暂无摘要。

Wetlands have declined in area and quality at an accelerating pace in the last 50 years. Yet, the last 50 years is when international attention has been focussed on wetlands through the Ramsar Convention. An analysis of how the convention has evolved over the past 50 years suggests it has been drifting away from its original mandate in a maladaptive manner, and this drift is a problem for achieving its original objectives. A review of the strategic plans of the convention revealed two key conditions for institutional drifting and the associated lack of success. The first condition lies in its unique situation as a non-UN convention, which reduces the convention\'s visibility and interactivity with other biodiversity-related conventions, agencies, or programmes. The second condition is an increasing number of conventions dealing with biodiversity issues, all forcing the Ramsar Convention to seek different roles in an increasingly competitive institutional landscape. A more effective future for the convention arguably lies in reasserting its original mandate, but with cognisance of the changed environmental pressures of the twenty-first century. While this would narrow its increasingly broad focus, such a reorientation will allow wetlands and waterfowl to start a track to recovery, backed by active and focused Contracting Parties in a renewed international convention on wetland conservation, management, and sustainable use.

We utilized lead (Pb) stable isotopes to identify the source of acute Pb poisoning in a Tundra Swan (Cygnus columbianus) and evaluated overall Pb exposure. Upon necropsy, we obtained samples of blood, liver, kidney, heart, thigh, breast, femur, and metallic objects (i.e., fishing sinker, spring and swivels) from the gizzard for Pb isotopic analysis. Pb isotope ratios of blood and soft tissues were essentially identical to the Pb ratios of the sinker, the likely source of acute poisoning. The spring and swivels had lower Pb content and ratios distinct from tissue, suggesting no significant contribution to poisoning. Femur Pb isotopic composition was the most distinct biological sample and indicative of a combination of sources. These results demonstrate isotopic analysis as a viable method for determining the source of acute Pb poisoning, and that Pb isotope ratios in bone most likely record a lifetime-averaged metric of Pb exposure.

Mute swans (Cygnus olor) of the Anatidae family are common in wetlands of Europe. They winter in Africa, Asia and some parts of Europe. The species is exposed to many pathogens in its places of residence, including parasites possibly introduced from tropical countries by other species of birds that take long wanderings and occupy a similar ecological niche. One such case is the infection of the Sarconema eurycerca, nematode belonging to the Filarioidea family. It invades the bird\'s myocardium and, according to some authors, this nematode may be one of the main causes of swans\' deaths. The material for the present study was an approximately 2 year old female mute swan, which during the flight fell suddenly to the ground in Pomorskie Voivodeship (Poland, 53°50\'18″N 18°12\'54″E) in November. During the examination and medical observation, weakness, diarrhea and infestation with lice were found. The cause of its eventual death was attributed to a failure of the circulatory system. Post mortem, two abscesses with diameters of 2-3 cm were found in its liver parenchyma. Three nematodes were visible in the epicardium and many more in myocardium. Upon cutting open the heart, small yellowish foci, about 1 mm in diameter were scattered over valves. On the basis of morphological features, infection by Sarconema eurycerca was concluded. As far as we are aware, in Poland there were no earlier reports of this parasite infecting a swan.