scholarly journals Abundance and Characteristics of Microplastics in Seawater and Corals From Reef Region of Sanya Bay, China

2021 ◽  
Vol 8 ◽  
Author(s):  
Xinming Lei ◽  
Hao Cheng ◽  
Yong Luo ◽  
Yuyang Zhang ◽  
Lei Jiang ◽  
...  

Microplastics (MPs) contamination is widespread in the coral reef ecosystems leading to the exposure of both corals and other biotas. Knowledge gaps still exist concerning patterns in MPs abundance spatially. This work quantified the MPs abundance and characteristics in the seawater and corals in the Sanya Bay, Hainan Island. MPs abundance was detected in the seawater and coral samples ranging from 15.50 to 22.14 items L–1, and 0.01 to 3.60 items polyp–1, respectively. We found the predominant size and type of MPs in seawater and corals were smaller than 2 mm and fiber. Further analysis revealed that the characteristics of MPs in the corals were significantly different from those in the seawater environment, indicating that the MPs are selectively enriched in corals. Furthermore, the MPs particles ingested and retained in coral tissue may be related to the polyp size. This study shows that MPs are present in the whole coral reef region and the coral community structure would be potentially harmed by these contaminants.

2021 ◽  
Vol 8 ◽  
Author(s):  
Graham Kolodziej ◽  
Michael S. Studivan ◽  
Arthur C. R. Gleason ◽  
Chris Langdon ◽  
Ian C. Enochs ◽  
...  

Since the appearance of stony coral tissue loss disease (SCTLD) on reefs off Miami in 2014, this unprecedented outbreak has spread across the entirety of Florida’s coral reef tract, as well as to many territories throughout the Caribbean. The endemic zone reached the upper Florida Keys by 2016, resulting in partial or complete mortality of coral colonies across numerous species. Disease was first observed at Cheeca Rocks (Islamorada, Florida) in the beginning of 2018, with reports of coral mortality peaking mid-year. The disease was still present at Cheeca Rocks as of March 2020, however, to a lesser degree compared to the initial outbreak. Annual monitoring efforts have been ongoing at Cheeca Rocks since 2012, including repeated benthic photomosaics of a 330 m2 survey zone, spanning six replicate sites. As such, a repository of coral community composition data exists for before and after the disease outbreak that was analyzed to assess the impacts of SCTLD on reef communities at an upper Florida Keys inshore reef. Cheeca Rocks is hypothesized to be a resilient reef due to its persistent high coral cover despite its inshore location, which subjects corals to fluctuating water quality and marginal environmental conditions. Coral populations here have been shown to recover from bleaching events and heat stress with minimal coral mortality. Though colonies of coral species characterized as highly and moderately susceptible to SCTLD (e.g., Colpophyllia natans, Diploria labyrinthiformis, Pseudodiploria strigosa, Orbicella annularis, and O. faveolata) suffered mortality as a result of the outbreak with an average loss of 16.42% relative cover by species, the overall impacts on coral cover and community structure were relatively low, contributing to a loss of total coral cover of only 1.65%. Comparison of photomosaic data to other studies indicate Cheeca Rocks may not have been affected as severely as other sites on Florida’s coral reef tract, underlying this site’s potential role in coral resilience to stressors including bleaching events, land-based pollution, and disease epizootics.


2019 ◽  
Author(s):  
Luis M. Montilla ◽  
Emy Miyazawa ◽  
Alfredo Ascanio ◽  
María López-Hernández ◽  
Gloria Mariño-Briceño ◽  
...  

ABSTRACTThe characteristics of coral reef sampling and monitoring are highly variable, with numbers of units and sampling effort varying from one study to another. Numerous works have been carried out to determine an appropriate effect size through statistical power, however, always from a univariate perspective. In this work, we used the pseudo multivariate dissimilarity-based standard error (MultSE) approach to assess the precision of sampling scleractinian coral assemblages in reefs of Venezuela between 2017 and 2018 when using different combinations of number of transects, quadrats and points. For this, the MultSE of 36 sites previously sampled was estimated, using four 30m-transects with 15 photo-quadrats each and 25 random points per quadrat. We obtained that the MultSE was highly variable between sites and is not correlated with the univariate standard error nor with the richness of species. Then, a subset of sites was re-annotated using 100 uniformly distributed points, which allowed the simulation of different numbers of transects per site, quadrats per transect and points per quadrat using resampling techniques. The magnitude of the MultSE stabilized by adding more transects, however, adding more quadrats or points does not improve the estimate. For this case study, the error was reduced by half when using 10 transects, 10 quadrats per transect and 25 points per quadrat. We recommend the use of MultSE in reef monitoring programs, in particular when conducting pilot surveys to optimize the estimation of the community structure.


