Influence of Environmental Factors on Biotic Responses to Nutrient Enrichment in Agricultural Streams1

Maret, Terry R., Christopher P. Konrad, and Andrew W. Tranmer, 2010. Influence of Environmental Factors on Biotic Responses to Nutrient Enrichment in Agricultural Streams. Journal of the American Water Resources Association (JAWRA) 46(3):498-513. DOI: 10.1111/j.1752-1688.2010.00430.x Abstract: The influence of environmental factors on biotic responses to nutrients was examined in three diverse agricultural regions of the United States. Seventy wadeable sites were selected along an agricultural land use gradient while minimizing natural variation within each region. Nutrients, habitat, algae, macroinvertebrates, and macrophyte cover were sampled during a single summer low-flow period in 2006 or 2007. Continuous stream stage and water temperature were collected at each site for 30 days prior to sampling. Wide ranges of concentrations were found for total nitrogen (TN) (0.07-9.61 mg/l) and total phosphorus (TP) (<0.004-0.361 mg/l), but biotic responses including periphytic and sestonic chlorophyll a (RCHL and SCHL, respectively), and percent of stream bed with aquatic macrophyte (AQM) growth were not strongly related to concentrations of TN or TP. Pearson’s coefficient of determination (R²) for nutrients and biotic measures across all sites ranged from 0.08 to 0.32 and generally were not higher within each region. The biotic measures (RCHL, SCHL, and AQM) were combined in an index to evaluate eutrophic status across sites that could have different biotic responses to nutrient enrichment. Stepwise multiple regression identified TN, percent canopy, median riffle depth, and daily percent change in stage as significant factors for the eutrophic index (R² = 0.50, p < 0.001). A TN threshold of 0.48 mg/l was identified where eutrophic index scores became less responsive to increasing TN concentrations, for all sites. Multiple plant growth indicators should be used when evaluating eutrophication, especially when streams contain an abundance of macrophytes.     

Formal mentoring versus supervisor and coworker relationships: differences in perceptions and impact

Formal mentoring programs in two companies were examined regarding (1) the extent to which mentees and mentors agreed on the nature of the mentoring relationships and (2) the extent to which dimensions of mentoring relationships were related to outcomes for the mentees, compared with the extent to which dimensions of supervisory and coworker relationships were related to the same outcomes: job satisfaction, organizational commitment, and turnover intentions. Mentors were at least two hierarchical levels above the mentee, and both were part of the companyies' formal mentoring program. Sixty‐one pairs of mentors and mentees participated. Overall, there was little agreement between mentees and mentors regarding the nature of the mentoring relationship. Furthermore, the mentoring relationship was not related to mentee outcomes, while supervisory and coworker relationships were. It is suggested that, if one desires to affect job satisfaction, turnover intentions, and organizational commitment, mentoring functions may be best performed by supervisors and coworkers rather than assigned formal mentors from higher up in the organizational hierarchy. Copyright © 2003 John Wiley & Sons, Ltd.     

Need for adaptation strategy against global sea level rise: an example from Saudi coast of Arabian gulf

This paper reports sea level rise (SLR) scenarios causing land loss, environmental degradation and destruction of infrastructure in the Saudi coast of the Arabian Gulf. Human development structures such as, sea ports, desalination plants, industrial establishments, commercial buildings, fish farms etc. will be impacted, leading to great economic losses. A systematic analysis on the current environmental setting of east coast of Kingdom of Saudi Arabia (KSA) versus the existing infrastructure assets indicates that a 1?m sea level rise in Arabian Gulf affects approximately 650?km² land area, along the Saudi coastline of ~1,800?km in 1:50,000 scale. Three simulation scenarios were created with respect to 1?m, 2?m and 3?m rises from the present mean sea level and its impacts were assessed. Maps depicting major infrastructure assets, ecologically sensitive elements, historical locations, anthropogenic zones, and Environmental Sensitivity Indices (ESI) were used for overlaying the sea level change map, in a Geographic Information System (GIS) platform. In general, the Jubail Marine Park area will have serious impact due to SLR. The inundation of low?Clying lands will affect the mangroves species of Dawhat Ad Dafi, coral reefs, coastal salt marshes, groundwater aquifers, and fish stocks. The risk of inundation on the Abu Ali Island, given their status as marine sanctuary of international importance, is particularly high. As an adaptation strategy, it is proposed that the KSA should implement Integrated Coastal Zone Management Plan (ICZMP) for the Arabian Gulf coast without further delay for the protection of its vulnerable resources and for sustainable development.     

Utilizing a 'systems' approach to improve the management of waste from healthcare facilities: best practice case studies from England and Wales.

Changes in environmental legislation and standards governing healthcare waste, such as the Hazardous Waste Regulations are expected to have a significant impact on healthcare waste quantities and costs in England and Wales. This paper presents findings from two award winning case study organizations, the Cardiff and Vale NHS Trust and the Cornwall NHS Trust on 'systems' they have employed for minimizing waste. The results suggest the need for the development and implementation of a holistic range of systems in order to develop best practice, including waste minimization strategies, key performance indicators, and staff training and awareness. The implications for the sharing of best practice from the two case studies are also discussed.     

Lead pollution in East Trinidad resulting from lead recycling and smelting activities

Several problems of acute lead poisoning in children have been identified over the past three years in Trinidad. In all cases investigated so far, continual exposure to lead from battery recycling or from lead-smelter wastes have been found responsible. In East Trinidad, illicit dumping of lead wastes from such sources has resulted in several sites becoming heavily contaminated. Some of these sites are in environmentally sensitive areas, including rivers and wetlands, and require urgent remedial action. Results of monitoring studies at several of these sites show lead levels as high as 75% by weight. The potential for surface and ground water contamination exists, as evidenced by leaching of lead into surrounding areas.     

Sustaining Jamaica's forests: The protected areas resource conservation project

This study examines Jamaica's attempt to protect a tropical forest reserve. The biophysical setting, and the types and magnitude of forest development pressures are reviewed. Next, Jamaica's approach to developing new land-use strategies and compatible environmental protection and economic development programs are examined. Finally, the practical and theoretical implications by which institutions can be designed to encourage planning for sustainable development are reviewed. The implications suggest how to provide an appropriate mix of cooperation and market competition, by which people acting in their own interests accomplish socially equitable economic development, while protecting the environment for the benefit of future generations. The experience illustrates that effective long-term protection of natural areas requires the building of local relationships and support, the development of local economic activities supportive of conservation, the defining of clear boundaries, and significant monitoring and enforcement. Long-term protection of the Blue and John Crow mountains, and other important natural areas of Jamaica, will also require the development of a workable and enforceable system of land-use planning for the island, and adjustments to the economic incentive structure so that sustainable, nonextractive uses of natural capital are placed on equal footing with other economic uses (e.g., coffee production).