Literature Library

Currently indexing 10051 titles

Integrating Fuzzy Logic and Statistics to Improve the Reliable Delimitation of Biogeographic Regions and Transition Zones

Citation Information: Syst Biol (2012) doi: 10.1093/sysbio/sys061

Authors: Jesús Olivero, Ana L. Márquez and Raimundo Real

Abstract: This study uses the amphibian species of the Mediterranean basin to develop a consistent procedure based on fuzzy sets with which biogeographic regions and biotic transition zones can be objectively detected and reliably mapped. Biogeographical regionalizations are abstractions of the geographical organization of life on Earth that provide frameworks for cataloguing species and ecosystems, for answering basic questions in biogeography, evolutionary biology, and systematics, and for assessing priorities for conservation. On the other hand, limits between regions may form sharply defined boundaries along some parts of their borders, whereas elsewhere they may consist of broad transition zones. The fuzzy set approach provides a heuristic way to analyse the complexity of the biota within an area; significantly different regions are detected whose mutual limits are sometimes fuzzy, sometimes clearly crisp. Most of the regionalizations described in the literature for the Mediterranean biogeographical area present a certain degree of convergence when they are compared within the context of fuzzy interpretation, as many of the differences found between regionalizations are located in transition zones, according to our case study. Compared with other classification procedures based on fuzzy sets, the novelty of our method is that both fuzzy logic and statistics are used together in a synergy in order to avoid arbitrary decisions in the definition of biogeographic regions and transition zones.

Long-term region-wide declines in Caribbean corals

Citation Information: Science 15 August 2003: Vol. 301 no. 5635 pp. 958-960

DOI: 10.1126/science.1086050

Authors: Toby A. Gardner, Isabelle M. Côté, Jennifer A. Gill, Alastair Grant and Andrew R. Watkinson

Abstract: We report a massive region-wide decline of corals across the entire Caribbean basin, with the average hard coral cover on reefs being reduced by 80%, from about 50% to 10% cover, in three decades. Our meta-analysis shows that patterns of change in coral cover are variable across time periods but largely consistent across subregions, suggesting that local causes have operated with some degree of synchrony on a region-wide scale. Although the rate of coral loss has slowed in the past decade compared to the 1980s, significant declines are persisting. The ability of Caribbean coral reefs to cope with future local and global environmental change may be irretrievably compromised.

Top 10 List: 
Coral Reef Management

Recent region-wide declines in Caribbean reef fish abundance

Citation Information: Current Biology; Volume 19, Issue 7, 14 April 2009, Pages 590–595

Authors: Michelle J. Paddack, John D. Reynolds, Consuelo Aguilar, Richard S. Appeldoorn, Jim Beets, Edward W. Burkett, Paul M. Chittaro, Kristen Clarke, Rene Esteves, Ana C. Fonseca, Graham E. Forrester, Alan M. Friedlander, Jorge García-Sais, Gaspar González-Sansón, Lance K.B. Jordan, David B. McClellan, Margaret W. Miller, Philip P. Molloy, Peter J. Mumby, Ivan Nagelkerken, Michael Nemeth, Raúl Navas-Camacho, Joanna Pitt, Nicholas V.C. Polunin, Maria Catalina Reyes-Nivia, D. Ross Robertson, Alberto Rodríguez-Ramírez, Eva Salas, Struan R. Smith, Richard E. Spieler, Mark A. Steele, Ivor D. Williams, Clare L. Wormald, Andrew R. Watkinson, Isabelle M. Côté

Abstract: Profound ecological changes are occurring on coral reefs throughout the tropics [1], [2] and [3], with marked coral cover losses and concomitant algal increases, particularly in the Caribbean region [4]. Historical declines in the abundance of large Caribbean reef fishes likely reflect centuries of overexploitation [5], [6] and [7]. However, effects of drastic recent degradation of reef habitats on reef fish assemblages have yet to be established. By using meta-analysis, we analyzed time series of reef fish density obtained from 48 studies that include 318 reefs across the Caribbean and span the time period 1955–2007. Our analyses show that overall reef fish density has been declining significantly for more than a decade, at rates that are consistent across all subregions of the Caribbean basin (2.7% to 6.0% loss per year) and in three of six trophic groups. Changes in fish density over the past half-century are modest relative to concurrent changes in benthic cover on Caribbean reefs. However, the recent significant decline in overall fish abundance and its consistency across several trophic groups and among both fished and nonfished species indicate that Caribbean fishes have begun to respond negatively to habitat degradation.

