scholarly journals On the small‐scale fractal geometrical structure of a living coral reef barrier

2020 ◽  
Vol 45 (12) ◽  
pp. 3042-3054 ◽  
Author(s):  
Damien Sous ◽  
Frédéric Bouchette ◽  
Erik Doerflinger ◽  
Samuel Meulé ◽  
Raphael Certain ◽  
...  
Keyword(s):  
Coral Reef ◽  
Geometrical Structure ◽  
Small Scale ◽  
Living Coral

scholarly journals Keanekaragaman dan Biomassa Ikan Karang serta Keterkaitannya dengan Tutupan Karang Hidup di Perairan Manggis, Kabupaten Karangasem, Bali

2018 ◽  
Vol 5 (2) ◽  
pp. 164
Author(s):  
I Made Raditya Putra ◽  
I Gusti Ngurah Putra Dirgayusa ◽  
Elok Faiqoh
Keyword(s):  
Coral Reef ◽  
Reef Fish ◽  
Coral Reef Fish ◽  
Coral Cover ◽  
Total Biomass ◽  
Live Coral ◽  
Strong Positive Correlation ◽  
Living Coral ◽  
Positive Correlation ◽  
Live Coral Cover

The existence of coral reef fish is closely related to the availability of coral reef resource as a habitat. Coral reef fish is a biota that has a fascination with a variety of color patterns and fascinating. Differences in coral cover conditions will affect the abundance of coral reef fish, especially those with strong linkages to living corals. This research was conducted in June - August 2017 by using line intercept transect (LIT) method for coral cover percentage and visual census method for biodiversity and biomass of coral reef fish with 3 research stations in Manggis waters, Karangasem. From the research results, it shows that the diversity index ranged between 2.54 - 2.70 which means the diversity of coral reef fish in the medium category and the stability of the community is in the medium. Furthermore, total biomass of coral reef fish ranged between 186,17 - 1692,08 kg / ha. The results stated that the percentage of live coral cover in Manggis waters ranged from 3.83% to 12.44% which means that live coral cover is categorized as bad. A very strong positive correlation between living coral conditions and coral reef fish biomass was 92.42%. Meanwhile, the relationship between living coral conditions and the diversity of coral reef fish had a strong positive correlation of 65.4%. The diversity of coral reef fish in waters is not only caused by live coral cover; however, it is caused by coral reef ecosystems that are associated in the bottom of the waters.

scholarly journals Small-Scale Variability Dominates Benthic Coverage and Diversity Across the Jardines de La Reina, Cuba Coral Reef System

2019 ◽  
Vol 6 ◽  
Author(s):  
Leslie Hernández-Fernández ◽  
Roberto González de Zayas ◽  
Laura Weber ◽  
Amy Apprill ◽  
Maickel Armenteros
Keyword(s):  
Coral Reef ◽  
Small Scale ◽  
Reef System ◽  
Coral Reef System

scholarly journals Small-Scale Habitat Structure Modulates the Effects of No-Take Marine Reserves for Coral Reef Macroinvertebrates

PLoS ONE ◽  
2013 ◽  
Vol 8 (3) ◽  
pp. e58998 ◽  
Author(s):  
Pascal Dumas ◽  
Haizea Jimenez ◽  
Christophe Peignon ◽  
Laurent Wantiez ◽  
Mehdi Adjeroud
Keyword(s):  
Coral Reef ◽  
Habitat Structure ◽  
Marine Reserves ◽  
Small Scale

scholarly journals Complexities and Uncertainties in Transitioning Small-Scale Coral Reef Fisheries

2016 ◽  
Vol 3 ◽  
Author(s):  
Pierre Leenhardt ◽  
Matthew Lauer ◽  
Rakamaly Madi Moussa ◽  
Sally J. Holbrook ◽  
Andrew Rassweiler ◽  
...  
Keyword(s):  
Coral Reef ◽  
Small Scale ◽  
Coral Reef Fisheries

scholarly journals Reef growth and limestone erosion

2015 ◽  
Author(s):  
David Blakeway
Keyword(s):  
Coral Reef ◽  
Coral Reefs ◽  
Rock Type ◽  
Small Scale ◽  
Growth Forms ◽  
Reef Growth ◽  
Extraterrestrial Life ◽  
Fluid Medium ◽  
Biogenic Structures ◽  
Steep Slopes

Because the shapes and forms of many coral reefs resemble karst (erosion landforms created by dissolution of limestone), it is widely believed that those reefs have grown on karst foundations, and that Holocene growth perpetuates the underlying topography. However, this concept has become difficult to reconcile with the growing amount of seismic and coring evidence demonstrating that several karst-like reef features are entirely constructional. Here I use cellular automata simulations to show that coral reefs resemble karst limestones not because they are built on karst foundations, but because reef growth and limestone erosion are fundamentally the same process, running in opposite directions. Coral reef landscapes are in fact inverse karst—the basic spectrum of reef growth forms mirrors the basic spectrum of limestone erosion forms. In both growth and erosion, the development of form is a self-organised phenomenon emerging from the cumulative action of small-scale processes. The essential morphological control in both cases is slope stability, which depends on the composition of each system: coral type in reefs and lithology (rock type) in limestones. Solid, well cemented reefs and limestones, which can maintain steep slopes without collapsing, produce nodular reefs and pinnacle karst respectively, whereas unconsolidated, friable reefs and limestones, which frequently collapse, produce cellular reefs and cone karst.The growth forms produced in the model should theoretically apply to all modular skeleton-building organisms growing in a fluid medium, and may therefore provide useful templates in the search for extraterrestrial life. While none of the model forms can be considered unequivocally diagnostic of life, because all could conceivably arise through inanimate crystallisation, the model’s seemingly accurate rendition of biogenic carbonate morphology on earth suggests that it may provide a useful foundation for evaluating and exploring the range of macroscale self-organised biogenic structures that could arise on other planets.

