To see the other types of publications on this topic, follow the link: Reefs.
Journal articles on the topic 'Reefs'
Create a spot-on reference in APA, MLA, Chicago, Harvard, and other styles
Consult the top 50 journal articles for your research on the topic 'Reefs.'
Next to every source in the list of references, there is an 'Add to bibliography' button. Press on it, and we will generate automatically the bibliographic reference to the chosen work in the citation style you need: APA, MLA, Harvard, Chicago, Vancouver, etc.
You can also download the full text of the academic publication as pdf and read online its abstract whenever available in the metadata.
Browse journal articles on a wide variety of disciplines and organise your bibliography correctly.
1
Dechnik, Belinda, Jody M. Webster, Luke Nothdurft, Gregory E. Webb, Jian-xin Zhao, Stephanie Duce, Juan C. Braga, Daniel L. Harris, Ana Vila-Concejo, and Marji Puotinen. "Influence of hydrodynamic energy on Holocene reef flat accretion, Great Barrier Reef." Quaternary Research 85, no. 1 (January 2016): 44–53. http://dx.doi.org/10.1016/j.yqres.2015.11.002.
Full textAbstract:
AbstractThe response of platform reefs to sea-level stabilization over the past 6 ka is well established for the Great Barrier Reef (GBR), with reefs typically accreting laterally from windward to leeward. However, these observations are based on few cores spread across reef zones and may not accurately reflect a reef's true accretional response to the Holocene stillstand. We present a new record of reef accretion based on 49 U/Th ages from Heron and One Tree reefs in conjunction with re-analyzed data from 14 reefs across the GBR. We demonstrate that hydrodynamic energy is the main driver of accretional direction; exposed reefs accreted primarily lagoon-ward while protected reefs accreted seawards, contrary to the traditional growth model in the GBR. Lateral accretion rates varied from 86.3 m/ka–42.4 m/ka on the exposed One Tree windward reef and 68.35 m/ka–15.7 m/ka on the protected leeward Heron reef, suggesting that wind/wave energy is not a dominant control on lateral accretion rates. This represents the most comprehensive statement of lateral accretion direction and rates from the mid-outer platform reefs of the GBR, confirming great variability in reef flat growth both within and between reef margins over the last 6 ka, and highlighting the need for closely-spaced transects.
2
LA PORTA, BARBARA, and LUISA NICOLETTI. "Sabellaria alveolata (Linnaeus) reefs in the central Tyrrhenian Sea (Italy) and associated polychaete fauna." Zoosymposia 2, no. 1 (August 31, 2009): 527–36. http://dx.doi.org/10.11646/zoosymposia.2.1.36.
Full textAbstract:
The aim of this research was to analyze the morphological features of Sabellaria alveolata reefs and the associated polychaete fauna in three different coastal areas of the Tyrrhenian Sea (Mediterranean Sea, Italy). We assessed the relationship between the physical structure of the reefs and the associated fauna. We also investigated possible connections between polychaete assemblage structure and reef development on spatial and temporal scales. Reefs were morphologically described, and the polychaete assemblages were studied using community indices, as well as multivariate and univariate statistics. Three different reef states were described, linked to their respective phase of development. The structure of the associated polychaete assemblages differed according to the relevant reef’s phase of development. Species richness was high in reefs in destruction phase, while it decreased in recovering reefs.
3
Rafly, Nidzar Muhammad, I. Wayan Gede Astawa Karang, and Widiastuti Widiastuti. "Hubungan Rugositas Terumbu Karang terhadap Struktur Komunitas Ikan Corallivor dan Herbivor di Perairan Pemuteran, Bali." Journal of Marine Research and Technology 3, no. 1 (February 28, 2020): 6. http://dx.doi.org/10.24843/jmrt.2020.v03.i01.p02.
Full textAbstract:
Reef fishes are the highest number of organisms that can be found in coral reefs in which the abundance depends on the healthy of this ecosystem. Reef fishes are mainly consisted of corallivorous and herbivorous fish. Corralivorous fish feeds on coral polyps while herbivorous fish feeds on algae. Therefore these fishes are an important indicators in the resilience of coral reefs. Studies showed that its abundance is strongly correlated with reef’s conture (rugosity). Pemuteran waters is one of developing tourists attraction in the north Bali island. However, the data of reef fishes and coral reefs in Pemuteran waters remain limited. Therefore, this research aimed to study the reef` condition and rugosity in Pemuteran waters, also to examine the correlation between reefs fishes and reefs rugosity in this area. There were four stations according to purposive sampling method. Data of corallivorous and herbivorous fishes were collected by using the underwater visual census with a 40 m2 transect. Reef rugosity index were determined by using chain transect method. Results showed that reef rugosity in Pemuteran waters was in the medium to high category. Reef rugosity has strong correlation with the total abundance and diversity of corallivorous fishes. However, reef rugosity was only strong correlated with the total abundance but not with the diversity of herbivorous fishes.
4
Baronio, Mateus de A., and Daniel J. Bucher. "Artificial crevice habitats to assess the biodiversity of vagile macro-cryptofauna of subtidal rocky reefs." Marine and Freshwater Research 59, no. 8 (2008): 661. http://dx.doi.org/10.1071/mf07170.
Full textAbstract:
Reef cryptofauna (animals inhabiting cracks and crevices) represent much of a reef’s biodiversity yet are seldom studied owing to their inaccessibility. Subtidal rocky reefs off Brunswick Heads and Byron Bay in northern New South Wales, Australia support benthic communities ranging from coral-dominated offshore reefs to kelp beds of Ecklonia radiata on inshore reefs. It was hypothesised that differential exposure to river discharge and the East Australian Current, as well as proximity to other reef habitats, may produce differences in recruitment and persistence of cryptofauna between superficially similar reefs within a small geographical range. Artificial crevice habitats were deployed at similar depths on three inshore reefs supporting similar Ecklonia densities. Although the species richness of crevice fauna was similar at all reefs, the species composition differed significantly along with the assemblages recruited in different seasons and to different crevice sizes. Neither reef faunas nor that of varying crevice sizes changed consistently with the seasons, yet all crevices appeared equally accessible to colonists. These results demonstrate the potential inadequacy of classifying reef communities for management of regional biodiversity based on the visual dominance of a few species that may not be as sensitive to environmental variables as many of the less obvious taxa.
5
Gómez-Andújar, Nicolás X., and Edwin A. Hernandez-Delgado. "Spatial benthic community analysis of shallow coral reefs to support coastal management in Culebra Island, Puerto Rico." PeerJ 8 (October 14, 2020): e10080. http://dx.doi.org/10.7717/peerj.10080.
Full textAbstract:
Caribbean coral reefs provide essential ecosystem services to society, including fisheries, tourism and shoreline protection from coastal erosion. However, these reefs are also exhibiting major declining trends, leading to the evolution of novel ecosystems dominated by non-reef building taxa, with potentially altered ecological functions. In the search for effective management strategies, this study characterized coral reefs in front of a touristic beach which provides economic benefits to the surrounding coastal communities yet faces increasing anthropogenic pressures and conservation challenges. Haphazard photo-transects were used to address spatial variation patterns in the reef’s benthic community structure in eight locations. Statistically significant differences were found with increasing distance from the shoreline, reef rugosity, Diadema antillarum density, among reef locations, and as a function of recreational use. Nearshore reefs reflected higher percent macroalgal cover, likely due to increased exposure from both recreational activities and nearby unsustainable land-use practices. However, nearshore reefs still support a high abundance of the endangered reef-building coral Orbicella annularis, highlighting the need to conserve these natural shoreline protectors. There is an opportunity for local stakeholders and regulatory institutions to collaboratively implement sea-urchin propagation, restoration of endangered Acroporid coral populations, and zoning of recreational densities across reefs. Our results illustrate vulnerable reef hotspots where these management interventions are needed and recommend guidelines to address them.
6
de Goeij, Jasper M., Dick van Oevelen, Mark J. A. Vermeij, Ronald Osinga, Jack J. Middelburg, Anton F. P. M. de Goeij, and Wim Admiraal. "Surviving in a Marine Desert: The Sponge Loop Retains Resources Within Coral Reefs." Science 342, no. 6154 (October 3, 2013): 108–10. http://dx.doi.org/10.1126/science.1241981.
Full textAbstract:
Ever since Darwin’s early descriptions of coral reefs, scientists have debated how one of the world’s most productive and diverse ecosystems can thrive in the marine equivalent of a desert. It is an enigma how the flux of dissolved organic matter (DOM), the largest resource produced on reefs, is transferred to higher trophic levels. Here we show that sponges make DOM available to fauna by rapidly expelling filter cells as detritus that is subsequently consumed by reef fauna. This “sponge loop” was confirmed in aquarium and in situ food web experiments, using 13C- and 15N-enriched DOM. The DOM-sponge-fauna pathway explains why biological hot spots such as coral reefs persist in oligotrophic seas—the reef’s paradox—and has implications for reef ecosystem functioning and conservation strategies.
7
SVAVARSSON, JÖRUNDUR, and NIEL L. BRUCE. "New and little-known gnathiid isopod crustaceans (Cymothoida) from the northern Great Barrier Reef and the Coral Sea." Zootaxa 3380, no. 1 (July 5, 2012): 1. http://dx.doi.org/10.11646/zootaxa.3380.1.1.
