Download or read book The Effects of Hurricanes and Bioerosion Upon Benthic Communities on Coral Reefs written by David P. Moran and published by . This book was released on 1984 with total page 308 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book The Mexican Caribbean Reefs written by Ameris Ixchel Contreras Silva and published by . This book was released on 2023 with total page 0 pages. Available in PDF, EPUB and Kindle. Book excerpt: The Mexican Caribbean is home to many coral reefs with a high ecological and economic value for people in the country and beyond. Nevertheless, these ecosystems are highly threatened due to a combination of global (anthropogenic climate change) and local stressors (mass tourism, land-based pollution, and overuse of resources). The decline of the wider Caribbean coral reefs has been alarming, with an average loss of 40 percent of absolute coral cover since the late 1970s. However, the current literature lacks spatiotemporal information on the coral and macroalgae cover development and longitudinal studios regarding the stressors causing changes in Mexican Caribbean reefs. Therefore, this thesis aimed first to understand the benthic dynamics of change and the main stressors causing these changes to finally propose a conceptual framework to improve coral reef management. A large-scale spatiotemporal analysis between 1978 and 2016 on coral and macroalgae cover in the Mexican Caribbean reefs was conducted through meta-analysis. Here, findings revealed that hard coral cover decreased from ~ 26 % in the 1970s to 16 % in 2016, whereas macroalgae cover increased from ~ 16 % in the 1980s to ~ 30 % in 2016. Both groups showed high spatiotemporal variability. Hard coral cover declined by 12 % from 1978 to 2004 but increased again by 5 % between 2005 and 2016, indicating some coral recovery after the 2005 mass bleaching event and hurricane impacts. Additionally, a cumulative impact assessment on hard coral and macroalgae benthic communities exposed to multiple stressors (thermal stress, nutrient inflow, sedimentation, hurricane impact, and anthropisation) was conducted using an extensive remote sensing data collection. These data were coupled with 91 coral reef monitoring sites from 2005 to 2016, and the estimates of the change in coral and macroalgae cover percentage were related to each factor considered a potential stressor impacting reefs. Results showed that sea surface temperature increased by 0.30 °C in 12 years, and bleaching susceptibility strongly influenced coral cover change, followed by the negative effect of anthropogenic activities, which incorporates the increasing pressures of urban hubs. The water quality predictors, primarily the particulate organic carbon (used as a proxy for sedimentation and nutrients), only affected macroalgae cover. The only adverse effect on macroalgae was sea surface temperature and chlorophyll-a interaction. Analyses here revealed that global warming impacts on coral reefs occur parallel with local pressures, such as increases in nutrients and suspended sediments through coastal development. The future of Mexican Caribbean coral reefs is at high risk due to cumulative impacts from local and global stressors despite monitoring and restoration efforts over the past few decades, which begs the question of why and how protection and management may be improved. Consequently, a conceptual framework was generated focusing on an integrated management strategy to improve the understanding of the unique and vital services that coral reef ecosystems in the Mexican Caribbean provide. Within this spectrum, a Cybercartographic atlas was proposed because it offers an excellent method for creating a conceptual framework for such a management tool. The ultimate objective is to make arguments accessible that serve as a baseline for assisting and setting priorities for governance in political decisions.
Download or read book Life and Death Of Coral Reefs written by Charles Birkeland and published by Springer Science & Business Media. This book was released on 1997-01-31 with total page 564 pages. Available in PDF, EPUB and Kindle. Book excerpt: Illustrated throughout, this book presents what is known about factors that "shift the balance" between accretion and erosion, recruitment and mortality, stony corals and filamentous algae, recovery and degradation - the life and death of coral reefs.
