Measures of turbidity in coastal waters, Coconut Island, Oahu, Hawaii, August 31 - September 2, 2005: workshop proceedings

摘要

A three day workshop on turbidity measurements was held at the Hawaii Institute of MarineudBiology from August 3 1 to September 2, 2005. The workshop was attended by 30 participantsudfrom industry, coastal management agencies, and academic institutions. All groups recognizedudcommon issues regarding the definition of turbidity, limitations of consistent calibration, and theudlarge variety of instrumentation that nominally measure "turbidity." The major recommendations,udin order of importance for the coastal monitoring community are listed below:ud1. The community of users in coastal ecosystems should tighten instrument designudconfigurations to minimize inter-instrument variability, choosing a set of specificationsudthat are best suited for coastal waters. The IS0 7027 design standard is not tight enough.udAdvice on these design criteria should be solicited through the ASTM as well as Federaludand State regulatory agencies representing the majority of turbidity sensor end users.udParties interested in making turbidity measurements in coastal waters should developuddesign specifications for these water types rather than relying on design standards madeudfor the analysis of drinking water.ud2. The coastal observing groups should assemble a community database relating output ofudspecific sensors to different environmental parameters, so that the entire community ofudusers can benefit from shared information. This would include an unbiased, parallel studyudof different turbidity sensors, employing a variety of designs and configuration in theudbroadest range of coastal environments.ud3. Turbidity should be used as a measure of relative change in water quality rather than anudabsolute measure of water quality. Thus, this is a recommendation for managers touddevelop their own local calibrations. See next recommendation.ud4. If the end user specifically wants to use a turbidity sensor to measure a specific waterudquality parameter such as suspended particle concentration, then direct measurement ofudthat water quality parameter is necessary to correlate with 'turbidity1 for a particularudenvironment. These correlations, however, will be specific to the environment in whichudthey are measured. This works because there are many environments in which waterudcomposition is relatively stable but varies in magnitude or concentration. (pdf contains 22 pages)