatively benign.
- by Alain Duran and +1
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- Corals, Coral Reef Ecology, Coral Reef Resilience
- by Jerald Wilson and +1
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- Coral Reefs, Tsunami, Coral Reef Ecology, Biophysical Ecology
Coral bleaching events threaten the sustainability of the Great Barrier Reef (GBR). Here we show that bleaching events of the past three decades have been mitigated by induced thermal tolerance of reef-building corals, and this protective... more
Coral bleaching events threaten the sustainability of the Great Barrier Reef (GBR). Here we show that bleaching events of the past three decades have been mitigated by induced thermal tolerance of reef-building corals, and this protective mechanism is likely to be lost under near-future climate change scenarios. We show that 75% of past thermal stress events have been characterized by a temperature trajectory that subjects corals to a protective, sub-bleaching stress, before reaching temperatures that cause bleaching. Such conditions confer thermal tolerance, decreasing coral cell mortality and symbiont loss during bleaching by over 50%. We find that near-future increases in local temperature of as little as 0.5°C result in this protective mechanism being lost, which may increase the rate of degradation of the GBR.
- by Rebecca Klaus and +3
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- Coral Reefs, Coral Reef Ecology
Timely information is critical for coral reef managers and decision-makers to implement sustainable management measures. A Coral Reef Resilience Index (CRRI) was developed with a GIS-coupled decision-making tool applicable for Caribbean... more
Timely information is critical for coral reef managers and decision-makers to implement sustainable management measures. A Coral Reef Resilience Index (CRRI) was developed with a GIS-coupled decision-making tool applicable for Caribbean coral reef ecosystems. The CRRI is based on a five-point scale parameterized from the quantitative characterization of benthic assemblages. Separate subindices such as the Coral Index, the Threatened Species Index, and the Algal Index also provide specific information regarding targeted benthic components. This case study was based on assessments conducted in 2014 on 11
reef sites located across 3 geographic zones and 3 depth zones along the southwestern shelf of the island of Puerto Rico, Caribbean Sea. There was a significant spatial and bathymetric gradient (p < 0.05) in the distribution of CRRI values indicating higher degradation of inshore reefs. Mean global CRRI ranged from 2.78 to 3.17 across the shelf, ranking them as “fair.” The Coral Index ranged from 2.60 to 3.76, ranking reefs from “poor” to “good,” showing a general cross-shelf trend of improving conditions with increasing distance from pollution sources. Turbidity and ammonia were significantly correlated to CRRI scores. Multiple recommendations are provided based on coral reef conditions
according to observed CRRI rankings.
This is an identification guide to the most common shallow-water coral species in Puerto Rico. It was written in Spanish. Esta es una guia para la identificacion de las especies de corales mas comunes de las aguas llanas de Puerto Rico.... more
This is an identification guide to the most common shallow-water coral species in Puerto Rico. It was written in Spanish. Esta es una guia para la identificacion de las especies de corales mas comunes de las aguas llanas de Puerto Rico. Esta escrito en español.