Full textAbstract:
Ten species of Gnathiidae (Crustacea, Isopoda, Cymothoida) including six new species, are reported from Lizard Islandand nearby reefs, northern Great Barrier Reef and reefs of the Coral Sea (Chesterfield Reefs, Mellish Reef and MarionReef): Gnathia wistari sp. nov. (Lizard Island region and Capricorn Group, southern Great Barrier Reef), Gnathia coral-maris sp. nov. (Mellish Reef), Gnathia varanus sp. nov. (Lizard Island group), Gnathia marionis sp. nov. (Marion Reef),Gnathia hamletgast sp. nov. (Chesterfield Reefs) and Elaphognathia australis sp. nov. (Chesterfield Reefs). New locali-ties are reported for four other species: Gnathia aureamaculosa Ferreira and Smit, 2009 and Gnathia masca Farquharsonand Smit, 2012 from Lizard Island and nearby reefs; Gnathia falcipenis Holdich and Harrison, 1980 and Gnathia variobranchia Holdich and Harrison, 1980 from Lizard Island, Wistari Reef, Heron Island and Chesterfields Reefs.
8
Hattori, Akihisa, and Takuro Shibuno. "Habitat use and coexistence of three territorial herbivorous damselfish on different-size patch reefs." Journal of the Marine Biological Association of the United Kingdom 93, no. 8 (July 22, 2013): 2265–72. http://dx.doi.org/10.1017/s0025315413000829.
Full textAbstract:
In local reef fish communities, species richness increases with increasing reef area. At Ishigaki Island, Japan, species richness is much lower on large reefs in the shallow back reef than that expected from random placement model simulations (RPMS). As three aggressive territorial herbivorous damselfish, Stegastes nigricans, Stegastes lividus and Hemiglyphidodon plagiometopon, coexist only on such large reefs, we focused on these species and examined patterns of their distribution and abundance on 84 patch reefs of various sizes (area and height). We also examined their aggressive intra- and interspecific behavioural interactions and habitat use on the two large reefs (the largest complex patch reef and the large flat patch reef) among the 84 patch reefs. While the abundance of both S. lividus and H. plagiometopon was highly correlated with patch reef area, that of S. nigricans was closely correlated with patch reef height. For S. nigricans and S. lividus, interspecific interactions occurred significantly more frequently than intraspecific interactions on the large flat patch reef. However, there was no significant difference in frequencies of the two interaction types on the largest complex patch reef, where they three-dimensionally segregated conspecific territories. This study suggested that reef height as well as reef area influence the distribution and abundance of these territorial herbivorous damselfish in the shallow back reef. As large patch reefs cannot be tall allometrically in shallow back reefs, relatively flat patch reefs may not have the high species richness expected from RPMS based on reef area.
9
Sievers, Katie T., Eva C. McClure, Rene A. Abesamis, and Garry R. Russ. "Multi-Scale Coral Reef and Seascape Habitat Variables Combine to Influence Reef Fish Assemblages." Fishes 9, no. 4 (April 15, 2024): 137. http://dx.doi.org/10.3390/fishes9040137.
Full textAbstract:
While benthic characteristics of coral reef habitats are a major driver of the structure of coral reef fish assemblages, non-reef habitats adjacent to coral reefs (e.g., mangroves, seagrass beds, and macroalgal beds) can affect reef fish assemblages. Here, we investigate how reef fish assemblages respond to local-scale benthic habitats within a coral reef and larger-scale adjacent seascape features (habitats within 500 m of coral reefs) on Siquijor Island in the Philippines. We examined an abundance of species for the entire reef fish assemblage and within the assemblages of parrotfishes (subfamily Scarinae) and wrasses (family Labridae). Five distinct habitat types were identified in a cluster analysis, which incorporated benthic characteristics within coral reefs and habitats adjacent to coral reefs. We found that the diversity and structure of coral reef fish assemblages were affected by benthic characteristics within coral reefs and also by benthic habitat types adjacent to coral reefs. Individual species responses and juveniles of certain species demonstrated uniquely high abundances in habitat clusters characterized by the non-reef habitats surrounding coral reefs. Considering coral reef habitats and adjacent non-reef habitats as a holistic, interconnected seascape will provide better estimations of the drivers of the structures of coral reef fish assemblages.
10
Turner, John, and Rebecca Klaus. "Coral reefs of the Mascarenes, Western Indian Ocean." Philosophical Transactions of the Royal Society A: Mathematical, Physical and Engineering Sciences 363, no. 1826 (January 15, 2005): 229–50. http://dx.doi.org/10.1098/rsta.2004.1489.
Full textAbstract:
The reefs of the Mascarenes differ in structure and stage of development. Mauritius is the oldest island, bound by a discontinuous fringing reef and small barrier reef, with large lagoon patch reefs. Rodrigues has nearly continuous fringing reefs bounding an extensive lagoon with deep channels and few patch reefs. Réunion, the youngest island, has short stretches of narrow fringing reefs along southwestern coasts. The islets of St Brandon are bound to the east by an extensive arc of fringing reef. Reef mapping of the Mascarenes using satellite imagery provides an estimate of 705 km 2 of shallow reef habitats. These areas have been modified over geological time by changes in sea level, ocean–atmosphere disturbances and biological and chemical forcing. Further modification has resulted from historical changes in land–use patterns. Recent economic development has placed many of these reefs at risk from anthropogenic impact. The reefs of the Mascarenes have escaped mass mortality from bleaching to date, which increases their conservation significance within the wider Indian Ocean. The reefs are poorly protected. A case study shows how a geographic information system incorporating reef–habitat maps can help formulate and demonstrate Marine Protected Area boundaries.
11
Edinger, Evan N., John M. Pandolfi, and Russell A. Kelley. "Community structure of Quaternary coral reefs compared with Recent life and death assemblages." Paleobiology 27, no. 4 (2001): 669–94. http://dx.doi.org/10.1666/0094-8373(2001)027<0669:csoqcr>2.0.co;2.
Full textAbstract:
This paper assesses the reliability with which fossil reefs record the diversity and community structure of adjacent Recent reefs. The diversity and taxonomic composition of Holocene raised fossil reefs was compared with those of modern reef coral life and death assemblages in adjacent moderate and low-energy shallow reef habitats of Madang Lagoon, Papua New Guinea. Species richness per sample area and Shannon-Wiener diversity (H′) were highest in the fossil reefs, intermediate in the life assemblages, and lowest in the death assemblages. The taxonomic composition of the fossil reefs was most similar to the combination of the life and death assemblages from the modern reefs adjacent to the two fossil reefs. Depth zonation was recorded accurately in the fossil reefs. The Madang fossil reefs represent time-averaged composites of the combined life and death assemblages as they existed at the time the reef was uplifted.Because fossil reefs include overlapping cohorts from the life and death assemblages, lagoonal facies of fossil reefs are dominated by the dominant sediment-producing taxa, which are not necessarily the most abundant in the life assemblage. Rare or slow-growing taxa accumulate more slowly than the encasing sediments and are underrepresented in fossil reef lagoons. Time-averaging dilutes the contribution of rare taxa, rather than concentrating their contribution. Consequently, fidelity indices developed for mollusks in sediments yield low values in coral reef death and fossil assemblages. Branching corals dominate lagoonal facies of fossil reefs because they are abundant, they grow and produce sediment rapidly, and most of the sediment they produce is not exported.Fossil reefs distinguished kilometer-scale variations in community structure more clearly than did the modern life assemblages. This difference implies that fossil reefs may provide a better long-term record of community structure than modern reefs. This difference also suggests that modern kilometer-scale variation in coral reef community structure may have been reduced by anthropogenic degradation, even in the relatively unimpacted reefs of Madang Lagoon. Holocene and Pleistocene fossil reefs provide a time-integrated historical record of community composition and may be used as long-term benchmarks for comparison with modern, degraded, nearshore reefs. Comparisons between fossil reefs and degraded modern reefs display gross changes in community structure more effectively than they demonstrate local extinction of rare taxa.
12
Granneman, Jennifer E., and Mark A. Steele. "Effects of reef attributes on fish assemblage similarity between artificial and natural reefs." ICES Journal of Marine Science 72, no. 8 (May 23, 2015): 2385–97. http://dx.doi.org/10.1093/icesjms/fsv094.
Full textAbstract:
Abstract Artificial reefs are used to enhance populations of marine organisms, but relatively few studies have quantitatively evaluated which attributes of reef structure are most critical in determining whether assemblages of organisms on artificial reefs are similar to those on natural reefs. Using five pairs of artificial and natural reefs that spanned 225 km in the Southern California Bight, we evaluated how well fish assemblages on artificial reefs mimicked those on natural reefs and which attributes of reefs best predicted assemblage structure. Along underwater visual transects, we quantified fish species richness, density, and size structure, as well as substrate structure (rugosity and cover of substrate types), giant kelp density, and invertebrate density. Artificial reefs that were more similar in physical structure to natural reefs (low relief, low rugosity, and composed of small- to medium -sized boulders) supported fish assemblages that were similar to those on natural reefs. Fish species richness was not significantly different between artificial and natural reefs, but density and biomass tended to be higher on average on artificial reefs, body size was slightly smaller, and assemblage structure differed between the two reef types. Generally, artificial reefs extended higher off the seabed, were made of larger boulders, had higher rugosity, harboured more invertebrates, and supported less giant kelp. At both the within-reef (transect) and whole-reef scales, fish density and biomass were positively correlated with complex substrate structure, positively correlated with invertebrate density, and negatively correlated with giant kelp abundance, which was sparse or absent on most artificial reefs. Our results indicate that artificial reefs can support fish assemblages that are similar to those found on natural reefs if they are constructed to match the physical characteristics of natural reefs, or they can be made to exceed natural reefs in some regards at the expense of other biological attributes.
13
Newman, Stephen J., David McB Williams, and Garry R. Russ. "Patterns of zonation of assemblages of the Lutjanidae, Lethrinidae and Serranidae (Epinephelinae) within and among mid-shelf and outer-shelf reefs in the central Great Barrier Reef." Marine and Freshwater Research 48, no. 2 (1997): 119. http://dx.doi.org/10.1071/mf96047.
