Meristic variation in Sebastes (Scorpaenidae), with an analysis of character association and bilateral pattern and their significance in species separation

This report presents meristic data for nearly all of the known species of Sebasles. Rudimentary caudal ray counts tend to be higher in more active species. The number of caudal rays supported by the hypurals is consistently 14, whereas the number of branched caudal rays varies between 11 and 13. Vertebral counts and most fin-ray counts tend to be lower in species or populations in warmer latitudes, except for pectoral ray counts which tend to have an opposite geographic pattern. On the basis of the small magnitude of meristic and morphometric differences and the lack of other differences between northern and southern samples of "Sebasles caurinus," Sebaslichlhys vexillaris Jordan and Gilbert is regarded as a junior synonym of Sebasles caurinus Richardson. The patterns of bilateral variation in paired meristics are analyzed and their mechanism discussed. The frequency distribution of pectoral ray counts in their right-left combination is shown to be useful in species separation. No association was found between any combination of two meristic features in any species. The author proposes that intrasample associations between meristic features are evidence of sampling heterogeneity. (PDF file contains 21 pages.)

Ground water-surface water interactions sensor technology, Savannah, Georgia, March 7-9, 2005: workshop proceedings

The Alliance for Coastal Technologies (ACT) held a Workshop on Sensor Technology for Assessing Groundwater-Surface Water Interactions in the Coastal Zone on March 7 to 9,2005 in Savannah, GA. The main goal of the workshop was to summarize the general parameters, which have been found to be useful in assessing groundwater-surface water (GW-SW) interactions in the coastal zone. The workshop participants (Appendix I) were specifically charged with identifying the types of sensor systems, if any, that have been used to obtain time-series data and to make known which parameters may be the most amenable to the development/application of sensor technology. The group consisted of researchers, industry representatives, and environmental managers. Four general recommendations were made: 1. Educate coastal managers and agencies on the importance of GW-SW interactions, keeping in mind that regulatory agencies are driven by a different set of rules than researchers: the focus is on understanding the significance of the problem and providing solutions. ACT could facilitate this process in two ways. First, given that the research literature on this subject is fairly diffuse, ACT could provide links from its web site to fact sheets or other literature. Second, ACT could organize a focused meeting for managers and/or agency groups. Encourage development of primary tools for quantifying flow. The most promising technology in this respect is flow meters designed for flux chambers, mainly because they should be simple to use and can be made relatively inexpensively. However, it should be kept in mind that they provide only point measurements and several would need to be deployed as a network in order to obtain reliable flow estimates. For evaluating system wide GW-SW interactions, tools that integrate the signal over large areas would be required. Suggestions include a user-friendly hydrogeologic models, keeping in mind that freshwater flow is not the entire story, or continuous radon monitors. Though the latter would be slightly more difficult to use in terms of background knowledge, such an instrument would be low power and easy to operate and maintain. ACT could facilitate this recommendation by identifying funding opportunities on its web site and/or performing evaluations of existing technologies that could be summarized on the web site. (pdf contains 18 pages)

The significance of fish handling, preservation and processing in the development of Nigeria inland fishery with special reference to Kainji Lake

The traditional approach to fish handling, preservation and processing technology in inland fishery is critically examined using the experience in Kainji Lake as a model. The need to uplift the fishermen technology is emphasized with the ultimate expectations of improvement in fish quality

Structure of the limbs and its significance for the ecology and systematics of the family Chydoridae. [Translation of: Voprosy Gidrobiologii, p385, 1965]

For an explanation of the dynamics of numbers of chydorids, appearing a massive group in the littoral of fresh water bodies, the structure of the limbs of 29 species was studied.

Significance of the photoperiod for the development of Cyclops vicinus. [Translation from: Zoologischer Anzeiger Supplementband 33, 190-195, 1969.]

The significance of the photoperiod, a well-known phenomenon with arthropods, for the development of Cyclops vicinus were studied in laboratory conditions. There are indications that the point of the development process (development of the eggs and proportion of sexes) can be influenced through the photoperiod.

Ecological significance of seasonal variation in clutch-size of Arctodiaptomus bacillifer in alpine lakes of high altitudes (Val Bognanco) [Translation from: Bollettino di Zoologia 37 491-492, 1970]

This brief paper describes the significance of seasonal variation in clutch-size of the copepod Arctodiaptomus bacillifer in alpine lakes of high altitudes (Val Bognanco). Seasonal dynamics of the zooplankton of these lakes was studied during summer and autumn of 1968 and 1969and results are summarised.