Download or read book Encyclopedia of Modern Coral Reefs written by David Hopley and published by Springer Science & Business Media. This book was released on 2010-11-26 with total page 1226 pages. Available in PDF, EPUB and Kindle. Book excerpt: Coral reefs are the largest landforms built by plants and animals. Their study therefore incorporates a wide range of disciplines. This encyclopedia approaches coral reefs from an earth science perspective, concentrating especially on modern reefs. Currently coral reefs are under high stress, most prominently from climate change with changes to water temperature, sea level and ocean acidification particularly damaging. Modern reefs have evolved through the massive environmental changes of the Quaternary with long periods of exposure during glacially lowered sea level periods and short periods of interglacial growth. The entries in this encyclopedia condense the large amount of work carried out since Charles Darwin first attempted to understand reef evolution. Leading authorities from many countries have contributed to the entries covering areas of geology, geography and ecology, providing comprehensive access to the most up-to-date research on the structure, form and processes operating on Quaternary coral reefs.
Download or read book Global Climate Change and Coral Reefs written by Clive R. Wilkinson and published by IUCN. This book was released on 1994 with total page 140 pages. Available in PDF, EPUB and Kindle. Book excerpt: A global overview of the potential impacts of climate change and sea level rise on coral reefs, and of the implications of such impacts for ecological sustainable use of coral reefs. Includes information on the status and trends of reef conservation and use around the world, and suggestions for management of reefs in a changing world.
Download or read book Exploring the Potential for Artificial Reefs in Coral Reef Restoration written by Audie Kirk Kilfoyle and published by . This book was released on 2017 with total page pages. Available in PDF, EPUB and Kindle. Book excerpt: Coral reefs are being negatively impacted by various causes worldwide, and direct intervention is often warranted following disturbance to restore or replace lost ecosystem structure and function. An experimental coral reef restoration study involving standardized artificial reef modules (ReefballsTM) was conducted in Mexicos Yucatan Peninsula in the towns of Puerto Morelos and Akumal. The purpose was to explore the use of artificial structure for restoration and mitigation applications in a highly diverse and dynamic Caribbean coral reef environment by applying and evaluating the performance of select experimental treatments hypothesized to accelerate development of the associated biota. The first treatment consisted of invertebrate enhancing artificial substrate padding material, which provided structurally complex refuge space for mobile epifaunal/infaunal invertebrates and other benthic organisms. The second treatment consisted of coral transplants, intended to provide additional structural complexity and kick-start development of stony coral populations. The third treatment consisted of settlement plates which were intended to provide data on coral recruitment and survival rates. Multiple hypotheses relating to the interactions between experimental treatments and the resulting macroalgal, non-coral invertebrate, stony coral, and coral reef fish assemblages were examined, and comparisons were made between natural and artificial substrates. In Puerto Morelos there were 40 modules; 10 controls and 10 of each of 3 treatments: substrate pads, coral transplants, and settlement plates. In Akumal there were 12 modules; 6 controls and 3 of each of 2 treatments: substrate pads and settlement plates. Following module deployment, 6 biannual monitoring trips were made over the course of three years to assess the development of the biota, with a final 7th trip made six years post-deployment. Divers conducted non-destructive visual surveys to evaluate total abundance, species richness, size class distribution, and assemblage structure of coral reef fishes. Other monitoring work included coral recruit surveys, mobile epifaunal invertebrate collections from substrate pads, and digital imaging of coral transplants, natural reef reference corals, and benthic quadrat areas. Hurricane Dean compromised the Akumal study site during the first year of the study, but Puerto Morelos was unaffected. There the modules developed biotic assemblages that differed from what was found on the natural reef, and the data suggests that the substrate pads may have had an effect on the development of faunal assemblages. Lobophora variegata macroaglae and Desmapsamma anchorata sponge were the major contributors to benthic community composition, and both had significantly greater coverage on the substrate pads treatment modules. Lobophora grew rapidly and peaked within the first year, while sponges increased steadily throughout the first three years of the study, surpassing the coverage of macroalgae before the end of the second year, much to the detriment of coral transplants and many coral recruits. By the end of the study, over 75% of the transplants were overgrown by D. anchorata, and density of new coral recruits on the Pads treatment modules was lower than the other treatments and controls. Coral recruitment was dominated by Porites astreoides on all treatments and controls, and the number of corals increased steadily throughout the study. The controls had consistently greater numbers of corals than the treatments, as well as lower percent coverage of macroalgae and sponges. Total abundance and species richness of reef fishes was generally unaffected by the treatments. However, at the family and species level, several differences were detected, particularly for the substrate pads treatment and to a lesser extent for the coral transplants treatment. For future restoration or mitigation efforts utilizing similar or identical treatments to artificial substrates, this study suggests that, in the absence of routine maintenance, greater success may be achieved after waiting several years post-deployment for the initial wave of unchecked growth by benthic organisms (i.e., macroalgae and sponges) to reach a balance point before a large investment of resources is devoted to coral transplanting. Further recommendations include routine monthly or quarterly on-site maintenance to enhance transplant survival, as well as a longer monitoring window to assess community development in response to experimental treatments. The results of this study suggest that the experimental treatments did indeed have an effect on the biota, but whether or not the effect was beneficial largely depends upon perspective. The Pads treatment in particular had the greatest effect on both reef fish and benthic community development, however, it was not beneficial for stony coral recruitment. Additional research is needed to fully understand the long-term performance and effects of the padding material on biotic assemblage development for future restoration or mitigation projects.