Top 10 List: 
Coral Reef Management

Global gradients of coral exposure to environmental stresses and implications for local management

Citation Information: Maina J, McClanahan TR, Venus V, Ateweberhan M, Madin J (2011) Global Gradients of Coral Exposure to Environmental Stresses and Implications for Local Management. PLoS ONE 6(8): e23064. doi:10.1371/journal.pone.0023064

Abstract:

Background

The decline of coral reefs globally underscores the need for a spatial assessment of their exposure to multiple environmental stressors to estimate vulnerability and evaluate potential counter-measures.

Methodology/Principal Findings

This study combined global spatial gradients of coral exposure to radiation stress factors (temperature, UV light and doldrums), stress-reinforcing factors (sedimentation and eutrophication), and stress-reducing factors (temperature variability and tidal amplitude) to produce a global map of coral exposure and identify areas where exposure depends on factors that can be locally managed. A systems analytical approach was used to define interactions between radiation stress variables, stress reinforcing variables and stress reducing variables. Fuzzy logic and spatial ordinations were employed to quantify coral exposure to these stressors. Globally, corals are exposed to radiation and reinforcing stress, albeit with high spatial variability within regions. Based on ordination of exposure grades, regions group into two clusters. The first cluster was composed of severely exposed regions with high radiation and low reducing stress scores (South East Asia, Micronesia, Eastern Pacific and the central Indian Ocean) or alternatively high reinforcing stress scores (the Middle East and the Western Australia). The second cluster was composed of moderately to highly exposed regions with moderate to high scores in both radiation and reducing factors (Caribbean, Great Barrier Reef (GBR), Central Pacific, Polynesia and the western Indian Ocean) where the GBR was strongly associated with reinforcing stress.

Conclusions/Significance

Despite radiation stress being the most dominant stressor, the exposure of coral reefs could be reduced by locally managing chronic human impacts that act to reinforce radiation stress. Future research and management efforts should focus on incorporating the factors that mitigate the effect of coral stressors until long-term carbon reductions are achieved through global negotiations.

Top 10 List: 
Coral Reef Management

World Atlas of Coral Reefs

Citation Information: Spalding MD, Ravilious C, Green EP (2001) World Atlas of Coral Reefs. University of California Press, London, England

Description: Coral reefs are one of the most biologically diverse habitats in the world, host to an extraordinary variety of marine plants and animals. They are also one of the world's most fragile and endangered ecosystems. The growth of mass tourism, combined with the boom in popularity of scuba diving, has brought these spectacular ecosystems to public attention across the planet.

Coral reefs provide essential fish habitat, support endangered and threatened species, and harbor protected marine mammals and turtles. They are a significant source of food, provide income and employment through tourism and marine recreation, and offer countless other benefits to humans, including supplying compounds for pharmaceuticals. Yet coral reefs around the world are rapidly being degraded by a number of human activities, such as overfishing, coastal development, and the introduction of sewage, fertilizer, and sediment.

World Atlas of Coral Reefs provides the first detailed and definitive account of the current state of our planet's coral reefs. With its wealth of authoritative and up-to-date information, the finest maps available, and detailed descriptive texts and images by leading experts, this full-color volume will be a critical resource for anyone interested in these vital environments.

World Atlas of Coral Reefs contains eighty-four full-page newly researched and drawn color maps, together with more than two hundred color photos illustrating reefs, reef animals, and images taken from space by NASA astronauts during the 2000 and 2001 space shuttle flights. The authors provide a wealth of information on the geography, biodiversity, and human uses of coral reefs, as well as details about the threats to their existence.

