Literature Library

Currently indexing 9708 titles

Selecting MPAs to conserve groundfish biodiversity: the consequences of failing to account for catchability in survey trawls

Citation Information: ICES J. Mar. Sci. (2009) 66 (1): 82-89. doi: 10.1093/icesjms/fsn181

Authors: Helen M. Fraser, S. P. R. Greenstreet and Gerjan J. Piet

Abstract: Fishing has affected North Sea groundfish species diversity. Defining Marine Protected Areas (MPAs) to address this will rely on groundfish surveys. Species-specific catch efficiencies vary between trawl gears, and apparent species diversity distributions are influenced by the type of gear used in each survey. It may be that no single survey depicts actual diversity distributions. Two MPA scenarios designed to protect groundfish species diversity are described, the first based on unadjusted International Bottom Trawl Survey data and the second based on the same data adjusted to take account of catchability. Spatial overlap between these scenarios is low. Assuming that the adjusted data best describe the actual species diversity distribution, the level of diversity safeguarded by MPAs, based on unadjusted data, is determined. A fishing effort redistribution model is used to estimate the increase in fishing activity that is likely to occur in MPAs that take catchability into account, if closed areas based solely on the unadjusted groundfish data were implemented. Our results highlight the need to take survey-gear catchability into account when designating MPAs to address fish-species diversity issues.

Investigating the consequences of Marine Protected Areas for the South African deep-water hake (Merluccius paradoxus) resource

Citation Information: ICES J. Mar. Sci. (2009) 66 (1): 72-81. doi: 10.1093/icesjms/fsn187

Authors: Charles T. T. Edwards, Rébecca A. Rademeyer, Doug S. Butterworth and Éva E. Plagányi

Abstract: Protected areas are often touted as important management tools to mitigate the uncertainty inherent in marine ecosystems, and thereby improve the long-term prospects for sustainable resource use. However, although they certainly play an important role in conservation, their usefulness in improving fishery yields is contentious. We present a simulation model that explores spatial closure options, and apply it to the demersal hake trawl fishery off South Africa. The model is based on the age-structured approach used for current assessments, representing the dynamics of the deep-water hake Merluccius paradoxus within a zonally disaggregated spatial system. Fitting the model to two zones, which demarcate a potential closed area from the remaining fished area, we investigate the consequences that such a protected area could have for the fishery. Our model suggests that area closures would have a negligible benefit for the fishery, regardless of the level of hake movement between areas. This is likely the result of the model's simplicity, and we suggest additional factors that should be considered to quantify the impact of Marine Protected Areas on the fishery more reliably.

Evidence of the top–down role of predators in structuring sublittoral rocky-reef communities in a Marine Protected Area and nearby areas of the Canary Islands

Citation Information: ICES J. Mar. Sci. (2009) 66 (1): 64-71. doi: 10.1093/icesjms/fsn176

Authors: Sabrina Clemente, José Carlos Hernández and Alberto Brito

Abstract: Differences in the sea urchin Diadema aff. antillarum population structure, which have been attributed to removal of predatory fish through overfishing, are observed throughout the Canary Islands. Low urchin abundances and a “desired conservation state” are currently found in Mar de Las Calmas Marine Protected Area and nearby fished areas (FAs) in El Hierro Island, in contrast to the occurrence of high urchin densities and the “undesired conservation state” in the highly FAs (HFAs) of Tenerife Island. Under these different levels of fishing pressure, we consider a set of ecological variables potentially affecting urchin populations (settlement, recruitment, adult urchin densities, predation rates, and abundance of urchin fish predators) to infer their magnitude and relative importance in addressing community-wide changes. No differences in settlement and recruitment rates were found, but predation pressure was higher in El Hierro, where adult density was low and predation rates were high. The combination of these factors provides evidence of a top–down control of sublittoral reef communities. Although the effect of protection was less clear, we demonstrate the positive effects of reduced fishing effort in enhancing trophic cascade processes and reducing the establishment of barren grounds.

