Evaluating approaches and technologies for monitoring organic contaminants in the aquatic environment, Ann Arbor, MI, July 21-23, 2006: workshop proceedings

The Alliance for Coastal Technologies (ACT) convened a workshop on Evaluating Approaches and Technologies for Monitoring Organic Contaminants in the Aquatic Environment in Ann Arbor, MI on July 21-23, 2006. The primary objectives of this workshop were to: 1) identify the priority management information needs relative to organic contaminant loading; 2) explore the most appropriate approaches to estimating mass loading; and 3) evaluate the current status of the sensor technology. To meet these objectives, a mixture of leading research scientists, resource managers, and industry representatives were brought together for a focused two-day workshop. The workshop featured four plenary talks followed by breakout sessions in which arranged groups of participants where charged to respond to a series of focused discussion questions. At present, there are major concerns about the inadequacies in approaches and technologies for quantifying mass emissions and detection of organic contaminants for protecting municipal water supplies and receiving waters. Managers use estimates of land-based contaminant loadings to rivers, lakes, and oceans to assess relative risk among various contaminant sources, determine compliance with regulatory standards, and define progress in source reduction. However, accurately quantifying contaminant loading remains a major challenge. Loading occurs over a range of hydrologic conditions, requiring measurement technologies that can accommodate a broad range of ambient conditions. In addition, in situ chemical sensors that provide a means for acquiring continuous concentration measurements are still under development, particularly for organic contaminants that typically occur at low concentrations. Better approaches and strategies for estimating contaminant loading, including evaluations of both sampling design and sensor technologies, need to be identified. The following general recommendations were made in an effort to advance future organic contaminant monitoring: 1. Improve the understanding of material balance in aquatic systems and the relationship between potential surrogate measures (e.g., DOC, chlorophyll, particle size distribution) and target constituents. 2. Develop continuous real-time sensors to be used by managers as screening measures and triggers for more intensive monitoring. 3. Pursue surrogate measures and indicators of organic pollutant contamination, such as CDOM, turbidity, or non-equilibrium partitioning. 4. Develop continuous field-deployable sensors for PCBs, PAHs, pyrethroids, and emerging contaminants of concern and develop strategies that couple sampling approaches with tools that incorporate sensor synergy (i.e., measure appropriate surrogates along with the dissolved organics to allow full mass emission estimation).[PDF contains 20 pages]

Historia de la piscicultura del pejerrey en Chascomús

El pejerrey Odontesthes bonariensis es uno de los peces de aguas continentales más emblemáticos de la Argentina y una de las especies más estudiada desde diferentes aspectos: ecológico, sistemático, morfológico, fisiológico, genético, etc. (López et al. 1991). Durante los años 1891 y 1892 se realizaron las primeras experiencias de piscicultura,lográndose por primera vez la reproducción artificial en 1904. Su amplia distribución actual es consecuencia de las siembras que se realizaron desde el antiguo Vivero de Piscicultura del Ministerio de Agricultura y Ganadería de la Nación y de la Estación Hidrobiológica del Ministerio de Asuntos Agrarios de la provincia de Buenos Aires, ambos establecimientos ubicados en la ciudad de Chascomús. En el presente trabajo se realiza una aproximación a la historia de la piscicultura del pejerrey en Chascomús, la que se divide en tres períodos: 1) Antecedentes de piscicultura, importancia de la pesca comercial en el sistema de lagunas Encadenadas de Chascomús y primeras medidas tomadas para conservar la explotación de las lagunas hacia fines del siglo XIX. 2) Etapa del antiguo Vivero (Ministerio de Agricultura de la Nación), desde 1904 hasta 1939. 3) Etapa de la Estación Hidrobiológica (Ministerio de Asuntos Agrarios, provincia de Buenos Aires), desde 1943 hasta el presente.