Top 10 List: 
Coral Reef Management

Coral Health and Disease

Citation Information: Rosenberg E, Loya Y (eds) (2004) Coral Health and Disease. Springer-Verlag, New York

Description: This book opens with case studies of reefs in the Red Sea, Caribbean, Japan, Indian Ocean and the Great Barrier Reef. A section on microbial ecology and physiology describes the symbiotic relations of corals and microbes, and the microbial role in nutrition or bleaching resistance of corals. Coral diseases are covered in the third part. The volume includes 50 color photos of corals and their environments

Top 10 List: 
Coral Reef Management

Reef Fisheries

Citation Information: Polunin NVC, Robert CM (eds) (1996) Reef Fisheries. Chapman & Hall, London

Description: Reef ecosystems extend throughout the tropics. Exploited by small-scale fishers, reefs supply food for millions of people, but, worldwide, there are growing worries about the productivity and current state of these ecosystems. Reef fish stocks display many features of fisheries elsewhere. However, habitat spatial complexity, biological diversity within and among species, ecosystem intricacy and variable means of exploitation make it hard to predict sustainable modes and levels of fishing.

Top 10 List: 
Coral Reef Management

Coral Reef Conservation

Citation Information: Cote IM, Reynolds JD (eds) (2006) Coral Reef Conservation. Cambridge University Press

Description: Coral reefs are the 'rain forests' of the ocean, containing the highest diversity of marine organisms and facing the greatest threats from humans. As shallow-water coastal habitats, they support a wide range of economically and culturally important activities, from fishing to tourism. Their accessibility makes reefs vulnerable to local threats that include over-fishing, pollution and physical damage. Reefs also face global problems, such as climate change, which may be responsible for recent widespread coral mortality and increased frequency of hurricane damage. This book summarises the current state of knowledge about the status of reefs, the problems they face, and potential solutions. The topics considered range from concerns about extinction of coral reef species to economic and social issues affecting the well-being of people who depend on reefs. The result is a multi-disciplinary perspective on problems and solutions to the coral reef crisis.

Top 10 List: 
Coral Reef Management

Coral Reefs of the Indian Ocean: Their Ecology and Conservation

Citation Information: Coral reefs of the Indian Ocean; their ecology and conservation by T. R. McClanahan, C.R.C. Sheppard & D. O. Obura (eds), Oxford University Press, Oxford, 2000. 525 pages.

Description: Coral reefs are among Earth's most diverse, productive, and beautiful ecosystems, but until recently, their ecology and the means to manage them have been poorly understood and documented. In response to the inadequate information base for coral reefs, this book reviews the ecological and conservation status of coral reefs of the Western Indian Ocean, bringing together presentations of the region's leading scientists and managers working on coral reefs.

Coral Reefs of the Indian Ocean: Their Ecology and Conservation starts with a general overview of the biogeography of the region and a historical account of attempts to conserve this ecosystem. It goes on to describe the state of the reefs in each of the countries with coral reefs, and it concludes with a series of management case studies.
The book also summarizes most of the existing ecological information on reefs in this region and efforts at management, making it useful for students, teachers, and investigators interested in tropical or marine ecology, conservation biology and management, and environmental sciences.

Top 10 List: 
Coral Reef Management

Food Webs and the Dynamics of Marine Reefs

Citation Information: McClanahan TR, Branch GM (eds) (2008) Food Webs and the Dynamics of Marine Reefs. Oxford University Press, New York

Description: Biologists have made significant advances in our understanding of the Earth's shallow subtidal marine ecosystems, but the findings on these disparate regions have never before been documented and gathered in a single volume. Now, in Food Webs and the Dynamics of Marine Reefs, Tim R. McClanahan and George M. Branch fill this lacuna with a comparative and comprehensive collection of nine essays written by experts on specific aquatic regions. Each essay focuses on the food webs of a respective ecosystem and the factors affecting these communities, from the intense and direct pressure of human influence on fisheries to the multi-vector contributors to climate change. The book covers nine shallow water marine ecosystems from selected areas throughout the world: four coral reef systems, three hard bottom systems, and two kelp systems. In summarizing their organization, human influence on them, and recent developments in these ecosystems, the authors contribute to our understanding of their ecological organization and management. Food Webs and the Dynamics of Marine Reefs will be a useful tool for all benthic marine investigators, providing an expert, comparative view of these aquatic regions.

