Adsorptive Media Investigations and Testing for Improved Performance of Stormwater Treatment Systems in the Tahoe Basin

Retrofit activities, such as improving hydrology and incorporating more advanced treatment methods into systems where feasible, may improve phosphorus (P) removal performance of current Best Management Practices (BMPs). In the recent past, chemical treatment systems such as chemical dosing and the use of adsorptive media have become more prevalent for treating stormwater and hold promise for improving the P removal performance of stormwater treatment BMPs (Bachand et al., 2005; Patel et al., 2005). Our primary objective for this project has been to investigate whether adsorptive media hold any promise for improving P removal performance of stormwater basins and treatment wetlands at Lake Tahoe.... (PDF contains 99 pages)

In situ measurement of dissolved inorganic carbon speciation in natural waters, pH, pC02, TA, & TC02, Honolulu, Hawaii, February 16-18, 2005: workshop proceedings

The Alliance for Coastal Technology (ACT) convened a workshop on the in situ measurement of dissolved inorganic carbon species in natural waters in Honolulu, Hawaii, on February 16, 17, and 18, 2005. The workshop was designed to summarize existing technologies for measuring the abundance and speciation of dissolved inorganic carbon and to make strategic recommendations for future development and application of these technologies to coastal research and management. The workshop was not focused on any specific technology, however, most of the attention of the workshop was on in situ pC02 sensors given their recent development and use on moorings for the measurement of global carbon fluxes. In addition, the problems and limitations arising from the long-term deployment of systems designed for the measurement of pH, total dissolved inorganic carbon (DIC), and total alkalinity (TA) were discussed. Participants included researchers involved in carbon biogeochemistry, industry representatives, and coastal resource managers. The primary questions asked during the workshop were: I. What are the major impediments to transform presently used shipboard pC02 measurement systems for use on cost-eficient moorings? 2. What are the major technical hurdles for the in situ measurement of TA and DIC? 3. What specific information do we need to coordinate efforts for proof of concept' testing of existing and new technologies, inter-calibration of those technologies, better software development, and more precise knowledge quantzjjing the geochemistry of dissolved inoeanic carbon species in order to develop an observing system for dissolved inorganic carbon? Based on the discussion resulting from these three questions, the following statements were made: Statement No. 1 Cost-effective, self-contained technologies for making long-term, accurate measurements of the partial pressure of C02 gas in water already exist and at present are ready for deployment on moorings in coastal observing systems. Statement No. 2 Cost-effective, self-contained systems for the measurement of pH, TA, and DIC are still needed to both fully define the carbonate chemistry of coastal waters and the fluxes of carbon between major biogeochemical compartments (e.g., air-sea, shelf-slope, water column-sediment, etc.). (pdf contains 23 pages)

The brine and gas content of sea ice with attention to low salinities and high temperatures

Based on the well known sea ice phase diagram, equations are derived for determining the brine and gas content of sea Ice for high temperatures (range 0 to -2 °C) and low salinities. The presently widely used equations of Cox and Weeks (1982) are valid only for temperatures below -2°C. Fresh-water ice is used as a boundary condition for the equations. The relative salt concentrations in brine are_assumed to be the same as in normal (or standard) seawater. Two sets of equations are presented: 1) accurate formulae based on UNESCO standard sea water equations, and 2) approximate formulae based on general properties of weak solutions. The approximate formulae are not essentially different from the classical system which basically assumes the freezing point to be a linear function of fractional salt content. The agreement between the two approaches is excellent and the approximate system is good enough for most applications.

Classification of Coastal Communities Reporting Commercial Fish Landings in the U.S. Northeast Region: Developing and Testing a Methodology

The National Marine Fisheries Service is required by law to conduct social impact assessments of communities impacted by fishery management plans. To facilitate this process, we developed a technique for grouping communities based on common sociocultural attributes. Multivariate data reduction techniques (e.g. principal component analyses, cluster analyses) were used to classify Northeast U.S. fishing communities based on census and fisheries data. The comparisons indicate that the clusters represent real groupings that can be verified with the profiles. We then selected communities representative of different values on these multivariate dimensions for in-depth analysis. The derived clusters are then compared based on more detailed data from fishing community profiles. Ground-truthing (e.g. visiting the communities and collecting primary information) a sample of communities from three clusters (two overlapping geographically) indicates that the more remote techniques are sufficient for typing the communities for further in-depth analyses. The in-depth analyses provide additional important information which we contend is representative of all communities within the cluster.