Download or read book Coral Reefs at the Crossroads written by Dennis K. Hubbard and published by Springer. This book was released on 2016-07-27 with total page 314 pages. Available in PDF, EPUB and Kindle. Book excerpt: In this book, contributors from diverse backgrounds take a first step toward an integrated view of reefs and the significance of their recent decline. More than any other earth system, coral reefs sit at a disciplinary crossroads. Most recently, they have reached another crossroads - fundamental changes in their bio-physical structure greater than those of previous centuries or even millennia. Effective strategies to mitigate recent trends will require an approach that embraces the myriad perspectives from across the scientific landscape, but will also need a mechanism to transform scientific understanding into social will and political implementation.
Download or read book Coral Reefs and Climate Change written by Jonathan Turnbull Phinney and published by American Geophysical Union. This book was released on 2006-01-10 with total page 251 pages. Available in PDF, EPUB and Kindle. Book excerpt: Published by the American Geophysical Union as part of the Coastal and Estuarine Studies, Volume 61. The effects of increased atmospheric carbon dioxide and related climate change on shallow coral reefs are gaining considerable attention for scientific and economic reasons worldwide. Although increased scientific research has improved our understanding of the response of coral reefs to climate change, we still lack key information that can help guide reef management. Research and monitoring of coral reef ecosystems over the past few decades have documented two major threats related to increasing concentrations of atmospheric CO2: (1) increased sea surface temperatures and (2) increased seawater acidity (lower pH). Higher atmospheric CO2 levels have resulted in rising sea surface temperatures and proven to be an acute threat to corals and other reef-dwelling organisms. Short periods (days) of elevated sea surface temperatures by as little as 1–2°C above the normal maximum temperature has led to more frequent and more widespread episodes of coral bleaching-the expulsion of symbiotic algae. A more chronic consequence of increasing atmospheric CO2 is the lowering of pH of surface waters, which affects the rate at which corals and other reef organisms secrete and build their calcium carbonate skeletons. Average pH of the surface ocean has already decreased by an estimated 0.1 unit since preindustrial times, and will continue to decline in concert with rising atmospheric CO2. These climate-related Stressors combined with other direct anthropogenic assaults, such as overfishing and pollution, weaken reef organisms and increase their susceptibility to disease.
Download or read book Coral Reefs of the Eastern Tropical Pacific written by Peter W. Glynn and published by Springer. This book was released on 2016-08-12 with total page 666 pages. Available in PDF, EPUB and Kindle. Book excerpt: This book documents and examines the state of health of coral reefs in the eastern tropical Pacific region. It touches on the occurrence of coral reefs in the waters of surrounding countries, and it explores their biogeography, biodiversity and condition relative to the El Niño southern oscillation and human impacts. Additionally contained within is a field that presents information on many of the species presented in the preceding chapters.