Full textAbstract:
Visual censuses were used to quantify the distribution and abundance of the Lutjanidae, Lethrinidae and Serranidae in three reef zones (windward reef slope, lagoon, back reef) of three reefs on the mid shelf and three reefs on the outer continental shelf in the central region of the Great Barrier Reef. Significant spatial variability was identified in the abundances of many species between locations (outer-shelf and mid-shelf communities), between reefs (high-abundance v. low-abundance reefs), and within reefs (characteristic communities within zones on individual reefs). Species of the Lutjanidae, Lethrinidae and Serranidae were found to occur in assemblages that were characteristic of major zones (windward reef slopes, lagoons and leeward back reefs), this pattern being consistent within and among shelf locations. Care will need to be taken in determining the appropriate spatial scales of sampling in any future experiments (e.g. manipulations of fishing pressure) to ensure that the effects of smaller-scale spatial differences are not confounded when larger-scale comparisons are made.
14
LeFebre, Brianna, Phil Saye, and James S. Henkel. "A Report on the Artificial Reef Use in Grenada, West Indies." Journal of Marine Science and Engineering 12, no. 2 (January 31, 2024): 253. http://dx.doi.org/10.3390/jmse12020253.
Full textAbstract:
Coral reef rehabilitation in the Caribbean is of major ecological and economic importance in the West Indies. Local organizations in Grenada constructed a cement pyramid artificial reef structure with rugosity (termed “The Pyramid”) and placed a number of these artificial reefs in a shallow marine area fringing two major natural reefs in the southwest coastal region of Grenada. Benthic data for two nearby natural reefs were compared to the benthic evaluation of the artificial reef pyramids. This comparison demonstrated that the artificial reef pyramids were similar in many respects to the natural reefs but were significantly different in macro- and coralline algae cover, two key indicators of reef health. This report is the first benthic evaluation of an artificial reef through comparison to natural reefs in Grenada.
15
Robertson, D. Ross, Omar Domínguez-Dominguez, Yareli Margarita López Aroyo, Rigoberto Moreno Mendoza, and Nuno Simões. "Reef-associated fishes from the offshore reefs of western Campeche Bank, Mexico, with a discussion of mangroves and seagrass beds as nursery habitats." ZooKeys 843 (May 9, 2019): 71–115. http://dx.doi.org/10.3897/zookeys.843.33873.
Full textAbstract:
A series of small emergent coral reefs and shallow, submerged coralliferous banks are scattered along the western edge of Campeche Bank (southwest Gulf of Mexico), 150–200 km offshore from the Yucatán Peninsula, Mexico. Here a reasonably comprehensive, annotated checklist of reef-associated fishes for one reef, Cayo Arcas (expanded from 162 to 209 species) is presented, with preliminary checklists of such fishes from three other emergent reefs (Cayo Arenas, Triángulo Oeste, Triángulo Este) and four submerged bank reefs (Banco Obispo Norte, Banco Obispo Sur, Banco Nuevo and Banco Pera). During 2017–18 a total of 260 species was observed or collected from those reefs, and previous studies and georeferenced museum records in the global aggregator Fishnet2 added another 101 shallow-living species recorded on or adjacent to those reefs. Some coral-reef fishes are thought to be strongly dependent on seagrass and mangrove areas as nursery habitats for maintenance of their local populations on reefs near to those habitats. The abundance of a number of such “nursery” species on these Campeche reefs indicates otherwise, as there are no seagrass- or mangrove habitats for reef fishes within ~ 150 km of the study reefs. Other isolated Caribbean-area reefs that lack mangroves and, in some cases, seagrasses, also support many such nursery species of reef-fishes.
16
Boakes, Zach, Alice E. Hall, Georgia CA Jones, Rahmadi Prasetijo, Richard Stafford, and Yunaldi Yahya. "Artificial coral reefs as a localised approach to increase fish biodiversity and abundance along the North Bali coastline." AIMS Geosciences 8, no. 2 (2022): 303–25. http://dx.doi.org/10.3934/geosci.2022018.
Full textAbstract:
<abstract> <p>Coral reefs face worldwide decline from threats such as climate change, destructive fishing practices, overfishing and pollution. Artificial reefs have shown potential as a method to mitigate localised habitat loss and biodiversity decline on degraded coral reefs. The health of coral reefs in Indonesia and their associated faunal populations have displayed a downward trend in recent decades, and community-managed non-government organisations have started using artificial reefs to restore local degraded reef habitats. In this study, we demonstrate how locally-managed NGOs and communities in north Bali, Indonesia have implemented artificial reef projects, and assess the associated benefits to biodiversity. Using Remote Underwater Video (RUV) over a 3 month period in north Bali, fish assemblages on two artificial reefs of different ages (new and mature) were compared to two nearby natural habitats: degraded sand flats and relatively healthy coral reefs. When compared with a nearby degraded sand habitat, both artificial reefs displayed a significantly higher number of species, which for the mature artificial reef was not statistically different to a nearby coral reef. Community structure was also compared, again showing similarity between artificial reefs and natural coral reefs, but differing in a few species, including specific damselfish and wrasse. This study is one of few which highlight the potential of artificial reef habitat enhancement in Indonesia, and suggests that these structures can provide ecologically equivalent mobile faunal communities to a natural reef on a localised scale. As such, well designed projects may be able to provide some local ecosystem services lost from degraded coral reefs, and become an important focus for coastal communities.</p> </abstract>
17
Lipps, Jere H. "Reef Restoration—the Good and the Bad, A Paleobiologic Perspective." Paleontological Society Papers 17 (October 2011): 139–52. http://dx.doi.org/10.1017/s1089332600002503.
Full textAbstract:
Little good and a lot of bad come from reef restoration. Reefs damaged by humans and nature are “restored” using unnatural materials as substrata quickly occupied by corals and fish. This is commonly considered good, for seemingly the reef has been returned to a “healthy” state; fish can be caught again and tourists return for the “beautiful reefs”. Restoration, the act of reestablishing a former state, has never been accomplished on a reef; rather reefs have been manipulated to conform to particular human values without regard for the entire reef—its ecology, trophodynamics, hydrodyamics, physical or chemical characteristics of pseudo-substrata, geochemistry, nutrient supply, and even reef aesthetics among a multitude of others. People seemingly cannot leave well enough alone when it comes to reefs that have been noticeably damaged. Yet, that is exactly what reefs need—time without interference. Careful analysis of the total consequences of various methods is required. Reefs evolved over millions of years in one of the harshest environments on earth—the air-water interface. They are well adapted to recover from physical damage of almost any sort. Reefs are not fragile. Thoughtful assistance would help, using materials occurring naturally within reef systems, by involving regional stakeholders in natural processes of restoration, and by stringent protection regulations and agreements. Opportunistic “restoration” by well-meaning, misguided or avaricious people without careful consideration of what really constitutes a reef is a major mistake that will eventually degrade reefs and need restoration itself. Protection of reefs is the best option, followed by letting natural restorative processes take place over long times.
18
Yang, Zhen, Guozhang Fan, Wei Yan, Xuefeng Wang, Guoqing Zhang, Zhili Yang, Zuofei Zhu, et al. "Types and Evolution of the Miocene Reefs Based on Seismic Data in the Beikang Basin, South China Sea." Journal of Marine Science and Engineering 12, no. 2 (February 19, 2024): 360. http://dx.doi.org/10.3390/jmse12020360.
Full textAbstract:
During the Miocene, several reefs formed in the Beikang Basin, South China Sea, which may be potential targets for hydrocarbon exploration. This is due to the environment that developed as a result of the collision, splitting, and splicing of the Nansha Block, which was influenced by the Neogene expansion of the area. However, studies on the types, distribution, controlling factors, and evolution stages of these reefs are scarce. In this study, we used high-resolution seismic data and extensive well-drilling records to gain insights into the evolution of reefs in this particular area. Six distinct types of reefs, namely, the point reef, the platform-edge reef, the block reef, the bedded reef, the pinnacle reef, and the atoll reef, were identified based on our data. These reefs underwent four stages of development. During the initial stage, a few small-sized point reefs emerged in the basin and experienced significant growth during the early Middle Miocene. In the flourishing stage, the reefs predominantly thrived around the Central Uplift and Eastern Uplift areas. In the recession stage, the reefs began to deteriorate during the late Middle Miocene period as a result of the rapid increase in relative sea level caused by tectonic subsidence. In the submerged stage, since the Late Miocene, as the relative sea level continued to rise steadily over time, many reefs that had previously flourished surrounding the Central Uplift and Eastern Uplift areas became submerged underwater, with only a handful of atoll reefs surviving near islands located on the Eastern Uplift. This study indicated the presence of a significant number of well-preserved reefs in the Beikang Basin that have experienced minimal subsequent diagenesis and therefore exhibit high potential as reservoirs for oil and gas exploration.
19
Chapman, Nicola D., Colin G. Moore, Dan B. Harries, and Alastair R. Lyndon. "The community associated with biogenic reefs formed by the polychaete, Serpula vermicularis." Journal of the Marine Biological Association of the United Kingdom 92, no. 4 (July 22, 2011): 679–85. http://dx.doi.org/10.1017/s0025315411000701.
