Traditional Collection Methods Research Articles

The Use of Mesocosms in Marine Oil Spill Ecological Research and Development

Abstract Introduction: The use of chemical and biological agents (e.g. dispersants and bioremediation agents, respectively), as well as certain physical oil removal techniques (e.g. high-pressure, hot-water applications to oiled shorelines) during oil spill response operations requires consideration both of the gross effectiveness of such oil removal/displacement techniques and of the ecological impact of the response technique. Accordingly, the intent of response technology optimization requires the identification of suitable response agents, their application strategies, determination of mass oil removal effectiveness, and efficient coordination of alternative response strategies with conventional measures, all compared with traditional mechanical collection methods and evaluation or relative response ecological impacts. These issues often need to be examined in an experimental setting in order to acquire information required to make more effective decisions during oil spill response and cleanup operations. Controlled field studies that are designed to identify optimal response and clean-up strategies, while valuable for realism, are expensive and often difficult to implement because of regulatory barriers (Reilly et al., 1994)). Conversely, results from small scale laboratory testing do not incorporate sufficient environmental realism (variables and scale) to permit confident predictions about real-world situations. However, bounded and partly enclosed outdoor experimental units, or 'mesocosms', can closely simulate natural aquatic environments (Odum, 1984). Such test systems provide a simulation of real-world exposure without the costs of a controlled-release field study. Mesocosms can serve to bridge the gap between large-scale field experiments, with their inherent control difficulties, laboratory experiments which can be statistically replicated but suffer from a lack of environmental realism (Rodgers et al., 1996). Mesocosms have strengths and weaknesses depending upon system design. Therefore, the type of ecological research to be conducted will dictate the choice of mesocosm design. The following discussion presents design requirements and scientific considerations for mesocosm simulations of marine environments impacted by oil spills. Two existing mesocosm systems for marine oil spill ecological research in both pelagic and nearshore environments are reviewed in some detail - the Marine Ecosystem Research Laboratory (MERL) in Narragansett, Rhode Island, and the Coastal Oil-Spill Simulation System (COSS), in Corpus Christi, Texas.

Reference Works from Selected Small Alternative Presses

Alternative presses, a subset of small presses, have hundreds of titles in print, many of substantial quality. Most of the titles are unknown to librarians and fall to be included in traditional collection development aids or methods. A few are worthwhile reference works. In this article, Anderson introduces 44 titles from 26 presses. The bibliography is arranged by press name with complete contact information. The introduction outlines why alternative press books fail to get recognized and why they should be taken seriously.

In situ and laboratory sediment toxicity testing with ceriodaphnia dubia

AbstractEcological assessments of sites containing hazardous wastes are improved by field testing. In situ exposures of Ceriodaphnia dubia were conducted in a stream impacted by several effluents, a combined sewer overflow and a creosote treatment operation. Sediments contained high levels of metals and polynuclear aromatic hydrocarbons. Fish and macroinvertebrate community indices were depressed. Ceriodaphnia dubia were placed in sediment exposure chambers in the stream for 48 h and also exposed to sediments that were simultaneously collected in the laboratory. Percent survival was generally higher in situ as compared to static laboratory exposures; however, overlying water toxicity was lower in laboratory assays. Average survival rates in elutriate fractions were slightly higher than interstitial or solid‐phase exposures, and filtration reduced both elutriate and interstitial fraction toxicity. In situ sediment exposures proved to be sensitive indicators of both degraded and nondegraded stream conditions. Results show traditional sample collection and laboratory toxicity test methods may alter the water and sediment toxicity that occurs in situ. This highlights the importance of laboratory validation and in situ testing in aquatic safety assessments.

The antarctic diatoms Thalassiosira dichotomica (Kozlova) comb. nov. and T. ambigua kozlova

Two small antarctic diatoms, usually missed by traditional collection methods, have been studied in light and electron microscopes. Porosira dichotomica has been transferred to Thalassiosira since its valve structure and process pattern agree better with that genus. T. dichotomica is unusual in that some lines of areola walls are extended, sail-like, out from the valve, supporting Kozlova's original drawings. T. ambigua, the smaller of the two, has many similarities in structure with T. dichotomica, but has granules on the margin, lacks the sail-like structures on the valve, and has minor differences in processes and areola size. Bands stay together in T. ambigua and show more fine structure than many species in the genus.

Trace metal determinations in blood obtained in evacuated collection tubes

Using atomic absorption spectrophotometry, we determined levels of iron, copper and zinc in serum or plasma samples collected in acid-washed containers and in commercially available evacuated tubes including one model equipped with rubber stoppers prepared by a process which reduces zinc contamination of the rubber. Serum or plasma from all evacuated tubes yielded iron and copper values which were comparable to those from serum obtained in acid-washed glass. Zinc values were higher from all evacuated tubes than from acid-washed glassware. Values obtained from samples collected in the specially-prepared tubes were 10% higher than values obtained from samples collected in acid-washed glassware. Thus, the specially-prepared evacuated tubes may only be useful in large-scale clinical screening studies. Traditional blood collection methods for zinc determination should be used when accuracy is required.