Spatially resolved fish population analysis for designing MPAs: influence on inside and neighbouring habitats

Citation Information: ICES J. Mar. Sci. (2009) 66 (1): 56-63. doi: 10.1093/icesjms/fsn191

Authors: Asbjørn Christensen, Henrik Mosegaard and Henrik Jensen

Abstract: The sandeel population analysis model (SPAM) is presented as a simulation tool for exploring the efficiency of Marine Protected Areas (MPAs) for sandeel stocks. SPAM simulates spatially resolved sandeel population distributions, based on a high-resolution map of all fishery-established sandbank habitats for settled sandeels, combined with a life-cycle model for survival, growth, and reproduction, and a three-dimensional hydrodynamic model for describing larval transport between the network of habitats. SPAM couples stock dynamics to ecosystem and anthropogenic forcing via well-defined drivers. The SPAM framework was tested using ICES statistical rectangle 37F2 as an MPA, and the impact on sandeel populations within the MPA and neighbouring habitats was investigated. Increased larval spillover compensated for lost catches inside the MPA. The temporal and spatial scales of stock response to MPAs demonstrated that ecosystem self-regulation must be included when modelling the efficiency of MPAs, and for lesser sandeel, that self-regulation partially counteracts the benefits of a fishing sanctuary. The use of realistic habitat connectivity is critical for both qualitative and quantitative MPA assessment. The results confirm that the stock levels are more sensitive to changes in life conditions of larval stages than later parts of the life cycle.

Movement patterns of four coral reef fish species in a fragmented habitat in New Caledonia: implications for the design of marine protected area networks

Citation Information: ICES J. Mar. Sci. (2009) 66 (1): 50-55. doi: 10.1093/icesjms/fsn165

Authors: Olivier Chateau and Laurent Wantiez

Abstract: Acoustic telemetry was used to examine the patterns of fish movements between a marine reserve and two unprotected reefs separated by large areas of lagoon soft bottoms (900–2000 m) in the South Lagoon Marine Park of New Caledonia. Four commercial fish species (Epinephelus maculatus, Plectropomus leopardus, Chlorurus microrhinos, and Scarus ghobban) were studied for 17 months (45 fish). Nine fish (20%) were detected on reefs other than the reef onto which they were released. Four patterns of inter-reef movement were identified during the survey, including home range relocations, movements larger than the scale of the study, many inter-reef movements within the study area, and punctual excursions outside the daily home range. The information gathered in this study demonstrates the ability of the fish to carry out medium-scale movements in a fragmented habitat. Consequently, the effectiveness of the reserve to protect the entire population is probably limited for these species. Because all the identified patterns implied at least one movement across the reserve boundaries, our results support the hypothesis that the Larégnère Marine Reserve, part of the South Lagoon Marine Park, could benefit the adjacent fished area through spillover.

The management of artisanal fishing within the Marine Protected Area of the Port-Cros National Park (northwest Mediterranean Sea): a success story?

Citation Information: ICES J. Mar. Sci. (2009) 66 (1): 41-49. doi: 10.1093/icesjms/fsn188

Authors: Gwenaël Cadiou, Charles F. Boudouresque, Patrick Bonhomme and Laurence Le Diréach

Abstract: The Port-Cros National Park, France (northwest Mediterranean Sea), established in 1963, is a Marine Protected Area (MPA) where, unlike no-take areas, artisanal fishing has been permitted (except trawling), owing to social and economic pressures. Nevertheless, restrictions on artisanal fishing have increased through a fishing charter (1999). In the meantime, recreational fishing was progressively banned, which has helped as a management tool to make the restrictions on artisanal fishing acceptable in social terms. Monitoring of the artisanal fishing (2000–2005) reveals the stability of the fishing fleet (9–13 vessels); of the fishing effort [number of fishing sets per day between 3.4 (±2.1) and 6.9 (±3.4) in spring, and 3.0 (±1.7) and 5.2 (±2.7) in summer]; and of yields [catch per unit effort between 1.27 (±0.72) and 1.68 (±1.44) kg 100 m of net−1 d−1]. Furthermore, based on an analysis of available data, artisanal fishing does not jeopardize the conservation objectives of the MPA, so that, from 1963 to date, the issue has changed from “What can be done to ban commercial fishing?” to “Is there any reason to ban commercial fishing?”.