Full textAbstract:
The study aims to provide the first detailed account of the diversity and composition of the community associated with biogenic reefs formed by serpulid worms. Ten reefs (aggregations of calcareous Serpula vermicularis tubes), spanning a broad size-range, were collected from Loch Creran, Scotland, a Special Area of Conservation designated principally for the protection of its biogenic reefs. Total faunal abundance was strongly linearly related to reef weight, whilst taxon richness exhibited a hyperbolic relationship with reef size. 278 taxa were recorded from the ten reefs, with a reef of 0.1 m2 area supporting 163 taxa and 12756 individuals, which appears to represent considerable augmentation of diversity and abundance for sedimentary areas of the loch where the reefs occur. The reef assemblage was dominated by polychaetes (94 taxa), molluscs (70 taxa) and crustaceans (45 taxa). Species composition varied with reef size, although reefs greater than 25 cm width exhibited relatively little variation. In comparison with other biogenic polychaete habitats, S. vermicularis reefs appear to support a highly diverse community, which exhibits a high degree of similarity with that found in association with aggregations of the horse mussel, Modiolus modiolus. The presence of the Connemara clingfish, Lepadogaster candollei, rarely recorded at such a northerly latitude, on several reefs, indicates that the reef habitat may provide a stronghold for this species at the edge of its biogeographical range.
20
Mwaura, Jelvas M., Dishon Murage, Juliet F. Karisa, Levy M. Otwoma, and Hashim O. Said. "Artificial reef structures and coral transplantation as potential tools for enhancing locally-managed inshore reefs: a case study from Wasini Island, Kenya." Western Indian Ocean Journal of Marine Science 21, no. 2 (February 27, 2023): 83–94. http://dx.doi.org/10.4314/wiojms.v21i2.8.
Full textAbstract:
Many severely degraded reefs in the western Indian Ocean region show no signs of natural recovery and have remained for decades as barren, unconsolidated coral rubble fields with depleted commercially important fish groups. Consequently, several restoration techniques have been designed and developed to mitigate the localized impacts on coral reefs. Evaluating the efficacy of combined use of artificial reef structures and coral transplantation in enhancing habitat and recovery of key functions in severely degraded reefs is key to improved conservation of coral reefs. In this study, the survivorship rate of corals transplanted on reef structures is assessed, and changes in coral and fish abundance on artificial reef units and nearby natural reefs over time are compared. Coral cover on artificial reef structures increased from a mean of 17 % one year after initial attachment of fragments to 41 % after two years, with Acropora corals providing the highest cover. The artificial reef structures were also rapidly colonized by reef fish, with fish densities of 18±13 indiv./100 m2 showing an increase of about three fold higher than on natural reefs after two years. Greater numbers of commercially important fish groups (e.g., Lutjanids and Acanthurids) were observed on artificial reefs while natural reefs harboured more small sized fish (Pomacentrids and Labrids). These findings provide insights for artificial reef projects that are capable of restoring the regenerative capacity of the human-induced coral rubble beds.
21
Burke, C. D., and S. J. Mazzullo. "Biotic and sedimentologic comparison of patch reefs on the north and south shelf of Belize, Central America." Paleontological Society Special Publications 6 (1992): 45. http://dx.doi.org/10.1017/s2475262200006055.
Full textAbstract:
Holocene patch-reefs occur throughout the shallow marine platform, to the lee of the barrier reef in northern and southern Belize, Central America. Patch reefs on the northern shelf that occur within an areally extensive patch reef complex (Mexico Rocks) indicate that differences exist between reefs here and well-studied patch reefs on the southern shelf that have been used by workers as a general model for patch reef development throughout Belize. This model proposes that patch reefs on the Belizean shelf are dominated by typical Atlantic-Caribbean, biotically-zoned coral assemblages of Acropora palmata and A. cervicornis that kept up or caught up with Holocene sea level rise during the last 8000 years to form large “keep up” or in some instances “catch up” reefs.In contrast to those in the south, the northern patch reefs are not biotically zoned, are dominated by Montastrea annularis rather than Acropora spp., and are much younger (400 years old) than those in the south. In addition, northern shelf patch reefs developed predominantly by lateral growth in a milieu of static sea level and are herein called “accretion” type reefs. These differences in biotic and sedimentologic parameters between reefs on the northern and southern shelves imply fundamentally different ecologic and sea level history controls on patch reef formation from north to south. A leading contributor to the variation among the reefs along the Belizean shelf may be species-specific growth rates of the coral species that initiate each patch reef, and response to sea level fluctuation versus stasis through time.
22
Stanley Jr, George D., and Christopher A. McRoberts. "A coral reef in the Telkwa Range, British Columbia: the earliest Jurassic example." Canadian Journal of Earth Sciences 30, no. 4 (April 1, 1993): 819–31. http://dx.doi.org/10.1139/e93-068.
Full textAbstract:
An end-Triassic mass extinction profoundly affected reef ecosystems that flourished in the Late Triassic Tethys seaway. The collapse of Late Triassic coral–sponge reefs was followed by an Early Jurassic (Hettangian–Sinemurian) perturbation interval with a near-global absence of reefs and sharp reductions in diversity. A Jurassic (Sinemurian) reef in the Hazelton Group of central British Columbia appears to fill the gap. Its paleoecology and composition show it to be the first large-framework example in North America and perhaps the world. It demonstrates that the reef-building Triassic coral, Phacelostylophyllum, survived the extinction event and was constructing reefs in Early Jurassic time during a global reef eclipse. The reef is a 48 m thick bioherm that grew within the island-arc complex of Stikinia. Following a decrease in volcanism, reef building began with bivalves growing upon water-lain tuffs. The reef was dominated by large dendroid–phaceloid corals, primarily Phacelostylophyllum rugosum, a species known from the Upper Triassic of Italy, which produced extensive constructional framework. Other fossils include bivalves, solitary and colonial corals, and a variety of dwellers and reef destroyers. Three stages of growth are present. During siliciclastic deposition, the reef mound grew into a bioherm with steep relief and flanking beds. Two intervals of arrested growth marked by pyroclastic lenses and hard grounds punctuated the reef's history. The reef was finally overwhelmed by volcaniclastic sediment, was uplifted, and developed paleokarst. The reef is unique in understanding the dynamics of recovery after the end-Triassic mass extinction.
23
Carroll, Steven, and Greg Beresford. "Combining reflection tomography with layer replacement for velocity analysis of near‐surface reefs." GEOPHYSICS 61, no. 2 (March 1996): 561–69. http://dx.doi.org/10.1190/1.1443982.
Full textAbstract:
Reefs in the Browse Basin on the Australian North West Shelf typically have strong lateral velocity inhomogeneity on the reef flanks and produce an irregular sea‐floor topography. The combination of these two factors reduces the effectiveness of conventional velocity analysis as moveout on common midpoint (CMP) gathers is no longer hyperbolic. Consequently, the velocity structure on the reef flanks cannot be resolved properly. An accurate velocity structure is needed for these reefs if seismic data acquired in the vicinity are to be migrated correctly. Tomographic velocity analysis, using a simultaneous iterative reconstruction technique (SIRT), was found to improve the velocity analysis of the reef when compared to conventional analysis. However, the reef’s profile and rapid internal velocity gradients prevent accurate raypath determination. This technique can be further improved by preconditioning the data with wave‐equation datuming. The water is replaced with an average reef velocity by downward and upward continuation. This effectively removes most of the raypath distortions resulting from ray bending at the sea floor, thus reducing the nonlinearity of the forward modeling and improving the convergence of an iteratively linearized inversion. The velocities obtained from this method give an accurate picture of the reef’s internal velocity structure, as well as the lower portion of the seismic section below the reef.
24
PENNY, AMELIA, ANDRÉ DESROCHERS, and BJÖRN KRÖGER. "METAZOAN REEF CONSTRUCTION IN A MIDDLE ORDOVICIAN SEASCAPE: A CASE STUDY FROM THE MINGAN ARCHIPELAGO, QUEBEC." PALAIOS 35, no. 8 (August 27, 2020): 327–41. http://dx.doi.org/10.2110/palo.2020.010.
Full textAbstract:
ABSTRACT The Ordovician (485–444 Ma) saw a global shift from microbial- to skeletal-dominated reefs, and the rise of corals and bryozoans as important reef-builders. Hypothetically, increasingly morphologically diverse and abundant reef-building metazoans increased spatial habitat heterogeneity in reef environments, an important component of reefs' capacity to support diverse communities. Quantifying the spatial scale and extent of this heterogeneity requires three-dimensional exposures of well-preserved reefs whose composition and spatial arrangement can be measured. The Darriwilian (c. 467–458 Ma) carbonate sequence of the Mingan Archipelago, Quebec, presents such exposures, and also provides an opportunity to establish how the distribution of skeletal-dominated metazoan reefs contributed to, and was influenced by, seafloor relief. This study includes two transects through a 200–300 m wide paleo-reef belt, which developed along a rocky paleo-coast line. The reefs are typically micrite-rich, meter-scale mounds, locally forming larger complexes. Here, we present quantitative evaluations of the composition of these reefs, and detailed mapping of reef distributions. There is high compositional heterogeneity between reefs at spatial scales ranging from meters to kilometers, contributed by differences in the volumetric contribution of skeletal material to the reef core, and in the identity of the dominant reef-builders. We suggest that the abundance and morphological diversity of Middle Ordovician reef building metazoans made them important contributors to environmental and substrate heterogeneity, likely enhancing the diversity of reef-dwelling communities.
25
Galbraith, Gemma F., Benjamin J. Cresswell, Mark I. McCormick, Thomas C. Bridge, and Geoffrey P. Jones. "Contrasting hydrodynamic regimes of submerged pinnacle and emergent coral reefs." PLOS ONE 17, no. 8 (August 16, 2022): e0273092. http://dx.doi.org/10.1371/journal.pone.0273092.