2020 ◽  
Vol 12 (21) ◽  
pp. 9052
Author(s):  
Yu-Rong Cheng ◽  
Chi-Hsiang Chin ◽  
Ding-Fa Lin ◽  
Chao-Kang Wang

In recent decades, coral reefs worldwide have been impacted annually by climate change and anthropogenic impacts. Marine parks are utilized to protect coral reef ecosystems and to ensure it is in sustainable use. In the present study, a 15-year change in coverage and composition of a hard coral community at Dongsha Atoll Marine National Park (DAMNP) was examined from 2005 to 2019. The reef has experienced several disturbances, including 11 typhoons and six coral bleaching events. A 34.39% decline in coral coverage had been recorded over the past 15 years in response to multiple and recurrent natural disturbances. The coral communities and functional ecology of the Dongsha Atoll changed during this period. The average dissimilarities in coral communities ranged from 55.38 to 59.02%. The dramatic decrease in the abundance of branching corals in addition to a slight increase in massive and encrusting corals suggest the habitat has simplified. The degraded coral reef communities represent a low resilience ecosystem, even though the DAMNP has been established. Without effective management, the coral reef ecosystem of the Dongsha Atoll may not persist due to repeated impacts from recurrent disturbances.


2016 ◽  
Vol 64 (3) ◽  
Author(s):  
Marco Agustín Liñán-Cabello ◽  
Aramis Olivos-Ortiz ◽  
Sonia Quijano-Scheggia ◽  
Daniela Muñiz Anguiano ◽  
María Luisa Reséndiz-Flores ◽  
...  

Coral reef ecosystems are under stress of different origins, from factors including sedimentation, fragmentation, overfishing, and tourism, depending on their geographical location, depth, and proximity to recreation areas. In this study of Juluapan Lagoon, we examined the relationship between various water-quality attributes and the status indicators of the coral community at La Boquita reef. During 2011 (12 months of sampling), six monitoring stations in the Juluapan lagoon were established in order to observe the gradient of the distribution of the physicochemical parameters: three stations on the upper part, or BI, (S4 to S6) and three more in the lower part, or BII, (S1 to S3). A control station (CS) was located in the coral reef close to the lagoon channel, and where dissolved inorganic nutrients and cellular carbon content were determined. Additionally, we considered the monitoring of three of the eight largest coral structures/headlands of this community: the first was the station closest to the channel communicating with Juluapan lagoon (C1), the second was in the intermediate region with respect to that lagoon (C2), and the third was farthest from the channel (C3). Three line intercept transects (LIT) 30 m in length and perpendicular to the coast provenance were established in each station, and the parameters indicative of the status of corals were evaluated in an area of 60 m2 on each transect (180 m2 by the station). Turbidity, evidence of fishing, signs of settling, algal coverage, abundance of fish, rate of sediment, and coral health records (as for CoralWach chart) were determined in situ and from digital photographs and videos. Considering various community status indicators used in the reef area, we could recognize a state of general deterioration, which was reflected in the loss of 17 % of coral coverage. The main anthropogenic disturbances in adjacent areas to La Boquita reef included wastewater discharges into the lagoon, tourist developments in the coastal zone, deforestation and erosion resulting from inappropriate development, and the runoff of nutrients from agricultural lands nearby the lagoon. All these significantly contributed to the nutrient-enriched waters of the lagoon, especially in summer, with negative effects on the coral community. Continued exposure to these factors, coupled with the lack of control over other anthropogenic components, has promoted the maintenance of a chronic stress state in the studied coral community. Our findings highlight the need for the development of appropriate coastal management and conservation policies for the coral reefs of the Mexican Pacific Coast.


2017 ◽  
Vol 25 (10) ◽  
pp. 1123-1130 ◽  
Author(s):  
Hongying Zhou ◽  
Xuemei Yao ◽  
Li Li ◽  
Taonian Geng ◽  
Ying Zhang

2015 ◽  
Vol 1 (5) ◽  
pp. e1500328 ◽  
Author(s):  
Hannah C. Barkley ◽  
Anne L. Cohen ◽  
Yimnang Golbuu ◽  
Victoria R. Starczak ◽  
Thomas M. DeCarlo ◽  
...  

Ocean acidification threatens the survival of coral reef ecosystems worldwide. The negative effects of ocean acidification observed in many laboratory experiments have been seen in studies of naturally low-pH reefs, with little evidence to date for adaptation. Recently, we reported initial data suggesting that low-pH coral communities of the Palau Rock Islands appear healthy despite the extreme conditions in which they live. Here, we build on that observation with a comprehensive statistical analysis of benthic communities across Palau’s natural acidification gradient. Our analysis revealed a shift in coral community composition but no impact of acidification on coral richness, coralline algae abundance, macroalgae cover, coral calcification, or skeletal density. However, coral bioerosion increased 11-fold as pH decreased from the barrier reefs to the Rock Island bays. Indeed, a comparison of the naturally low-pH coral reef systems studied so far revealed increased bioerosion to be the only consistent feature among them, as responses varied across other indices of ecosystem health. Our results imply that whereas community responses may vary, escalation of coral reef bioerosion and acceleration of a shift from net accreting to net eroding reef structures will likely be a global signature of ocean acidification.


