J.E. Tamis

Development and application of a species sensitivity distribution for temperature-induced mortality in the aquatic environment

Current European legislation has static water quality objectives for temperature effects, based on the most sensitive species. In the present study a species sensitivity distribution (SSD) for elevated temperatures is developed on the basis of temperature sensitivity data (mortality) of 50 aquatic species. The SSD applies to risk assessment of heat discharges that are localized in space or time. As collected median lethal temperatures (LT50 values) for different species depend on the acclimation temperature, the SSD is also a function of the acclimation temperature. Data from a thermal discharge in The Netherlands are used to show the applicability of the developed SSD in environmental risk assessment. Although restrictions exist in the application of the developed SSD, it is concluded that the SSD approach can be applied to assess the effects of elevated temperature. Application of the concept of SSD to temperature changes allows harmonization of environmental risk assessment for stressors in the aquatic environment. When a synchronization of the assessment methods is achieved, the steps to integration of risks from toxic and nontoxic stressors can be made.

Rational application of chemicals in response to oil spills may reduce environmental damage.

Oil spills, for example those due to tanker collisions and groundings or platform accidents, can have huge adverse impacts on marine systems. The impact of an oil spill at sea depends on a number of factors, such as spill volume, type of oil spilled, weather conditions, and proximity to environmentally, economically, or socially sensitive areas. Oil spilled at sea threatens marine organisms, whole ecosystems, and economic resources in the immediate vicinity, such as fisheries, aquaculture, recreation, and tourism. Adequate response to any oil spill to minimize damage is therefore of great importance. The common response to an oil spill is to remove all visible oil from the water surface, either mechanically or by using chemicals to disperse the oil into the water column to biodegrade. This is not always the most suitable response to an oil spill, as the chemical application itself may also have adverse effects, or no response may be needed. In this article we discuss advantages and disadvantages of using chemical treatments to reduce the impact of an oil spill in relation to the conditions of the spill. The main characteristics of chemical treatment agents are discussed and presented within the context of a basic decision support scheme.

Towards quantitative ecological risk assessment of elevated carbon dioxide levels in the marine environment

The environmental impact of elevated carbon dioxide (CO2) levels has become of more interest in recent years. This, in relation to globally rising CO2 levels and related considerations of geological CO2 storage as a mitigating measure. In the present study effect data from literature were collected in order to conduct a marine ecological risk assessment of elevated CO2 levels, using a Species Sensitivity Distribution (SSD). It became evident that information currently available from the literature is mostly insufficient for such a quantitative approach. Most studies focus on effects of expected future CO2 levels, testing only one or two elevated concentrations. A full dose-response relationship, a uniform measure of exposure, and standardized test protocols are essential for conducting a proper quantitative risk assessment of elevated CO2 levels. Improvements are proposed to make future tests more valuable and usable for quantitative risk assessment.

Estimating the impact of petroleum substances on survival in early life stages of cod (Gadus morhua) using the dynamic energy budget theory.

To estimate the impact of accidental oil-spills on cod fisheries a model framework is developed in which a Dynamic Energy Budget (DEB) model is applied to assess mortality caused by petroleum substances in early life stages. In this paper we report on a literature search and DEB analyses, aiming for cod specific DEB-parameters. Furthermore, we explored the relevance of Fathead minnow DEB-parameters as surrogate by comparing LC50 values calculated from DEB-parameters with literature. Cod specific DEB-parameters could not be estimated based on available literature. LC50 values calculated from Fathead minnow DEB-parameters were higher than literature LC50 for early life stages of fish. Applying an extrapolation factor of 50 to the DEB-parameters resulted in LC50 values that were below literature irrespective of life stage. Therefore, we propose to use the last as an estimate for early life stages in cod and recommend relevant experiments with individual petroleum substances on cod.

Kwetsbare soorten voor energie-infrastructuur in Nederland : overzicht van effecten van hernieuwbare energie-infrastructuur en hoogspanningslijnen op de kwetsbare soorten vogels, vleermuizen, zeezoogdieren en vissen, en oplossingsrichtingen voor een natuurinclusieve energietransitie

De cumulatieve impact van energie-infrastructuur kan een belangrijke rol spelen bij de populatieontwikkeling van kwetsbare soorten door sterfte en habitatverlies als gevolg van aanvaringen met die energie-infrastructuur of het verstorende effect van dergelijke infrastructuur. In dit rapport wordt een zo actueel en volledig mogelijk overzicht gegeven van de staat van kennis en de relatieve kwetsbaarheid van vogels, vleermuizen, zeezoogdieren en vissen in relatie tot de impact van windturbines, hoogspanningslijn en, waterkrachtcentrales en zonnepaneelvelden. Voor deze soortgroepen en energie-infrastructuur worden de kwetsbare soorten gerangschikt op basis van hun kwetsbaarheid en wordt inzichtelijk gemaakt waar de verspreiding van de kwetsbaarste soorten overlapt met de energie-infrastructuur. We evalueren hoe de cumulatieve impact van energie-infrastructuur op de soortgroepen gekwantificeerd kan worden nu en in de toekomst, en hoe die impact zich verhoudt tot andere antropogene drukfactoren voor de kwetsbaarste soorten. We bespreken mitigatie- en compensatiemaatregelen die in potentie kunnen voorkomen dat Nederlandse populaties van soorten afnemen als gevolg van de huidige en toekomstige energie-infrastructuur op zee en op land. Tot slot worden suggesties gedaan voor het opvullen van de belangrijkste kennishiaten en oplossingsrichtingen die het mogelijk maken de effecten op kwetsbare soorten bij de verdere groei van energie-infrastructuur op land en op zee te minimaliseren.

How including ecological realism impacts the assessment of the environmental effect of oil spills at the population level: The application of matrix models for Arctic Calanus species

For oil spill responses, assessment of the potential environmental exposure and impacts of a spill is crucial. Due to a lack of chronic toxicity data, acute data is used together with precautionary assumptions. The effect on the Arctic keystone (copepod) species Calanus hyperboreus and Calanus glacialis populations is compared using two approaches: a precautionary approach where all exposed individuals die above a defined threshold concentration and a refined (full-dose-response) approach. For this purpose a matrix population model parameterised with data from the literature is used. Population effects of continuous exposures with varying durations were modelled on a range of concentrations. Just above the chronic No Observed Effect Concentration (which is field relevant) the estimated population recovery duration of the precautionary approach was more than 300 times that of the refined approach. With increasing exposure concentration and duration, the effect in the refined approach converges to the maximum effect assumed in the precautionary approach.