Harris C.A.,Brunel University |
Scott A.P.,CEFAS Weymouth Laboratory |
Johnson A.C.,CEH |
Panter G.H.,Astra Zeneca Brixham Environmental Laboratory |
And 3 more authors.
Environmental Science and Technology | Year: 2014
We have become progressively more concerned about the quality of some published ecotoxicology research. Others have also expressed concern. It is not uncommon for basic, but extremely important, factors to apparently be ignored. For example, exposure concentrations in laboratory experiments are sometimes not measured, and hence there is no evidence that the test organisms were actually exposed to the test substance, let alone at the stated concentrations. To try to improve the quality of ecotoxicology research, we suggest 12 basic principles that should be considered, not at the point of publication of the results, but during the experimental design. These principles range from carefully considering essential aspects of experimental design through to accurately defining the exposure, as well as unbiased analysis and reporting of the results. Although not all principles will apply to all studies, we offer these principles in the hope that they will improve the quality of the science that is available to regulators. Science is an evidence-based discipline and it is important that we and the regulators can trust the evidence presented to us. Significant resources often have to be devoted to refuting the results of poor research when those resources could be utilized more effectively. © 2014 American Chemical Society.
Llope M.,University of Oslo |
Llope M.,Spanish Institute of Oceanography |
Daskalov G.M.,CEFAS Lowestoft Laboratory |
Daskalov G.M.,Bulgarian Academy of Science |
And 7 more authors.
Global Change Biology | Year: 2011
It is well known that human activities, such as harvesting, have had major direct effects on marine ecosystems. However, it is far less acknowledged that human activities in the surroundings might have important effects on marine systems. There is growing evidence suggesting that major reorganization (i.e., a regime shift) is a common feature in the temporal evolution of a marine system. Here we show, and quantify, the interaction of human activities (nutrient upload) with a favourable climate (run-off) and its contribution to the eutrophication of the Black Sea in the 1980s. Based on virtual analysis of the bottom-up (eutrophication) vs. top-down (trophic cascades) effects, we found that an earlier onset of eutrophication could have counteracted the restructuring of the trophic regulation at the base of the food web that resulted from the depletion of top predators in the 1970s. These enhanced bottom-up effects would, however, not propagate upwards in the food web beyond the zooplankton level. Our simulations identified the removal of apex predators as a key element in terms of loss of resilience that inevitably leads to a reorganization. Once the food web has been truncated, the type and magnitude of interventions on the group replacing the apex predator as the new upper trophic level have no effect in preventing the trophic cascade. By characterizing the tipping point at which increased bottom-up forcing exactly counteracts the top-down cascading effects, our results emphasize the importance of a comprehensive analysis that take into account all structuring forces at play (including those beyond the marine system) at a given time. © 2010 Blackwell Publishing Ltd.
Simon E.,VU University Amsterdam |
Lamoree M.H.,VU University Amsterdam |
Hamers T.,VU University Amsterdam |
Weiss J.M.,VU University Amsterdam |
And 4 more authors.
Environmental Science and Technology | Year: 2010
A cleanup method was developed to remove coextracted lipids and natural hormones from biota samples in order to test the endocrine-disrupting (ED) capacity of their extracts in in vitro bioassays. Unspiked and spiked fish tissues were cleaned with a combination of dialysis, gel permeation chromatography (GPC), and normal-phase liquid chromatography (NP-HPLC). The spiking mixture consisted of a broad range of environmental pollutants (endocrine disruptors and genotoxic compounds). Chemical recoveries of each test compound, and thyroidhormone-like and (anti)androgenic activities of the cleaned extracts were investigated. Despite the chemical and toxicological complexity of the spiking mixture and the sequential sample treatment, chemical analysis revealed acceptable recoveries on average: 89 ± 8% after each cleanup step separately and 75 ± 3% after the whole extraction and cleanup procedure in the extracts. In addition, recovered activities in the bioassays were in good agreement with the spiking levels. The developed cleanup method proved to be capable of lipid and natural hormone removal from fish extracts, enabling the measurement of selected endocrine-hormone-like activities in T4 *-TTR and AR-CALUX bioassays. The method can be used as a sample preparation method of biota samples for toxicity profiling and effectdirected analysis (EDA). © 2010 American Chemical Society.
Ulrich C.,Technical University of Denmark |
Wilson D.C.K.,IFM AAU |
Nielsen J.R.,Technical University of Denmark |
Bastardie F.,Technical University of Denmark |
And 3 more authors.
Ocean and Coastal Management | Year: 2012
The inconsistency of single-species objectives in a mixed-fisheries context has repeatedly been highlighted as a key issue in the current European Common Fishery Policy, and it has long been suggested that this issue would be better addressed through fleet (group of vessels) and métier (type of activity) - based approaches. Since the late 1980s, when such approaches were first introduced, there have been substantial developments in this area of science, to the point where the concepts of fleet and métier now underpin the whole EC Data Collection Framework. However, their implementation in the management system has been slow and difficult, being hampered by a number of intrinsic issues. Mixed fisheries are an ongoing "governance headache" combining management complexity, scientific uncertainty and political sensitivity. This paper summarises the current state of play for fleet-based approaches in EU fisheries management, and highlights our views on both their potential and the challenges they face in the context of the future CFP. As a convenient layer between the current single-stock level and the level of the individual vessel, fleet/metier- approaches could potentially address a wide range of issues, especially with regards to the policy emphasis on ecosystem-based fisheries management. However, the rigid categorisation they induce may not properly address the flexibility of individual vessels, and should therefore be supplemented by more detailed considerations at the local scale. © 2012 Elsevier Ltd.
Trenkel V.M.,French Research Institute for Exploitation of the Sea |
Beecham J.A.,CEFAS Lowestoft Laboratory |
Blanchard J.L.,Imperial College London |
Edwards C.T.T.,Imperial College London |
Lorance P.,French Research Institute for Exploitation of the Sea
Aquatic Living Resources | Year: 2013
The status of an exploited population is ideally determined by monitoring changes in abundance and distributional range and pattern over time. Area of occupancy is a measure of the current distribution. Unfortunately, for many populations, scientific abundance and distribution information is not readily available. To evaluate the reliability of commercial fishing data for deriving occupancy indicators that could serve as proxies for stock abundance, we investigated four questions: 1) Occupancy changes with stock biomass, but is this change strong enough to make occupancy a sensitive indicator of population biomass? 2) Fishing boats follow fish, but when does such activity alter the positive macroecological relationship between occupancy and abundance? 3) When does the activity of pursuing fish adversely affect occupancy estimates derived from catch and effort data? 4) How does uncertainty in fishing effort data affect occupancy estimates? Spatial simulations mimicking the dynamics of four deep-water fish species showed that biomass-occupancy relationships can be weak. Fishers following fish can modify the spatial distribution of target species, even reversing the sign of the biomass-occupancy relationship in certain cases, and can affect the reliability of occupancy indicators, which can also be impaired by error in effort data. Using commercial catch and effort data and abundance indices for deep-sea fish populations to the west of the British Isles it was found that only for roundnose grenadier might occupancy provide insights into biomass changes. In conclusion, care should be taken when using occupancy for evaluating range changes in cases where fishing might have modified spatial distributions, uncertain commercial data are used or when the abundance-occupancy relationship is too flat. © 2013 EDP Sciences, IFREMER, IRD.