Pharmacology, Toxicology and Environmental Health Commons^™

Ecology In A Cost-Benefit Society: The Issues, Valery E. Forbes, Peter Calow

Valery Forbes Publications

Is there a role for ecology in a cost-benefit society? As a prelude to a collection of papers arising from a conference on this theme held at Roskilde University in June 2004, this paper summarizes divergent approaches to public policy decision making. Whether based on strict cost-benefit analysis or wide-ranging discussion, we make the point that decisions need to be informed by an understanding of the causes behind environmental problems and their consequences, through impaired ecosystem services, on the economy. Taking this forward will require forums that bring ecologists, economists, and regulators into active and constructive dialogue.

Influence Of Biotransformation On Trophic Transfer Of The Pah, Fluoranthene, Annemette Palmqvist, Lene Juel Rasmussen, Valery E. Forbes

Valery Forbes Publications

The persistence of polycyclic aromatic hydrocarbons (PAHs) in marine sediments may be influenced by benthic invertebrate bioturbation. Through processes such as deposit-feeding and enhancement of microbial metabolic activity PAHs may be remobilized from the sediment compartment, and either transferred to organisms at higher trophic levels or to the overlying water column, both processes inevitably changing the bioavailability of the PAH. Accumulation of contaminants from one level in the food chain to the next depends on feeding rate and assimilation efficiency, two factors that basically vary with food quality and contaminant type. Though it is generally believed that pre-consumptive biotransformation will …

Effects On The Function Of Three Trophic Levels In Marine Plankton Communities Under Stress From The Antifouling Compound Zinc Pyrithione, M. Hjorth, I. Dahllöf, Valery E. Forbes

Valery Forbes Publications

This study aimed to investigate functional responses of natural marine planktonic communities to stress from the antifouling compound zinc pyrithione (ZPT). Isotope labelling techniques (¹⁴C) were applied to study bacterial incorporation of leucine, photosynthetic activity of phytoplankton and grazing of labelled prey by zooplankton communities for 6 days after exposures to nominal concentrations of 0, 5, 25, 50 nM ZPT in a mesocosm experiment in Isefjord, Denmark.

Significant direct effects were visible on chlorophyll α concentrations, which decreased in all exposed communities, to between 48 and 36% of control concentrations on Day 3, 1 day after the last …

Differences In Pah Tolerance Between Capitella Species: Underlying Biochemical Mechanisms, Lis Bach, Annemette Palmqvist, Lene Juel Rasmussen, Valery E. Forbes

Valery Forbes Publications

The polychaete Capitella capitata consists of a species complex within which differences in tolerance to tox­icants have been observed. For example, it has been shown that Capitella sp. S is more sensitive (e.g., in terms of survival, growth and reproduction) to PAH and other stressors than the more opportunistic Capi­tella sp. I, which is able to take up and biotransform the PAH fluoranthene (Flu). In the present study, an in­vestigation was performed to examine whether differences in tolerance between Capitella species sp. I and sp. S are due to differences in biotransformation, measured as the amount of Flu-metabolites produced by …

Joint Effects Of Population Density And Toxicant Exposure On Population Dynamics Of Capitella Sp. I, Valery E. Forbes, Richard M. Sibly, Inez Linke-Gamenick

Valery Forbes Publications

Very few studies have analyzed the dependence of population growth rate on population density, and even fewer have considered interaction effects of density and other stresses, such as exposure to toxic chemicals. Yet without such studies we cannot know whether chemicals harmful at low density have effects on carrying capacity or, conversely, whether chemicals reducing carrying capacity are also harmful at low density, impeding a population’s capacity to recover from disturbance. This study examines the combined effects of population density and a toxicant (fluoranthene) on population growth rate (pgr) and carrying capacity using the deposit-feeding polychaete Capitella sp. I as …

Uncertainties In Sediment Quality Weight-Of-Evidence (Woe) Assessments, Graeme E. Batley, G. Allen Burton, Peter M. Chapman, Valery E. Forbes

Valery Forbes Publications

Uncertainties in sediment quality assessments are discussed in five categories: (1) sediment sampling, transport and storage; (2) sediment chemistry; (3) ecotoxicology; (4) benthic community structure; and (5) data uncertainties and QA/QC. Three major exposure routes are considered: whole sediments, and waters in sediment pores and at the sediment-water interface. If these uncertainties are not recognized and addressed in the assessment process, then erroneous conclusions may result. Recommendations are provided for addressing the identified uncertainties in each of the key areas. The purpose of this paper is to improve the reporting of sediment quality assessments.

