Cessation of hole-digging by the crab Helograpsus haswellianus: A resource-conserving adaptation

Cases where the mud crab Helograpsus haswellianus (Whitelegge) have dug too many holes and collapsed the mud surface are not observed in the field. Experiments have shown that there is a specific density of holes above which the mud collapses. H. haswellianus at different densities in closed cages do not dig holes over this density. Instead, two or more individuals occupy existing holes on a short-term basis. The significance of this behaviour is discussed.     

Ergonomics: It's Here to Stay,Despite the OSHA Standard Repeal

Congress repealed OSHA's Ergonomics Program Standard. But ergonomics remains an important health and safety issue for businesses. Moreover, additional regulation in this area is likely to come in the future. © 2001 John Wiley & Sons, Inc.     

Potential exposure to diazinon during yard applications

Applicators applying diazinon to yards were monitored to determine potential exposures received while using this commonly available pesticide around the home. Diazinon was applied to lawns and shrubs using compressed air or hose-end sprayers. Even with minimal clothing, the largest mean exposure received during any of the applications was estimated to be less than 0.2% of a lethal dose per hour. Exposure to the hands accounted for 85% or more of the total exposure, so simply protecting the hands would have essentially eliminated exposure.     

Adsorption and detection of some phenolic compounds by rice husk ash of Kenyan origin

Rice husk ash (RHA) obtained from a rice mill in Kenya has been used as an inexpensive and effective adsorbent (and reagent) for the removal (and detection) of some phenolic compounds in water. The abundantly available rice mill waste was used in dual laboratory-scale batch experiments to evaluate its potential in: (i) the removal of phenol, 1,3-dihydroxybenzene (resorcinol) and 2-chlorophenol from water; and (ii) the detection of 1,2-dihydroxybenzene (pyrocatechol) and 1,2,3-trihydroxybenzene (pyrogallol) present in an aqueous medium. The studies were conducted using synthetic water with different initial concentrations of the phenolic compounds. The effects of different operating conditions (such as contact time, concentration of the phenolic compounds, adsorbent quantity, temperature, and pH) were assessed by evaluating the phenolic compound removal efficiency as well as the extent of their color formation reactions (where applicable). RHA exhibits reasonable adsorption capacity for the phenolic compounds and follows both Langmuir and Freundlich isotherm models. Adsorption capacities of 1.53 x 10(-4), 8.07 x 10(-5), and 1.63 x 10(-6) mol g(-1) were determined for phenol, resorcinol and 2-chlorophenol, respectively. Nearly 100% adsorption of the phenolic compounds was possible and this depended on the weight of RHA employed. For the detection experiments, pyrocatechol and pyrogallol present in water formed coloured complexes with RHA, with the rate of colour formation increasing with temperature, weight of RHA, concentration of the phenolic compounds and sonication. This study has proven that RHA is a useful agricultural waste product for the removal and detection of some phenolic compounds.     

Long-term relationships between SO2 and NOx emissions and SO4(2-) and NO3- concentration in bulk deposition at the Hubbard Brook Experimental Forest, NH

A highly significant second-order polynomial relation between SO(2) emissions and SO(4)(2-) concentrations during 1970-2000 (r(2)= 0.80, p= <0.001), and a linear relation between NO(x) and NO(3)(-) concentrations during 1991-2000 (r(2)= 0.67, p= 0.004) in bulk precipitation were found for the Hubbard Brook Experimental Forest, NH based on emissions from a 24 h, back-trajectory determined source area. Earlier periods (1965-1980) for SO(2)ratio SO(4)(2-) and longer periods (1965-2000) for NO(x)ratio NO(3)(-) had poorer linear relations, r(2)= 0.03, p= 0.51 and r(2)= 0.22, p= 0.004, respectively. Methodology by the US Environmental Protection Agency for calculating emissions data during this period has changed significantly and frequently, making trend analysis difficult. Given the large potential for errors in estimating emissions and to a lesser extent, deposition, the robust relations between SO(2) emissions and SO(4)(2-) concentrations in bulk precipitation at the Hubbard Brook Experimental Forest show that careful, long-term measurements from a single monitoring site can provide sound and reasonable data on trends in air pollution.     

IMPLEMENTATION OF BIORETENTION SYSTEMS: A WISCONSIN CASE STUDY1

ABSTRACT: The implementation of various bioretention systems was analyzed, including rain gardens, vegetated swales, trenches, and infiltration basins in the St. Francis subdivision, Cross Plains, Wisconsin. Through the examination of archival data and interviews with key participants, it was found that although regulatory and political pressures encouraged the inclusion of bioretention, current standards for storm water management prevailed. The developers had to meet both existing requirements and anticipated rules requiring infiltration. As a result, bioretention systems simply supplemented, rather than replaced, traditional storm water practices. The confusion surrounding dual standards contributed to substantial delays in the negotiations among relevant stakeholders in the watershed. It is concluded that the St. Francis subdivision serves as both a cautionary tale and a bioretention success story. As a caution, this situation demonstrates the need for careful review and refinement of existing storm water ordinances to incorporate water quality improvement technologies, such as bioretention. The demonstrated success of the St. Francis development, however, is that it became a positive prototype for best management storm water practices elsewhere in the region. In addition, the water quality monitoring data from the site has contributed to development of a new county ordinance, the first in Wisconsin to address both quantity and quality of storm water runoff.     

