News

Published on February 1, 2016

Previous studies have suggested that phosphorus (P) deficiency can increase the sensitivity of microalgae to toxic trace metals, potentially due to reduced metal detoxification at low cell P quota. The existing evidence is, however, inconsistent. This study was set up to determine the combined effects of zinc (Zn) and P supplies on Zn and P bioaccumulation and growth of the green microalgae Pseudokirchneriella subcapitata. Zinc toxicity was investigated in (i) a 24 h growth rate assay with cells varying in initial cell P quota with no supplemental P during Zn exposure and in (ii) a 48 h growth assay initiated with cells at the end of a 14-days steady state culture at three P addition rates (RARs) between 0.8 and 1.6 day−1. Our data at two experimental scenarios and the prediction under various relevant scenarios suggest a weaker effect of secondary stress factor (Zn) when nutrient deficiency (first stress factor) is prevailing.

Published on January 27, 2016

For the second year in a row, the Flanders Marine Institute (VLIZ) organized the PlaneetZee@work competition. As a committed partner of VLIZ, GhEnToxLab hosted an interactive day on marine sciences for high school students. On Tuesday 26 January, 30 fourth-year students of the Barnum school of Roeselare visited our lab to learn - hands on - about the effects of different stressors on the marine environment. After an introductory presentation and a guided tour of our facilities, the students participated in five workshops. Each workshop, organized by five of our PhD students, covered current, high profile issues like: harmful algal blooms, ocean acidification and (micro-)plastic pollution. Additionally workshops on innovative environmental DNA monitoring techniques and basic marine toxicity testing provided insights into new and current ecotoxicological methods. We would like to thank the students for their vibrant enthusiasm and wish them all the best with their further research activities leading to the development and presentation of their scientific posters on these topics.

Published on January 11, 2016

We determined whether a realistic mixture of hydrophobic chemicals affects the growth dynamics of a marine diatom and how this effect compares to the effect of temperature, light regime and nutrient conditions. Passive dosing was used to expose a marine diatom to a realistic mixture of hydrophobic compounds accumulated from Belgian coastal waters using passive samplers. Although ∑7PCBs exceeded the environmental quality standards (2 ng L− 1), we did not observe adverse ecotoxicological effects in a 72 h algal growth inhibition test with P. tricornutum. Natural drivers such as nutrients, temperature and light availability, explaining about 85% of the observed variability, are more important drivers of the growth of P. tricornutum than the mixture of organic pollutants present in Belgian coastal waters.

Published on December 15, 2015

As part of the lectures marine ecology of Prof. Janssen, students of several master programs went on a field trip to the Opal coast in France. In the shadow of the fortress of Ambleteuse they experienced the forces of tidal action in terms of ecological zonation on rocky shores, sandy beaches and within the salt marshes of the river Slack.

Next to the field trip to Ambleteuse, the bioscience engineering students boarded the research vessel Simon Stevin. A video compilation of this excursion can be found on the Media menu.

Published on November 12, 2015

On Sunday the 22nd of November, many research institutes in Flanders open their doors to the general audience for Science Day, an event coordinated by the Flemish Government. The Flanders Marine Institute is also opening its doors from 10am to 5pm. GhenToxLab Researchers are also present! They will take visitors on an interactive tour in the Molecular Lab of the Marine Station Ostend and will explain how DNA plays an important role in developing new techniques to assess biodiversity.

Published on November 5, 2015

Between November 2nd and December 7th, our postdoctoral researcher Gert Everaert performs a research stay at the Norwegian Institute for Water Research (NIVA). The Niva is a non-profit research foundation which researches, monitors and assesses freshwater, coastal and marine environments and environmental technology. Gert will collaborate closely with the scientific staff of the section ‘Contaminants in the aquatic environment’. The research stay is supported by a travel grant of the ‘Fonds voor wetenschappelijk onderzoek  (FWO)’.

Published on September 15, 2015

The chronic toxicity of Ni is strongly dependent on the physico-chemistry of freshwater environments. Metal bioavailability models predict metal toxicity in receiving waters by taking into account the effects of pH and the formation of (in)organic ligand on metal bioavailability and the effects of cations, such as Ca & Mg, on metal uptake. Currently, the Environmental Quality Standard (EQS) for Ni in the Water Framework Directive (WFD) is bioavailability based. Although some of the available chronic Ni bioavailability models are only validated for pH up to 8.2, a considerable fraction of the European surface waters has a pH above 8.2. Therefore, we investigated the effect of a change in pH from 8.2 to 8.7 on chronic Ni toxicity to 3 invertebrate and 2 plant species. Next, we investigated whether the existing chronic Ni bioavailability models could be used to predict chronic Ni toxicity above pH 8.2.

Published on September 9, 2015

As the human population continues to expand, scientists and politicians are faced with a simple question: will we be able to feed ourselves in the future? Many of our food sources are at peak productivity and only in a few sectors, such as the aquaculture industry, is significant growth feasible. However, these sectors are also faced with global concerns like climate change. The rise of sea surface temperature will affect marine ecosystems in drastic ways. Among others, pathogens and harmful algae are expected to benefit from a warmer environment. As a result, both wild and cultured bivalves will become more frequently exposed to these stressors.

Published on August 10, 2015

At the moment, 2 GhenToxLab members are joining the 100th ESA conference in Baltimore, USA (August 9-11). With over 250 contributed talks and poster sessions, this is the biggest ecological conference worldwide. Today, filling the gap between ecology and toxicology is one of the main research themes in our lab. As such, Jonathan De Raedt and Jan Baert present their poster “The effect of dispersal along a stress gradient in micro-algae communities”.

Published on July 17, 2015
For the Marine Environmental Research Special Issue on “Particles in Oceans”, we contributed with a comprehensive review on microplastics in sediments. For this review we analysed literature dating back to the 1970s, in order to gain insights in the worldwide occurrence of microplastics in sediments, processes that drive their distribution and effects of this type of pollution on sediment associated organisms. Based on this extensive literature review (over 120 publications), we were able to identify several shortcomings in microplastics research and formulate recommendations to deal with these issues in the future. Although important advances have been made in the past decade, we describe the need for standardisation and harmonisation of sampling and extraction techniques, and the need for more realistic effect assessments for microplastics.
 

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