Full textAbstract:
Hydrodynamics on coral reefs vary with depth, reef morphology and seascape position. Differences in hydrodynamic regimes strongly influence the structure and function of coral reef ecosystems. Submerged coral reefs on steep-sided, conical bathymetric features like seamounts experience enhanced water circulation as a result of interactions between currents and the abrupt physical structure. There may also be similar interactions between smaller pinnacles and regional water currents in offshore locations (crests > 10 m), while shallow reefs (crests <10 m) may be more subject to surface currents driven by wind, waves and tide. Here we tested whether coral pinnacles experienced stronger and more variable currents compared to emergent reefs at the same depth in both nearshore and offshore positions. Current speeds and temperature were monitored for 12 months at 11 reefs, representing the three different reef categories: submerged offshore pinnacles, emergent offshore reefs and emergent nearshore reefs. We found different patterns in current speeds and temperature among reef types throughout the year and between seasons. Submerged pinnacles exhibited stronger, more variable current speeds compared to both near and offshore emergent reefs. We found seasonal changes in current speeds for pinnacle and nearshore reefs but no variation in current strength on offshore reefs. Whilst instantaneous current directions did reflect the seascape position of individual sites, there was no difference in the directional variability of current speeds between reef types. Annual daily average temperatures at all reef types were not strongly seasonal, changing by less than 2 °C throughout the year. Daily temperature ranges at specific sites however, exhibited considerable variability (annual range of up to 6.5 °C), particularly amongst offshore emergent reefs which experienced the highest temperatures despite greater exposure to regional-scale circulation patterns. Additionally, we found a consistent mismatch between satellite sea surface temperatures and in-situ temperature data, which was on average 2 °C cooler throughout the annual study period. Our results suggest that distinct hydrodynamic processes occur on smaller submerged structures that are physically analogous to seamounts. Our findings highlight important nuances in environmental processes that occur on morphologically distinct coral reef habitats and these are likely to be important drivers for the community dynamics of organisms that inhabit these reefs.
26
Almaarif, Joko Samiaji, and Thamrin Thamrin. "ABUNDANCE OF CORAL FISH SPECIES AND THE CONDITION OF CORAL REEFS IN THE WATERS OF THE TIKUS ISLAND, BENGKULU CITY." Asian Journal of Aquatic Sciences 3, no. 1 (April 9, 2020): 20–28. http://dx.doi.org/10.31258/ajoas.3.1.20-28.
Full textAbstract:
Coral reefs are one of the ecosystems that have ecological functions for marine life, one of which is reef fish. Coral fish are marine biota that live in association with coral reefs. This study aims to determine the abundance of reef fish, the condition of coral reefs and the relationship between abundance of reef fish and coral reefs. This research was conducted in June 2019 in the waters of Tikus Island, Bengkulu City. The method used is a survey method. Data collection on reef fish was carried out using the Underwater Visual Census (UVC) method and coral reefs condition data colletion is done using the Line Intercept Transect (LIT) method. The abundance of reef fish found at the study site averages in the abundant category. At station I, an abundance of reef fish was 2,18 ind/m2, at station II it was 4,18 ind/m2, and at station III it was 1,27 ind/m2. While the average condition of coral reefs at the study site is include in the medium category. At station I, the percentage of live coral cover was 39,30% or include in the medium category. At station II, the percentage of live coral cover was 50,94% or include in the good category. And at station III, the percentage of live coral cover was 46,32% or include in the medium category. Coral fish and coral reefs have a fairly close relationship. Reef fish use coral reefs as a place to find food, shelter and spawn or breed.
27
TUULING, IGOR, and TOM FLODÉN. "Silurian reefs off Saaremaa and their extension towards Gotland, central Baltic Sea." Geological Magazine 150, no. 5 (April 30, 2013): 923–36. http://dx.doi.org/10.1017/s0016756813000101.
Full textAbstract:
AbstractThe Silurian reefs off Saaremaa in the Baltic Sea were studied by means of high-resolution seismic reflection profiling. The abundance and diversity of the reefs increases off Saaremaa concomitantly with the deepening of the Baltic Silurian Basin towards Gotland. The peak of the reefs around Saaremaa occurred during the Middle Wenlock. The reef facies retreated further off Saaremaa during the Late Wenlock, became episodically restored around the island during the early Ludlow and finally ceased during the late Ludlow. A similar SW–NE–SW migration of reefs reflects an alternating transgressive–regressive pattern in the nearshore shallow shelf environment, where already minor sea-level fluctuations strongly influenced the conditions for reef growth. During the early Wenlock, a bathymetric break with a large barrier-reef-like structure divided the shallow shelf offshore Saaremaa facially into back-reef and southerly sloping fore-reef areas. The width of this SW-migrating barrier (c. 8 km) and the extent of reef bodies within it (c. 4 km) are the largest known in the Baltic region. During the Silurian, the reefs between Saaremaa and Gotland were flourishing to a much larger extent than is visible today. The primary Silurian reef pattern was increasingly destroyed towards Gotland by later erosion. This has resulted in a large area void of Wenlock reefs off northern Gotland. Off southern Gotland, the narrow conical low-energy deeper-water reefs prevail, as the wave-agitated shallow-water facies with larger and lenticular Wenlock and Ludlow reefs are largely eroded around the Gotland Deep.
28
Jouffray, Jean-Baptiste, Lisa M. Wedding, Albert V. Norström, Mary K. Donovan, Gareth J. Williams, Larry B. Crowder, Ashley L. Erickson, et al. "Parsing human and biophysical drivers of coral reef regimes." Proceedings of the Royal Society B: Biological Sciences 286, no. 1896 (February 13, 2019): 20182544. http://dx.doi.org/10.1098/rspb.2018.2544.
Full textAbstract:
Coral reefs worldwide face unprecedented cumulative anthropogenic effects of interacting local human pressures, global climate change and distal social processes. Reefs are also bound by the natural biophysical environment within which they exist. In this context, a key challenge for effective management is understanding how anthropogenic and biophysical conditions interact to drive distinct coral reef configurations. Here, we use machine learning to conduct explanatory predictions on reef ecosystems defined by both fish and benthic communities. Drawing on the most spatially extensive dataset available across the Hawaiian archipelago—20 anthropogenic and biophysical predictors over 620 survey sites—we model the occurrence of four distinct reef regimes and provide a novel approach to quantify the relative influence of human and environmental variables in shaping reef ecosystems. Our findings highlight the nuances of what underpins different coral reef regimes, the overwhelming importance of biophysical predictors and how a reef's natural setting may either expand or narrow the opportunity space for management interventions. The methods developed through this study can help inform reef practitioners and hold promises for replication across a broad range of ecosystems.
29
Copertino, Jessica L., Katherine Harris, Lyndsey Chute, and Linda J. Walters. "Impact of Oyster (Crassostrea virginica) Reef Restoration on Benthic Invertebrates and Coastal Birds in a Subtropical Estuary." Sustainability 14, no. 4 (February 18, 2022): 2371. http://dx.doi.org/10.3390/su14042371.
Full textAbstract:
In order to mitigate the degradation of eastern oyster (Crassostrea virginica) reefs in Mosquito Lagoon (ML) along the east coast of central Florida, oyster reef restoration efforts have been in place for over 14 years. These restored reefs are successful in terms of universal oyster metrics (i.e., density, shell height, reef height) and are similar to natural reefs. However, little is known about the impact of this restoration on bird populations. ML provides a habitat for many bird species, including several listed as “threatened” by the Florida Fish and Wildlife Conservation Commission. Many of these birds rely on oyster reefs for foraging and loafing habitats. As benthic invertebrates serve as an important food source for coastal birds, we monitored the abundances and diversity of these organisms on live, restored, and dead reefs. We collected sediment samples from the reef sites pre-restoration, and one month, six months, one year, two years, and three years post-restoration. We counted benthic invertebrates present in the sediment samples, and sorted them by taxa (polychaetes, amphipods, isopods, gastropods, bivalves, decapods). Benthic invertebrate abundances on restored reefs became similar to live reefs over time (species composition, density), indicating that the prey base on restored reefs was similar to that of live reefs within 6 months. A second objective of this study was to determine if restored oyster reefs reach the same abundances, foraging behaviors, and diversity of bird species on natural, live reefs. We conducted monthly bird surveys to assess bird utilization of live, restored, and dead reefs. After three years, the abundances, behaviors, and assemblages of birds on restored reefs were similar to live reefs.
30
Obolski, Uri, Lilach Hadany, and Avigdor Abelson. "Potential contribution of fish restocking to the recovery of deteriorated coral reefs: an alternative restoration method?" PeerJ 4 (February 29, 2016): e1732. http://dx.doi.org/10.7717/peerj.1732.
Full textAbstract:
Counteracting the worldwide trend of coral reef degeneration is a major challenge for the scientific community. A crucial management approach to minimizing stress effects on healthy reefs and helping the recovery of disturbed reefs is reef protection. However, the current rapid decline of the world’s reefs suggests that protection might be insufficient as a viable stand-alone management approach for some reefs. We thus suggest that the ecological restoration of coral reefs (CRR) should be considered as a valid component of coral reef management, in addition to protection, if the applied method is economically applicable and scalable. This theoretical study examines the potential applicability and outcomes of restocking grazers as a restoration tool for coral reef recovery—a tool that has not been applied so far in reef restoration projects. We studied the effect of restocking grazing fish as a restoration method using a mathematical model of degrading reefs, and analyzed the financial outcomes of the restocking intervention. The results suggest that applying this restoration method, in addition to protection, can facilitate reef recovery. Moreover, our analysis suggests that the restocking approach almost always becomes profitable within several years. Considering the relatively low cost of this restoration approach and the feasibility of mass production of herbivorous fish, we suggest that this approach should be considered and examined as an additional viable restoration tool for coral reefs.