- by Abimarie Otaño-Cruz and +2
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- Climate Change, Conservation Biology, Climatology, Fisheries
• Despite covering less than 0.1% of the sea floor area, coral reefs provide nearly US$9.8 trillion globally of social, economic and cultural services each year and provide habitat for over 25% of marine fish species. • The rate of... more
• Despite covering less than 0.1% of the sea floor area, coral reefs provide nearly US$9.8 trillion globally of social, economic and cultural services each year and provide habitat for over 25% of marine fish species. • The rate of warming in coral reef areas has increased from ~0.04°C/decade over the past century to 0.2°C/ decade over recent decades (1985-2012). Across this period, reefs were exposed to prolonged, high temperatures that caused bleaching once every six years. However, within the last three decades, as the planet has warmed the frequency of bleaching stress has increased threefold. • The latest climate models predict that ocean warming will cause annual coral bleaching for almost all reefs by 2050. They also predict that disease is as likely to be a future cause of coral mortality as coral bleaching. Unabated temperature increases will produce serious consequences for coral reef ecosystems and dependent communities. • The proportion of reefs in which ocean chemistry will allow coral reefs to grow has decreased from 98% (ca. 1780) to 38% (ca. 2006) due to ocean acidification and continues to drop. • Tropical cyclones can reduce thermal stress but can physically damage reefs. Ocean warming may increase the severity of cyclones. Warming-related coral bleaching has likely reduced the ability of reefs to recover from cyclone damage. • Sea-level rise is predicted to accelerate. Historically reefs have not been able to keep up with rapid sea-level rise, and this is even less likely in the future if ocean warming and acidification slow reef growth. • Loss of coral reefs would diminish the services these ecosystems provide, such as coastal protection from storm waves, habitat for reef fauna, and tourism. Predictions of ecosystem service losses from ocean warming and acidification globally reach US$1 trillion/year by 2100. • Reducing atmospheric CO 2 is critical for coral reefs to continue. While reduced emissions will slow ocean warming and acidification, current CO 2 levels already exceed the 320-350 ppm needed for healthy coral reefs. While this is pursued, enhancing reef resilience through targeted management actions will help reefs to resist and recover from disturbance. Local actions to mitigate climate change impacts may be necessary to preserve reef resources.
- by Mark Eakin and +1
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- Coral Reef Ecology, Coral Bleaching, Coral Reef
Many hermatypic corals are broadcast spawners. Little is known about the dispersal potential of their planktonic larvae. Settlement can begin 2-3 days post-fertilization, but competency may last for a month or more. Hydrographic models... more
Many hermatypic corals are broadcast spawners. Little is known about the dispersal potential of their planktonic larvae. Settlement can begin 2-3 days post-fertilization, but competency may last for a month or more. Hydrographic models can be use d to estimate larval dispersal, but they require information about the swimming behavior of the larvae during transport, including buoyancy and vertical swimming behavior. Coral eggs are positively buoyant when released, but embryos and larvae with time become less buoyant and acquire the ability to swim downwards. The time-course of such developmental changes is needed to couple with hydrographic data to model dispersal curves. Such data are presented here for the major Caribbean hermatype, Montastraea faveolata. Larval buoyancy was measured as ascent rate in a volumetric pipette, and measured every 6 hours for 3.25 hours post-fertilization. V ertical swimming behavior was measured as vertical distribution of the larvae within 2 L graduated cylinders, placed on an orbital shaker table, measured every 6 hours from 40 hours to 8.5 days post-fertilization. Newly fertilized eggs (non-swimming) had an ascent rate of 1.82 mm s-1, and this decreased linearly to 1.04 mm s-1 over the following 2.3 days, by which time many larvae were swimming. Over 80 % of the larvae remained within the top 4 cm of the 40 cm-tall cylinder over the first 2.5 days postfertilization. Diel vertical migration became apparent after ca. 3 daysdownwards in dark, upwards in light), and became more pronounced over time. However, even 8 days post-fertilization, less than 20 % of the larvae were at the bottom of the cylinder at the end of the dark period. These results show that while some larvae of this species can settle within a few days, most do not develop strong bottom seeking behavior until much later, and could be dispersed far from their site of o rigin.
Fragments of dead coral belonging to Pocillopora Lamarck, 1816 were used during a 1-year period as artificial micro-habitats and positioned at a coral reef community at Islas Marietas, Bahía Banderas, on the west coast of Mexico, to... more
Fragments of dead coral belonging to Pocillopora Lamarck, 1816 were used during a 1-year period as artificial micro-habitats and positioned at a coral reef community at Islas Marietas, Bahía
Banderas, on the west coast of Mexico, to attract and capture isopods. Three species of isopods, totaling 961 specimens were collected. The dominant species was Joeropsis dubia (Menzies, 1951) (Joeropsididae) (83.03% of the total number of specimens), followed by Califanthura squamosissima (Menzies, 1951) (Paranthuridae) (9.78%), and Paracerceis sculpta (Holmes, 1904) (Sphaeromatidae) (7.18%). The average density of isopods was of 12.0 × 10−2 ind. · cm−2. A positive relationship between water temperature and total density of individuals during the sampling period was found. Annual water temperature changes influenced the abundance of each species in a similar way, with the higher abundances associated to the lower temperatures, which is also related to an increase in primary productivity and the presence of upwellings in the area.
