Circumpolar status of Arctic ptarmigan: Population dynamics and trends

Rock ptarmigan (Lagopus muta) and willow ptarmigan (L. lagopus) are Arctic birds with a circumpolar distribution but there is limited knowledge about their status and trends across their circumpolar distribution. Here, we compiled information from 90 ptarmigan study sites from 7 Arctic countries, where almost half of the sites are still monitored. Rock ptarmigan showed an overall negative trend on Iceland and Greenland, while Svalbard and Newfoundland had positive trends, and no significant trends in Alaska. For willow ptarmigan, there was a negative trend in mid-Sweden and eastern Russia, while northern Fennoscandia, North America and Newfoundland had no significant trends. Both species displayed some periods with population cycles (short 3–6 years and long 9–12 years), but cyclicity changed through time for both species. We propose that simple, cost-efficient systematic surveys that capture the main feature of ptarmigan population dynamics can form the basis for citizen science efforts in order to fill knowledge gaps for the many regions that lack systematic ptarmigan monitoring programs.

     

Sustainably Harvesting a Large Carnivore? Development of Eurasian Lynx Populations in Norway During 160 Years of Shifting Policy

The management of large carnivores in multiuse landscapes is always controversial, and managers need to balance a wide range of competing interests. Hunter harvest is often used to limit population size and distribution but is proving to be both controversialand technically challenging. Eurasian lynx (Lynx lynx) are currently managed as a game species in Norway. We describe an adaptive management approach where quota setting is based on an annual census and chart the population development through the period 1996–2008, as management has become significantly more sophisticated and better informed by the increased availability of scientific data. During this period the population has been through a period of high quotas and population decline caused by fragmented management authority and overoptimistic estimates of lynx reproduction, followed by a period of recovery due to quota reductions. The modern management regime is placed in the context of shifting policy during the last 160 years, during which management goals have moved from extermination stimulated by bounties, through a short phase of protection, and now to quota-regulated harvest. Much management authority has also been delegated from central to local levels. We conclude that adaptive management has the potential to keep the population within some bounded limits, although there will inevitably be fluctuation.     

Electrostatic spark ignition of sensitive dust clouds of MIE<1 mJ

Accidental electrostatic sparks in industrial plant producing/handling powders/dusts occur whenever a non-earthed electrically conducting object has been charged tribo-electrically to a high voltage and suddenly discharges its energy to earth via an air gap of appropriate length. When assessing the electrostatic spark ignition hazard in an industrial plant, the parameters of prime concern are the capacitances C of electrically conducting plant items that may become charged tribo-electrically, the voltages U to which they may become charged, and the minimum electric spark ignition energies (MIE) of the dust clouds of concern. Whenever , there is a possibility of accidental electrostatic spark ignition.

Current standard apparatuses for determining MIE of dust clouds have a lower spark energy limit of 2–3 mJ. In an investigation by the present authors, discussed in detail elsewhere, a new spark generator capable of producing synchronized capacitive sparks of energies down to the order of 0.01 mJ was developed and used for testing a selection of ignition-sensitive powders for MIE. Several of the MIEs found were 1–2 orders of magnitude lower than the lower energy limit of current standard test apparatus. Other experiments by the present authors, also reported elsewhere, have shown that quite low MIEs can be found for some dusts even with a less optimal synchronization mechanism, which may occur accidentally in practice.

The main object of the present paper is to discuss possible practical concerns arising from the finding that clouds in air of some dusts can have very low MIEs. In such cases, one may have to pay attention to even minor C values, i.e. minor plant items. Alternatively, with larger C values, even quite low voltages may give rise to hazardous spark discharges.

However, some types of fine metal powders of low MIEs will quite readily form electrically conductive layers on the solid surfaces with which they make contact. Hence, electrostatic spark ignition inside process equipment containing such dusts may be less probable than in the case of process equipment containing non-conducting dusts of correspondingly low MIEs.

There may be a need for a new standard test method for determination of MIEs of dust clouds in the <1 mJ range.     

Willingness to pay to protect cold water corals

There is increasing pressure to use currently untapped resources in the deep sea, raising questions regarding ecosystem service trade-offs in these often unknown areas. We assessed the trade-offs between protection of cold-water coral reefs and economic activities, such as fisheries and petroleum extraction, through a survey of a representative sample of the populations of Norway and Ireland. Choice-experiment surveys were conducted in workshop settings and through the internet. Both survey approaches provided some similar results, such as preferences for protection. Our cross-country comparison showed the general public in Norway and Ireland was willing, despite possible conflict with extractive and consumptive economic activities in the deep sea, to protect cold-water corals as habitat for fish. On average, people were willing to pay NKr 341 and NKr 424 for a small and large increase in protected areas respectively, and NKr 880 if the area is important habitat for fish, all else held equal. However, there was large variation across individuals and countries. Norwegian respondents valued pure existence of cold-water corals more than the Irish respondents, and the latter were less willing to trade off industrial activities than the former. Nonetheless, the findings support conservation of cold-water corals and more generally of ocean environments that provide habitat for fish, which the current deep sea governance systems are not adequately designed or sufficiently well-structured to secure.