Toxicant Impacts On Density-Limited Populations: A Critical Review Of Theory, Practice, And Results, Valery E. Forbes, Richard M. Sibly, Peter Calow

Valery Forbes Publications

Most natural populations experience some density dependence, and longterm average rates of population growth are likely to be close to zero (i.e., steady state). An essential question, therefore, is how and to what extent do density-dependent effects influence the responses of populations to toxicant impacts? Here we consider three general types of interaction between density dependence and toxicant effects: additive, less than additive, and more than additive. If we know enough about the life-history dynamics of an organism and how its life-history traits are affected by density and toxicant exposure, we should be able to use life-history models to predict …

Effects Of Chronic Fluoranthene Exposure On Sibling Species Of Capitella With Different Development Modes, Inez Linke-Gamenick, Valery E. Forbes, Nuria Méndez

Valery Forbes Publications

Toxic effects of the polycyclic aromatic hydrocarbon fluoranthene (FLU) on life-history traits and their demographic consequences were investigated in 3 non-interbreeding Capitella sibling species with different physiological tolerances and developmental modes: sensitive Capitella sp. S from oxygen-rich intertidal sediments of the North Sea (Germany); tolerant Capitella sp. M from sediments near shallow hydrothermal vents off Milos (Greece), a habitat low in organic matter with steep abiotic gradients and high sulfide concentrations; tolerant Capitella sp. I from New York (USA), known to dominate eutrophicated/polluted environments. Both Capitella spp. M and I can develop into hermaphrodites and have lecithotrophic larval development. In …

Effects Of Fluoranthene And Ambient Oxygen Levels On Survival And Metabolism In Three Sibling Species Of Capitella (Polychaeta), Inez Linke-Gamenick, Bent Vismann, Valery E. Forbes

Valery Forbes Publications

The successful persistence of Capitella spp. in disturbed and/or oil-polluted habitats is widely known, but demographic adaptations might be only part of the explanation and little is known about differences among species. The present study investigates ecophysiological effects of the common PAH (polycyclic aromatic hydrocarbon) fluoranthene (FLU) on juvenile and adult survival, comparing 3 sibling species of Capitella (Polychaeta; Capitellidae). Subsequently, the influence of FLU on the aerobic and anaerobic metabolism in the most 'sensitive' species, Capitella sp. S, and most 'tolerant' species, Capitella sp. I, was assessed. Oxygen uptake and internal succinate concentration (an indicator of anaerobic metabolism) were …

Review Of Genes And The Environment By R. H. Burdon, Valery E. Forbes

Valery Forbes Publications

How diverse aspects of an organism’s environment influence the structure and function of its genes is of profound importance for understanding the molecular basis of evolution as well as the causes of disease, cancer and aging. Genes and the Environment addresses these issues from a molecular biological perspective. The author covers both natural environmental influences, such as extreme temperatures and water stress, as well as humancaused environmental influences, such as exposure to toxic chemicals. The author makes an effort to compare and contrast prokaryotic and eukaryotic systems and highlights distinctions between major groups of eukaryotes e.g., plants versus animals. to …

Density-Dependent Effects Of A Toxicant On Life-History Traits And Population Dynamics Of A Capitellid Polychaete, Inez Linke-Gamenick, Valery E. Forbes, Richard M. Sibly

Valery Forbes Publications

The toxic effects of the widespread polycyclic aromatic hydrocarbon (PAH), fluoranthene (FLU), on Life-history traits of Capitella sp. M as a function of population density were investigated in a life-table-response-experiment (LTRE) lasting 134 d. Animals from laboratory cultures were exposed to 6 different FLU concentrations (range 0 to 80 μg FLU [g dry wt sed]^–1, ppm) at 3 population densities (range 529 to 36 842 worms m^–2), and survivorship, growth rate until maturity, and reproductive parameters were recorded. Fluoranthene exposure significantly reduced juvenile survivorship in a concentration- dependent manner, whereas population density had no effect on …

Studying Stress In Ecological Systems: Implications For Ecological Risk Assessment And Risk Management, Valery E. Forbes

Valery Forbes Publications

In many of the world’s habitats abiotic stress is a key force controlling the distribution and abundance of species. As a result of human activities, the role of abiotic stress appears to be increasing in many areas in the form of habitat alteration or destruction, chemical contamination, and large-scale climatic shifts. An important scientific goal, therefore, is to develop approaches for assessing and predicting damage to ecological systems arising from abiotic stress. Moreover, determining how interactions between human-caused stresses and natural environmental stresses impact biological systems is an active area of research. This Invited Feature highlights some of the main …

