Heavy metals in leachate from simulated green roof systems

The contribution of green roofs to urban water quality, either as sinks or sources of pollutants, is an open question. This study examined leaching of Cd, Fe, Ni, Pb, and Zn from simulated green roof systems that had been deployed under field conditions and naturally leached for 22 months. The objectives were to determine if Arkalyte (an expanded clay), when mixed with pine bark as a substrate, leached metals and if so, whether leaching was influenced by the depth of substrate, structural components of the green roof system, or wet/dry deposition. Leachate was collected from each system after wet deposition events in June 2007, October 2007, February 2008, and April 2008 and analyzed. The concentration of four elements routinely exceeded USEPA water quality criteria for chronic and/or acute toxicity and were therefore of possible relevance to water quality, particularly for Pb. The frequency and intensity of local wet deposition influenced the volume of leachate recovered from the systems and in some instances the corresponding metal concentration in the leachate. There were no consistent trends with respect to depth and metal concentration in the leachate, due perhaps to the confounding effects caused by leaching of metals from materials used to construct the built-in-place systems and from inputs from deposition. Further evaluation of this substrate and the structural materials is needed to determine if their use in green roof systems will improve or degrade urban water quality.     

Fishers' knowledge and seahorse conservation in Brazil

From a conservationist perspective, seahorses are threatened fishes. Concomitantly, from a socioeconomic perspective, they represent a source of income to many fishing communities in developing countries. An integration between these two views requires, among other things, the recognition that seahorse fishers have knowledge and abilities that can assist the implementation of conservation strategies and of management plans for seahorses and their habitats. This paper documents the knowledge held by Brazilian fishers on the biology and ecology of the longsnout seahorse Hippocampus reidi. Its aims were to explore collaborative approaches to seahorse conservation and management in Brazil; to assess fishers' perception of seahorse biology and ecology, in the context evaluating potential management options; to increase fishers' involvement with seahorse conservation in Brazil. Data were obtained through questionnaires and interviews made during field surveys conducted in fishing villages located in the States of Piauí, Ceará, Paraíba, Maranhão, Pernambuco and Pará. We consider the following aspects as positive for the conservation of seahorses and their habitats in Brazil: fishers were willing to dialogue with researchers; although captures and/or trade of brooding seahorses occurred, most interviewees recognized the importance of reproduction to the maintenance of seahorses in the wild (and therefore of their source of income), and expressed concern over population declines; fishers associated the presence of a ventral pouch with reproduction in seahorses (regardless of them knowing which sex bears the pouch), and this may facilitate the construction of collaborative management options designed to eliminate captures of brooding specimens; fishers recognized microhabitats of importance to the maintenance of seahorse wild populations; fishers who kept seahorses in captivity tended to recognize the condtions as poor, and as being a cause of seahorse mortality.     

Science – A life fully lived: Joe Sodroski wins the 2006 Retrovirology Prize

The 2006 M Jeang Retrovirology Prize for HIV research has been awarded to Dr Joe Sodroski