Complex networks are everywhere, such as the power grid network, the airline network, the protein-protein interaction network, and the road network. The networks are ‘robust yet fragile’, which means that the networks are robust against random failures but fragile under malicious attacks. The cascading failures, system-wide disasters and intentional attacks on these networks are deserving of in-depth study. Researchers have proposed many solutions to improve the robustness of these networks. However whilst many solutions preserve the degree distribution of the networks, little attention is paid to the community structure of these networks. We argue that the community structure of a network is a defining characteristic of a network which identifies its functionality and thus should be preserved. In this paper, we discuss the relationship between robustness and the community structure. Then we propose a 3-step strategy to improve the robustness of a network, while retaining its community structure, and also its degree distribution. With extensive experimentation on representative real-world networks, we demonstrate that our method is effective and can greatly improve the robustness of networks, while preserving community structure and degree distribution. Finally, we give a description of a robust network, which is useful not only for improving robustness, but also for designing robust networks and integrating networks.
The following titles are freely-available, or include a link to a preprint or postprint.
Knowledge of the spatial distribution and habitat associations of species in relation to the environment is essential for their management and conservation. Habitat suitability models are useful in quantifying species-environment relationships and predicting species distribution patterns. Little is known, however, about the stability and performance of habitat suitability models when projected into new areas (spatial transferability) and how this can inform resource management. The aims of this study were to model habitat suitability of Norway lobster (Nephrops norvegicus) in five fished areas of the Northeast Atlantic (Aran ground, Irish Sea, Celtic Sea, Scotland Inshore and Fladen ground), and to test for spatial transferability of habitat models among multiple regions. Nephrops burrow density was modelled using generalised additive models (GAMs) with predictors selected from four environmental variables (depth, slope, sediment and rugosity). Models were evaluated and tested for spatial transferability among areas. The optimum models (lowest AICc) for different areas always included depth and sediment as predictors. Burrow densities were generally greater at depth and in finer sediments, but relationships for individual areas were sometimes more complex. Aside from an inclusion of depth and sediment, the optimum models differed between fished areas. When it came to tests of spatial transferability, however, most of the models were able to predict Nephrops density in other areas. Furthermore, transferability was not dependent on use of the optimum models since competing models were also able to achieve a similar level of transferability to new areas. A degree of decoupling between model ‘fitting’ performance and spatial transferability supports the use of simpler models when extrapolating habitat suitability maps to different areas. Differences in the form and performance of models from different areas may supply further information on the processes shaping species’ distributions. Spatial transferability of habitat models can be used to support fishery management when the information is scarce but caution needs to be applied when making inference and a multi-area transferability analysis is preferable to bilateral comparisons between areas.
- After almost 10 years of discussions, States finally agreed to launch negotiations for the elaboration of an international legally binding instrument dedicated to the conservation and sustainable use of marine biodiversity in ABNJ.
- The process will take a two-step approach: (1) a Preparatory Committee (PrepCom) will make recommendations to the UNGA on the elements of a draft text by the end of 2017; (2) the UNGA will then decide on the convening and date of an intergovernmental conference by the end of its 72nd session (i.e. September 2018).
- The historic nature of the decision taken by the States, and the enthusiasm demonstrated by many delegations and observers, does not mean the forthcoming negotiation process will be easy. The road ahead is paved with difficult choices and complex challenges.
Marine ecosystems can experience regime shifts, in which they shift from being organized around one set of mutually reinforcing structures and processes to another. Anthropogenic global change has broadly increased a wide variety of processes that can drive regime shifts. To assess the vulnerability of marine ecosystems to such shifts and their potential consequences, we reviewed the scientific literature for 13 types of marine regime shifts and used networks to conduct an analysis of co-occurrence of drivers and ecosystem service impacts. We found that regime shifts are caused by multiple drivers and have multiple consequences that co-occur in a non-random pattern. Drivers related to food production, climate change and coastal development are the most common co-occurring causes of regime shifts, while cultural services, biodiversity and primary production are the most common cluster of ecosystem services affected. These clusters prioritize sets of drivers for management and highlight the need for coordinated actions across multiple drivers and scales to reduce the risk of marine regime shifts. Managerial strategies are likely to fail if they only address well-understood or data-rich variables, and international cooperation and polycentric institutions will be critical to implement and coordinate action across the scales at which different drivers operate. By better understanding these underlying patterns, we hope to inform the development of managerial strategies to reduce the risk of high-impact marine regime shifts, especially for areas of the world where data are not available or monitoring programmes are not in place.