Spatial variability of seabird distribution associated with environmental factors: a case study of marine Important Bird Areas in the Azores

Citation Information: ICES J. Mar. Sci. (2009) 66 (1): 29-40. doi: 10.1093/icesjms/fsn175

Authors: Patrícia Amorim, Miguel Figueiredo, Miguel Machete, Telmo Morato, Ana Martins and Ricardo Serrão Santos

Abstract: The spatial structure and distribution at sea of Cory's shearwaters (Calonectris diomedea borealis), common terns (Sterna hirundo), and roseate terns (Sterna dougallii) were analysed in the Azores for various environmental factors: sea surface temperature, chlorophyll a concentration, distance to fronts, wind, distance to island shore or tern colonies, distance to seamounts, seabed slope, and depth. Data on seabird sightings were collected by observers on board fishing vessels, 2002–2006. Generalized linear modelling (GLM) explained 43 and 11% of the abundance variability for terns (both species pooled) and Cory's shearwaters, respectively. Variability in seabird abundance was mainly explained by month, wind, distance to shore and/or tern colonies, and distance to seamounts. Variogram modelling indicated that species distribution presented a small-scale spatial structure (i.e. low autocorrelation). Cory's shearwater predictive distribution maps showed widespread distribution patterns of abundance, despite occurring at a greater intensity around the islands and around some seamounts, which are areas of fishery interest. Conversely, terns were essentially concentrated near the shore. The establishment of marine important bird areas should be encouraged close to seabird colonies and around some seamount areas.

Challenges facing a network of representative marine protected areas in the Mediterranean: prioritizing the protection of underrepresented habitats

Citation Information: ICES J. Mar. Sci. (2009) 66 (1): 22-28. doi: 10.1093/icesjms/fsn164

Authors: Ameer Abdulla, Marina Gomei, David Hyrenbach, Giuseppe Notarbartolo-di-Sciara and Tundi Agardy

Abstract: The high endemism of the Mediterranean Sea provides strong motivation to develop a comprehensive plan for the conservation of its biodiversity and the management of its marine resources. Increasingly, this ecosystem-level approach calls for a comprehensive network of marine protected areas (MPAs) representative of the richness and diversity of this shared basin. Today, Mediterranean MPAs do not represent the diverse geography and habitats in the region. Despite a recent declaration on trawling restrictions in deep waters (>1000 m), there are no true deep-sea Mediterranean MPAs. All but one (98.9%) of the 94 marine areas currently under some type of protection or management are coastal. Moreover, 69 (73.4%) are located along the basin's northern shore, highlighting the lack of MPAs in the south and east coasts. Yet, these underrepresented regions and habitats are ecologically distinctive by virtue of their particular oceanographic and biogeographic conditions. We identify several obstacles to Mediterranean MPA implementation and discuss how they can be overcome through strategic MPA network planning, contending that regional disparities in governance, institutional structures, wealth distribution, social capital, and availability of ecological data are responsible for discrepancies in the establishment and effectiveness of MPAs in this region.

The role of marine protected areas in environmental management

Citation Information: ICES J. Mar. Sci. (2009) 66 (1): 16-21. doi: 10.1093/icesjms/fsn163

Author: Simon Jennings

Abstract: Marine protected areas (MPAs) are one of several tools used to meet management objectives for the marine environment. These objectives reflect political and societal views, and increasingly reconcile fishery and conservation concerns, a consequence of common high-level drivers, such as the World Summit on Sustainable Development. The contribution of MPAs to meeting objectives should be assessed in conjunction with other tools, taking account of the management systems of which they are part. Many of the same factors determine the success of MPAs and other management tools, such as quality of governance and the social and economic situation of people using marine goods and services. Diverse legislation governs MPA designation. Designation could be simplified by prearranged and prenegotiated agreements among all relevant authorities. Agreements could specify how to make trade-offs among objectives, interpret scientific advice, ensure effective engagement among authorities and stakeholders, deal with appeals, and support progressive improvement. The jurisdiction and competence of fishery management authorities mean that they are well placed to contribute to the design, designation, and enforcement of MPAs. Their strengths include well-established procedures for accessing scientific advice, the capacity to work across multiple jurisdictions, experience with MPA management, and access to vessels and personnel for enforcement.