Kabupaten Siau Tagulandang Biaro (SITARO) merupakan kabupaten yang terdiri dari 3 gugusan pulau utama, yaitu Pulau Siau, Tagulandang dan Biaro yang masuk kedalam Provinsi Sulawesi Utara dimana memiliki 47 pulau dimana 12 pulaunya sudah... more
Kabupaten Siau Tagulandang Biaro (SITARO) merupakan kabupaten yang terdiri dari 3 gugusan pulau utama, yaitu Pulau Siau, Tagulandang dan Biaro yang masuk kedalam Provinsi Sulawesi Utara dimana memiliki 47 pulau dimana 12 pulaunya sudah berpenghuni dan sisanya tidak. Terletak pada koordinat 20 07’ 48” - 20 48’ 36” LU dan 1250 09’ 36” - 1250 29’ 24” BT, wilayah ini berbatasan dengan Kabupaten Kepulauan Sangihe di bagian utara, laut Maluku di timur, Kab. Minahasa Utara di bagian selatan dan laut Sulawesi di sisi barat (Sitaro dalam angka, 2017).
Kabupaten Sitaro memiliki potensi sumber daya kelautan dan pesisir yang besar dikarenakan letaknya yang masuk kedalam area segitiga terumbu karang dunia (coral triangle). Informasi mengenai ekositem pesisir yang sudah lama tidak terupdate mengakibatkan pentingnya dilakukan inventarisasi ulang mengenai kondisi terkini dilokasi tersebut. Kegiatan survei dilakukan tahun 2017 dititik beratkan pada lokasi sekitar Perairan Pulau Siau yaitu di DPL Matole (Pulau Buhias), DPL Tapile (Pulau laweang dan Mahoro) dan DPL Makalehi (Pulau Makalehi). Teridentifikasi 40 genera karang keras dan 188 species ikan karang dari 34 famili dimana famili Pomacentridae mendominasi baik jumlah biomassa maupun kelimpahannya . Secara umum substrat dasar sebagian besar berisi alga yang mendominasi rata-rata 52,88 % dari total substrat dan karang keras yang hanya 37,64%. Nilai kekasaran bentang substrat dasar atau rugosity memperlihatkan lokasi dangkal lebih kasar/ berkontur dibandingkan lokasi dalam yang banyak didominasi patahan karang dan pasir.
Kondisi ikan karang dimana kelimpahan dan biomassanya saling melengkapi yakni lokasi tertinggi terdapat di Tapile Kontrol 1 dan terendah di Matole Kontrol. Berdasarkan selang ukuran dan trophic group menunjukan ikan dari kelompok Pomacentridae dan Anthiinae sub famili Serranidae yang merupakan pemakan planktivore mendominasi dari segi kelimpahan dan biomassanya. Penggabungan dengan data tahun 2014 dimana dilakukan pada lokasi dangkal dimana total penyelaman menjadi 25 lokasi yakni Biaro (7 lokasi penyelaman), Siau (12 lokasi penyelaman) dan Tagulandang (6 lokasi penyelaman). Secara keseluruhan lokasi di Bohanga memiliki tutupan karang keras teringgi sebesar 63,25% dan terendah di DPL Tapile sebesar 12,50%. Lokasi di Biaro memiliki tutupan karang yang paling tinggi dibandingkan lokasi lainnya begitu juga tutupan alaganya yang paling rendah, hal ini menunjukan lokasi biaro memiliki kondisi ekosistem terumbu karang paling baik dibandingkan dua lokasi lainnya di SIau dan Tagulandang.