31
Morgan, Kyle M., Chris T. Perry, Rudy Arthur, Hywel T. P. Williams, and Scott G. Smithers. "Projections of coral cover and habitat change on turbid reefs under future sea-level rise." Proceedings of the Royal Society B: Biological Sciences 287, no. 1929 (June 17, 2020): 20200541. http://dx.doi.org/10.1098/rspb.2020.0541.
Full textAbstract:
Global sea-level rise (SLR) is projected to increase water depths above coral reefs. Although the impacts of climate disturbance events on coral cover and three-dimensional complexity are well documented, knowledge of how higher sea levels will influence future reef habitat extent and bioconstruction is limited. Here, we use 31 reef cores, coupled with detailed benthic ecological data, from turbid reefs on the central Great Barrier Reef, Australia, to model broad-scale changes in reef habitat following adjustments to reef geomorphology under different SLR scenarios. Model outputs show that modest increases in relative water depth above reefs (Representative Concentration Pathway (RCP) 4.5) over the next 100 years will increase the spatial extent of habitats with low coral cover and generic diversity. More severe SLR (RCP8.5) will completely submerge reef flats and move reef slope coral communities below the euphotic depth, despite the high vertical accretion rates that characterize these reefs. Our findings suggest adverse future trajectories associated with high emission climate scenarios which could threaten turbid reefs globally and their capacity to act as coral refugia from climate change.
32
Ryan, Georgina, George Bernardel, John Kennard, Andrew T. Jones, Graham Logan, and Nadege Rollet. "A pre-cursor extensive Miocene reef system to the Rowley Shoals reefs, Western Australia: evidence for structural control of reef growth or natural hydrocarbon seepage?" APPEA Journal 49, no. 1 (2009): 337. http://dx.doi.org/10.1071/aj08021.
Full textAbstract:
Numerous Miocene reefs and related carbonate build-ups have been identified in the Rowley Shoals region of the central North West Shelf, offshore Western Australia. The reefs form part of an extensive Miocene reef tract over 1,600 km long, which extended northward into the Browse and Bonaparte basins and southward to North West Cape in the Carnarvon Basin—comparable in length to the modern Great Barrier Reef. Growth of the vast majority of these Miocene reefs failed to keep pace with relative sea-level changes in the latest Miocene, whereas reef growth continued on the central North West Shelf to form the three present-day atolls of the Rowley Shoals: Mermaid, Clerke and Imperieuse reefs. In the Rowley Shoals region, scattered small build-ups and local reef complexes were first established in the Early Miocene, but these build-ups were subsequently terminated at a major Mid Miocene sequence boundary. Widespread buildups and atoll reefs were re-established in the Middle Miocene, and the internal stacking geometries of the reefs appear to relate to distinct growth phases that are correlated with eustatic sea-level fluctuations. These geometries include: a basal aggradational buildup of early Middle Miocene age; a strongly progradational growth phase in the late Middle to early Late Miocene that constructed large reef atolls with infilling lagoon deposits; and a back-stepped aggradational growth phase that formed smaller reef caps in the early–latest Late Miocene. Growth of the majority of the reefs ceased at a major sea-level fall in the Late Miocene (Messinian), and only the reefs of the present-day Rowley Shoals (Mermaid, Clerke and Imperieuse reefs, as well as a drowned shoal to the southwest of Imperieuse Reef) continued to grow after this event. Growth of the Rowley Shoals reefs continued to keep pace with Pliocene-Recent sea-level changes, whereas the surrounding shelf subsided to depths of 230–440 m. We conclude that initial reef growth in the Rowley Shoals region was controlled by transpressional reactivation and structuring of the Mermaid Fault Zone during the early stage of collision between the Australian and Eurasian plates. During this structural reactivation, seabed fault scarps and topographic highs likely provided ideal sites for the initiation of reef growth. The subsequent growth and selective demise of the reefs was controlled by the interplay of eustatic sea-level variations and differential subsidence resulting from continued structural reactivation of the Mermaid Fault Zone. In contrast to models proposed in other regions, there is no direct evidence that active or palaeo hydrocarbon seepage triggered or controlled growth of the Rowley Shoals reefs or their buried Miocene predecessors.
33
Zampa, Greta, Annalisa Azzola, Carlo Nike Bianchi, Carla Morri, Alice Oprandi, and Monica Montefalcone. "Patterns of change in coral reef communities of a remote Maldivian atoll revisited after eleven years." PeerJ 11 (October 24, 2023): e16071. http://dx.doi.org/10.7717/peerj.16071.
Full textAbstract:
Coral reefs are exposed worldwide to several global and local human pressures including climate change and coastal development. Assessing the effects of such pressures on coral reef communities and the changes they undergo over time is mandatory to understand their possible future trends. Nonetheless, some coral reefs receive no or little scientific attention, as in the case of Huvadhoo Atoll that is an under-studied region in the southernmost area of the Maldives (Indian Ocean). This study analyzes the changes occurring over time in eight coral reefs (four inner reefs within the atoll lagoon and four outer reefs on the ocean side) at Huvadhoo Atoll, firstly surveyed in 2009 and revisited in 2020 using the same field methods. The cover of 23 morphological benthic descriptors (including different growth forms of Acropora) was taken into account and then grouped into three categories (i.e., hard coral, other benthic taxa and abiotic descriptors) to analyze the change in the composition of the coral reef community. Significant changes (e.g., increase in hard coral cover and decrease in abiotic descriptors) were observed in the inner reefs as compared to the outer reefs, which showed less variability. A significant decrease in tabular Acropora cover was observed in both inner and outer reefs, with possible negative effects on reef complexity and functioning. By comparing two time periods and two reef types, this study provides novel information on the change over time in the community composition of Maldivian coral reefs.
34
Zweifler (Zvifler), Adi, Michael O’Leary, Kyle Morgan, and Nicola K. Browne. "Turbid Coral Reefs: Past, Present and Future—A Review." Diversity 13, no. 6 (June 7, 2021): 251. http://dx.doi.org/10.3390/d13060251.
Full textAbstract:
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.
35
Becker, Alistair, Matthew D. Taylor, and Michael B. Lowry. "Monitoring of reef associated and pelagic fish communities on Australia’s first purpose built offshore artificial reef." ICES Journal of Marine Science 74, no. 1 (August 4, 2016): 277–85. http://dx.doi.org/10.1093/icesjms/fsw133.
Full textAbstract:
Artificial reefs now form part of an integrated approach to enhance fisheries around the world. A responsible approach to artificial reef deployment calls for clear, well defined goals prior to any reef being placed in the field, followed by subsequent monitoring to assess whether these goals are being achieved. In this study, to evaluate if an artificial reef off Sydney was meeting its goal of providing quality fishing opportunities through the establishment of a complex fish assemblage, a 4-year monitoring program was designed. This program examined the response of reef-associated and pelagic fishes to the deployment of a purpose built offshore reef, relative to control reefs. Fish were observed immediately following deployment, but the artificial reef fish assemblage remained distinct from the three natural control reefs throughout the monitoring period. Also, the artificial reef displayed inter-annual variability associated with successional processes, which was not evident on the natural reefs. Fish length data indicated that the artificial reef was providing resources for both juvenile and adults of a number of species. This study demonstrates artificial reefs can provide habitats for a diverse group of fish, but the assemblages are unlikely to mimic those on natural reefs. We have also shown that longer term monitoring periods, covering multiple years are required to gain a robust understanding of the response of fish to reef deployment. This information can be used to understand the benefits and limitations of future artificial reef deployments.
36
Ma, L., C. Becker, L. Weber, C. Sullivan, B. Zgliczynski, S. Sandin, M. Brandt, TB Smith, and A. Apprill. "Biogeography of reef water microbes from within-reef to global scales." Aquatic Microbial Ecology 88 (March 31, 2022): 81–94. http://dx.doi.org/10.3354/ame01985.
Full textAbstract:
Seawater microorganisms play an important role in coral reef ecosystem functioning and can be influenced by biological, chemical, and physical features of reefs. As coral reefs continue to respond to environmental changes, the reef seawater microbiome has been proposed as a conservation tool for monitoring perturbations. However, the spatial variability of reef seawater microbial communities is not well studied, limiting our ability to make generalizable inferences across reefs. In order to better understand how microorganisms are distributed at multiple spatial scales, we examined seawater microbial communities in Florida Reef Tract and US Virgin Islands reef systems using a nested sampling design. On 3 reefs per reef system, we sampled seawater at regular spatial intervals close to the benthos. We assessed the microbial community composition of these waters using ribosomal RNA gene amplicon sequencing. Our analysis revealed that reef water microbial communities varied as a function of reef system and individual reefs, but communities did not differ within reefs and were not significantly influenced by benthic composition. For the reef system and inter-reef differences, abundant microbial taxa were found to be potentially useful indicators of environmental difference due to their high prevalence and variance. We further examined reef water microbial biogeography on a global scale using a secondary analysis of 5 studies, which revealed that microbial communities were more distinct with increasing geographic distance. These results suggest that biogeography is a distinguishing feature for reef water microbiomes, and that development of monitoring criteria may necessitate regionally specific sampling and analyses.
37
Kang, Myounghee, Takeshi Nakamura, and Akira Hamano. "A methodology for acoustic and geospatial analysis of diverse artificial-reef datasets." ICES Journal of Marine Science 68, no. 10 (September 2, 2011): 2210–21. http://dx.doi.org/10.1093/icesjms/fsr141.