Testing a Device to Exclude Ovigerous Blue Crabs, Callinectes sapidus, from Commercial Pots

North Carolina fishery managers are considering methods to offer greater protection to the blue crab, Callinectes sapidus, spawning stock while maintaining a viable commercial fishery for female blue crabs in high salinity estuaries. We tested how effectively wire rectangles, or excluders, of two internal sizes, 45x80 mm and 45x90 mm, would prevent entry of ovigerous female (sponge) crabs into pots relative to control pots (without excluders) while maintaining sizes and catch rates of male and nonsponged female hard crabs. Field sampling among three pot designs (two excluder sizes and control pots) was conducted in Core Sound, N.C., during 2004–06. Median sizes (carapace widths) of mature female crabs were not different among the three pot types. However, median sizes of male crabs and sponge crabs were greater in control pots than pots with either size of excluder. Catch rates of mature female crabs from control pots were greater than from pots with 45x85 mm excluders. Catch rates of legal male and sponge crabs from control pots were greater than from pots with either size of excluder. Results indicate that using excluders involves a tradeoff between reducing catches and sizes of sponge crabs while also reducing sizes and catches of legally harvestable nonsponge crabs; moreover, the reduction in total catch and sizes would be greater for legal male crabs than for legal nonsponged female crabs. In high salinity waters close to North Carolina’s existing no-harvest blue crab sanctuaries, where females typically dominate catches of hard crabs, the benefit of using excluders to prevent entry of sponge crabs may outweigh a potentially modest decrease in landings of nonsponged females.

A general framework for integrating environmental time series into stock assessment models: model description, simulation testing, and example

We present a method to integrate environmental time series into stock assessment models and to test the significance of correlations between population processes and the environmental time series. Parameters that relate the environmental time series to population processes are included in the stock assessment model, and likelihood ratio tests are used to determine if the parameters improve the fit to the data significantly. Two approaches are considered to integrate the environmental relationship. In the environmental model, the population dynamics process (e.g. recruitment) is proportional to the environmental variable, whereas in the environmental model with process error it is proportional to the environmental variable, but the model allows an additional temporal variation (process error) constrained by a log-normal distribution. The methods are tested by using simulation analysis and compared to the traditional method of correlating model estimates with environmental variables outside the estimation procedure. In the traditional method, the estimates of recruitment were provided by a model that allowed the recruitment only to have a temporal variation constrained by a log-normal distribution. We illustrate the methods by applying them to test the statistical significance of the correlation between sea-surface temperature (SST) and recruitment to the snapper (Pagrus auratus) stock in the Hauraki Gulf–Bay of Plenty, New Zealand. Simulation analyses indicated that the integrated approach with additional process error is superior to the traditional method of correlating model estimates with environmental variables outside the estimation procedure. The results suggest that, for the snapper stock, recruitment is positively correlated with SST at the time of spawning.

Sequential analysis for testing quality standard of fish ham and sausage

Fish sausages are finely ground fish flesh, either of a single species or mixed, homogenised with starch, sugar, fat, spices and preservatives, generally filled in cylindrical synthetic or natural casings and pasteurised. Similar products containing small pieces of quality fish and lard are termed "fish ham". They are highly relished products in Japan, annual consumption exceeding 2 lakh tones. Preliminary studies have shown that they can catch a lucrative market in our country. However, being a pasteurised product which is often consumed as such without any further cooking, strict quality control measures have to be enforced so as to avoid food poisoning hazards. Besides physical characteristics like absence of damages, pin-holes, curliness and air pockets as well as jelly strength, texture and flavour, chemical characteristics like pH and acid values, moisture, carbohydrate and fat contents and volatile bases have to be assessed. A very important test that has to be carried out along with the above, before passing a lot for free distribution is the bacteriological examination to avoid the presence of pathogenic organisms.