Mapping coral reef environments

2017 ◽  
Vol 41 (6) ◽  
pp. 803-833 ◽  
Author(s):  
Sarah M. Hamylton

Coral reef environments support high levels of marine biodiversity, they are important sites for coastal habitation and they provide a range of goods and ecosystem services such as nearshore fisheries, economic revenue from tourism and breeding sites for seabirds and turtles. Mapping is a fundamental activity that underpins our understanding of coral reef environments and helps to shape policies in resource management and conservation. This is particularly the case for quantifying the area of landcover types associated with reef environments, including coral patches, seagrasses and mangroves, but also for monitoring how these change over time and modelling how spatial patterns apparent on reefs are related to environmental drivers. Field techniques and aerial photography have historically played a crucial role in mapping coral reef environments, which has recently seen a transition toward the processing of satellite remote sensing images. This paper examines a series of maps produced of Low Isles, the most mapped island on the Great Barrier Reef, to review historical methods for mapping coral reefs because of the critical importance of understanding how past maps were made, which determines appropriate uses to which they can be put. Recent advances and future opportunities for the application of mapping technologies to coral reefs are also evaluated, including the use of unmanned aerial vehicle (UAV) platforms for airborne surveys, delivery of information through web-based platforms and improvements in the quality of information for making and presenting maps. Maps have transformed the way we have responded to both historic and contemporary coral reef problems. This timely review communicates how maps, and the fast growing technologies that are employed to produce them, are central to our understanding of coral reef environments. Recent advances that may drive exciting new environmental management tools are identified.

PeerJ ◽  
2019 ◽  
Vol 7 ◽  
pp. e6379 ◽  
Author(s):  
Joseph D. DiBattista ◽  
James D. Reimer ◽  
Michael Stat ◽  
Giovanni D. Masucci ◽  
Piera Biondi ◽  
...  

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.


PeerJ ◽  
2019 ◽  
Vol 7 ◽  
pp. e6532 ◽  
Author(s):  
James Davis Reimer ◽  
Piera Biondi ◽  
Yee Wah Lau ◽  
Giovanni Diego Masucci ◽  
Xuan Hoa Nguyen ◽  
...  

Marine biodiversity and derived ecosystem services are critical to the healthy functioning of marine ecosystems, and to human economic and societal well-being. Thus, an understanding of marine biodiversity in different ecosystems is necessary for their conservation and management. Coral reefs in particular are noted for their high levels of biodiversity, and among the world’s coral reefs, the subtropical Ryukyu Islands (RYS; also known as the Nansei Islands) in Japan have been shown to harbor very high levels of marine biodiversity. This study provides an overview of the state of marine biodiversity research in the RYS. First, we examined the amount of English language scientific literature in the Web of Science (WoS; 1995–2017) on six selected representative taxa spanning protists to vertebrates across six geographic sub-regions in the RYS. Our results show clear taxonomic and sub-region bias, with research on Pisces, Cnidaria, and Crustacea to be much more common than on Dinoflagellata, Echinodermata, and Mollusca. Such research was more commonly conducted in sub-regions with larger human populations (Okinawa, Yaeyama). Additional analyses with the Ocean Biogeographic Information System (OBIS) records show that within sub-regions, records are concentrated in areas directly around marine research stations and institutes (if present), further showing geographical bias within sub-regions. While not surprising, the results indicate a need to address ‘understudied’ taxa in ‘understudied sub-regions’ (Tokara, Miyako, Yakutane, Amami Oshima), particularly sub-regions away from marine research stations. Second, we compared the numbers of English language scientific papers on eight ecological topics for the RYS with numbers from selected major coral reef regions of the world; the Caribbean (CAR), Great Barrier Reef (GBR), and the Red Sea (RES). As expected, the numbers for all topics in the RYS were well below numbers from all other regions, yet within this disparity, research in the RYS on ‘marine protected areas’ and ‘herbivory’ was an order of magnitude lower than numbers in other regions. Additionally, while manuscript numbers on the RYS have increased from 1995 to 2016, the rate of increase (4.0 times) was seen to be lower than those in the CAR, RES, and GBR (4.6–8.4 times). Coral reefs in the RYS feature high levels of both endemism and anthropogenic threats, and subsequently they contain a concentration of some of the world’s most critically endangered marine species. To protect these threatened species and coral reef ecosystems, more data are needed to fill the research gaps identified in this study.


2007 ◽  
Vol 31 (4) ◽  
pp. 421-434 ◽  
Author(s):  
Anders Knudby ◽  
Ellsworth LeDrew ◽  
Candace Newman

Coral reefs are hotspots of marine biodiversity, and their global decline is a threat to our natural heritage. Conservation management of these precious ecosystems relies on accurate and up-to-date information about ecosystem health and the distribution of species and habitats, but such information can be costly to gather and interpret in the field. Remote sensing has proven capable of collecting information on geomorphologic zones and substrate types for coral reef environments, and is cost-effective when information is needed for large areas. Remote sensing-based mapping of coral habitat variables known to influence biodiversity has only recently been undertaken and new sensors and improved data processing show great potential in this area. This paper reviews coral reef biodiversity, the influence of habitat variables on its local spatial distribution, and the potential for remote sensing to produce maps of these habitat variables, thus indirectly mapping coral reef biodiversity and fulfilling information needs of coral reef managers.