Download or read book Effects of Marine Protected Areas on Benthic Community Structure and Ecological Processes on Coral Reefs in Hawai i written by Danielle Jayewardene and published by . This book was released on 2009 with total page 210 pages. Available in PDF, EPUB and Kindle. Book excerpt: Despite a wealth of information on the effects of Marine Protected Areas (MPAs), the direct influence of marine protection on specifically coral communities has yet to be fully established. The goal of my dissertation research was to determine whether, in the Main Hawaiian Islands, MPAs influence coral communities and ecological processes with direct and indirect effects to these. My specific research objectives were to determine the effects of MPAs on: (1) the composition of the benthic community; (2) grazing by parrotfishes; (3) predation on coral by fishes; and (4) the balance between bioerosion and accretion of the reef framework. While I found a trend of greater herbivorous fish populations at sites with greater levels of marine protection, this was not associated with a predictable benthic community composition such as low macro- or filamentous turf algal cover, high crustose coralline algal cover and coral cover, or low densities of Tripneustes gratilla and Echinometra mathaei urchins My grazing study demonstrated that algal reduction rates by parrotfishes were positively related to parrotfish biomass, and were proportionately greater per unit biomass for large compared to small parrotfishes. I found fish predation on coral by Arothron meleagris and Cantherhines dumerilli to be prevalent across study sites, and focused on the most common Hawaiian coral species. Predation by A. meleagris on Porites compressa appeared to have little effect when the coral was abundant and when lesions healed efficiently, but limited P. compressa population growth once corals become sparse, and/or the size of corals become very small. The carbonate budget I developed, while simplified, showed study reefs to have net accretion, and this to be driven primarily by growth of the coral community.
Download or read book The Impact of Hurricane Lenny on Coral Reefs and Its Relevance to Pleistocene Reef Communities written by and published by . This book was released on 2001 with total page pages. Available in PDF, EPUB and Kindle. Book excerpt: Storms such as hurricanes can dramatically impact a coral reef. In November 1999, Hurricane Lenny traveled an unusual west to east path across the central Caribbean approximately 480 kilometers north of the island of Curacao. Reef damage surveys at 33 sites conducted just months after the storm documented occurrences of toppling, fragmentation, tissue damage, bleaching, and smothering due to the storm. Several factors influenced the degree of damage experienced by the reef, including the trend of the shoreline, coral growth form, colony size, and water depth. Curacao's location outside of the major hurricane belt and well south of the track of Hurricane Lenny shows that rarely disturbed reefs can incur significant damage by storm-generated waves that travel across a great distance. Pleistocene reef communities on the island preserve the same species of corals and reef zonation present on many modern reefs throughout the Caribbean. Transects conducted along the fossil reefs show that different reef paleoenvironments (reef crest vs backreef) have different relative abundances of components. These different environments also preserve corals in the position of growth to differing extents. Many large coral colonies are preserved in growth position with the presence of few or no encrusting or boring organisms. These observations suggest a very rapid burial, possibly associated with a major regression while the corals were still alive. Although storm features on modern reefs, such as toppling and fragmentation, may potentially be preserved in the Pleistocene reefs of Curacao, these features are difficult to differentiate from those that were produced by other natural day-to-day processes such as bioerosion and processes involved with a rapid regression, including large-scale movement of sands from nearshore beaches or dunes.
Download or read book Biogenic Reefs at Risk Facing Globally Widespread Local Threats and Their Interaction with Climate Change written by Massimo Ponti and published by Frontiers Media SA. This book was released on 2022-01-07 with total page 165 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Metabolic Responses of Shallow Tropical Benthic Microcosm Communities to Perturbation written by Environmental Research Laboratory (Narragansett, R.I.) and published by . This book was released on 1979 with total page 72 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book The Future of Coral Reefs Subject to Rapid Climate Change Lessons from Natural Extreme Environments written by Emma F. Camp and published by Frontiers Media SA. This book was released on 2019-01-22 with total page 198 pages. Available in PDF, EPUB and Kindle. Book excerpt: Examination of corals and reef-associated organisms which endure in extreme coral reef environments is challenging our understanding of the conditions that organisms can survive under. By studying individuals naturally adapted to unfavorable conditions, we begin to better understand the important traits required to survive rapid environmental and climate change. This Research Topic, comprising reviews, and original research articles, demonstrates the current state of knowledge regarding the diversity of extreme coral habitats, the species that have been studied, and the knowledge to-date on the mechanisms, traits and trade-offs that have facilitated survival.