Marine Protected Areas as a tool for fishery management and ecosystem conservation: an Introduction

Citation Information: ICES J. Mar. Sci. (2009) 66 (1): 1-5. doi: 10.1093/icesjms/fsn186

Authors: Erik Hoffmann and Angel Pérez-Ruzafa

Abstract: This special issue of the ICES Journal of Marine Science is dedicated to Marine Protected Areas (MPAs) and presents a range of papers from the “European Symposium on Marine Protected Areas as Tool for Fisheries Management and Ecosystem Conservation”. This introduction provides a brief overview of key points from presentations, and discussions, and two science-policy roundtable sessions.

The symposium was convened by two European research projects, PROTECT (2005–2008; and EMPAFISH (2005–2008;, funded by the Sixth Framework Programme of the European Commission. The projects address the application of MPAs as a tool for ecosystem conservation and fishery management, from offshore fishing closures to coastal MPAs in temperate waters. The symposium was hosted at University of Murcia, Spain, with support from the European Commission, International Council for the Exploration of the Sea (ICES), Spanish Ministry of Agriculture, Fisheries and Food, Regional Ministry for Agriculture and Water (Murcia) and Fundación Séneca (Region of Murcia), Nordic Council of Ministers, Fundación Cajamurcia, National Institute of Aquatic Resources (Denmark), and University of Murcia.

The symposium organizing committee consisted of Erik Hoffmann (PROTECT coordinator), Ole Vestergaard and Thomas Kirk Sørensen (National Institute of Aquatic Resources, Denmark), Ángel Pérez-Ruzafa (EMPAFISH coordinator), Concepción Marcos, Fuensanta Salas, and José Antonio Garcia Charton (University of Murcia), and Jean Boncoeur (University of Western Brittany, France). The review and selection of papers and organization of sessions were undertaken by a committee of scientist from across Europe covering a broad range of disciplines (members are listed below).

Australia’s deep-water reserve network: implications of false homogeneity for classifying abiotic surrogates of biodiversity

Citation Information: ICES J. Mar. Sci. (2009) 66 (1): 214-224. doi: 10.1093/icesjms/fsn189

Authors: Alan Williams, Nicholas J. Bax, Rudy J. Kloser, Franziska Althaus, Bruce Barker and Gordon Keith

Abstract: Australia’s southeast network of deep-water marine reserves, declared in July 2007, was designed using a hierarchy that represented the distribution of marine biodiversity as a nested set of bioregions. In this hierarchy, geomorphic units, individual or aggregations of seabed geomorphic features, are the finest scale used in the design process. We evaluated the interaction between two hierarchical levels (depth and geomorphic features), using video survey data on seamounts and submarine canyons. False within-class homogeneity indicated that depth, size, complexity, configuration, and anthropogenic impact need to be added as modifiers to allow geomorphic features to act as surrogates for biodiversity distribution. A consequence of using unmodified geomorphic surrogates, and of not correctly nesting geomorphic features within depth, is the diminished recognition of the importance and comparative rarity of megafaunal biodiversity of the continental margin (<1500-m depths). We call this area the zone of importance, because it is where targeted marine impacts coincide with the greatest megafaunal biodiversity. Refining the geomorphic classification is desirable for future biodiversity characterization, but an alternative approach is to define patterns in biodiversity and abiotic variables jointly, and to utilize finer scale information and provide a classification that preserves the maximum information of both datasets.