Kelimpahan ikan karang yang terdapat di Kabupaten Sitaro tertinggi terdapat di lokasi DPL Makalehi dan terendah di lokasi DPL Matole sebesar. Rata-rata Pulau Biaro memiliki kelimpahan tertinggi (15.725,83 no.ha-1 (±36,40 SE)) dibandingkan Pulau Siau (14.225,85 no.ha-1 (± 25,93 SE)) dan Tagulandang (10.376,67 no.ha-1 (± 21,44 SE)). Biomassa ikan karang di Kabupaten Sitaro tertinggi terdapat di lokasi Lasange dan terendah di desa Humbia. Rata-rata biomassa tertinggi terdapat di Biaro sebesar 588,93 kg.ha-1 (± 36,40 SE) disusul Siau sebesar 317,00 kg.ha-1 (± 25,93 SE) dan terendah di Tagulandang sebesar 253,63 kg.ha-1 (± 21,44 SE). Ikan famili Pomacentridae secara keseluruhan baik selang ukuran maupun trophic group memiliki kelimpahan dan biomassa terbesar di semua lokasi penyelaman di Kab. Sitaro.
Climate change has significantly impacted tropical ecosystems critical for sustaining local economies and community livelihoods at global scales. Coastal ecosystems have largely declined, threatening the principal source of protein,... more
Climate change has significantly impacted tropical ecosystems critical for sustaining local economies and community livelihoods at global scales. Coastal ecosystems have largely declined, threatening the principal source
of protein, building materials, tourism-based revenue, and the first line of defense against storm swells and sea
level rise (SLR) for small tropical islands. Climate change has also impacted public health (i.e., altered distribution and increased prevalence of allergies,water-borne, and vector-borne diseases). Rapid human population growth
has exacerbated pressure over coupled social–ecological systems, with concomitant non-sustainable impacts on
natural resources,water availability, food security and sovereignty, public health, and quality of life,which should
increase vulnerability and erode adaptation and mitigation capacity. This paper examines cumulative and synergistic
impacts of climate change in the challenging context of highly vulnerable small tropical islands. Multiple adaptive strategies of coupled social–ecological ecosystems are discussed. Multi-level, multi-sectorial responses are necessary for adaptation to be successful.
Shallow reef habitats dominated with living corals is relatively accessible all times of the day and could be useful to consider as a natural mesocosm. This study was conducted at Paraviwella near shore reef patch, Tangalle, Southern Sri... more
Shallow reef habitats dominated with living corals is relatively accessible all times of the day and could be useful to consider as a natural mesocosm. This study was conducted at Paraviwella near shore reef patch, Tangalle, Southern Sri Lanka (6° 01’ 17.07” N, 80° 48’ 01.21” E) from 25 April 2014 to 10 September 2014 to examine the current status of the substratum composition. Line Intercept Transects (LITs) method was used for benthic composition study (number of transects = 6, length = 25m and area 3500 m). Temperature (T), Salinity (S), Turbidity (Tb) and Dissolved Oxygen (DO) were measured in sea water collected from transect locations. Results disclosed that sea water quality at Paraviwella reef were within the suitable condition for growth of corals and other associated organisms (T=29 ± 1°C, D=54 ± 17 cm, S=34 ± 1ppt, Tb=3 ± 0.6 NTU, DO=8.6 ± 1 ppm). Transect study showed that living corals (64.7 ± 18.9%) and algae (19.2 ± 13.4%) were dominant life forms represented by highe...