Top 10 List: 
Coral Reef Management

Adapting to a Changing Environment: Confronting the consequences of climate change

Citation Information: T R McClanahan and Joshua E Cinner; New York: Oxford University Press, 2012.

Description: For those who depend on the bounty of the sea for their livelihoods, climate change and its consequences (warming water, coral bleaching, rising sea levels) could spell disaster. The region comprising the eastern coastline of Africa and the islands of the western Indian Ocean--home to many of the Earth's most impoverished people--is particularly vulnerable to significant climate impacts.

Focusing on coral reef fisheries in these areas, which collectively support millions of people, this book provides a tool box of options for confronting the consequences of climate change through building local-scale adaptive capacity and improving the condition of natural resources. This requires strengthening a society's flexibility, assets, learning, and social organizations, as well as restricting or limiting its resource use. These two broad concepts--building social capacity and limiting certain types of resource use--interact in complicated ways, requiring coordinated actions. The authors argue that adaptation solutions are context dependent, determined in part by local resource conditions, human adaptive capacity, and exposure to climate change impacts, but also by a people's history, culture, and aspirations.

Providing an up-to-date and original synthesis of environmental stress, natural resources, and the socioeconomics of climate change, Adapting to a Changing Environment develops a framework to provide governments, scientists, managers, and donors with critical information about local context, encouraging the implementation of nuanced actions that reflect local conditions.

Top 10 List: 
Coral Reef Management

Life and Death of Coral Reefs

Citation Information: Life and Death of Coral Reefs. Edited by Charles Birkeland. Springer, 1997. 536 pages.

Description: Coral reefs have shaped the surface of our planet far more than has any other ecosystem. They are dynamic systems, producing limestone at the rate of 400-2,000 tons per hectare per year, and influencing the chemical balance of the world's oceans. Coral reefs have been around since before the prairies or other ecosystems of flowering plants existed, yet they vanish about a million years before other groups of organisms each time there is a global mass extinction. They return after each catastrophe, however, following a long period of absence. Although coral reefs are the most productive communities in the sea, the fisheries of coral reefs are among the most vulnerable to overexploitation. Despite having the power to create the most massive structures in the world made by living creatures (including man), the thin veneer of living tissue of coral reef is particularly sensitive to natural disturbances and effects of human activities. Coral reefs are the first to go during periods of climate change, but they have always come back. This combination of attributes, creative power and fragility, resilience and sensitivity, makes management of coral-reef systems a challenge to science. Over 70% of the coral reefs in the Caribbean and Asian waters have been degraded, and perhaps a third of the 400 species of corals in Japanese waters are in danger of local extinction unless effective coastal management practices are established. 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. Insight into the factors controlling the direction of these processes is essential for appropriate management decisions.

Top 10 List: 
Coral Reef Management

The Ecology of Fishes on Coral Reefs

Citation Information: The Ecology of Fishes on Coral Reefs. Edited by Peter F. Sale. Academic Press. San Diego. 1991. 754 pages. $75.00. (Available from the American Fisheries Society for $71.25.)

Description: This book provides a comprehensive and up-to-date review of the ecology of coral reef fishes presented by top researchers from North America and Australia. Immense strides have been made over the past twenty years in our understanding of ecological systems in general and of reef fish ecology in particular. Many of the methodologies that reef fish ecologists use in their studies will be useful to a wider audience of ecologists for the design of their ecological studies. Significant among the impacts of the research on reef fish ecology are the development of nonequilibrium models of community organization, more emphasis on the role of recruitment variability in structuring local assemblages, the development and testing of evolutionary models of social organization and reproductive biology, and new insights into predator-prey and plant-herbivore interactions.

Top 10 List: 
Coral Reef Management

Reduction of Wind and Swell Waves by Mangroves

Citation Information: McIvor, A.L., Möller, I., Spencer, T. and Spalding. M. (2012) Reduction of wind and swell waves by mangroves. Natural Coastal Protection Series: Report 1. Cambridge Coastal Research Unit Working Paper 40. Published by The Nature Conservancy and Wetlands International. 27 pages. ISSN 2050-7941.