Human dimensions of Marine Protected Areas

Citation Information: ICES J. Mar. Sci. (2009) 66 (1): 6-15. doi: 10.1093/icesjms/fsn182

Authors: Anthony Charles and Lisette Wilson

Abstract: Planning, implementing, and managing Marine Protected Areas (MPAs) requires that attention be paid not only to the biological and oceanographic issues that influence the performance of the MPA, but equally to the human dimensions: social, economic, and institutional considerations that can dramatically affect the outcome of MPA implementation. This paper explores ten human dimensions that are basic to the acceptance and ultimate success of MPAs: objectives and attitudes, “entry points” for introducing MPAs, attachment to place, meaningful participation, effective governance, the “people side” of knowledge, the role of rights, concerns about displacement, MPA costs and benefits, and the bigger picture around MPAs. These people-orientated factors and their impact on the success and effectiveness of MPAs are examined in relation to experiences with MPAs globally, and in relation to two Canadian examples specifically, one coastal (Eastport, Newfoundland) and the other offshore (the Gully, Nova Scotia).

Ocean Acidification and the Channel Islands National Marine Sanctuary: Cause, effect, and response

Citation Information: Conservation Working Group, Channel Islands National Marine Sanctuary Advisory Council. Ocean Acidification and the Channel Islands National Marine Sanctuary: Cause, effect and response. September 19, 2008. Prepared by the Environmental Defense Center, Santa Barbara, California. 42 pgs.

Executive Summary: Designated in 1980, the Channel Islands National Marine Sanctuary (CINMS or “the Sanctuary”) encompasses 1,128 square nautical miles from the Mean High Water Line to approximately six nautical miles (NM) offshore of the five northern Channel Islands—Santa Barbara, Anacapa, Santa Cruz, Santa Rosa, and San Miguel Islands, as well as Richardson Rock and Castle Rock.

Because it harbors “an exceptionally rich and diverse biota,”3 CINMS is one of 14 sites overseen by the National Marine Sanctuary Program (NMSP), authorized by Congress to “identify, designate, and manage areas of the marine environment of special national, and in some cases international, significance due to their conservation, recreational, ecological, historical, research, educational, or aesthetic qualities.” Congress ordered the NMSP to “maintain the natural biological communities” of designated Sanctuaries, and “to protect and, where appropriate, restore and enhance the natural habitats, populations, and ecological processes.”5 Based on these mandates, the stated primary purposes of CINMS designation and resource management are “preserving and protecting this unique and fragile ecological community.”

Of course, the physical and biological resources of the Sanctuary are not confined within those boundaries, but flow, drift and move in and out of them. Many species found within the Sanctuary and Santa Barbara Channel (SBC, or “the Channel”) arrive here after traveling hundreds or even thousands of miles, and the area’s ocean waters and meteorological systems gyrate, ebb and flow in cycles of far greater scale than the Sanctuary’s 1,128 square NM.

Similarly, human activities that occur beyond the Sanctuary’s geographic boundaries— and the reach of its protective regulations— yield consequences that can adversely impact its natural resources and qualities.

Progress with Marine Protected Areas since Durban, and future directions

Citation Information: PARKS Vol 17 No 2 DURBAN

Authors: Dan Laffoley, Kristina Gjerde and Louisa Wood

Description: A new paper in the IUCN journal Parks reviews global progress on the designation of MPAs since the 2003 World Parks Congress in Durban, South Africa. The paper focuses in particular on two MPA-related recommendations from the Congress: one that called for building a global representative system of MPA networks, and one that called for improved protection of high seas biodiversity and ecosystem processes. The authors acknowledge that some progress has been made in both respects, but that it has been too little to reach agreed-upon targets. "It is evident from statistics on MPAs that significantly more action is needed not just from a biodiversity perspective but increasingly from the climate change perspective," write authors Dan Laffoley, Kristina Gjerde, and Louisa Wood, all of IUCN.