The number of ecophysiological studies involving reef corals has increased markedly over the last 20 years, driven primarily by the concern over the potential effects of anthropogenic change on coral communities. In particular, the... more
The number of ecophysiological studies involving reef corals has increased markedly over the last 20 years, driven primarily by the concern over the potential effects of anthropogenic change on coral communities. In particular, the evaluation of the effects of global climate change has prompted major research efforts into understanding the consequences of both rising seawater temperatures and ocean acidification on the physiology of corals. In recent years the recognition that corals harbour not only symbiotic algae but also a diverse microbial consortium, which may both influence and be influenced by the physiology of the animal host, has added an extra layer of complexity to this biological system known collectively as the 'coral holobiont'. The present review draws together an extensive literature on ecophysiological responses of the coral holobiont to anthropo-genic change, with specific references to the latest molecular and genetic developments in the field. It also highlights gaps in our basic understanding of coral physiology and draws attention to the value of extreme physical habitats in elucidating the acclimatory and adaptive scope of reef corals to climate change.
Coral reefs are in decline worldwide and monitoring activities are important for assessing the impact of disturbance on reefs and tracking subsequent recovery or decline. Monitoring by field surveys provides accurate data but at highly... more
Coral reefs are in decline worldwide and monitoring activities are important for assessing the impact of disturbance on reefs and tracking subsequent recovery or decline. Monitoring by field surveys provides accurate data but at highly localised scales and so is not cost-effective for reef scale monitoring at frequent time points. Remote sensing from satellites is an alternative and complementary approach. While remote sensing cannot provide the level of detail and accuracy at a single point than a field survey, the statistical power for inferring large scale patterns benefits in having complete areal coverage. This review considers the state of the art of coral reef remote sensing for the diverse range of objectives relevant for management, ranging from the composition of the reef: physical extent, benthic cover, bathymetry, rugosity; to environmental parameters: sea surface temperature, exposure, light, carbonate chemistry. In addition to updating previous reviews, here we also consider the capability to go beyond basic maps of habitats or environmental variables, to discuss concepts highly relevant to stakeholders, policy makers and public communication: such as biodiversity, environmental threat and ecosystem services. A clear conclusion of the review is that advances in both sensor technology and processing algorithms continue to drive forward remote sensing capability for coral reef mapping, particularly with respect to spatial resolution of maps, and synthesis across multiple data products. Both trends can be expected to continue.
- by John D. Hedley and +7
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- Coral Reefs, Satellite remote sensing, Coral Reef Ecology
Unsustainable land uses may result in poor watershed management, increased soil erosion, poorly-planned urban development, increased runoff, and sewage pollution, creating an environmental stress gradient across coastal coral reefs. This... more
Unsustainable land uses may result in poor watershed management, increased soil erosion, poorly-planned urban development, increased runoff, and sewage pollution, creating an environmental stress gradient across coastal coral reefs. This study was aimed at: 1) Evaluating water quality within and outside the Canal Luis Peña Natural Reserve (CLPNR), Culebra Island, Puerto Rico; 2) Determining if there was any significant environmental stress gradient associated to land-based non-point source pollution; and 3) Characterizing shallow-water coral reef communities across the gradient. Strong gradient impacts associated 293 to sediment-laden and nutrient-loaded runoff pulses, in combination with non-point raw sewage pulses, and sediment bedload, impacted coastal coral reefs. Water quality showed significant spatio-temporal fluctuations (p<0.0001), largely responding to heavy rainfall and subsequent runoff pulses. Benthic community structure showed significant spatial variation along the environmental stress gradient (p=0.0002). Macroalgae, dead coral surfaces, algal turf, and low coral species richness, species diversity index (H'c), and evenness (J'c) dominated benthic assemblages across reefs frequently impacted by runoff pulses and sediment bedload. The combination of fecal coliform and enterococci concentrations were correlated with variation in benthic community structure (Rho=0.668; p=0.0020). The combined variation in salinity, dissolved oxygen and enterococci concentrations explained 75% of the observed spatial variation in benthic assemblages (R 2 =0.7461; p=0.0400). Local human stressors affected coral reefs within no-take CLPNR and risk analyses suggest it may offset its ecological benefits. There is a need to design and implement integrated coastal-watershed management strategies to address multiple land use activities, including erosion-control best management practices, watershed reforestation, and sewage pollution control.
