Quantifying the response of marine species to physiochemical stressors at different levels of biological organisation

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Growth of Corophium volutator under laboratory conditions

Temperature-dependent growth is an important factor in the population model of Corophium volutator that was developed to translate responses in a 10-day acute bioassay to ecological consequences for the population. The growth rate, however, was estimated from old data, based on a Swedish population. Therefore, new growth rates are estimated herein from two experiments using Corophium volutator. To save time, a tool was developed to use image analysis to measure Corophium volutator. The experiments show that Corophium volutator has a low growth rate at low temperatures (5¿10°C). At higher temperatures no difference in growth rate between 15°C and 25°C was found. The growth rate from these experiments is comparable to data found in literature. A new relationship between temperature and individual growth was estimated, and incorporated into the Corophium population model. As the model also uses the same temperature relationship for reproduction, the modelled population growth rate at different temperatures changes as a result of the new data. The new growth rate and the updated temperature relationship result in reduced tolerance to external stressors, as previously predicted by the model

A weight-of-evidence approach to assessing the ecological impact of organotin pollution in Dutch marine brackish waters; combining risk prognosis and field monitoring using common periwinkles (Littorina littorea)

In the present study an integrated ecological risk assessment based on multiple lines of evidence (LOEs) was evaluated in order to better assess the risk from TBT in Dutch harbours and open coastal waters. On the basis of spatial distributions of measured tributyltin (TBT) concentrations in sediments and suspended matter, predictions of the intersex index (ISI) in Littorina littorea and the ecological risk expressed as the Potentially Affected Fraction (PAF) of species were made. The results were compared to actual ISI measurements and presence of L. littorea in the field. The PAF calculated on the basis of TBT levels for open coastal waters ranged from 4.2% to 15.3%; for harbours it ranged from 3.5% to 26.9%. Significant intersex levels were observed only in waters where the risk was calculated above 10% PAF. This study suggests that the absence of L. littorea from some harbours with high ecological risk values can be explained by high TBT concentrations. A call is made for the use of integrated approaches like weight-of-evidence (WOE) to help practitioners improve ecological risk assessment

Time and concentration dependency in the potentially affected fraction of species: the case of hydrogen peroxide treatment of ballast water

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Time and concentration dependency in the potentially affected fraction of species: the case of hydrogen peroxide treatment of ballast water

Transport of large volumes of ballast water contributes greatly to invasions of species. Hydrogen peroxide (H2O2) can be used as a disinfectant to prevent the spread of exotic species via ballast water. Instead of using environmental risk assessment techniques for protecting a certain fraction of the species from being affected, the present study aimed to apply these techniques to define treatment regimes of H2O2 and effectively eliminate as many species as possible. Based on time-dependent dose¿response curves for five marine species (Corophium volutator, Artemia salina, Brachionus plicatilis, Dunaliella teriolecta, and Skeletonema costatum), time-dependent species-sensitivity distributions (SSDs) were derived for different effect sizes. The present study showed that H2O2 can be used effectively to treat ballast water but that relatively high concentrations and long treatment durations are required to eliminate the vast majority of species in ballast water. The described toxicant effectiveness approach using SSDs also has other potential fields of application, including short-term application of biocides