Executive Summary: Coastal populations are particularly vulnerable to the impacts of extreme events such as storms and hurricanes, and these pressures may be exacerbated through the influence of climate change and sea level rise. Coastal ecosystems such as mangrove forests are increasingly being promoted and used as a tool in coastal defence strategies. There remains, however, a pressing need to better understand the roles that ecosystems can play in defending coasts. This report focuses on mangrove forests and the role they can play in reducing wind and swell waves. While mangrove forests are usually found on shores with little incoming wave energy, they may receive larger waves during storms, hurricanes and periods of high winds. Large wind and swell waves can cause flooding and damage to coastal infrastructure. By reducing wave energy and height, mangroves can potentially reduce associated damage.

All evidence suggests that mangroves can reduce the height of wind and swell waves over relatively short distances: wave height can be reduced by between 13 and 66% over 100 m of mangroves. The highest rate of wave height reduction per unit distance occurs near the mangrove edge, as waves begin their passage through the mangroves.

A number of characteristics of mangroves affect the rate of reduction of wave height with distance, most notably the physical structure of the trees. Waves are most rapidly reduced when they pass through a greater density of obstacles. Mangroves with aerial roots will attenuate waves in shallow water more rapidly than those without. At greater water depths, waves may pass above aerial roots, but the lower branches can perform a similar function. The slope of the shore and the height of the waves also affect wave reduction rates through mangroves.

Organic micropollutants in coastal waters from NW Mediterranean Sea: Sources distribution and potential risk

Citation Information: Environment International; Volume 46, 1 October 2012, Pages 50–62

Authors: Juan Sánchez-Avila, Romà Tauler, Silvia Lacorte

Abstract: This study provides a first estimation on the sources, distribution and risk of organic micropollutants (OMPs) in coastal waters from NW Mediterranean Sea. Polycyclic aromatic hydrocarbons, polychlorinated biphenyls, organochlorinated pesticides, polybrominated diphenyl ethers, phthalates and alkylphenols were analyzed by solid phase extraction and gas chromatography coupled to tandem mass spectrometry (SPE–GC–EI-MS/MS). River waters and wastewater treatment plant effluents discharging to the sea were identified as the main sources of OMPs to coastal waters, with an estimated input amount of around of 25,800 g d 1. The concentration of ΣOMPs in coastal areas ranged from 17.4 to 8442 ng L 1, and was the highest in port waters, followed by coastal and river mouth seawaters. A summarized overview of the patterns and sources of OMP contamination on the investigated coastal sea waters of NW Mediterranean Sea, as well as of their geographical distribution was obtained by Principal Component Analysis of the complete data set after its adequate pretreatment. Alkylphenols, bisphenol A and phthalates were the main contributors to ΣOMPs and produced an estimated significant pollution risk for fish, algae and the sensitive mysid shrimp organisms in seawater samples. The combination of GC-MS/MS, chemometrics and risk analysis is proven to be useful for a better control and management of OMP discharges

Detection of a Diverse Marine Fish Fauna Using Environmental DNA from Seawater Samples

Citation Information: Thomsen PF, Kielgast J, Iversen LL, Møller PR, Rasmussen M, et al. (2012) Detection of a Diverse Marine Fish Fauna Using Environmental DNA from Seawater Samples. PLoS ONE 7(8): e41732. doi:10.1371/journal.pone.0041732

