Long-Term Monitoring of Ecological Conditions In Gray’s Reef National Marine Sanctuary: Comparison of soft-bottom benthic assemblages and contaminant levels in sediments and biota in Spring 2000 and 2005

As part of an ongoing program of benthic sampling and related assessments of sediment quality at Gray’s Reef National Marine Sanctuary (GRNMS) off the coast of Georgia, a survey of soft-bottom benthic habitats was conducted in spring 2005 to characterize condition of macroinfaunal assemblages and levels of chemical contaminants in sediments and biota relative to a baseline survey carried out in spring 2000. Distribution and abundance of macrobenthos were related foremost to sediment type (median particle size, % gravel), which in turn varied according to bottom-habitat mesoscale features (e.g., association with live bottom versus flat or rippled sand areas). Overall abundance and diversity of soft-bottom benthic communities were similar between the two years, though dominance patterns and relative abundances of component species were less repeatable. Seasonal summer pulses of a few taxa (e.g., the bivalve Ervilia sp. A) observed in 2000 were not observed in 2005. Concentrations of chemical contaminants in sediments and biota, though detectable in both years, were consistently at low, background levels and no exceedances of sediment probable bioeffect levels or FDA action levels for edible fish or shellfish were observed. Near-bottom dissolved oxygen levels and organic-matter content of sediments also have remained within normal ranges. Highly diverse benthic assemblages were found in both years, supporting the premise that GRNMS serves as an important reservoir of marine biodiversity. A total of 353 taxa (219 identified to species) were collected during the spring 2005 survey. Cumulatively, 588 taxa (371 identified to species) have been recorded in the sanctuary from surveys in 2000, 2001, 2002, and 2005. Species Accumulation Curves indicate that the theoretical maximum should be in excess of 600 species. Results of this study will be of value in advancing strategic science and management goals for GRNMS, including characterization and long-term monitoring of sanctuary resources and processes, as well as supporting evolving interests in ecosystem-based management of the surrounding South Atlantic Bight (SAB) ecosystem. (PDF contains 46 pages)

Veränderungen der Farbe und thermischen Stabilität der Muskelproteine von Räucherforellen während der Kühllagerung

The aim of the investigation was to prove if different farming conditions like conventional and organical farming of rainbow trout may cause differences in quality which are detectable by physical methods such as colour measurement and differential scanning calorimetry. Colour measurement revealed remarkable differences in lightness. Smoked trouts originating from conventionally farmed fish were much lighter than those of organically farmed trouts. This difference in L* could already be found when colour measurements were taken on the raw material. However, during chilled storage differences were equalized. Redness and yellowness were not significantly influenced by farming and did not change remarkably during chill storage. Based on earlier investigations on changes in thermal stability caused by heating, DSC curves of smoked trout could be used to verify that the core temperature of smoked fish had reached at least 60 °C during hot smoking process. This temperature is demanded by the guidelines of the German Food Code. In the DSC curves only the actin peak was still visible. All other proteins were obviously denatured during the hot smoking. When DSC curves were taken from smoked trout after different durations of chilled storage it could be seen that the denaturation temperature of actin decreased almost linearly with progression of storage time.

Analyzing standard curves in the chemistry of waters used for aquaculture

A practical guide is given to help aquaculture researchers identify and correct common problems associated with the colorimetric analysis of water. Hints in making standard solutions, choosing standard concentrations for making a standard curve and making measurements are included. Various types of standard curves and some problems are outlined and details provided regarding the evaluation of standard curves.

Daily rainfall along the United States Pacific Coast appears to conform to a square-root normal probability distribution

EXTRACT (SEE PDF FOR FULL ABSTRACT): As part of a study of climatic influences on landslide initiation, a statistical analysis of long-term (>40 years) records of daily rainfall from 24 Pacific coastal stations, from San Diego to Cape Flattery, disclosed an unexpected result - the square root of the daily rainfall closely approximates a normal distribution function. ... This paper illustrates the use of the square-root-normal distribution to analyze variations in precipitation along the mainland United States Pacific Coast with examples of orographic enhancement, rain shadows, and increase in precipitation frequency with geographic latitude.

A comparative study on the embryonic development of gynogen, triploid, haploid and normal diploid embryos of stinging catfish, Heteropneustes fossilis

UV irradiation and cold shock were applied on the eggs of stinging catfish, Heteropneustes fossilis, to produce haploid,. gynogen and triploid embryos. A comparative account of the various features· of embryonic development in chromosomally manipulated groups viz. haploid, gynogen and triploid and non-manipulated normal diploid group of H fossilis has been discussed. A slow development and delayed hatching were observed in gynogen and triploid embryos compared to those in normal diploid (control) groups. Mass mortality was observed in all chromosomally manipulated groups particularly during the gastrulation stage. The hatchlings of the gynogen, triploid and normal diploid were similar in overall appearance.