Full textAbstract:
Abstract Kang, M., Nakamura, T., and Hamano, A. 2011. A methodology for acoustic and geospatial analysis of diverse artificial-reef datasets. – ICES Journal of Marine Science, 68: 2210–2221. A methodology is introduced for understanding fish-school characteristics around artificial reefs and for obtaining the quantitative relationship between geospatial datasets related to artificial-reef environments using a new geographic information system application. To describe the characteristics of fish schools (energetic, positional, morphological characteristics and dB difference range), acoustic data from two artificial reefs located off the coast of Shimonoseki, Yamaguchi prefecture, Japan, were used. To demonstrate the methodology of the geospatial analysis, diverse datasets on artificial reefs, such as fish-school characteristics, marine-environmental information from a conductivity, temperature, and depth sensor, information on artificial reefs, seabed geographic information, and sediment information around the reefs, were utilized. The habitat preference of fish schools was demonstrated quantitatively. The acoustic density of fish schools is described with respect to the closest distance from reefs and the preferred reef depths, the relationship between fish schools and environmental information was visualized in three dimensions, and the current condition of the reefs and their connection to seabed type is represented. This geospatial method of analysis can provide a better way of comprehensively understanding the circumstances around artificial-reef environments.
38
Stoddart, D. "Theory and Reality: The Success and Failure of the Deductive Method in Coral Reef Studies-Darwin to Davis." Earth Sciences History 13, no. 1 (January 1, 1994): 21–34. http://dx.doi.org/10.17704/eshi.13.1.wp354u3281532021.
Full textAbstract:
W. M. Davis's monograph The Coral Reef Problem (1928) and his voluminous other publications on coral reefs present his unambiguous support for Darwin's evolutionary model of the development of reef types through slow subsidence of reef foundations. Davis claimed to find unequivocal support for his views in the features of now-elevated reefs. Since his deductions, expressed in sequential block diagrams, were based on his incorrect belief that elevated reefs eroded rapidly, he was compelled to reject paleontological evidence that many elevated reefs are old. Thus to support his theoretical position he systematically misrepresented the geomorphic history of, for example, the Lau Islands, Eua, the Loyalty Islands, Jaluit Atoll and Mangaia. Not surprisingly this work did not impress contemporaries who had experience of these reefs in the field.
39
Apprill, A., H. Holm, AE Santoro, C. Becker, M. Neave, K. Hughen, A. Richards Donà, et al. "Microbial ecology of coral-dominated reefs in the Federated States of Micronesia." Aquatic Microbial Ecology 86 (April 22, 2021): 115–36. http://dx.doi.org/10.3354/ame01961.
Full textAbstract:
Microorganisms are central to the functioning of coral reef ecosystems, but their dynamics are unstudied on most reefs. We examined the microbial ecology of shallow reefs within the Federated States of Micronesia. We surveyed 20 reefs surrounding 7 islands and atolls (Yap, Woleai, Olimarao, Kosrae, Kapingamarangi, Nukuoro, and Pohnpei), spanning 875053 km2. On the reefs, we found consistently higher coral coverage (mean ± SD = 36.9 ± 22.2%; max 77%) compared to macroalgae coverage (15.2 ± 15.5%; max 58%), and low abundances of fish. Reef waters had low inorganic nutrient concentrations and were dominated by Synechococcus, Prochlorococcus, and SAR11 bacteria. The richness of bacterial and archaeal communities was significantly related to interactions between island/atoll and depth. High coral coverage on reefs was linked to higher relative abundances of Flavobacteriaceae, Leisingera, Owenweeksia, Vibrio, and the OM27 clade, as well as other heterotrophic bacterial groups, consistent with communities residing in waters near corals and within coral mucus. Microbial community structure at reef depth was significantly correlated with geographic distance, suggesting that island biogeography influences reef microbial communities. Reefs at Kosrae Island, which hosted the highest coral abundance and diversity, were unique compared to other locations; seawater from Kosrae reefs had the lowest organic carbon (59.8-67.9 µM), highest organic nitrogen (4.5-5.3 µM), and harbored consistent microbial communities (>85% similar), which were dominated by heterotrophic cells. This study suggests that the reef-water microbial ecology on Micronesian reefs is influenced by the density and diversity of corals as well as other biogeographical features.
40
Hanke, Marc H., Haille Leija, Robert A. S. Laroche, Shailee Modi, Erin Culver-Miller, Rachel Sanchez, and Neha Bobby. "Localized Placement of Breakwater Reefs Influences Oyster Populations and Their Resilience after Hurricane Harvey." Ecologies 3, no. 3 (September 18, 2022): 422–34. http://dx.doi.org/10.3390/ecologies3030030.
Full textAbstract:
Populations of the eastern oyster (Crassostrea virginica) have been historically declining due to both natural and anthropogenic stressors. In response, oyster reefs have been created with many different approaches. This study utilized intertidal reefs constructed with oyster shells recycled from local restaurants to provide oyster settlement substrate, reef-associated faunal habitat, and a barrier to prevent marsh erosion. The objective of this study was to determine how oyster population characteristics changed over four years (2016–2019) on five different reefs within Sweetwater Lake, Galveston Bay, Texas, with a secondary objective to examine how oyster populations responded after Hurricane Harvey. Over the study period, five different reefs were sampled each summer by removing five bags per reef to determine oyster abundance and size demography. For the three years of the study (2017–2019), we also quantified oyster spat recruitment to the reefs. Oyster abundance and size (shell height) varied interactively by year and reef number, whereas oyster recruitment was significantly lower following Hurricane Harvey and then returned to pre-storm levels. Our results further highlight the importance of reef placement for breakwater-style reefs, as it appears the hydrodynamics within Sweetwater Lake influenced both oyster abundance and size among individual reefs. While the created reefs receive limited larval influx due to the narrow opening between Sweetwater Lake and Galveston Bay proper, this limited connectivity seemed to prevent mass mortality from the freshwater influx from Hurricane Harvey. Therefore, projects creating oyster reefs should consider local and regional landscape factors for the long-term success of oyster populations and robustness to natural disasters.
41
Lesser, Michael P., Marc Slattery, and Curtis D. Mobley. "Biodiversity and Functional Ecology of Mesophotic Coral Reefs." Annual Review of Ecology, Evolution, and Systematics 49, no. 1 (November 2, 2018): 49–71. http://dx.doi.org/10.1146/annurev-ecolsys-110617-062423.
Full textAbstract:
Mesophotic coral reefs, currently defined as deep reefs between 30 and 150 m, are linked physically and biologically to their shallow water counterparts, have the potential to be refuges for shallow coral reef taxa such as coral and sponges, and might be a source of larvae that could contribute to the resiliency of shallow water reefs. Mesophotic coral reefs are found worldwide, but most are undescribed and understudied. Here, we review our current knowledge of mesophotic coral reefs and their functional ecology as it relates to their geomorphology, changes in the abiotic environment along depth gradients, trophic ecology, their reproduction, and their connectivity to shallow depths. Understanding the ecology of mesophotic coral reefs, and the connectivity between them and their shallow water counterparts, is now a primary focus for many reef studies as the worldwide degradation of shallow coral reefs, and the ecosystem services they provide, continues unabated.
42
Granneman, Jennifer E., and Mark A. Steele. "Fish growth, reproduction, and tissue production on artificial reefs relative to natural reefs." ICES Journal of Marine Science 71, no. 9 (May 23, 2014): 2494–504. http://dx.doi.org/10.1093/icesjms/fsu082.
Full textAbstract:
Abstract The extent to which artificial reefs may be useful for mitigation of environmental impacts, fisheries management, and conservation depends in part upon how well the organisms that live on them fare. We tested whether fish living on artificial reefs were in similar condition (weight-at-length), grew, foraged, reproduced, and produced tissue at rates similar to those on natural reefs. We studied five artificial–natural reef pairs spread over >200 km in the Southern California Bight. Underwater visual transects were used to quantify density and size structure of four target species (Paralabrax clathratus, Paralabrax nebulifer, Semicossyphus pulcher, and Embiotoca jacksoni), which were also collected to measure foraging success, condition, growth, reproductive output, and tissue production. Generally, fish living on artificial reefs fared as well or better than those on natural reefs, with some exceptions. Semicossyphus pulcher fared better on artificial reefs, having higher foraging success, fecundity, densities, and tissue production. Embiotoca jacksoni grew faster on natural reefs, and P. nebulifer was in slightly better condition on natural reefs. Total fish tissue production tended to be higher on artificial reefs than on natural reefs, though this pattern was not evident on all reef pairs. Tissue production was positively correlated with the abundance of large boulders, which was higher on artificial reefs than natural reefs. The similar or greater production of fish tissue per cubic metre on artificial reefs relative to natural reefs indicates that these artificial habitats are valuable in producing fish biomass. Fish living on artificial reefs fared as well as those living on natural reefs, indicating that well-designed artificial reefs can be useful tools for mitigation, conservation, and fisheries management.
43
Rogers, Caroline S. "Coral Reef Resilience through Biodiversity." ISRN Oceanography 2013 (February 17, 2013): 1–18. http://dx.doi.org/10.5402/2013/739034.
Full textAbstract:
Irrefutable evidence of coral reef degradation worldwide and increasing pressure from rising seawater temperatures and ocean acidification associated with climate change have led to a focus on reef resilience and a call to “manage” coral reefs for resilience. Ideally, global action to reduce emission of carbon dioxide and other greenhouse gases will be accompanied by local action. Effective management requires reduction of local stressors, identification of the characteristics of resilient reefs, and design of marine protected area networks that include potentially resilient reefs. Future research is needed on how stressors interact, on how climate change will affect corals, fish, and other reef organisms as well as overall biodiversity, and on basic ecological processes such as connectivity. Not all reef species and reefs will respond similarly to local and global stressors. Because reef-building corals and other organisms have some potential to adapt to environmental changes, coral reefs will likely persist in spite of the unprecedented combination of stressors currently affecting them. The biodiversity of coral reefs is the basis for their remarkable beauty and for the benefits they provide to society. The extraordinary complexity of these ecosystems makes it both more difficult to predict their future and more likely they will have a future.