Reef‐building corals are at risk of extinction from ocean warming. While some corals can enhance their thermal limits by associating with dinoflagellate photosymbionts of superior stress tolerance, the extent to which symbiont communities... more
Reef‐building corals are at risk of extinction from ocean warming. While some corals can enhance their thermal limits by associating with dinoflagellate photosymbionts of superior stress tolerance, the extent to which symbiont communities will reorganize under increased warming pressure remains unclear. Here we show that corals in the hottest reefs in the world in the Persian Gulf maintain associations with the same symbionts across 1.5 years despite extreme seasonal warming and acute heat stress (≥35°C). Persian Gulf corals predominantly associated with Cladocopium (clade C) and most also hosted Symbiodinium (clade A) and/or Durusdinium (clade D). This is in contrast to the neighbouring and milder Oman Sea, where corals associated with Durusdinium and only a minority hosted background levels of Cladocopium. During acute heat stress, the higher prevalence of Symbiodinium and Durusdinium in bleached versus nonbleached Persian Gulf corals indicates that genotypes of these background genera did not confer bleaching resistance. Within symbiont genera, the majority of ITS2 rDNA type profiles were unique to their respective coral species, confirming the existence of host‐specific symbiont lineages. Notably, further differentiation among Persian Gulf sites demonstrates that symbiont populations are either isolated or specialized over tens to hundreds of kilometres. Thermal tolerance across coral species was associated with the prevalence of a single ITS2 intragenomic sequence variant (C3gulf), definitive of the Cladocopium thermophilum group. The abundance of C3gulf was highest in bleaching‐resistant corals and at warmer sites, potentially indicating a specific symbiont genotype (or set of genotypes) that may play a role in thermal tolerance that warrants further investigation. Together, our findings indicate that co‐evolution of host–Symbiodiniaceae partnerships favours fidelity rather than flexibility in extreme environments and under future warming.
- by Andrew Bauman and +1
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- Climate Change, The Persian Gulf, Coral Reefs, Symbiodinium
This Technical Memorandum is part of a series of three reports that provide a quantitative spatial and temporal characterization of marine biological communities associated with marine protected areas in the U.S. Caribbean. This work... more
This Technical Memorandum is part of a series of three reports that provide a quantitative spatial and
temporal characterization of marine biological communities associated with marine protected areas in the
U.S. Caribbean. This work was conducted as part of NOAA’s Coral Reef Conservation Program (CRCP)
Caribbean Coral Reef Ecosystem Monitoring (CREM) project; a partnership effort between NOAA’s National
Ocean Service (NOS), National Centers for Coastal Ocean Science (NCCOS), Center for Coastal Monitoring
and Assessment Biogeography Branch (CCMA-BB), U.S. Virgin Islands Department of Planning and Natural
Resources – Division of Fish and Wildlife, U.S. Geological Survey (USGS), National Park Service (NPS), the
University of the Virgin Islands (UVI), and the University of Hawaii (UH). The integration of NOAA/NPS led
efforts with data generated by VI-DPNR provide spatial and temporal patterns in fish and benthic communities
to characterize St. John coral reef ecosystems. The data and analyses in this report are intended to provide
essential baseline biological information to support management decision making. This project was funded
by CRCP, NOAA’s NCCOS, and the NPS Natural Resource Preservation Program (NRPP) at Virgin Islands
National Park (VIIS) and NPS’s South Florida/Caribbean Inventory and Monitoring Program (SFCN).
Les séries sédimentaires Liasiques dans le Haut Atlas Oriental (Jbel Bou Dahar) montre des variations de faciès et d'epaisseur ,depuis la plateforme interne jusqu'au bassin. Les études lithostratigrahiques executées ont permettent de... more
Les séries sédimentaires Liasiques dans le Haut Atlas Oriental (Jbel Bou Dahar) montre
des variations de faciès et d'epaisseur ,depuis la plateforme interne jusqu'au bassin.
