Texas Nameplate Company: A Profile of Environmental Success

An initially ignored customer request started a small Texas company on the road to environmental excellence. Ten years later, it offers an example of solid accomplishment—with more achievements sure to come. © 2001 John Wiley & Sons, Inc.     

Meta-analysis: trophic level, habitat, and productivity shape the food web effects of resource subsidies

Studies of the effects of cross-habitat resource subsidies have been a feature of food web ecology over the past decade. To date, most studies have focused on demonstrating the magnitude of a subsidy or documenting its effect in the recipient habitat. Ecologists have yet to develop a satisfactory framework for predicting the magnitude of these effects. We used 115 data sets from 32 studies to compare consumer responses to resource subsidies across recipient habitat type, trophic level, and functional group. Changes in consumer density or biomass in response to subsidies were inconsistent across habitats, trophic, and functional groups. Responses in stream cobble bar and coastline habitats were larger than in other habitats. Contrary to expectation, the magnitude of consumer response was not affected by recipient habitat productivity or the ratio of productivity between donor and recipient habitats. However, consumer response was significantly related to the ratio of subsidy resources to equivalent resources in the recipient habitat. Broad contrasts in productivity are modified by subsidy type, vector, and the physical and biotic characteristics of both donor and recipient habitats. For this reason, the ratio of subsidy to equivalent resources is a more useful tool for predicting the possible effect of a subsidy than coarser contrasts of in situ productivity. The commonness of subsidy effects suggests that many ecosystems need to be studied as open systems.     

Life around the North Water ecosystem: Natural and social drivers of change over a millennium

The formation of the North Water in Smith Sound about 4500 years ago, as evidenced by the establishment of bird colonies and human presence, also initiated a long-term anthropogenic agent as part of this High Arctic ecosystem. Different epochs have influenced the human occupation in the area: immigration pulses from Canada and Alaska, trade with meteorite iron throughout the Arctic, introduction of new technologies by whalers and explorers, exploitation of resources by foreigners, political sequestration, export of fox and seal skins and later narwhal products, and recently fishing. Physical drivers in terms of weather and climate affecting the northern hemisphere also impact accessibility and productivity of the ecosystem, with cascading effects on social drivers, again acting back on the natural ecologies. Despite its apparent isolation, the ecosystem had and still has wide ranging spatial ramifications that extend beyond the High Arctic, and include human activity. The challenge is to determine what is internal and what is external to an ecosystem.     

Use of Australian cladocerans to generate life-cycle toxicity data

Cladocerans (or water-fleas) are important animals in freshwater exosystems. They are widely used in toxicity tests because of their small size, ease of culture, and sensitivity to chemicals. They are particularly suited to life-cycle tests because newly-hatched young can produce offspring in less than one week. Most data are available for European and North American species, and may be not be appropriate to Australian conditions. In the present study, eight Australian cladocerans were evaluated in three-brood life-cycle tests over ten days or less. Species were evaluated by duration of life cycle, ease of handling, numbers of young produced in three broods, and stability in laboratory culture.Ceriodaphnia cfdubia was the best test species. The greatest number of young, the highest survival rate and the shortest time to produce three broods were achieved in filtered Sydney mains water, aged in the presence of fish, using blended trout pellets and alfalfa as food.     

Metal concentrations in seabirds of the New Zealand region

Concentrations of the heavy metals cadmium, copper, lead, zinc, mercury and, in some individuals, methyl mercury were determined in a range of tissues of 64 tropical, subtropical, subantarctic and antarctic seabird taxa mostly from the New Zealand region. Although apparently natural, levels of cadmium and mercury in some species greatly exceed those known to have toxic effects in some terrestrial birds. Copper and zinc levels exhibited less inter-species variation than the non-essential metals cadmium and mercury. Cadmium concentrations were highest in kidney tissues but uniformly low in feathers. Total mercury concentrations showed most inter-species variation. Mean methyl mercury levels in liver tissues of several large procellariiforms represented less than 5% of the corresponding mean total mercury level. Lead concentrations were generally low or below the limits of detection, but elevated levels were measured in some coastal or scavenging species. In a significant number of species, mean concentrations of liver cadmium and mercury and kidney cadmium were greater in adults than in young birds. The reverse was true for copper. Mean zinc levels in liver did not differ between adults and young. High levels of cadmium in some species seem likely to be due to diet, whereas high levels of mercury probably reflect more closely the moult intervals which constrain the ability of birds to eliminate methyl mercury.     

Ethics and the Genetic Engineering of Food Animals

Biotechnology applied to traditional foodanimals raises ethical issues in three distinctcategories. First are a series of issues that arise inthe transformation of pigs, sheep, cattle and otherdomesticated farm animals for purposes that deviatesubstantially from food production, including forxenotransplantation or production of pharmaceuticals.Ethical analysis of these issues must draw upon theresources of medical ethics; categorizing them asagricultural biotechnologies is misleading. The secondseries of issues relate to animal welfare. Althoughone can stipulate a number of different philosophicalfoundations for the ethical assessment of welfare,most either converge on Bernard Rollins principle ofwelfare conservation (Rollin, 1995), or devolve intodebates over the ethical significance of animaltelos or species integrity. The principle of welfareconservation prohibits disfunctional geneticengineering of food animals, but would permit alteringanimals biological functions, especially when (as inmaking animals less susceptable to pain or suffering)do so improves an individual animals well being.Objections to precisely this last form of geneticengineering stress telos or species integrity asconstraints on modification of animals, and thisrepresents the third class of ethical issues. Most whohave formulated such arguments have failed to developcoherent positions, but the notion of species being,derived from the 19th century German tradition,presents a promising way to analyze the basis forresisting the transformation of animal natures.