44
Pasaribu, Roberto Patar. "Comparison of Coral Propagation Growth by Using Coconut Shell Media and Paralon Concrete Media on Wangi-Wangi Island, Wakatobi Regency, Indonesia." International Journal of Oceanography & Aquaculture 7, no. 3 (2023): 1–10. http://dx.doi.org/10.23880/ijoac-16000247.
Full textAbstract:
Coral reef ecosystems are coastal ecosystems that are rich in biodiversity. At this time many coral reefs are in a damaged condition which results in reduced coral reef ecosystems. Therefore, it is necessary to anticipate that coral reefs are not lost or reduced. Saving coral reefs can be done by propagation of coral with artificial reef. This study aims to carry out coral reef propagation techniques by using Coconut Shell Media and Paralon Concrete Media and see comparisons of coral reef growth. The research was conducted from March to June 2021 in Wangi-Wangi Island, Wakatobi, and Province Southeast Sulawesi. From the results of observations and measurements for 11 weeks, the absolute average growth of coral reefs on coconut shell media is 1.05 mm while on concrete media is 0.54 mm. Coral growth rate on coconut shell media is 0.10 mm/week and on concrete media is 0.05 mm/week. The survival rate of coral reefs on coconut shell media is 94.4% while on concrete media is 88.8%.
45
Chong, Lisa, Keith Mille, Holly Abeels, Victor Blanco, and Ed Camp. "Artificial Reefs and People: How We Create Them and How They Affect Us." EDIS 2021, no. 2 (April 14, 2021): 6. http://dx.doi.org/10.32473/edis-fa231-2021.
Full textAbstract:
Artificial reefs are constructed to provide several important ecosystem services to coastal communities and fisheries around the world, and their deployment results in significant socio-ecological and economic effects. To understand these effects, this document gives an overview of the agencies and people involved in the use of artificial reefs, how the implementation of these reefs influences their perception, and what issues are associated with their deployment. This document also specifically describes the process by which most artificial reefs are implemented in Florida. While there is extensive research on ecological aspects of artificial reefs and reef fish, there is a need for more research on the effects of the implementation of artificial reefs on humans and the coastal communities and how their respective experiences and perceptions influence artificial reef and fisheries management actions and involvement.
46
Espriella, Michael, and Vincent Lecours. "Using Drone Imagery to Map Intertidal Oyster Reefs along Florida’s Gulf of Mexico Coast." Gulf and Caribbean Research 34 (2023): 89–96. http://dx.doi.org/10.18785/gcr.3401.14.
Full textAbstract:
Eastern oyster (Crassostrea virginica) reefs offer vital ecosystem services and support economically and culturally important fisheries. However, environmental and anthropogenic stressors have led to significant decline in oyster reef coverage globally and locally in places like the Suwannee Sound in Florida, USA. Current monitoring methods are insufficient for timely and accurate assessment of oyster resources in the region. Here we demonstrate how drone imagery can be used to delineate intertidal oyster reef coverage rapidly and reliably. The high spatial resolution offered by drone imagery enables accurate delineations. We use a segmentation algorithm to delineate reefs, which produces consistently detailed outlines that are more representative of reef morphology than manual delineations. In total, 1,394 reefs were delineated, which corresponds with 497, 670 m2 of reef area. Of the delineated reefs, 236 (17%) were newly mapped, aligning with 19,848 m2 of newly mapped intertidal oyster reef habitat. The overlapping drone imagery also enabled the production of digital surface models, which were used to calculate volume to area ratio as an indicator of reef condition. These delineations and features serve as accurate baseline data that can be compared to future surveys to monitor how reefs are changing over time in the Suwannee Sound. These methods can also be expanded to other geographical areas and can aid in identifying early signs of decline in oyster reefs.
47
Shashar, Nadav, Asa Oren, Re’em Neri, Omer Waizman, Natalie Chernihovsky, and Jenny Tynyakov. "Artificial Reef Deployment Reduces Diving Pressure from Natural Reefs—The Case of Introductory Dives in Eilat, Red Sea." Oceans 5, no. 1 (February 7, 2024): 71–80. http://dx.doi.org/10.3390/oceans5010005.
Full textAbstract:
Artificial reefs have been suggested as alternative dive sites to mitigate human pressure on natural reefs. Despite the conceptual appeal of artificial reefs, there is a paucity of empirical evidence regarding their effectiveness in achieving this objective. Here, we report that a small artificial reef deployed adjacent to a local coral marine protected area caused a shift in the routes taken by introductory dives and nearly eliminated their visitations to the natural fringing reef within the MPA. This behavioral shift among divers persisted for more than a decade following the AR deployment. These findings underscore the efficacy of well-designed and appropriately located artificial reefs as valuable instruments in the conservation of coral reefs.
48
Hogan, S., EAK Murphy, MP Volaric, MCN Castorani, P. Berg, and MA Reidenbach. "Influence of oyster reefs on infauna and sediment spatial distributions within intertidal mudflats." Marine Ecology Progress Series 686 (March 24, 2022): 91–106. http://dx.doi.org/10.3354/meps13983.
Full textAbstract:
Oysters are described as estuarine ecosystem engineers because their reef structures provide habitat for a variety of flora and fauna, alter hydrodynamics, and affect sediment composition. To what spatial extent oyster reefs influence surrounding infauna and sediment composition remains uncertain. We sampled sediment and infauna across 8 intertidal mudflats at distances up to 100 m from oyster reefs within coastal bays of Virginia, USA, to determine if distance from reefs and physical site characteristics (reef elevation, local hydrodynamics, and oyster cover) explain the spatial distributions of infauna and sediment. Total infauna density increased with distance away from reefs; however, the opposite was observed for predatory crustaceans (primarily crabs). Our results indicate a halo surrounding the reefs of approximately 40 m (using an increase in ~25% of observance as the halo criterion). At 90 m from reefs, bivalves and gastropods were 70% more likely to be found (probability of observance), while there was an approximate 4-fold decrease for large crustaceans compared to locations adjacent to reefs. Increases in percent oyster reef cover and/or mean reef area did not statistically alter infauna densities but showed a statistical correlation with smaller sediment grain size, increased organic matter, and reduced flow rates. Weaker flow conditions within the surrounding mudflats were also associated with smaller grain sizes and higher organic matter content, suggesting multiple drivers on the spatial distribution of sediment composition. This study emphasizes the complexity of bio-physical couplings and the considerable spatial extent over which oyster reefs engineer intertidal communities.
49
Yamano, Hiroya, Osamu Abe, Hiroyuki Kitagawa, Etsuko Niu, and Toshio Nakamura. "Coral Reef Evolution at the Leeward Side of Ishigaki Island, Southwest Japan." Radiocarbon 43, no. 2B (2001): 899–908. http://dx.doi.org/10.1017/s0033822200041564.
Full textAbstract:
In comparison with windward coral reefs, the facies and evolution of leeward coral reefs has been discussed to a lesser extent. By accelerator mass spectrometry (AMS) carbon-14 dating of coral specimens collected from the trench excavated across a modern coral reef during a fishery port repair, we revealed the internal facies and Holocene evolution of a leeward reef in Ishigaki Island, Ryukyu Islands, southwest Japan. The reef facies can be split into three facies: the tabular Acropora framework facies, the tabular Acropora reworked facies, and the unconsolidated bioclast facies. The tabular Acropora reworked facies first formed a ridge by 3500 BR Then, the tabular Acropora framework facies grew both upward and seaward. The accumulation rates of the tabular Acropora framework facies ranged from 2.2 to 8.3 m/ka. Thus, the reef framework facies and accumulation rates of this leeward reef is similar to those of windward reefs, although the age of the reef top is younger than that of windward reefs.
50
Benson, Gabriel W., Melinda J. Donnelly, Paul E. Sacks, and Linda J. Walters. "Documenting Loss and Fragmentation of Intertidal Oyster (Crassostrea virginica) Reefs in a Subtropical Estuary." Environments 10, no. 8 (August 1, 2023): 133. http://dx.doi.org/10.3390/environments10080133.
Full textAbstract:
Intertidal reefs of Crassostrea virginica (eastern oyster) provide ecologically valuable habitat in estuaries along the Atlantic coast of North America. In Mosquito Lagoon, a shallow-water estuary on the east coast of central Florida, USA, historical aerial imagery was used to document a 24% decline in the live C. virginica reef area between 1943 and 2009. Using 2021 imagery, every living and dead reef in the same region was manually digitized to identify changes during the intervening 12 years. Positive impacts of C. virginica reef restoration that took place between 2007 and 2021 were also digitized to quantify long-term restoration impact. Natural, live C. virginica reef coverage throughout the system was found to have decreased by 50.6% between 2009 and 2021 and, thus, 62.6% between 1943 and 2021. This was attributed to reef fragmentation, reef footprint loss, boating activity, and mangrove expansion. Of the 2542 live reefs identified using 2009 imagery, 219 reefs fragmented, 988 reefs no longer had an identifiable footprint, and 598 reefs contained visible mangroves with non-continuous canopies. Conservatively, 63.6% of directly restored reef area was classified as living reef in 2021, and 74.5% of restoration projects were more than 50% live reef. Dead reef area decreased by 57.9% throughout the system. Understanding changes in C. virginica reef acreage, reef numbers, and mangrove expansion is essential for resource management, restoration practices, and tracking climate change impacts on publicly protected estuaries.