Factors influencing submerged macrophyte presence in fresh and brackish eutrophic waters and their impact on carbon emissions

In agricultural landscapes of North-Western Europe, the majority of water bodies do not meet the targets set by the European Water Framework Directive due to a lack of submerged macrophytes and associated biodiversity. These eutrophic waters can also be a substantial source of methane (CH4) and carbon dioxide (CO2) to the atmosphere. Here we present a two-year field experiment on the island of Goeree-Overflakkee (southwest Netherlands), conducted in six drainage ditches varying in salinity, where we monitored four permanent plots per ditch and varied the presence of both fish and macrophytes. We aimed to: 1) investigate factors limiting submerged macrophyte growth, focussing on exclusion of grazing pressure and bioturbation by fish; and 2) quantify the CO2 and CH4 emission under these conditions. Even in highly eutrophic, semi turbid ditches with fluctuating salinity levels and sulphide presence in the root zone, submerged macrophytes established successfully after introduction when the influence of grazing and bioturbation by fish was excluded. In the exclosures, diffusive CH4 and CO2 emissions, but not ebullitive CH4 emissions were significantly reduced. The spontaneous development of submerged macrophytes in the exclosures without macrophyte introduction underlined the effect of grazing and bioturbation by fish and suggest that abiotic conditions did not hamper submerged macrophyte development. Our results provide important insights into the influential factors for submerged macrophyte development and potential for future management practices. Large-scale fish removal may stimulate submerged macrophyte growth and reduce methane emissions, albeit that the macrophyte diversity will likely stay low in our study region due to fluctuating salinity and eutrophic conditions.</p

The Alberta Pipeline Environmental Steering Committee: A Model for Cooperative Resolution of Issues

In the past, industry and government independently conducted research and gathered information to address environmental issues. The results were not always mutually accepted."/jats:p" "jats:p"A number of emerging environmental issues arose in the mid 1980’s that demanded mutual resolution. As a result, the Alberta Pipeline Environmental Steering Committee was established in 1988."/jats:p" "jats:p"The Committee initially consisted of industry and government representatives. The membership has since been increased to include landowner representation, local government, federal interests and contractors."/jats:p" "jats:p"The Committee has four main purposes:"/jats:p" "jats:p"1. To assist government, industry and other interest groups in their pursuit of environmental protection and economical pipeline planning, construction, operation, abandonment and reclamation in Alberta;"/jats:p" "jats:p"2. To act as a vehicle for government to receive input from industry and other interest groups during policy formation;"/jats:p" "jats:p"3. To identify, prioritize and make recommendations for workable solutions on Alberta pipeline environmental issues and;"/jats:p" "jats:p"4. To help implement recommendations by organizations represented on the Committee."/jats:p" "jats:p"The benefits of this model are agreement on issue identification and mutual resolution. The success of the model has resulted in it being adopted for other sectors as well

Testing of In Situ and Ex Situ Bioremediation Approaches for an Oil-Contaminated Peat Bog Following a Pipeline Break

A biotreatability test was performed on oil-contaminated sphagnum peat moss from a 1985 pipeline spill of light Pembina Cardium crude oil at a bog near Violet Grove in central Alberta. Four tests were designed to simulate several field treatment approaches and to collect critical data on toxicity and leachability of this material. These tests included a bioslurry test, a soil microcosm test, an aerated water saturated peat column test, and a standard toxicity characteristic leachate potential (TCLP) test."/jats:p" "jats:p"In the saturated peat column tests, two nutrient amendment rates and a surfactant were tested to quantify biostimulation effects from an in-situ treatment design. An innovative aeration technology called the GLR (Gas-Liquid Reactor) was used to create a constant supply of hyperoxygenated water prior to column injection. The GLR continuously produces air bubbles of less than 50 microns in diameter, thereby maximizing air surface area and thereby increasing gas transfer rates. Crude oil biodegradation was quantified by the reduction in both extractable hydrocarbons and toxicity of the peat solids."/jats:p" "jats:p"The results confirmed that bioremediation of the residual crude oil to non-toxic levels in the peat bog at Violet Grove will be successful. All three tests — bioslurry, soil microcosm, and soil columns — gave similar results of at least 74% biodegradation of the residual crude oil on the peat solids."/jats:p" "jats:p"In situ bioremediation using the GLR aerated water injection system or an ex situ landfarming or biopile approach should achieve the 1000 mg/kg total petroleum hydrocarbon criteria. Neither fertilizer nor surfactant amendments were necessary to enhance oil biodegradation in the in situ column tests. The TCLP test indicated that ex situ treatment would require an impermeable liner for leachate collection."/jats:p" "jats:p"The time required to achieve the final remediation goals will depend on climatic variable such as temperature and rainfall during active summer season bioremediation. It is anticipated that an in situ approach using recirculated aerated water would achieve the cleanup up criteria within one full field treatment season

Effects of androgenic-anabolic steroids on alipoproteins and lipoprotein (a)

Examen des effets de deux régimes d'administration de stéroides sur les lipides et lipoprotéines ainsi que la récupération de ces variables après l'arrêt de la prise, comme indicateurs du risque de maladie cardiovasculaire chez des hommes forts en bonne santé