Efficacy of road removal for restoring wildlife habitat: Black bear in the Northern Rocky Mountains, USA

Forest roads reduce habitat quality for wildlife, in part by increasing susceptibility to hunting and poaching. Road removal is an increasingly common strategy for restoring habitat; however, little is known about responses of wildlife to road removal versus other methods of road closure. We assessed effects of different types of road closure (gated, barriered, and recontoured) on black bear (Ursus americanus) frequency and habitat on 18 open and closed road pairs in the western USA. Over 4 years, 44 bears were photographed during 3545 camera-trap days. Bear frequency was significantly higher (2.4 versus 0.6/100 days, respectively) and human frequency was significantly lower (2.4 versus 361.6/100 days, respectively) on closed than on open roads. Additionally, abundance of fall foods was higher (23.9% and 12.8%, respectively) and line-of-sight (a measure of habitat security) shorter (54.9 versus 69.4 m, respectively) on closed compared to open roads. Bears were detected on closed but not on open roads during daytime, suggesting avoidance of humans. Among-road-treatment differences included significantly higher frequency of bears on recontoured than on gated or barriered roads (4.6, 1.6, and 0.5/100 days, respectively), and significantly higher cover of fall bear foods on recontoured than on gated or barriered roads (39.3%, 12.1% and 16.4%, respectively). Frequency of bears was negatively correlated with frequency of humans and line-of-sight distance and positively correlated with abundance of fall foods and hiding cover. Results suggest that while all types of road closure benefit sensitive wildlife, removal by recontour may be the most effective strategy for restoring habitat.     

The impact of subsidies upon fisheries management and sustainability: the case of the North Atlantic

This paper provides both an estimate and assessment of subsidies in fisheries in the North Atlantic. The subsidies are estimated, on the basis of data taken from an OECD study and the Sea Around US Project database, to be in the order of US$ 2.0–2.5 billion per year. The assessment of the impact of the subsidies upon resource management and sustainability requires an examination of the underlying economics of subsidies in fisheries. There is general agreement, to which we subscribe, that fisheries subsidies do great harm by exacerbating the problems arising from the ‘common pool’ aspects of capture fisheries. Many economists, however, believe it that, if the ‘common pool’ aspects of a fishery could be removed by, for example, establishing a full‐fledged property rights system, the negative impact of fisheries subsidies would prove to be trivial. This paper demonstrates that the aforementioned comfortable belief is unfounded. Fisheries subsidies can be seriously damaging, even if the ‘common pool’ aspects of the fishery are removed. There is also a widely held belief among economists and government officials that subsidies used for vessel decommissioning schemes, far from being harmful, actually have a beneficial impact upon resource management and sustainability, or are at worst, neutral. About 20% of the fisheries subsidies in the North Atlantic are directed towards these purposes. In this paper, we argue that these seemingly beneficial subsides can, in fact, be highly negative in their impact.     

Fisheries buybacks: a review and guidelines

Buybacks of fishing vessels, licences, access and other rights, and gear, sometimes called decommissioning schemes, have traditionally been a key policy tool to address overcapacity, overexploitation of fish stocks, and distributional issues in fisheries. Two more issues can be added, sustainable use of ecosystems and conservation of biodiversity (i.e. ecological public goods and services) and providing a transition to a more rationalized fishery. This study discusses reasons for buybacks; examines consequences; considers asymmetric information, design of buyback auctions and other design issues; buybacks as a transition to a rationalized industry with strong property rights and governance, financing and transnational fisheries; draws out key lessons from the international experience; and provides an overall evaluation.     

铀矿地质勘探设施退役整治工程现状及安全防护

指出了铀矿地质勘探设施在完成重要历史任务的同时也给生态环境带来了重大破坏,其退役整治工作越来越受到广泛关注。分析了铀矿地质勘探设施退役整治工程现状,提出了安全防护和后期监护的措施,以期提供参考。