The performance of procedures for selecting conservation areas: waterbirds in the UK

In recent years, much attention has been directed to the ways in which the most important areas for inclusion in reserve networks can be identified, and the most effective ways in which existing networks can be expanded. In contrast, rather little attention has been paid to the present and likely future performance of the approaches that have actually been employed. Using Wetland Bird Survey data, the effectiveness of the current Special Protection Area (SPA) network in the UK was assessed by comparing annual counts for 17 species of migratory waterbird on SPAs with the numbers supported by hypothetical site networks selected by five alternative site-selection methods. These analyses suggest that focusing on complementarity between component sites rather than applying criteria to each site individually improved the level of representation for each species, conserved a greater percentage of the national total across the 17 species and was robust over time.     

Numbers of wintering waterbirds in Great Britain, 1994/1995-1998/1999: I. Wildfowl and selected waterbirds

Estimates of the number of waterbirds (principally wildfowl) wintering in Great Britain are presented, based on data from the period 1994/1995-1998/1999. These update the previous estimates for 1987/1988-1991/1992. National estimates are used to derive 1% thresholds for waterbird species which in turn form the basis for the identification of nationally important wetland sites for subsequent conservation and protection. Estimates are also used to assess changes in numbers of those species for which monitoring data are insufficient to calculate annual indices of population change. Data for calculating the estimates come from a variety of sources including the Wetland Bird Survey (WeBS, a long-term scheme which counts waterbirds by day at wetlands), goose roost censuses, site-based surveys and published reviews. Generation of the estimates is made difficult by a number of methodological and data quality issues. To account for some of the methodological problems affecting WeBS data, new methods for generating estimates have been used which account for birds missed during the counts in a more comprehensive manner. These result in large increases in the estimated numbers for many of the relevant species, although most are still considered to be underestimates. To assess the biological change in numbers since the last assessment, estimates generated from the same methods used previously are also presented. These indicate that while the majority of species have experienced increases in numbers since the late 1980s there have been some notable declines. There is however scope for improving the accuracy of estimates derived from extensive, volunteer-based monitoring schemes such as WeBS.     

Genetically encoded sensors for ions and metabolites

Many of the genes encoding important trans porters and metabolic enzymes have been identified over the last ten years. Moreover it has been possible to study the biochemical properties of the corresponding proteins in great detail. It is expected that by 2,010 biochemical functions will have been assigned to many of the products of the approximately 30,000 Arabidopsis genes. We will get closer to understanding the biological function of the gene products by systematic analysis of mutants using knock-out and TILLING approaches. Metabolomics initiatives complement these approaches by providing insight into the changes in cellular ion and metabolite profiles in the mutants, thus giving information essential for the construction of cellular and whole plant models. However, one important dataset especially relevant to multicellular organisms is lacking: the knowledge of the spatial and temporal profiles of ions and metabolite levels at cellular and subcell ular levels. To address this issue, we have developed protein-based nanosensors for several metabolites, providing a set of tools for the determination of cytosolic and subcellular ion (e.g. iron and zinc) and metabolite levels in real time using fluorescence-based microscopy. The prototypes of these sensors were shown to function in vitro and also in vivo, i.e. in yeast and in mammalian cell cultures. One future goal is to expand the set of sensors to a wider spectrum of targets by using the natural spectrum of periplasmic binding proteins from bacteria and by computational design of proteins with altered binding pockets. Application of nanosensor technology to plant cells and tissues will help to elucidate the special and temporal distribution of ions and metabolites.     

Evaluation of the Ciliated Protozoa,Fabrea salina as a First Food for Larval Red Snapper,Lutjanus campechanus in a Large Scale Rearing Experiment

ABSTRACT

One of the major challenges of culturing of red snapper, Lutjanus campechanus, is providing an appropriate food source at onset of feeding. Ciliates are abundant in marine waters but their significance as a first food for fish larvae is poorly understood as many have no lorica to facilitate their identification in the gut of a larval fish. Fabrea salina is a naked heterotrich ciliate that can be mass cultured at densities up to 84 ± 10 ciliates/mL in 7 days. Its appropriateness as a first food for red snapper larvae was evaluated in a green-water setting using 1-m³ tanks. Larvae were stocked at 10/L, 36 h post-hatch, before first-feeding commenced. Larvae were fed either (1) copepod nauplii, 20–75 μm, only from days 1 to 10; (2) copepod nauplii from days 1 to 10 plus F. salina from days 1 to 5; or, (3) F. salina only from days 1 to 3 plus copepod nauplii from days 4 to 10. Copepod nauplii were added at 2/mL and ciliates were added at 5/mL. Survival after 28 days was 0.28 ± 0.15% for larvae given only copepod nauplii and 2.39 ± 2.75% for those given F. salina and copepod nauplii. Larvae given only F. salina did not survive past 4 days post-stocking. Larvae were more actively feeding in the tanks given F. salina and copepods as first foods with 34.6 ± 8.5% mean daily reduction in copepod nauplii compared to 15.8 ± 16.2% reduction when only nauplii were provided.     

Adsorption and degradation of four acidic herbicides in soils from southern Spain

BACKGROUND: Pesticide degradation and adsorption in soils are key processes determining whether pesticide use will have any impact on environmental quality. Pesticide degradation in soil generally results in a reduction in toxicity, but some pesticides have breakdown products that are more toxic than the parent compound. Adsorption to soil particles ensures that herbicide is retained in the place where its biological activity is expressed and also determines potential for transportation away from the site of action. Degradation and adsorption are complex processes, and shortcomings in understanding them still restrict the ability to predict the fate and behaviour of ionisable pesticides. This paper reports the sorption and degradation behaviour of four acidic pesticides in five soils from southern Spain. Results are used to investigate the influence of soil and pesticide properties on adsorption and degradation as well as the potential link between the two processes. RESULTS: Adsorption and degradation of four acidic pesticides were measured in four soils from Spain characterised by small organic matter (OM) contents (0.3-1.0%) and varying clay contents (3-66%). In general, sorption increased in the order dicamba < metsulfuron-methyl < 2,4-D < flupyrsulfuron-methyl-sodium. Both OM and clay content were found to be important in determining adsorption, but relative differences in clay content between soils were much larger than those in OM content, and therefore clay content was the main property determining the extent of herbicide adsorption for these soils. pH was negatively correlated with adsorption for all compounds apart from metsulfuron-methyl. A clear positive correlation was observed for degradation rate with clay and OM content (P < 0.01), and a negative correlation was observed with pH (P < 0.01). The exception was metsulfuron-methyl, for which degradation was found to be significantly correlated only with soil bioactivity (P < 0.05). CONCLUSIONS: Both OM and clay content were found to be important in determining adsorption, but relative differences in clay content between soils were much larger than those in OM content, and therefore clay content was the main property determining the extent of herbicide adsorption for soils of this type. pH was negatively correlated with adsorption for all compounds apart from metsulfuron-methyl. The contrasting behaviour shown for these four acidic pesticides indicates that chemical degradation in soil is more difficult to predict than adsorption. Most of the variables measured were interrelated, and different behaviours were observed even for compounds from the same chemical class and with similar structures.