1981 ◽  
Vol 32 (6) ◽  
pp. 975 ◽  
Author(s):  
P Gentien

This study of low molecular weight fluorescent compounds in coral reef environments (Davies, Keeper and Britomart Reefs) of the Great Barrier Reef of Australia at the latitude of Townsville, Queensland, shows that these compounds are more concentrated in the immediate vicinity of coral reefs and that differences in concentrations are related to the morphology of the reefs. Fluorescent metabolites are produced in vitro by all species of corals examined. The emission spectra of the compounds detected in the open environment and the metabolites recovered in vitro are very similar.


Author(s):  
Tenri A R ◽  
Danial Sultan ◽  
Asbar Asbar

Liukang Tuppabiring is a waters with marine biodiversity potential large enough to be developed and managed sustainably. Utilization around the coral reefs in the waters of the Liukang Tuppabiring sub-district currently tends to lead to destructive use, so it is necessary to take damage prevention measures immediately. The results showed the condition of coral cover in the medium and damaged, while at stations 1,2,3,4,6 (25,47-41.07%), while conditions were good at station 5 (56.20%). The number of individual reef fish is 290 individuals from 46 species of 22 genera 11 families. At the research location also identified one type of protected biota namely Hawksbill (Eretmochelys imbricata). Coral damage that occurred at 6 observation stations was more caused by the practice of using destructive and environmentally unfriendly fishing equipment such as bombs, trawls, and the use of poisons. The priority strategies undertaken in the management of coral reefs at the study site are 1) Management of environmentally friendly coral reefs where the community as a manager with strong support from the Government; 2) Making clear rules related to utilization in coral reef areas and establishing a POSMAKWAS institution to avoid more severe coral damage; 3) Improve supervision and law enforcement must be firm in relation to the use of fishing gear that can damage coral reef ecosystems.


Author(s):  
Hamzah MS ◽  
Rustam Rustam ◽  
Abdul Rauf

Liukang Tuppabiring is a waters with marine biodiversity potential large enough to be developed and managed sustainably. Utilization around the coral reefs in the waters of the Liukang Tuppabiring sub-district currently tends to lead to destructive use, so it is necessary to take damage prevention measures immediately. The results showed the condition of coral cover in the medium and damaged, while at stations 1,2,3,4,6 (25,47-41.07%), while conditions were good at station 5 (56.20%). The number of individual reef fish is 290 individuals from 46 species of 22 genera 11 families. At the research location also identified one type of protected biota namely Hawksbill (Eretmochelys imbricata). Coral damage that occurred at 6 observation stations was more caused by the practice of using destructive and environmentally unfriendly fishing equipment such as bombs, trawls, and the use of poisons. The priority strategies undertaken in the management of coral reefs at the study site are 1) Management of environmentally friendly coral reefs where the community as a manager with strong support from the Government; 2) Making clear rules related to utilization in coral reef areas and establishing a POSMAKWAS institution to avoid more severe coral damage; 3) Improve supervision and law enforcement must be firm in relation to the use of fishing gear that can damage coral reef ecosystems.


PeerJ ◽  
2018 ◽  
Vol 6 ◽  
pp. e4308 ◽  
Author(s):  
Tyler D. Eddy ◽  
William W.L. Cheung ◽  
John F. Bruno

Coral reefs are important habitats that represent global marine biodiversity hotspots and provide important benefits to people in many tropical regions. However, coral reefs are becoming increasingly threatened by climate change, overfishing, habitat destruction, and pollution. Historical baselines of coral cover are important to understand how much coral cover has been lost, e.g., to avoid the ‘shifting baseline syndrome’. There are few quantitative observations of coral reef cover prior to the industrial revolution, and therefore baselines of coral reef cover are difficult to estimate. Here, we use expert and ocean-user opinion surveys to estimate baselines of global coral reef cover. The overall mean estimated baseline coral cover was 59% (±19% standard deviation), compared to an average of 58% (±18% standard deviation) estimated by professional scientists. We did not find evidence of the shifting baseline syndrome, whereby respondents who first observed coral reefs more recently report lower estimates of baseline coral cover. These estimates of historical coral reef baseline cover are important for scientists, policy makers, and managers to understand the extent to which coral reefs have become depleted and to set appropriate recovery targets.


2024 ◽  
Vol 74 (10) ◽  
pp. 6139-2024
Author(s):  
MICHAŁ SCHULZ ◽  
ALEKSANDRA ŁOŚ ◽  
PATRYCJA SKOWRONEK ◽  
ANETA STRACHECKA

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.


Diversity ◽  
2021 ◽  
Vol 13 (6) ◽  
pp. 251
Author(s):  
Adi Zweifler (Zvifler) ◽  
Michael O’Leary ◽  
Kyle Morgan ◽  
Nicola K. Browne

Increasing evidence suggests that coral reefs exposed to elevated turbidity may be more resilient to climate change impacts and serve as an important conservation hotspot. However, logistical difficulties in studying turbid environments have led to poor representation of these reef types within the scientific literature, with studies using different methods and definitions to characterize turbid reefs. Here we review the geological origins and growth histories of turbid reefs from the Holocene (past), their current ecological and environmental states (present), and their potential responses and resilience to increasing local and global pressures (future). We classify turbid reefs using new descriptors based on their turbidity regime (persistent, fluctuating, transitional) and sources of sediment input (natural versus anthropogenic). Further, by comparing the composition, function and resilience of two of the most studied turbid reefs, Paluma Shoals Reef Complex, Australia (natural turbidity) and Singapore reefs (anthropogenic turbidity), we found them to be two distinct types of turbid reefs with different conservation status. As the geographic range of turbid reefs is expected to increase due to local and global stressors, improving our understanding of their responses to environmental change will be central to global coral reef conservation efforts.


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