Isotopes in teeth and a cryptic population of coastal freshwater seals

Human activities threaten the biodiversity of aquatic mammals across the globe. Conservation of these species hinges on the ability to delineate movements and foraging behaviors of animals, but gaining such insights is hampered by difficulties in tracing individuals over their lives. We determined isotope ratios in teeth (⁸⁷Sr/⁸⁶Sr, ¹³C/¹²C, and ¹⁸O/¹⁶O) to examine lifelong movement and resource-use patterns of a unique freshwater population of a wide-ranging pinniped species (harbor seal [Phoca vitulina]) that resides in Iliamna Lake, Alaska (U.S.A.). This population's potentially unique migratory behavior and use of different trophic resources are unknown. The isotope ratios we measured in teeth showed that seals were born in the lake, remained lifelong residents, and relied principally on resources produced from in the lake, even when seasonally abundant and nutrient-dense spawning anadromous fish (i.e., sockeye salmon [Oncorhynchus nerka]) were available in the lake. Our results illustrate how serial isotope records in teeth, particularly ⁸⁷Sr/⁸⁶Sr ratios, can be used to quantify how coastal mammal populations exploit both freshwater and marine ecosystems. Understanding lifelong patterns of habitat and resource use is essential information when designing effective conservation plans for threatened coastal mammals. We present the Iliamna Lake harbor seals as a unique case study into how isotope records within teeth can help reveal the cryptic ecology of such a population residing in an intact ecosystem. The results also provide critical baseline information for the Kvichak River system, which is facing an uncertain future due to proposed large-scale industrial development and a rapidly changing climate.     

Effects of Invasive Parasites on Bumble Bee Declines

Abstract: Bumble bees are a group of pollinators that are both ecologically and economically important and declining worldwide. Numerous mechanisms could be behind this decline, and the spread of parasites from commercial colonies into wild populations has been implicated recently in North America. Commercial breeding may lead to declines because commercial colonies may have high parasite loads, which can lead to colonization of native bumble bee populations; commercial rearing may allow higher parasite virulence to evolve; and global movement of commercial colonies may disrupt spatial patterns in local adaptation between hosts and parasites. We assessed parasite virulence, transmission mode, and infectivity. Microparasites and so‐called honey bee viruses may pose the greatest threat to native bumble bee populations because certain risk factors are present; for example, the probability of horizontal transmission of the trypanosome parasite Crithidia bombi is high. The microsporidian parasite Nosema bombi may play a role in declines of bumble bees in the United States. Preliminary indications that C. bombi and the neogregarine Apicystis bombi may not be native in parts of South America. We suggest that the development of molecular screening protocols, thorough sanitation efforts, and cooperation among nongovernmental organizations, governments, and commercial breeders might immediately mitigate these threats.     

Local Capacity for Groundwater Protection in Ontario

Preventing groundwater contamination is vastly cheaper than remediation. Recognizing this, attention in water and land management agencies in North America increasingly turn to groundwater protection. Local agencies, such as municipalities and watershed management districts, are vital to successful groundwater protection, but they face daunting challenges. In the United States, senior governments have recognized these challenges and provide considerable support for local agencies. In Ontario, Canada, local agencies are, to a much greater extent, on their own. The aims in this paper are to analyze factors that shape local capacity for groundwater protection, focusing on Ontario, and to recommend avenues for capacity building. Interrelationships among five dimensions of capacity (technical, financial, institutional, social, and political) are explored through an analysis of three smaller Ontario communities: City of Guelph (population 93,400), Town of Orangeville (population 22,188), and Town of Erin (population 11,000). Size clearly influences capacity for groundwater protection. However, other considerations unrelated to size appear to be as important. These other factors include the ability to form horizontal and vertical linkages with external agencies, political leadership and commitment, and citizen involvement. Thus, smaller communities in Ontario (and other jurisdictions with limited senior government support) would do well to focus on these areas at the same time as they develop their technical, financial, and institutional capacity.     

Changing Trends in World Metal Demand: The Case of Tin

This paper examines the changing trends in world tin demand for the period 1962–1985. In the early 1970s tin production peaked, and has since declined. The reasons for the decline are examined in terms of changes in product composition of income (i.e. mix of goods and services), changes in material composition of products, decline in gross domestic investment and the rising price of tin.     

The Evolution and Role of Non-OPEC Production in the International Oil Market

In 1982, for the first time since OPEC was founded in 1961, its production was surpassed by the non-OPEC countries in the world excluding the centrally planned economies. In that year, for the world as a whole, OPEC provided 35% of the oil consumed. The decline was brought about by a decrease in consumption and by a marked increase in production from non-OPEC sources. It is expected that non-OPEC producers will have the capacity to meet more than half of the world's oil requirements until the early 1990s, at which time OPEC producers will again assume the role of providing over 50% of the world's oil.     

The European Water Framework Directive: Water Quality Classification and Implications to Engineering Planning

The European Water framework directive (WFD) is probably the most important environmental management directive that has been enacted over the last decade in the European Union. The directive aims at achieving an overall good ecological status in all European water bodies. In this article, we discuss the implementation steps of the WFD and their implications for environmental engineering practice while focusing on rivers as the main receiving waters. Arising challenges for engineers and scientists are seen in the quantitative assessment of water quality, where standardized systems are needed to estimate the biological status. This is equally of concern in engineering planning, where the prediction of ecological impacts is required. Studies dealing with both classification and prediction of the ecological water quality are reviewed. Further, the combined emission–water quality approach is discussed. Common understanding of this combined approach is to apply the most stringent of either water quality or emission standard to a certain case. In contrast, for example, the Austrian water act enables the application of only the water quality based approach - at least on a temporary basis.     

Ecological Compensation in Dutch Highway Planning

The ecological compensation principle was introduced by the Dutch government in 1993. This principle is designed to enhance the input of nature conservation interests in decision-making on large-scale development projects and to counterbalance the ecological impacts of such developments when implemented. This article evaluates the application of the Dutch compensation principle in highway planning. Six current highway projects reveal consistent implementation of this principle, although provincial policies on compensation and a national method for identifying compensation measures are still under development. As the planning process has not yet been completed for all the projects, no general conclusions can be drawn on the impact of the compensation principle on highway decision-making. Nevertheless, several examples show that the principle stimulates project initiators to develop alternative routes or route sections in order to avoid or reduce ecological impacts and the need for coherent compensation measures. If the compensation principle is to be properly implemented in the context of highway planning, particular attention should be paid to the following aspects: (1) sequential assessment of overall project legitimacy and the necessity of intersecting protected areas and compensation measures, (2) the initiator's attempts to avoid and mitigate ecological impacts in developing alternative routes prior to compensation for impacts, and (3) the role of uncertain ecological impacts in identifying compensation measures, especially those concerning habitat isolation.