COAL ASH BASIN EFFECTS (PARTICULATES,METALS, ACIDIC pH) UPON AQUATIC BIOTA: AN EIGHT-YEAR EVALUATION1

ABSTRACT Coal ash effluent effects including particulates, acidic pH excursions, elemental concentrations and bioconcentration in selected organisms have been studied as changes in water quality and densities of benthic macroinvertebrate and mosquitofish (Gambusia affinis) populations in a swamp drainage system over an eight-year period. Three changes in the ash basin settling system were made between mid- 1973 and January 1982. Initial density of the aquatic biota was altered severely by heavy ash siltation, followed by acidic pH excursions and perhaps overall by elemental concentrations and bioaccumulation. Heavy ash siltation, followed by acidic Ph excursions (mean of 5.5, extreme of 3.5) after the addition of fly ash to the original settling basin system, had the most profound effect on biota. Dipterans (chironomids) and some odonates (Plathemis lydia and Libellula spp.) were resistant to heavy ash siltation, while mosquitofish, which showed no discernible responses to ash siltation, were absent at acidic pH, along with the few previously surviving invertebrate populations. Elemental concentrations of arsenic, cadmium, chromium, copper, selenium, and zinc did not appear to limit aquatic flora and fauna on a short-term, acute basis. Long, chronic elemental exposures may have been instrumental in retarding the recovery of all forms of aquatic life in the receiving system. Elemental concentrations (except for arsenic and selenium) in the receiving system were generally one to two orders of magnitude higher than the Water Quality Criteria set by the U.S. Environmental Protection Agency (1980) for protection of aquatic life for the minimum and 24-hour mean values. From collective elemental exposures in the receiving system, bioconcentration factors in macrophytes, invertebrates and fish were generally lower than those reported in the literature for laboratory, single elemental concentrations. By 1978, when the new settling basin systems were operating effectively, invertebrate populations were largely recovered, and mosquitofish populations recovered within one year afterward.     

Amphimixis and the individual in evolving populations: does Weismann’s Doctrine apply to all,most or a few organisms?

The German biologist August Weismann (1834–1914) proposed that amphimixis (sexual reproduction) creates variability for natural selection to act upon, and hence he became one of the founders of the Neo-Darwinian theory of biological evolution. He is perhaps best known for what is called “Weismann’s Doctrine” or “Weismann’s Barrier” (i.e. the irreversible separation of somatic and germ cell functionalities early during ontogeny in multicellular organisms). This concept provided an unassailable argument against “soft inheritance” sensu Lamarck and informed subsequent theorists that the only “individual” in the context of evolution is the mature, reproductive organism. Herein, we review representative model organisms whose embryology conforms to Weismann’s Doctrine (e.g. flies and mammals) and those that do not (e.g. freshwater hydroids and plants) based on this survey and the Five Kingdoms of Life scheme; we point out that most species (notably bacteria, fungi, protists and plants) are “non-Weismannian” in ways that make a canonical definition of the “individual” problematic if not impossible. We also review critical life history functional traits that allow us to create a matrix of all theoretically conceivable life cycles (for eukaryotic algae, embryophytes, fungi and animals), which permits us to establish where this scheme Weismann’s Doctrine holds true and where it does not. In addition, we argue that bacteria, the dominant organisms of the biosphere, exist in super-cellular biofilms but rarely as single (planktonic) microbes. Our analysis attempts to show that competition among genomic variants in cell lineages played a critical part in the evolution of multicellularity and life cycle diversity. This feature was largely ignored during the formulation of the synthetic theory of biological evolution and its subsequent elaborations.     

Environmental cross-compliance mitigates nitrogen and phosphorus pollution from Swiss agriculture

In 1993 the Swiss agricultural policy was revised with – amongst other goals – the objective of improving the environmental performance of agriculture. A voluntary agri-environmental scheme to promote integrated production (IP) was introduced. In 1999 the IP standards were integrated in cross compliance requirements and termed Proof of Ecological Performance (PEP). We evaluated the effectiveness of this policy in terms of reducing diffuse nitrogen (N) and phosphorus (P) pollution of ground and surface water. We combined monitoring schemes covering the reference period from before the introduction of IP/PEP (1990–1992) with the evaluation of cause/effect relationships in selected case-study areas. The evaluation showed an overall reduction of diffuse N and P pollution from agriculture even though some goals were not reached. Nitrate leaching declined, but only a 3–4 mg L⁻¹ reduction was observed rather than the intended decrease of 5 mg L⁻¹. The P pollution of surface waters from agriculture decreased by only 10–30% instead of 50%. The intended reduction of the nitrogen surplus of Swiss agriculture by 33% was not attained, but the P surplus of Swiss agriculture was more than halved. IP/PEP practices that improved N and P management included reduced N and P fertiliser inputs and pig and poultry feedstuffs with reduced N and P contents, both of which are a consequence of the requirement of equilibrated farm nutrient balances, as well as increased use of cover cropping and of conservation tillage systems.