Water pollution and the impact on the marine ecosystem

Wageningen Marine Research has extensive facilities for testing the impact of water pollution, wastewater, and the presence of substances such as nanoplastics in the marine environment. With our bioassays we conduct standardised laboratory tests to determine the toxicity of a substance or mixture. For more realistic research we mimic part of an ecosystem in mesocosms (a type of marine water pond) to facilitate the research of more subtle effects.

  • Waterverontreiniging en het effect op het mariene ecosysteem

Bioassays with marine, brackish, and freshwater organisms

Wageningen Marine Research offers a range of standardised marine water and fresh water bioassays suitable for ecotoxicological assessment of surface water, wastewater, sediments (whole sediment, elutriate, and pore water), and specific substances. The tests will be conducted with bacteria, algae, crustaceans, and fish in accordance with international research protocols.

Our solutions

Examples of the application of bioassays are:

  • Treated ballast water
  • Produced water from offshore platforms
  • Industrial wastewater
  • Rainwater run-off from motorways

If desired, the research results can be incorporated into a risk analysis in which local conditions will be considered to determine the environmental risk of the specific discharge.

The assessment of ballast water is performed in accordance with the guidelines set out by the International Maritime Organization (IMO) and the US Coast Guard. Discharges of produced water from offshore platforms are assessed in accordance with the Risk-Based Approach by NOGEPA.

We would be happy to discuss other applications with you.


In bioassays, the impact on a single plant or animal species is tested under standardised stable conditions. These are short-term tests and can be easily compared, but the test conditions in bioassays do not represent the situation in the field. Mesocosms are more suitable in that case. Mesocosms are a type of pond in which we can mimic part of the ecosystem. The advantage of mesocosms over a laboratory test is that species interactions and environmental conditions are included like in the field situation. A mesocosm study allows replication and proper control conditions that are never possible in a field study.  

Our solutions

We have 30 mesocosms at our disposal at our testing facility in Den Helder, each with a capacity of approximately 5 m3. These mesocosms are equipped with a community existing of plankton, benthic organisms, and potentially small fish. After an acclimation period, the development of this community under the influence of a treatment can be monitored for 8 to 12 weeks.

Traditionally, mesocosms are mostly used for toxicological research but they also offer potential for ecological research such as understanding and modelling the impact of climate change on ecological processes and procreation. Mesocosm research is always customised to answer specific questions.

Wageningen Marine Research mesocosms in Den Helder are used to study marine ecosystems. Contact our colleagues at Wageningen Environmental Research at the Sinderhoeve in Renkum with your questions about freshwater mesocosms.

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