Effects Of 4-N-Nonylphenol On Life-History Traits And Population Dynamics Of A Polychaete, Flemming T. Hansen, Valery E. Forbes, Thomas L. Forbes

Valery Forbes Publications

A Life-Table-Response Experiment lasting 78 d was performed to investigate the toxic effects of sediment-associated 4-n-nonylphenol (NP) on growth, reproduction, and survivorship of isolated hermaphrodites of the infaunal polychaete Capitella sp. I. Demographic effects were evaluated using both a fully age-classified and a simple twostage model to estimate population growth rates (λ). Decomposition analysis was performed to explore the contributions of each of the affected life-history traits to the effects observed on l. Elasticity analysis was applied to examine the relative sensitivity of λ to changes in each of the different life-history traits under different exposure levels.

In the lowest …

Toxicity And Toxicokinetics Of Cadmium In Capitella Sp. I: Relative Importance Of Water And Sediment As Routes Of Cadmium Uptake, Henriette Selck, Valery E. Forbes, Thomas L. Forbes

Valery Forbes Publications

The importance of dissolved versus sediment-bound cadmium as uptake routes for the deposit-feeding polychaete Capitella species I and the toxicity and toxicokinetics of cadmium from these exposure routes were investigated. Effects were reported as changes in worm growth rate, egestion rate and allometry. Radioactive cadmium (¹⁰⁹Cd) was used as a tracer to examine the uptake (5 d) and subsequent depuration (6 d) of cadmium. Both effects and kinetics were investigated in systems with and without sediment. Individual Capitella sp. I were exposed to (1) dissolved (i.e. –1). Worms in water-only treatments showed negative growth rates, which decreased linearly …

Particle Mixing By The Polychaete Capitella Species 1: Coupling Fate And Effect Of A Particle-Bound Organic Contaminant (Fluoranthene) In A Marine Sediment, Susanne D. Madsen, Thomas L. Forbes, Valery E. Forbes

Valery Forbes Publications

Particle mixing by the polychaete Capitella sp. 1 was investigated in a 22 d microcosm experiment in the presence and absence of the sediment-bound polycyclic aromatic hydrocarbon (PAH) fluoranthene. Mixing by Capitella sp. 1 (30000 ind. m^–2) was examined using glass bead tracers (diam. = 30 to 100 μm) with and without a pulse introduction of fluoranthene to the sediment surface. Worms had a profound effect on the sediment appearance and reworked sediment in a conveyor-belt fashion. The predominant mode of mixing was bioadvective, and the worms created a subsurface maximum in the glass bead tracer profiles. Glass …

Inducible Metabolism Of Fluoranthene By The Opportunistic Polychaete Capitella Sp. I, Valery E. Forbes, Thomas L. Forbes, Marianne Holmer

Valery Forbes Publications

The polychaete Capitella sp. I has been described as an enrichment opportunist and is one of very few species able to thrive in highly organic sediments heavily contaminated with polycyclic aromatic hydrocarbons (PAH) and other organic pollutants. We examined 3 plausible explanations for the success of Capitella sp. 1: (1) worms prevent uptake of PAH across body surfaces, (2) worms take up PAH but metabolize them effectively to excretable forms, and (3) worms utilize PAH as a carbon source. We examined the uptake and depuration of sediment-associated fluoranthene by Capitella sp. 1 and measured the metabolic loss of ingested 3-[ …

Changes In Feeding And Crawling Rates Of Hydrobia Truncata (Prosobranchia: Hydrobiidae) In Response To Sedimentary Chlorophyll-A And Recently Egested Sediment, Valery E. Forbes, Glenn R. Lopez

Valery Forbes Publications

Experiments combining fluorescent particle tracer techniques with time-lapse video recording demonstrated that the gastropod Hydrobia truncata decreases crawling rate on patches rich in chlorophyll-a, while maintaining a constant feeding rate as sedimentary chlorophyll-a content varies. In contrast, H. truncata decreases feeding rate but does not change crawling rate upon encounter with patches of recently egested sediment. Depression of feeding rate is less pronounced if the egested material is enriched in chlorophyll-a. For deposit feeders inhabiting highly reworked sediments, the majority of available material may consist of sediment that has been recently egested. For an animal that responds negatively to recently …