Abstract: Marine ecosystems worldwide are under threat with many fish species and populations suffering from human over-exploitation. This is greatly impacting global biodiversity, economy and human health. Intriguingly, marine fish are largely surveyed using selective and invasive methods, which are mostly limited to commercial species, and restricted to particular areas with favourable conditions. Furthermore, misidentification of species represents a major problem. Here, we investigate the potential of using metabarcoding of environmental DNA (eDNA) obtained directly from seawater samples to account for marine fish biodiversity. This eDNA approach has recently been used successfully in freshwater environments, but never in marine settings. We isolate eDNA from ½-litre seawater samples collected in a temperate marine ecosystem in Denmark. Using next-generation DNA sequencing of PCR amplicons, we obtain eDNA from 15 different fish species, including both important consumption species, as well as species rarely or never recorded by conventional monitoring. We also detect eDNA from a rare vagrant species in the area; European pilchard (Sardina pilchardus). Additionally, we detect four bird species. Records in national databases confirmed the occurrence of all detected species. To investigate the efficiency of the eDNA approach, we compared its performance with 9 methods conventionally used in marine fish surveys. Promisingly, eDNA covered the fish diversity better than or equal to any of the applied conventional methods. Our study demonstrates that even small samples of seawater contain eDNA from a wide range of local fish species. Finally, in order to examine the potential dispersal of eDNA in oceans, we performed an experiment addressing eDNA degradation in seawater, which shows that even small (100-bp) eDNA fragments degrades beyond detectability within days.

Spatial Variability of Benthic-Pelagic Coupling in an Estuary Ecosystem: Consequences for Microphytobenthos Resuspension Phenomenon

Citation Information: Ubertini M, Lefebvre S, Gangnery A, Grangeré K, Le Gendre R, et al. (2012) Spatial Variability of Benthic-Pelagic Coupling in an Estuary Ecosystem: Consequences for Microphytobenthos Resuspension Phenomenon. PLoS ONE 7(8): e44155. doi:10.1371/journal.pone.0044155

Abstract: The high degree of physical factors in intertidal estuarine ecosystem increases material processing between benthic and pelagic compartments. In these ecosystems, microphytobenthos resuspension is a major phenomenon since its contribution to higher trophic levels can be highly significant. Understanding the sediment and associated microphytobenthos resuspension and its fate in the water column is indispensable for measuring the food available to benthic and pelagic food webs. To identify and hierarchize the physical/biological factors potentially involved in MPB resuspension, the entire intertidal area and surrounding water column of an estuarine ecosystem, the Bay des Veys, was sampled during ebb tide. A wide range of physical parameters (hydrodynamic regime, grain size of the sediment, and suspended matter) and biological parameters (flora and fauna assemblages, chlorophyll) were analyzed to characterize benthic-pelagic coupling at the bay scale. Samples were collected in two contrasted periods, spring and late summer, to assess the impact of forcing variables on benthic-pelagic coupling. A mapping approach using kriging interpolation enabled us to overlay benthic and pelagic maps of physical and biological variables, for both hydrological conditions and trophic indicators. Pelagic Chl a concentration was the best predictor explaining the suspension-feeders spatial distribution. Our results also suggest a perennial spatio-temporal structure of both benthic and pelagic compartments in the ecosystem, at least when the system is not imposed to intense wind, with MPB distribution controlled by both grain size and bathymetry. The benthic component appeared to control the pelagic one via resuspension phenomena at the scale of the bay. Co-inertia analysis showed closer benthic-pelagic coupling between the variables in spring. The higher MPB biomass observed in summer suggests a higher contribution to filter-feeders diets, indicating a higher resuspension effect in summer than in spring, in turn suggesting an important role of macrofauna bioturbation and filter feeding (Cerastoderma edule).

Investigating the Potential Use of Environmental DNA (eDNA) for Genetic Monitoring of Marine Mammals

Citation Information: Foote AD, Thomsen PF, Sveegaard S, Wahlberg M, Kielgast J, et al. (2012) Investigating the Potential Use of Environmental DNA (eDNA) for Genetic Monitoring of Marine Mammals. PLoS ONE 7(8): e41781. doi:10.1371/journal.pone.0041781