Download or read book Coral Reefs in the Anthropocene written by Charles Birkeland and published by Springer. This book was released on 2015-11-03 with total page 283 pages. Available in PDF, EPUB and Kindle. Book excerpt: This volume investigates the effects of human activities on coral reefs, which provide important life-supporting systems to surrounding natural and human communities. It examines the self-reinforcing ecological, economic and technological mechanisms that degrade coral reef ecosystems around the world. Topics include reefs and limestones in Earth history; the interactions between corals and their symbiotic algae; diseases of coral reef organisms; the complex triangle between reef fishes, seaweeds and corals; coral disturbance and recovery in a changing world. In addition, the authors take key recent advances in DNA studies into account which provides new insights into the population biology, patterns of species distributions, recent evolution and vulnerabilities to environmental stresses. These DNA analyses also provide new understandings of the limitations of coral responses and scales of management necessary to sustain coral reefs in their present states. Coral reefs have been essential sources of food, income and resources to humans for millennia. This book details the delicate balance that exists within these ecosystems at all scales, from geologic time to cellular interactions and explores how recent global and local changes influence this relationship. It will serve as an indispensable resource for all those interested in learning how human activities have affected this vital ecosystem around the world.
Download or read book The Telegraph Messenger s New Year s Greeting written by and published by . This book was released on 1889 with total page pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Disentangling Human Degradation from Environmental Constraints written by James Robinson and published by . This book was released on 2017 with total page pages. Available in PDF, EPUB and Kindle. Book excerpt: Testing ecological theory at macroecological scales may be useful for disentangling abiotic influences from anthropogenic disturbances, and thus provide insights into fundamental processes that structure ecological communities. In tropical coral reef systems, our understanding of community structure is limited to small-scale studies conducted in moderately degraded regions, while larger regional or ocean scale analyses have typically focused on identifying human drivers of reef degradation. In this thesis, my collaborators and I combined stable isotope specimens, underwater visual censuses, and remote sensing data from 43 Pacific islands and atolls in order to examine the relative roles of natural environmental variation and anthropogenic pressures in structuring coral reef fish and benthic communities. First, at unexploited sites on Kiritimati Atoll (Kiribati), isotope estimates indicated that trophic level increased with body size across species and individuals, while negative abundance ~ body size relationships (size spectra) revealed distinct energetic constraints between energy-competing carnivores and energy-sharing herbivores. After demonstrating size structuring of reef fish communities in the absence of humans, we then examined evidence for size-selective exploitation impacts on coral reefs across the Pacific Ocean. Size spectra 'steepened' as human population density increased and proximity to market center decreased, reflecting decreases in large-bodied fish abundance, biomass, turnover rate, and mean trophic level. Depletion of large fish abundances likely diminishes functions such as bioerosion by grazers and food chain connectivity by top predators, further degrading reef community resilience. Next, we considered the relative strengths of abiotic, biotic and anthropogenic influences in determining reef benthic state across spatial scales. We found that from fine (0.25 km2) to coarse (1,024 km2) grain scales the phase shift index (a multivariate metric of the relative cover of hard coral and macroalgal) was primarily predicted by local abiotic and bottom-up influences, such that coral-dominated reefs occurred in warm, productive regions at sites exposed to low wave energy, irrespective of grazing or human impacts. Our size-based analyses of reef fish communities revealed novel exploitation impacts at ocean-basin scales, and provide a foundation for delineating energetic pathways and feeding interactions in complex tropical food webs. Furthermore, we demonstrate that abiotic constraints underpin natural variation among fish and benthic communities of remote uninhabited reefs, emphasizing the importance of accounting for local environmental conditions when developing quantitative baselines for coral reef ecosystems.
