Summing It Up : How Do We Evaluate the Total Public Interest ?
publication quickly rose to the top of the " all-time best seller list " of Great Lakes Fishery Commission publications. It has been widely circulated and widely used as a guide to Great Lakes fishery values by the Great Lakes fishery management community, mainly because little other information has been available on this topic. Managers have been increasingly required over the last decade or two to evaluate fisheries programs and needs by courts, by legislatures and by their own administrations. The 1979 publication was intended as a handy reference to current research findings on Great Lakes fishery values, in response to this need. However, it soon became apparent that more was needed. Managers needed a better explanation of the reasoning behind these evaluations. When economists use market-based ideas to examine non-market situations, either new terminology must be invented, or old terminology must be stretched into a new environment. Things easily get lost in the translation. This publication, then, is more than just an update. It is also an attempt to explain the reasoning behind these estimates, including some of the subtle differences between closely related values. We realize that one small publication such as this is still insufficient. Managers and administrators must take additional steps if they are to use the full power of economics to their benefit. All members of the committee that worked on this publication look forward to working with members of the management community in an effort to more fully utilize economic information, both on an individual basis and in more formal efforts such as those conducted by the Great Lakes Fishery Commission. We also welcome feedback on the usefulness of this publication, so we can improve the next one. These estimates were developed by a workshop or " committee " of economists, listed below, who have actively worked on Great Lakes fisheries values and impacts over the last few years. After this publication was drafted, all members were asked to verify and update the information, as well as to comment in any other way. Thus, this publication represents a consensus of a diverse group of economics researchers and practitioners from the region. The author has benefited from comments on earlier versions by almost all members of the group, particularly those of Leroy J. Hushak, as well as from comments We were gratified to see, in putting these data together, that many new studies have been …
EFFECTS OF GRANULAR 2',5-DICHLORO-4'- NITROSALICYLANILIDE (BAYER 73) ON BENTHIC MACROINVERTEBRATES IN A LAKE ENVIRONMENT
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Velocity moments in alongshore bottom stress parameterizations
The time-averaged alongshore bottom stress is an important component of nearshore circulation models. In a widely accepted formulation the bottom stress is proportional to , the time average of the product of the instantaneous velocity magnitude |u→| and the instantaneous alongshore velocity component υ. Both mean and fluctuating (owing to random, directionally spread waves) velocities contribute to . Direct estimation of requires a more detailed specification of the velocity field than is usually available, so the term is parameterized. Here direct estimates of based on time series of near-bottom currents observed between the shoreline and 8-m water depth are used to test the accuracy of parameterizations. Common parameterizations that are linear in the mean alongshore current significantly underestimate for moderately strong alongshore currents, resulting in overestimation of a drag coefficient determined by fitting modeled (with a linearized bottom stress) to observed alongshore currents. A parameterization based on a joint-Gaussian velocity field with the observed velocity statistics gives excellent overall agreement with the directly estimated and allows analytic investigation of the statistical properties of the velocity field that govern . Except for the weakest flows, depends strongly on the mean alongshore current and the total velocity variance but depends only weakly on the mean wave angle, wave directional spread, and mean cross-shore current. Several other nonlinear parameterizations of are shown to be more accurate than the linear parameterizations and are adequate for many modeling purposes.