The significance of sedimentation and sediments to phytoplankton growth in drinking-water reservoirs

In the mesotrophic-eutrophic Saidenbach Reservoir in Saxony, the nanoplankton and cyanobacteria have increased at the expense of diatom dominance, due to a doubling of the external phosphorus load in the last 15 years. However, the phosphorus sedimentation flux is still very high (up to 80% of the input), corresponding to more than 2 g m2 d-1 in terms of dry weight. There is a strong correlation between the abundance of diatoms in the euphotic zone and their sedimentation flux (with a delay of about 2 weeks). Only about 25% of the deposited material could be clearly attributed to plankton biomass; the remainder resulted from flocculation and precipitation processes or directly from the inflow of clay minerals. The ash content of the deposited material was high (73%). Thus the sedimentation flux can be considered to operate as an internal water-treatment/oligotrophication process within the lake. The neighbouring Neunzehnhain Reservoir still has a very clear water with a transparency up to 18 m depth. Though the sediment was not much lower than Saidenbach sediment in total phosphorus and total numbers of bacteria, sulphide was always absent and the ratio of Fe 2+ to Fe 3+ was very low in the upper (0- 5 cm) layer. Thus the external and internal phosphorus loads do not attain the critical level necessary to induce a ”phosphorus - phytoplankton” feedback loop.

The health significance of heterotrophic bacteria in drinking water

Tap water is not sterile; it contains organisms which grow in water distribution systems or inside taps and their fittings. The absence of known pathogenic bacteria is assured by the absence of the indicator organisms but concerns have been raised in the past few years that drinking water fulfilling the standards laid down in the EC Directive ECC 80/778 may still cause disease. These concerns have arisen from several sources: the fact that a cause has been identified in only half of all suspected waterborne outbreaks of disease; reports have suggested that heterotrophic bacteria possessing single pathogenic mechanisms such as haemolysin may cause disease; reports of heterotrophic organisms causing water contact diseases in hospitals. These concerns led to a reappraisal of the pathogenic potential of heteretrophic bacteria, by carrying out an extensive literature search and review commissioned by the UK Water Research Company. This research identified many papers showing an association between drinking water and heterotrophic bacteria but only very few reports of suspected waterborne disease associated with the heterotrophs. The organisms demonstrating potential to cause disease were species of Aeromonas and Yersinia, but typing of organisms identified in patients and isolated from the water revealed very few similarities. The potential of Aeromonas and Yersinia to cause waterborne disease is thought to be very low and the Communicable Disease Surveillance Centre database of laboratory infections due to these two genera of organisms was analysed to produce population-related incidences for each health region in England and Wales. Additionally a laboratory questionnaire revealed different levels of ascertainment of these two organisms in different laboratories of the Public Health Laboratory Service.

The significance of scale patterns and scale readings in the life history and habits of the salmon

This brief reports highlights the significance of scale readings of salmon. The reasons for colour change of scales and scale rings are briefly explained. Scale readings of salmon fry from the River Lune in the north west of England are presented. The salmon was captured in 1957/58.

Zooplankton: its biochemistry and significance in aquaculture

Zooplankton are an important food source for many species of fish. They can provide an inexpensive alternative to other commercial feeds. Zooplankton have several advantages, among them a faster growth and greater feed efficiency for some species. The flavor and texture of fish are also improved with zooplankton as feed. Further research is needed on the chemical composition of zooplankton, the development of zooplankton-based dry diets and the effects of the replacement of fish meal with zooplankton meal for commercial aquaculture species.

Resilient livelihoods and food security in coastal aquatic agricultural systems: Investing in transformational change

Aquatic agricultural systems (AAS) are diverse production and livelihood systems where families cultivate a range of crops, raise livestock, farm or catch fish, gather fruits and other tree crops, and harness natural resources such as timber, reeds, and wildlife. Aquatic agricultural systems occur along freshwater floodplains, coastal deltas, and inshore marine waters, and are characterized by dependence on seasonal changes in productivity, driven by seasonal variation in rainfall, river flow, and/or coastal and marine processes. Despite this natural productivity, the farming, fishing, and herding communities who live in these systems are among the poorest and most vulnerable in their countries and regions. This report provides an overview of the scale and scope of development challenges in coastal aquatic agricultural systems, their significance for poor and vulnerable communities, and the opportunities for partnership and investment that support efforts of these communities to secure resilient livelihoods in the face of multiple risks.