Overfishing of large predatory fish populations has resulted in lasting restructurings of entire marine food webs worldwide, with serious socio-economic consequences. Fortunately, some degraded ecosystems show signs of recovery. A key challenge for ecosystem management is to anticipate the degree to which recovery is possible. By applying a statistical food-web model, using the Baltic Sea as a case study, we show that under current temperature and salinity conditions, complete recovery of this heavily altered ecosystem will be impossible. Instead, the ecosystem regenerates towards a new ecological baseline. This new baseline is characterized by lower and more variable biomass of cod, the commercially most important fish stock in the Baltic Sea, even under very low exploitation pressure. Furthermore, a socio-economic assessment shows that this signal is amplified at the level of societal costs, owing to increased uncertainty in biomass and reduced consumer surplus. Specifically, the combined economic losses amount to approximately 120 million € per year, which equals half of today's maximum economic yield for the Baltic cod fishery. Our analyses suggest that shifts in ecological and economic baselines can lead to higher economic uncertainty and costs for exploited ecosystems, in particular, under climate change.
Concerns are growing at multiple levels of government about the effects of ocean acidification and increasing hypoxia events on ecosystems along the coasts of California, Oregon, Washington, and British Columbia. Thoughtful and strategic research and monitoring will be essential to improve understanding of these impacts and to develop effective management and mitigation options.
This report seeks to assist decision-makers across the public sector in supporting science to address ocean acidification and hypoxia. Working with the West Coast Ocean Acidification and Hypoxia Science Panel and other thought leaders, the California Ocean Science Trust has developed this vision for the future state of knowledge and role of science in improving our ability to understand and manage these threats on the West Coast.
In 2012, with support from NOAA’s Coral Reef Conservation Program (CRCP), the Gulf and Caribbean Fisheries Institute (GCFI) organized the first regional peer-to-peer workshop on ‘Building Compliance and Enhancing Enforcement for Marine Protected Areas in the Caribbean’, hosted by the Florida Keys National Marine Sanctuary and facilitated by MPA Enforcement International. Twenty-two MPA managers from fourteen countries and territories attended. In the course of the workshop, the participating MPA managers identified a common need to better understand best practices in MPA legislation. They expressed an interest in comparing MPA legislation across the Caribbean and in promoting the adoption of successful legislative techniques in their home countries so as to help achieve a more uniform approach to MPA enforcement throughout the region. This report seeks to address this need and to inform future efforts by Caribbean MPA managers and policy-makers to strengthen MPA enforcement.
Table of Contents:
- Adapting to Climate Change
- National Ocean Policy
- Cultural Resource Risks
- Bay-Delta Science Conference
- UPDATE: Deepwater Horizon
- Visualizing Wetland Change
- Marine Monument Expansion
- WOW! Record Salmon
- Quick Guide Climate Change
- Threatened Red Knot
- Whale Sculptures
- MARES Artic Study
- Conserving Coastal Wetlands
- Pacific Islands Climate Change
- Chukchi Sea Research
- World Parks Congress
- Waterbird Society Session
- Aloha from Maui!
- Carbon Sequestration Report.
- Tribal GIS Training
- Tracking Nitrate to the Gulf
- Coral Reef Initiatives
- Coastal Defense Tool
- Methane Seepage Discovery
- Science for Society
- Swan Days at Mattamuskeet
- Adaptive Coastal Park
- That’s Wrack
- Gulf of Mexico Shipwrecks
- Renewable Energy
- Envisioning Sea-Level Rise
- Regional News
- Eating Invasive Species
- The Surfing Bison
Tools, such as participatory three-dimensional modeling (P3DM), participatory video and the facilitated development of photo journals and civil society plans for action on climate change, can be used across the Caribbean islands to facilitate effective participation by local communities and other stakeholders. These tools are needed by people in the Caribbean to facilitate the identification of general policy priorities, as well as specific policies and actions needed on-the-ground and at the landscape and site level to address the impacts of climate change and extreme climatic events. These tools bring relevant knowledge - both traditional and indigenous knowledge - into consideration when decisions are being made about climate change. This approach to decision-making also contributes to increasing capacity of community groups, facilitates coordination and collaboration across sectors, and builds buy-in for plans for action on climate change.