Les études lithostratigrahiques executées ont permettent de séparées les formations
lithostratigraphiques et les discontinuités sédimentaires dans ce domaine du bassin Hautatlasique et particulierement dans le Haut Atlas oriental afin de reconstituer l'histoire
paléogéographique de Jbel Bou Dahar.
Le complexe récifal de Bou Dahar montre une très belle faune Liasique fourni par les
ammonites et/ou localement par des brachiopodes , grandes bivalves et l'extension verticale
des foraminifères benthiques sont comparables avec autres formations récifales marocains
(Bloc de Guigou) ,après avoir les relations des faunes au Trias-Lias-Jurassique .
L'inventaire paléontologique ,biostratigraphique et la description de certains taxons dans
le secteur de Toutia (Terminaison Ouest de Bou Dahar) ont permet de dressé une succession
stratigraphique depuis le bas vers le haut de Bou Dahar (Toutia)
La dernière partie consacrée au récifs pré-domériens au Lias et Jurassique et puis
entamer les hypothèses des causes possibles de la mort des récifs au Maroc qui sont
l'envasement et l'ennoyage.
Fiji is committed to, and is embarking upon, a process to significantly increase the number and coverage of Marine Protected Areas (MPAs) within the country. To help deliver on this commitment, the Marine Working Group of the Fiji... more
Fiji is committed to, and is embarking upon, a process to significantly increase the number and coverage of Marine
Protected Areas (MPAs) within the country.
To help deliver on this commitment, the Marine Working Group of the Fiji national Protected Area Committee (PAC),
established under the Environmental Management Act 2005, requested a review of previous efforts to describe marine
priority sites for Fiji. To this end, the then Department of Environment (now Ministry of Environment) and the then
Ministry of Fisheries and Forests (now Ministry of Fisheries) convened an expert workshop on the 19th and 20th July
2016. The Marine and Coastal Biodiversity Management in Pacific Island Countries (MACBIO) Project 1 and the Wildlife
Conservation Society (WCS) supported the workshop.
The objectives of the workshop were to review previous efforts to identify marine priority sites and prepare a report, with
maps, identifying updated Special, Unique Marine Areas (SUMAs) for Fiji.
Prior to the workshop, participants were provided with a range of resource material including, reports and maps from the
earlier prioritisation studies. During the workshop additional information was made available, largely maps and GIS with
new biophysical, spatial data. On the first day, participants were spilt into regional groups to review, amend and, in some
cases, add new site descriptions to the earlier work.
On the second day, participants were asked to rate each site based on the following criteria:
■ ■ Amount, detail, and nature of biological justification
■ ■ Geographic explicitness
■ ■ Information sources
■ ■ National or international obligations
A technical expert, who participated in the workshop, and who was familiar with a range of marine environments across
the Fiji Islands was engaged to review and compile the information gathered at the expert workshop. Post workshop
research was also conducted, through one-on-one interviews and additional mini-workshops. This information, together
with the workshop has been almagamated into this report. In total, 98 inshore and offshore Special, Unique Marine Areas
(SUMAs) were identified.
Site scores range from as low as 5 to as high as 12 (highest possible score). Both high and low scores are useful for
management; high-scoring sites can be prioritised with confidence, while lower-scoring sites can be highlighted for
needing more research or requiring protection for the purposes of ecosystem recovery, or even restoration efforts. Future
scoring systems may take into account levels of human use or impact, as this affects the intrinsic ecological value of a
habitat, assemblage, population or ecosystem. The identification and scoring of special, unique marine areas can guide
the next steps in creating a network of marine protected areas, future marine spatial planning, and also inform other
management measures (e.g. permit or licencing decisions) or environmental impact assessments (EIAs) that may be
relevant to these locations.