P. Calow

Fish energetics : new perspectives

Part I: Evolutionary aspects of energy budgets. Adaptive aspects of energy allocation - Peter Calow Metabolic scope in fishes - Imants G Priede Part II: Food and feeding. The application of optimal foraging theory to feeding behaviour in fish - Colin R Townsend and Ian J Winfield Energetics of feeding and digestion - T J Pandian and E Vivekanandan Laboratory methods in fish feeding and nutritional studies - Clive Talbot Protein and amino acid requirements - Albert G J Tacon and Colin B Cowey The hormonal control of metabolism and feeding - A J Matty and K P Lone Part III: Production. Growth - Malcolm Jobling Energetics of reproduction - Robert J Wootton Part IV: Energy budgets. Laboratory studies of energy budgets - Alan E Brafield Field studies of energy budgets - N M Soofiani and A D Hawkins Energetics and fish farming - Brian Knights Subject index. Systematic index.

Physiological costs of combating chemical toxicants: Ecological implications

1. Evidence is presented that combating the poisoning effects of toxic chemicals is metabolically costly. 2. This has implications for relating physiological stress responses observed at the level of individual organisms to population effects, and needs to be incorporated explicitly into models making this link. 3. The cost hypothesis also has implication for the evolution of stress resistance either as a fixed or facultative (inducible) response. Optimization models incorporating these ideas are reviewed and discussed.

The Daphnia bioassay: a critique

Daphnia magna is used widely as a standard ecotoxicological indicator organism, and protocols exist for its use in assessing the toxicity of substances under acute and chronic experimental conditions. Problems exist in repeatability of such bioassays between laboratories. Sources of variation are identified using a simple quantitative genetics model. Presenting specific examples, we conclude that these problems are tractable, but only if the genotype and culture conditions prior to and during tests are strictly controlled.

CONVERSION EFFICIENCIES IN HETEROTROPHIC ORGANISMS

1. The maximum possible efficiency at which living systems are able to convert input nutrients to their own biomass is between 70 and 80 %.

Species Sensitivity Distributions Revisited: A Critical Appraisal

We revisit the assumptions associated with the derivation and application of species sensitivity distributions (SSDs). Our questions are (1) Do SSDs clarify or obscure the setting of ecological effects thresholds for risk assessment? and (2) Do SSDs reduce or introduce uncertainty into risk assessment? Our conclusions are that if we could determine a community sensitivity distribution, this would provide a better estimate of an ecologically relevant effects threshold and therefore be an improvement for risk assessment. However, the distributions generated are typically based on haphazard collections of species and endpoints and by adjusting these to reflect more realistic trophic structures we show that effects thresholds can be shifted but in a direction and to an extent that is not predictable. Despite claims that the SSD approach uses all available data to assess effects, we demonstrate that in certain frequently used applications only a small fraction of the species going into the SSD determine the effects threshold. If the SSD approach is to lead to better risk assessments, improvements are needed in how the theory is put into practice. This requires careful definition of the risk assessment targets and of the species and endpoints selected for use in generating SSDs.

A Physiological Basis of Population Processes: Ecotoxicological Implications

Environmental toxicologists often want to use bioassays that can be carried out quickly, easily, and hence inexpensively on individual organisms, to make predictions about long-term impacts of toxicants at an ecological level (Maltby & Calow, 1990). More fundamentally, it is of interest for population dynamicists to understand to what extent processes within individuals, as compared with interactions between them, contribute to population changes (Metz & Diekmann, 1986). Here we explore models that provide the basis of links between physiological and population processes and point out some implications for the application of physiological bioassays in ecotoxicology.

A comparative study of genotype sensitivity to acute toxic stress using clones of Daphnia magna Straus

The genetic typing of laboratory strains of Daphnia magna revealed that although there are genetic differences between different testing laboratory strains, most laboratories culture single genotypes as clones. A comparative study was made of the performance of five of the more common clones in terms of neonate mortality under acute exposure to nine toxic chemicals. The range in clonal EC50 response was from less than one to more than two orders of magnitude in terms of concentration. Surprisingly, there was little pattern in rank order of response of clones exposed to different toxicants, thus suggesting that genotype-environment interactions were predominating. Nevertheless, it was suggested that specifying the genotype used in D. magna toxicity tests will result in increased test repeatability. Evidence indicating that culture environment may also significantly affect the performance of neonates in acute toxicity tests was also presented.

Ecology, Evolution and Energetics: A Study in Metabolic Adaptation

Publisher Summary This chapter discusses physiological adaptation in the organism. Organisms are treated as machines, energy transformers that are designed to work in a certain way and at certain levels of efficiency under particular ecological conditions. The concept of design is central to biological explanation and within this framework, this chapter discusses two general issues: the design criteria used in the evolution of metabolic machines and the various metabolic strategies important in the operation of these machines. The chapter discusses the way organisms work as energy transformers and the circumstances under which they transform energy and the reason they work in the way they do. In the first instance, one is concerned with the operation of organisms in ecosystems and only in a subsidiary way with the operation of organisms as part of ecosystem metabolism. The latter is, of course, the more usual problem and discusses “ecological energetic.”

Evaluating and monitoring the health of large-scale ecosystems

This is a comprehensive state-of-the-art review of approaches for evaluating and monitoring the health of large-scale ecosystems. The examples drawn from a range of large-scale systems - desert to marine - provide the reader with a clear understanding of the meaning and practical implications of the ecosystem health paradigm for integrated natural resource management. Further, tools and approaches for evaluating large-scale systems from the use of biomarkers to remote sensing are described in detail. The book is an invaluable source for environmental managers, scientists, students and institutions working in the fields of ecosystem evaluation and management.

A toxicologic and dermatologic assessment of cyclic and non-cyclic terpene alcohols when used as fragrance ingredients ☆

University of Missouri (Kansas City), c/o American Dermatology Associates, LLC, 6333 Long Avenue, Third Floor, Shawnee, KS 66216, USA Columbia University Medical Center, Department of Dermatology, 161 Fort Washington Avenue, New York, NY 10032, USA Malmo University Hospital, Department of Occupational and Environmental Dermatology, Sodra Forstadsgatan 101, Entrance 47, Malmo SE-20502, Sweden d Institute for Miliovurdering, Environmental Assessment Institute, Linnesgade 18, 1st Floor, Copenhagen 1361K, Denmark e Technical University of Munich, Institute for Toxicology and Environmental Hygiene, Hohenbachernstrasse 15-17, Freising-Weihenstephan D-85354, Germany Oregon Health Sciences University, Department of Dermatology L468, 3181 SW Sam Jackson Park Road, Portland, OR 97201-3098, USA Boston University School of Medicine, Department of Pathology and Laboratory Medicine, 715 Albany Street, L-804, Boston, MA 02118-2526, USA Hospital Cantonal Universitaire, Clinique et Policlinique de Dermatologie, 24, Rue Micheli-du-Crest, Geneve 14 1211, Switzerland Department of Pharmacology, University of Arizona, College of Medicine, 1501 North Campbell Avenue, P.O. Box 245050, Tucson, AZ 85724-5050, USA 3-27-1 Kaigamori, Aoba-ku, Sendai 981-0942, Japan