Download the related Policy Brief at http://www.canari.org/documents/CANARIPolicyBrief15English_000.pdf
Social valuation of ecosystem services and public policy alternatives is one of the greatest challenges facing ecological economists today. Frameworks for valuing nature increasingly include shared/social values as a distinct category of values. However, the nature of shared/social values, as well as their relationship to other values, has not yet been clearly established and empirical evidence about the importance of shared/social values for valuation of ecosystem services is lacking. To help address these theoretical and empirical limitations, this paper outlines a framework of shared/social values across five dimensions: value concept, provider, intention, scale, and elicitation process. Along these dimensions we identify seven main, non-mutually exclusive types of shared values: transcendental, cultural/societal, communal, group, deliberated and other-regarding values, and value to society. Using a case study of a recent controversial policy on forest ownership in England, we conceptualise the dynamic interplay between shared/social and individual values. The way in which social value is assessed in neoclassical economics is discussed and critiqued, followed by consideration of the relation between shared/social values and Total Economic Value, and a review of deliberative and non-monetary methods for assessing shared/social values. We conclude with a discussion of the importance of shared/social values for decision-making.
The Coral Triangle covers an area between the Indian and Pacific oceans that represents the global epicenter of abundant marine life and diversity. The region surrounding these oceans includes some or all of the land and seas of six countries—Indonesia, Malaysia, Papua New Guinea, the Philippines, Solomon Islands, and Timor-Leste.
This report provides general information on the status of biophysical characteristics; governance; socioeconomic characteristics; and threats to, and vulnerabilities of, the coral reef ecosystems of Indonesia, part of which lies within the Coral Triangle. It outlines Indonesia’s plans and initiatives and its progress toward the conservation and sustainable use of these ecosystems.
To further describe movement patterns and distribution of East Pacific green turtles (Chelonia mydas agassizii) and to determine threat levels for this species within the Eastern Pacific. In order to do this we combined published data from existing flipper tagging and early satellite tracking studies with data from an additional 12 satellite tracked green turtles (1996-2006). Three of these were tracked from their foraging grounds in the Gulf of California along the east coast of the Baja California peninsula to their breeding grounds in Michoacán (1337-2928 km). In addition, three post-nesting females were satellite tracked from Colola beach, Michoacán to their foraging grounds in southern Mexico and Central America (941.3-3020 km). A further six turtles were tracked in the Gulf of California within their foraging grounds giving insights into the scale of ranging behaviour. Turtles undertaking long-distance migrations showed a tendency to follow the coastline. Turtles tracked within foraging grounds showed that foraging individuals typically ranged up to 691.6 km (maximum) from release site location. Additionally, we carried out threat analysis (using the cumulative global human impact in the Eastern Pacific) clustering pre-existing satellite tracking studies from Galapagos, Costa Rica, and data obtained from this study; this indicated that turtles foraging and nesting in Central American waters are subject to the highest anthropogenic impact. Considering that turtles from all three rookeries were found to migrate towards Central America, it is highly important to implement conservation plans in Central American coastal areas to ensure the survival of the remaining green turtles in the Eastern Pacific. Finally, by combining satellite tracking data from this and previous studies, and data of tag returns we created the best available distributional patterns for this particular sea turtle species, which emphasized that conservation measures in key areas may have positive consequences on a regional scale.