2019 ◽  
Author(s):  
Aaron O’Dea ◽  
Mauro Lepore ◽  
Andrew H. Altieri ◽  
Melisa Chan ◽  
Jorge Manuel Morales-Saldaña ◽  
...  

AbstractThere is a consensus that Caribbean coral reefs are a pale shadow of what they once were, yet a reef’s pre-human state is typically assumed or estimated using space-for-time substitution approaches. These approaches may fail to account for past variation before human impact which could mislead conservation priorities and actions. In this study we use a suite of fossilised mid-Holocene (7.2-5.6 ka) fringing reefs in Caribbean Panama to define the Historical Range of Variation (HRV) in coral community structure before human-impact to provide context for the states of modern reefs in the same area. Using the abundances of coral taxa to quantify communities, we found that most of the modern coral communities exist in novel ecosystem states with no fossil precedence. We do however identify one modern reef that is indistinguishable in coral community structure from the mid-Holocene reefs. Reef-matrix cores show that the community on this reef has remained in a stable state for over 760 years, suggesting long-term resistance to the region-wide shift to novel states. Without historical context this robust and stable reef would be overlooked since it does not fulfil expectations of what a “pristine” coral reef should look like. This example illustrates how defining past variation using the fossil record can place modern degradation in historical context and improve conservation recommendations.


eLife ◽  
2020 ◽  
Vol 9 ◽  
Author(s):  
Bruno Sylvain Carturan ◽  
Jason Pither ◽  
Jean-Philippe Maréchal ◽  
Corey JA Bradshaw ◽  
Lael Parrott

The complexity of coral-reef ecosystems makes it challenging to predict their dynamics and resilience under future disturbance regimes. Models for coral-reef dynamics do not adequately account for the high functional diversity exhibited by corals. Models that are ecologically and mechanistically detailed are therefore required to simulate the ecological processes driving coral reef dynamics. Here, we describe a novel model that includes processes at different spatial scales, and the contribution of species’ functional diversity to benthic-community dynamics. We calibrated and validated the model to reproduce observed dynamics using empirical data from Caribbean reefs. The model exhibits realistic community dynamics, and individual population dynamics are ecologically plausible. A global sensitivity analysis revealed that the number of larvae produced locally, and interaction-induced reductions in growth rate are the parameters with the largest influence on community dynamics. The model provides a platform for virtual experiments to explore diversity-functioning relationships in coral reefs.


2020 ◽  
Vol 9 (2) ◽  
pp. 122
Author(s):  
Deli Wakano ◽  
Laury Marcia Chara Huwae

The waters of Kampung Baru Village are one of the waters in Banda Island, Central Maluku Regency, which has an abundance of marine life. The substrate conditions in these waters are rocky, rocky and sandy, surrounded by seagrass. On the coast of Kampung Baru Village, there are many marine biota, including crustaceans, gastropods, bivalves, echinoderms, sea cucumbers, starfish and others. Sea urchins are one of the most important biota because people in Kampung Baru Village use their gonads for daily consumption. The existence of sea urchins in coral reef ecosystems has a significant effect on the ecological balance. The purpose of this study was to determine the community structure of sea urchins in the coastal areas of Kampung Baru, Central Maluku Regency. It is necessary to do so so that the presence of sea urchins can be known so that the balance is well monitored. The method used is a quadratic linear transect. The results showed that the diversity of sea urchin species on the coast of the village of Kampung Baru, Banda Island, Central Maluku was 0.815, including the low category. The value of dominance is 0.512, which means there is a tendency for species to dominate. The density value is 0.065 and the distribution value is 0.277 which is included in the uniform category. Keywords: Community Structure, Sea Urchins, Kampung Baru, Banda Island


2018 ◽  
Vol 31 ◽  
pp. 08013
Author(s):  
Mada Rizmaadi ◽  
Johannes Riter ◽  
Siti Fatimah ◽  
Riyan Rifaldi ◽  
Arditho Yoga ◽  
...  

Increasing degradation coral reefs ecosystem has created many concerns. Reduction of this damage can only be done with good and proper management of coral reef ecosystem based on existing condition. The condition of coral reef ecosystem can be determined by assessing its community structure. This study investigates community structure of coral reef ecosystems around Saebus Island, Sumenep District, East Java, by using satellite imagery analysis and field observations. Satellite imagery analysis by Lyzenga methods was used to determine the observation stations and substrate distribution. Field observations were done by using Line Intercept Transect method at 4 stations, at the depth of 3 and 10 meters. The results showed that the percentage of coral reef coverage at the depth of 3 and 10 meters were 64.36% and 59.29%, respectively, and included in fine coverage category. This study found in total 25 genera from 13 families of corals at all stations. The most common species found were Acropora, Porites, and Pocillopora, while the least common species were Favites and Montastrea. Average value of Diversity, Uniformity and Dominancy indices were 2.94, 0.8 and 0.18 which include as medium, high, and low category, respectively. These results suggest that coral reef ecosystems around Saebus Island is in a good condition.


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