Abstract: The exploitation of non-invasive samples has been widely used in genetic monitoring of terrestrial species. In aquatic ecosystems, non-invasive samples such as feces, shed hair or skin, are less accessible. However, the use of environmental DNA (eDNA) has recently been shown to be an effective tool for genetic monitoring of species presence in freshwater ecosystems. Detecting species in the marine environment using eDNA potentially offers a greater challenge due to the greater dilution, amount of mixing and salinity compared with most freshwater ecosystems. To determine the potential use of eDNA for genetic monitoring we used specific primers that amplify short mitochondrial DNA sequences to detect the presence of a marine mammal, the harbor porpoise, Phocoena phocoena, in a controlled environment and in natural marine locations. The reliability of the genetic detections was investigated by comparing with detections of harbor porpoise echolocation clicks by static acoustic monitoring devices. While we were able to consistently genetically detect the target species under controlled conditions, the results from natural locations were less consistent and detection by eDNA was less successful than acoustic detections. However, at one site we detected long-finned pilot whale, Globicephala melas, a species rarely sighted in the Baltic. Therefore, with optimization aimed towards processing larger volumes of seawater this method has the potential to compliment current visual and acoustic methods of species detection of marine mammals.

Turning up the Heat: Increasing Temperature and Coral Bleaching at the High Latitude Coral Reefs of the Houtman Abrolhos Islands

Citation Information: Abdo DA, Bellchambers LM, Evans SN (2012) Turning up the Heat: Increasing Temperature and Coral Bleaching at the High Latitude Coral Reefs of the Houtman Abrolhos Islands. PLoS ONE 7(8): e43878. doi:10.1371/journal.pone.0043878

Abstract:

Backgr​ound

Coral reefs face increasing pressures particularly when on the edge of their distributions. The Houtman Abrolhos Islands (Abrolhos) are the southernmost coral reef system in the Indian Ocean, and one of the highest latitude reefs in the world. These reefs have a unique mix of tropical and temperate marine fauna and flora and support 184 species of coral, dominated by Acropora species. A significant La Niña event during 2011 produced anomalous conditions of increased temperature along the whole Western Australian coastline, producing the first-recorded widespread bleaching of corals at the Abrolhos.

Methodology/ Principal Find​ings

We examined long term trends in the marine climate at the Abrolhos using historical sea surface temperature data (HadISST data set) from 1900–2011. In addition in situ water temperature data for the Abrolhos (from data loggers installed in 2008, across four island groups) were used to determine temperature exposure profiles. Coupled with the results of coral cover surveys conducted annually since 2007; we calculated bleaching thresholds for monitoring sites across the four Abrolhos groups.

Conclusions/ Sig​nificance

Prioritizing Key Resilience Indicators to Support Coral Reef Management in a Changing Climate

Citation Information: McClanahan TR, Donner SD, Maynard JA, MacNeil MA, Graham NAJ, et al. (2012) Prioritizing Key Resilience Indicators to Support Coral Reef Management in a Changing Climate. PLoS ONE 7(8): e42884. doi:10.1371/journal.pone.0042884

Abstract: Managing coral reefs for resilience to climate change is a popular concept but has been difficult to implement because the empirical scientific evidence has either not been evaluated or is sometimes unsupportive of theory, which leads to uncertainty when considering methods and identifying priority reefs. We asked experts and reviewed the scientific literature for guidance on the multiple physical and biological factors that affect the ability of coral reefs to resist and recover from climate disturbance. Eleven key factors to inform decisions based on scaling scientific evidence and the achievability of quantifying the factors were identified. Factors important to resistance and recovery, which are important components of resilience, were not strongly related, and should be assessed independently. The abundance of resistant (heat-tolerant) coral species and past temperature variability were perceived to provide the greatest resistance to climate change, while coral recruitment rates, and macroalgae abundance were most influential in the recovery process. Based on the 11 key factors, we tested an evidence-based framework for climate change resilience in an Indonesian marine protected area. The results suggest our evidence-weighted framework improved upon existing un-weighted methods in terms of characterizing resilience and distinguishing priority sites. The evaluation supports the concept that, despite high ecological complexity, relatively few strong variables can be important in influencing ecosystem dynamics. This is the first rigorous assessment of factors promoting coral reef resilience based on their perceived importance, empirical evidence, and feasibility of measurement. There were few differences between scientists' perceptions of factor importance and the scientific evidence found in journal publications but more before and after impact studies will be required to fully test the validity of all the factors. The methods here will increase the feasibility and defensibility of including key resilience metrics in evaluations of coral reefs, as well as reduce costs. Adaptation, marine protected areas, priority setting, resistance, recovery.

Pages

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