Marine Protected Area Networks in the Coral Triangle: Development and Lessons

Citation Information: TNC (The Nature Conservancy), WWF (World Wildlife Fund), CI (Conservation International) and WCS (Wildlife Conservation Society). 2008. Marine protected area networks in the Coral Triangle: development and lessons. TNC, WWF, CI, WCS and the United States Agency for International Development, Cebu City, Philippines. 106 p

Description: The Marine Protected Area Networks in the Coral Triangle: Development and Lessons summarizes the results of the MPA Learning Partnership Project of TNC, CI, WWF, WCS and USAID. This book provides a comprehensive summary of the current status of six different MPA networks and their complexities. It analyzes MPA networks through their various stages of development including planning and design, implementation and evaluation as they are emerging within and around the Coral Triangle.

The contents represent the culmination of one year’s efforts, including working with the teams of six of the most advanced MPA networks in the region. The process of collecting information for this book involved activities in the field, conducting interviews, consultation workshops and interactions with stakeholders, government and nongovernment organizations, academic institutions and the private sector.

The work is attributed to the various specialists, technical experts and scientists who participated in the meetings and workshops, to whom heartfelt gratitude is expressed.

The editors and authors have attempted to provide a balanced view of the complex issues while looking at the many proposed solutions to marine and coastal management. It seems that MPAs are permanent yet evolving mechanisms, while MPA networks are developing. There is still much work to do in reaching the right balance of social and natural sciences and sustainable financing to make MPA networks effective and sustainable so they can thrive in the world’s most biodiverse region. 

Risk-based verification of large offshore systems

Citation Information: Proceedings of the Institution of Mechanical Engineers, Part M: Journal of Engineering for the Maritime Environment August 2012 vol. 226 no. 3 273-298

Authors: Jin Wang, Ben Matellini, Alan Wall, James Phipps

Abstract: This paper begins with a very brief review of the current status of offshore safety with particular reference to the UK sector. The risk-based verification concept is then described. Following identification of the research needs, a general risk-based verification framework is proposed with appropriate risk assessment contents incorporated into it. An example is then followed to demonstrate the proposed framework. The Health, Environment and Safety Information System (THESIS) software package is also used to facilitate the implementation of the framework. Finally, both the benefits and the limitations of risk-based verification in offshore applications are highlighted. The emphasis of the paper is focused on industrial applications.

Environmental and fisheries effects on Gracilechinus acutus (Echinodermata: Echinoidea) distribution: is it a suitable bioindicator of trawling disturbance?

Citation Information: González-Irusta, J. M., Punzón, A., and Serrano, A. Environmental and fisheries effects on Gracilechinus acutus (Echinodermata: Echinoidea) distribution: is it a suitable bioindicator of trawling disturbance? – ICES Journal of Marine Science, doi:10.1093/icesjms/fss102.

Abstract: Habitat preferences of Gracilechinus acutus in the southern Bay of Biscay were studied using data from autumn bottom-trawl surveys. Wet weight and number of specimens of G. acutus were obtained and related to environmental variables (depth, sediment type, and organic matter percentage) at each haul and to trawl fishing effort. With this information and the otter trawl effort data, the environmental requirements and the impact of the trawl fishery on G. acutus populations were analysed. Although the species was present in all depth strata and all sediment types studied, it had clear habitat preferences, as greater abundances and mean weight values were found at depths ranging from 71 to 200 m and in bottom sediments dominated by coarse and medium sands. The effect of disturbance by trawling on this echinoid was significant and clearly negative. Seabeds exposed to higher trawling disturbance showed lower values of urchin abundance and smaller urchins than areas with lower disturbance. Results of the present study confirm the initial hypothesis of the suitability of using this urchin as a bioindicator of trawling impact but only in areas with appropriate environmental conditions, highlighting the importance of attaining a wider knowledge on the essential habitat of the species.