The contribution of acoustic seafloor mapping techniques to outlining coral reef geomorphology: A case study in the Republic of Maldives (Magoodhoo Reef – Maldivian Archipelago)

2021 ◽  
Author(s):  
Alessandra Savini ◽  
Fabio Marchese ◽  
Luca Fallati ◽  
Sebastian Krastel ◽  
Aaron Micallef ◽  
...  
Keyword(s):  
Remote Sensing ◽  
Coral Reef ◽  
Morphological Changes ◽  
Remote Sensing Data ◽  
Circulation Pattern ◽  
Small Scale ◽  
Optical Remote Sensing ◽  
Patch Reefs ◽  
Reef Environments ◽  
Geomorphological Map

<p>Optical remote sensing data coupled with a dense network of field surveys have historically played a crucial role in geomorphological mapping of coral reef environments. Recently this field has undergone a major upgrade thanks to the integration of new advanced methods such as LiDAR, AUV-based and close-range digital photogrammetry and acoustic remote sensing techniques, which are able to investigate the deeper components of this complex geomorphic system. The new detailed maps can produce seamless digital elevation model (DEM) of coral reef environments, by integrating the elevation datasets acquired by the combination of the mentioned survey techniques.</p><p>In our work, a harmonised geomorphological map is generated for the Magoodhoo reef, which borders the southwestern discontinuous marginal rim of a subcircular atoll (i.e. Faafu Atoll) of the Maldivian archipelago. In its north-eastern sector the reef consists of a cuspate reef joined to an almost closed ring reef to the south-west, where Magoodhoo Island is located. The map was generated from the analysis of Sentinel data, orthomosaics and 3D optical models generated by the application of SfM techniques to UAV images, as well as bathymetry and backscatter intensity measurements. The latter were collected down to a depth of up to 120 m along the oceanward margin of the atoll's rim, and to a depth of roughly 60 m along the lagoonward margin. Direct observations were also performed using an observational ROV on the forereef and within the lagoon, and video-transects on the reef flat.</p><p>The oceanward margin shows steep terraced slopes that reveal a complex history of late Pleistocene/Holocene sea level oscillations, while the backreef slopes (toward the lagoon) are generally more gentle, although at places can show abrupt escarpments and overhangs. The lagoon submarine landscape is distinctly featured by patch reefs of variable shapes (from circular to sub-elongated) and dimensions (from few meters to 30m high). Their distribution is clearly controlled by the surface circulation pattern, regulated by the pass that borders the reef to the west. Towards the deeper edge of the mapped sector of the lagoon floor, where patch reefs are totally absent, intriguing small-scale depressions have been detected instead. The regular circular and concave shape calls for their interpretation as pockmarks, but their origin is still unknow due to the  lack of core samples and geochemical analysis in the area. New data are actually needed to precisely outline the sedimentary environments that feature Faafu Atoll and its inner lagoon. Nevertheless, the obtained geomorphological map and the mapped landforms shed new light and a more complete understanding on the processes that drive morphological changes of the entire Magoodhoo reef.</p>

scholarly journals Measuring coral reef decline through meta-analyses

2005 ◽  
Vol 360 (1454) ◽  
pp. 385-395 ◽  
Author(s):  
I.M Côté ◽  
J.A Gill ◽  
T.A Gardner ◽  
A.R Watkinson
Keyword(s):  
Coral Reef ◽  
Large Scale ◽  
Coral Cover ◽  
Meta Analysis ◽  
Cost Effective ◽  
Data Availability ◽  
Small Scale ◽  
Ecological Change ◽  
Live Coral ◽  
Scale Estimate

Coral reef ecosystems are in decline worldwide, owing to a variety of anthropogenic and natural causes. One of the most obvious signals of reef degradation is a reduction in live coral cover. Past and current rates of loss of coral are known for many individual reefs; however, until recently, no large-scale estimate was available. In this paper, we show how meta-analysis can be used to integrate existing small-scale estimates of change in coral and macroalgal cover, derived from in situ surveys of reefs, to generate a robust assessment of long-term patterns of large-scale ecological change. Using a large dataset from Caribbean reefs, we examine the possible biases inherent in meta-analytical studies and the sensitivity of the method to patchiness in data availability. Despite the fact that our meta-analysis included studies that used a variety of sampling methods, the regional estimate of change in coral cover we obtained is similar to that generated by a standardized survey programme that was implemented in 1991 in the Caribbean. We argue that for habitat types that are regularly and reasonably well surveyed in the course of ecological or conservation research, meta-analysis offers a cost-effective and rapid method for generating robust estimates of past and current states.

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