Immunodetection of planktonic algae

Interest in the identification and characterisation of cyanobacteria and dinoflagellates in aquatic environments is increasing rapidly due to the perceived roles of these organisms in primary production and nuisance aspects in terms of water treatment and public health. Techniques for the identification and quantification of these organisms currently are limited, and the application of molecular approaches provides fundamental taxonomic information and techniques of practical value. Antigenic properties of algal cells may be useful taxonomic markers. Immunodetection techniques utilise the specificity of the antibody/antigen association as a probe for recognising and distinguishing between microorganisms according to their cell- surface chemistry. Immunofluorescent detection of unicellular cyanobacteria and dinoflagellates has been studied with success in marine and freshwater ecosystems and a range of techniques and results are presented and discussed. The most recent advances in the study of planktonic algae have come with the application of continuous flow cytometric methods (CFC). Flow cytometry makes use of the autofluorescence properties of the algal cells, which alone can be used to demonstrate their presence and permit their quantification in natural water samples. When used in conjunction with immunolabelling techniques, the potential of CFC analysis is broadened to study the serological/strain composition of plankters in natural populations. Changes in algal strains represented within and between waters over periods of time are reported and discussed, along with the ecological issues thus raised.

The ionic composition of surface waters in the English Lake District, related to bedrock geology, with some singular facts and speculation on the existence of mineral-rich groundwaters

This article is based on a survey of tarns conducted mainly in the summers of 1983 to 1985, plus a survey made in the winter of 1985, in which streams were sampled on the wide variety of rock-types occurring on the fringes of the Lake District. Differences in composition of major ions and their concentrations in the surface waters of Cumbria reflect the complex geological structure of the region. At altitudes above 300 m, on Borrowdale Volcanics and Skiddaw Slates, surface waters are derived from atmospheric precipitation, with additional inputs of some ions - especially calcium and bicarbonate - from catchment rocks and soils. In some of the low-lying large lakes on the fringes of the central fells, water composition is also dominated by inputs from upper catchments; examples are Wastwater, Ullswater and Haweswater. However in other lakes there is evidence (Derwentwater and Bassenthwaite Lake) of inputs from saline groundwater.

Sea surface temperature and paleo-El Niño events in Santa Barbara Basin, AD 1841-1941

Like pages of a "natural coastal diary", successive layers of anoxic varved sediment in the central Santa Barbara Basin have been used by paleoceanographers to reconstruct aspects of past coastal climate. This report focuses on the end of the "Little Ice Age" (15th to 19th century) and on the beginning of this century, a period known to encompass extreme climate excursions and weather events in the Santa Barbara Basin and other parts of Southern California. El Niño events are known to disrupt Southern California's coastal ecosystems and to cause anomalous weather conditions, but El Niño events in Southern California before 1990 have been largely undocumented.

Arabian Sea sub-surface salinity minima (ASSM)

This paper presents the results of the study on the Arabian Sea sub-surface salinity minima (ASSM). The data collected under the North Arabian Sea Environment and Ecosystem Research (NASEER) programme and World Ocean Circulation Experiment (WOCE) has been used in the study. Study of the Arabian Sea water masses is most significant in understanding marine productivity and monsoonal reversal features. Analysis of the data shows that the Arabian Sea sub-surface salinity minima (ASSM) can be found between 25.8 to 26.0 Sigma Theta surfaces. ASSM originates from the south and south east. It is inferred from the results that the salt content of the ASSM varies during different seasons. Appreciable mixing of Arabian Sea salinity minima is observed over Murray Ridge.