DETERMINISTIC-SYSTEMIC RELATIONSHIPS IN OVERLAND FLOW ANALYSIS1

ABSTRACT: An analysis of storm runoff is presented, giving primary attention to deterministic-systemic relationships. So that system aspects can be emphasized, other aspects are kept simple; analysis is made for uniform rainfall on a strip of uniform width, limiting direct applicability to small areas. Two relationships between excess rain and time of concentration, one based on hydraulic parameters, the other on hydrologic characteristics, are combined in a solution for peak discharge. The hydraulic expression gives the interrelationship of time of concentration, excess rain, friction, length, and slope. The hydrologic relationship is achieved by converting ordinary intensity-duration curves to corresponding excess rain intensity-duration curves, thereby interrelating excess rain, time of concentration, and loss characteristics. The resulting solution for peak discharge allows for systemic feedback among both hydraulic and hydrologic parameters.     

Book reviews

Factor Four: Doubling Wealth, Halving Resource Use. Ernst von Weizacker, Amory Lovins & L. Hunter Lovins, 1997, London, Earthscan, ISBN 1 85383 407 6, £15.99 (hbk)

Local and Global: Management of Cities in the Information Age,. Jordi Borja & Manuel Castells, 1997, London, Earthscan, 277pp. ISBN 1 85383 441 6, £19.95 (pbk)

Wasted: counting the costs of global consumption. Michael Redclift, 1996, Earthscan, London, 173pp. ISBN 1 85383 360 6, £32.50(hbk), 1 85383 355 X, £12.95(pbk)

Eco-feminist Natures: race, gender, feminist theory and political action. Noel Sturgeon, 1997, New York, Routledge, ISBN 0 415 912504, £12.99 (pbk)

Global Warming and Global Politics. Matthew Paterson, 1996, London and New York, Routledge, ISBN 0 415 13871 X, US$85.00, UK£50.00, (hbk) ISBN 0 415 13872 8, US$20.99, UK£12.88, (pbk)

Managing for Local Sustainability: policy, problem-solving, practice and place. Valerie M. Brown (Ed.), 1997, Commonwealth of Australia, 314 pp. ISBN 0642 26464 3, Copies of the report can be obtained from: National Office of Local Government Commonwealth Department of the Environment, Sports and Territories, GPO Box 9834, Canberra ACT 2601. Tel: (06) 289 2222; fax (06) 289 2436.

Local Agenda 21, Local Authorities and Tourism: a United Kingdom perspective. David Leslie & Fiona Muir, 1996, Glasgow, Caledonian University, ISBN 0 948255 52 8, £9.00

Straws in the Wind: medieval urban environmental law — the case of Northern Italy. Ronald E. Zupko & Robert A. Laures, 1996, Boulder, CO, Westview Press, 152 pp. ISBN 0 8133 2972 8, £10.00 (pbk)     

新西兰通过实行转基因生物标签规定

新西兰卫生部已宣布，从2001年12月7日起，将对所有转基因食品，即该食品最终成品中引入了新的DNA或异源蛋白，实行强制标签制度。任何进口和国产的食品只要含有转基因成分都将要求贴上标签。新西兰食品主管部门在2000年12月上旬根据食品标准法典18款修正案(转基因技术生产的食品法规)公布了以上决定。     

Larval mortality during export to the sea in the fiddler crab Uca minax

Dense populations of the fiddler crab Uca minax (Le Conte 1855) are common along tidally influenced freshwater rivers and streams >50 km from the sea. Adults do not migrate from inland sites to release larvae, but instead release them directly into an environment where the zoeae cannot survive. Laboratory salinity tolerance experiments were used to determine how long larvae from the inland-most population of U. minax along the Pee Dee River, South Carolina, USA can survive zero salinity compared to larvae from a brackish water population (salinity 5) near the mouth of Winyah Bay in the same estuary. Larvae from the brackish water population were also exposed to a salinity of 5 and their survival tracked. These experiments were conducted from May to August 2004 and 2005. To determine if inland larvae suffered significant mortality in transit due to salinity stress, current profiles were measured in the field and used to model the time taken by a larva using ebb-tide transport to travel to permissive salinities. The laboratory tolerance experiments showed that larvae from the inland freshwater population had LT50’s of 4–5 days at 0 salinity, which were significantly longer than those of the brackish water zoeae (2–3 days). Zoeae from the brackish water population survived for at least one larval molt at a salinity of 5 with LT 50’s of ∼12 days. Estimated travel times to reach permissive salinities from the inland-most population based on current profiles were 3–5 days for larvae using night-time only ebb-tide transport and 1.5–2.5 days for those using ebb-tide transport both day and night. Previously published field data indicate that U. minax larvae do use both day- and night-time ebb-tide transport, and are found in high densities in the water column during the day. These results lead to the conclusion that U. minax stage I zoeae do not undergo significant salinity-induced mortality during their 50+ km trip to the sea.