There is a growing need to identify shark products in trade, in part due to the recent listing of five commercially important species on the Appendices of the Convention on International Trade in Endangered Species (CITES; porbeagle, Lamna nasus, oceanic whitetip, Carcharhinus longimanus scalloped hammerhead, Sphyrna lewini, smooth hammerhead, S. zygaena and great hammerhead S. mokarran) in addition to three species listed in the early part of this century (whale, Rhincodon typus, basking, Cetorhinus maximus, and white, Carcharodon carcharias). Shark fins are traded internationally to supply the Asian dried seafood market, in which they are used to make the luxury dish shark fin soup. Shark fins usually enter international trade with their skin still intact and can be identified using morphological characters or standard DNA-barcoding approaches. Once they reach Asia and are traded in this region the skin is removed and they are treated with chemicals that eliminate many key diagnostic characters and degrade their DNA (“processed fins”). Here, we present a validated mini-barcode assay based on partial sequences of the cytochrome oxidase I gene that can reliably identify the processed fins of seven of the eight CITES listed shark species. We also demonstrate that the assay can even frequently identify the species or genus of origin of shark fin soup (31 out of 50 samples).
The genetic enhancement of wild animals and plants for characteristics that benefit human populations has been practiced for thousands of years, resulting in impressive improvements in commercially valuable species. Despite these benefits, genetic manipulations are rarely considered for noncommercial purposes, such as conservation and restoration initiatives. Over the last century, humans have driven global climate change through industrialization and the release of increasing amounts of CO2, resulting in shifts in ocean temperature, ocean chemistry, and sea level, as well as increasing frequency of storms, all of which can profoundly impact marine ecosystems. Coral reefs are highly diverse ecosystems that have suffered massive declines in health and abundance as a result of these and other direct anthropogenic disturbances. There is great concern that the high rates, magnitudes, and complexity of environmental change are overwhelming the intrinsic capacity of corals to adapt and survive. Although it is important to address the root causes of changing climate, it is also prudent to explore the potential to augment the capacity of reef organisms to tolerate stress and to facilitate recovery after disturbances. Here, we review the risks and benefits of the improvement of natural and commercial stocks in noncoral reef systems and advocate a series of experiments to determine the feasibility of developing coral stocks with enhanced stress tolerance through the acceleration of naturally occurring processes, an approach known as (human)-assisted evolution, while at the same time initiating a public dialogue on the risks and benefits of this approach.
A rare opportunity to test hypotheses about potential fishery benefits of large-scale closures was initiated in July 2004 when an additional 28.4% of the 348,000 km2 Great Barrier Reef (GBR) region of Queensland, Australia was closed to all fishing. Advice to the Australian and Queensland governments that supported this initiative predicted these additional closures would generate minimal (10%) initial reductions in both catch and landed value within the GBR area with recovery of catches becoming apparent after three years. To test these predictions, commercial fisheries data from the GBR area and from the two adjacent (non-GBR) areas of Queensland were compared for the periods immediately prior to, and after the closures were implemented.
The observed means for total annual catch and value within the GBR declined from pre-closure (2000-2003) levels of 12,780t and $160 million, to initial post-closure (2005-2008) levels of 8,143t and $102 million; decreases of 35% and 36% respectively. Because the reference areas in the non-GBR had minimal changes in catch and value, the beyond-BACI analyses estimated initial net-reductions within the GBR of 35% for both total catch and value. There was no evidence of recovery in total catch levels or any comparative improvement in catch-rates within the GBR nine years after implementation. These results are not consistent with the advice to governments that the closures would have minimal initial impacts and rapidly generate benefits to fisheries in the GBR through increased juvenile recruitment and adult 'spillovers'. Instead, the absence of evidence of recovery in catches or catch-rates to date currently support an alternative hypothesis that where there is already effective fisheries management, the closing of areas to all fishing will generate reductions in overall catches similar to the percentage of the fished area that is closed.
Documenting the diversity of marine life is challenging because many species are cryptic, small, and rare, and belong to poorly known groups. New sequencing technologies, especially when combined with standardized sampling, promise to make comprehensive biodiversity assessments and monitoring feasible on a large scale. We used this approach to characterize patterns of diversity on oyster reefs across a range of geographic scales comprising a temperate location [Virginia (VA)] and a subtropical location [Florida (FL)]. Eukaryotic organisms that colonized multilayered settlement surfaces (autonomous reef monitoring structures) over a 6-mo period were identified by cytochrome c oxidase subunit I barcoding (>2-mm mobile organisms) and metabarcoding (sessile and smaller mobile organisms). In a total area of ∼15.64 m2 and volume of ∼0.09 m3, 2,179 operational taxonomic units (OTUs) were recorded from 983,056 sequences. However, only 10.9% could be matched to reference barcodes in public databases, with only 8.2% matching barcodes with both genus and species names. Taxonomic coverage was broad, particularly for animals (22 phyla recorded), but 35.6% of OTUs detected via metabarcoding could not be confidently assigned to a taxonomic group. The smallest size fraction (500 to 106 μm) was the most diverse (more than two-thirds of OTUs). There was little taxonomic overlap between VA and FL, and samples separated by ∼2 m were significantly more similar than samples separated by ∼100 m. Ground-truthing with independent assessments of taxonomic composition indicated that both presence–absence information and relative abundance information are captured by metabarcoding data, suggesting considerable potential for ecological studies and environmental monitoring.