Conservation of coastal stingrays: seasonal abundance and population structure of the short-tailed stingray Dasyatis brevicaudata at a Marine Protected Area

Citation Information: Le Port, A., Lavery, S., and Montgomery, J. C. Conservation of coastal stingrays: seasonal abundance and population structure of the short-tailed stingray Dasyatis brevicaudata at a Marine Protected Area – ICES Journal of Marine Science, doi:10.1093/icesjms/fss120

Abstract: Elasmobranch (shark, ray, and skate) populations around the world are in decline, and effective conservation measures are urgently needed. Marine Protected Areas (MPA) placed in locations important for key life-history stages may form part of an effective conservation strategy. In this context, we examined the seasonal abundance and population structure of the short-tailed stingray (Dasyatis brevicaudata) at an offshore MPA in northeastern New Zealand, and the reported use of this location as a mating ground. Diver surveys were conducted from 2004 to 2007 at the Poor Knights Islands Marine Reserve (PKIMR). During this time, we observed: (i) a substantial increase in adult and subadult numbers, particularly females during the suggested breeding season, and a corresponding increase in females bearing fresh mating scars; and (ii) large numbers of smaller (probably immature) D. brevicaudata individuals of both sexes from spring to autumn. These results suggest that the PKIMR acts as both a mating aggregation location and a nursery for this species. We suggest that for coastal stingrays such as D. brevicaudata, small MPAs may be effective at protecting key life-history stages, but that as movements outside of reserve boundaries also occur, additional management tools may also be necessary.

A novel approach for assistance with anti-collision decision making based on the International Regulations for Preventing Collisions at Sea

Citation Information: Proceedings of the Institution of Mechanical Engineers, Part M: Journal of Engineering for the Maritime Environment August 2012 vol. 226 no. 3 250-259

DOI: 10.1177/1475090211434869

Authors: Jinfen Zhang, Xinping Yan, Xianqiao Chen, Lingzhi Sang, Di Zhang

Abstract: Marine intelligent anti-collision regulations have been a means of dealing with a particularly dangerous problem for many years. As the foundation for making anti-collision decisions, the International Regulations for Preventing Collisions at Sea formulated by the International Maritime Organization should always be considered. Based on the International Regulations for Preventing Collisions at Sea, the minimum distance required for anti-collision by only the give-way ship (under normal situations) and by both the give-way ship and the stand-on ship steering simultaneously (under critical situations) under all possible encounter situations are studied respectively. Rather than regarding ships as a point, a restricted area where no evasive action of other ships is allowed is introduced. Furthermore, the ship’s manoeuvrability is taken into account. The proposed model is also assessed by the traditional parameters used in anti-collision such as the closest point of approach, the distance to the closest point of approach and the time to the closest point of approach. The study shows that the results obtained in this paper are important and complement the above-mentioned regulations so that navigators can make wise decisions.

Challenges to the Future Conservation of the Antarctic

Citation Information: Science 13 July 2012: Vol. 337 no. 6091 pp. 158-159

DOI: 10.1126/science.1222821

Authors: S. L. Chown, J. E. Lee, K. A. Hughes, J. Barnes, P. J. Barrett, D. M. Bergstrom, P. Convey, D. A. Cowan, K. Crosbie, G. Dyer, Y. Frenot, S. M. Grant, D. Herr, M. C. Kennicutt II, M. Lamers, A. Murray, H. P. Possingham, K. Reid, M. J. Riddle, P. G. Ryan, L. Sanson, J. D. Shaw, M. D. Sparrow, C. Summerhayes, A. Terauds, D. H. Wall

Abstract: The Antarctic Treaty System, acknowledged as a successful model of cooperative regulation of one of the globe's largest commons, is under substantial pressure. Concerns have been raised about increased stress on Antarctic systems from global environmental change and growing interest in the region's resources. Although policy-makers may recognize these challenges, failure to respond in a timely way can have substantial negative consequences. We provide a horizon scan, a systematic means for identifying emerging trends and assisting decision-makers in identifying policies that address future challenges. Previous analyses of conservation threats in the Antarctic have been restricted to matters for which available evidence is compelling. We reconsider these concerns because they might escalate quickly, judging from recent rapid environmental change in parts of Antarctica and increasing human interest in the region. We then focus on a more distant time horizon.


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