Native Papuans are relied on hunting for subsistence purposes and significantly contributed to traditional cultures. However, in Papua information on hunting is limited and largely restricted to anthropological setting with most observations were done on the forest sites in lowland and highland landscapes. This study focuses on the contribution of hunting on food security along the coastal forests at the Bird’s Head Peninsula. Do people live near coastal sites mostly rely on marine resources as protein source? We gathered data on hunting by the majority of Karon ethnic group in the Abun district of Tambrauw Regency at the Bird’s Head Peninsula of Papua, Indonesia. We used information from in-depth interviews with hunters and households meal survey at four villages of Abun: Waibem, Wau, Warmandi and Saubeba. Reasons for hunting were varies among respondents but mostly conducted for trade. Six species of mammals and three birds were commonly hunted by using six different hunting techniques. Wild pig and rusa deer were the major targets in hunting to meet the demand of meat for both trading and household consumption. Meals containing wildmeat was the most consumed meal, greater than meals containing fish, animal products and vegetables, and noodles.
This analysis of representativeness in 1,628 MPAs is based upon the presence/absence of major habitat types, key natural resources and ecologically important areas and processes. Nationally, MPAs are nominally representative of the major marine ecosystems of the U.S. with (a) 70% of select habitat types (e.g., beaches, corals, seagrass) found within MPAs of the 19 marine ecoregions and in at least one National System MPA in each ecoregion; (b) 82% of select birds, invertebrates and algal ecosystem features found within MPAs of the 19 marine ecoregions and in at least one National System MPA in each ecoregion; (c) 71% of select fish, marine mammal or sea turtle ecosystem features and Endangered Species Act (ESA) listed species found within MPAs of the 19 marine ecoregions and in at least one National System MPA in each ecoregion; and (d) 87% of select ecologically important ecosystem processes found within MPAs of the 19 marine ecoregions and in at least one National System MPA in each ecoregion.
This report also aims to indicate the strength of this representation (e.g., an ecosystem feature found in less than 1% of MPAs in an ecoregion versus more than 75%) by presenting “consumer report” graphics that indicate the relative prevalence of the presence of a resource (though not its spatial extent).
Official state response from Australia to the World Heritage Committee, in regards to Decision WHC 38 COM 7B.63, which essentially says Australia is indeed working to protect the GBR and that the Reef is not "in danger."
Consequences of reef phase shifts on fish communities remain poorly understood. Studies on the causes, effects and consequences of phase shifts on reef fish communities have only been considered for coral-to-macroalgae shifts. Therefore, there is a large information gap regarding the consequences of novel phase shifts and how these kinds of phase shifts impact on fish assemblages. This study aimed to compare the fish assemblages on reefs under normal conditions (relatively high cover of corals) to those which have shifted to a dominance of the zoantharian Palythoa cf. variabilis on coral reefs in Todos os Santos Bay (TSB), Brazilian eastern coast. We examined eight reefs, where we estimated cover of corals and P. cf. variabilis and coral reef fish richness, abundance and body size. Fish richness differed significantly between normal reefs (48 species) and phase-shift reefs (38 species), a 20% reduction in species. However there was no difference in fish abundance between normal and phase shift reefs. One fish species, Chaetodon striatus, was significantly less abundant on normal reefs. The differences in fish assemblages between different reef phases was due to differences in trophic groups of fish; on normal reefs carnivorous fishes were more abundant, while on phase shift reefs mobile invertivores dominated.