Pollutant effects in non-standard laboratory tests

tests have become increasingly relevant in recent years, as they can be used to address open questions from environmental risk assessment for individual species or groups of species more precisely. These experiments include three categories:

1. Tests with standard species and modified experimental designs
2. Single species tests with non-standard species
3. Short-term tests with natural species assemblages

Our team has worked intensively on the development and optimisation of such test procedures in recent years, so that we can offer you the following tested procedures as a service:

Population studies with Daphnia magna

Here, we have experience with different peak exposure scenarios and with experimental approaches including sediment.

Lemna-studies

Here we have a wide range of experience from experiments up to a test duration of 21 days with complex exposure scenarios.

Microalgae studies (e.g. with Pseudokirchneriella subcapitata, Desmodesmus subspicatus)

We develop methods for complex multi-peak exposure scenarios including recovery phases.

gaiac has extensive experience in conducting acute and chronic effect studies with aquatic non-standard organisms, also under GLP.  In this context, we offer both single species evaluations with peak or contant exposure scenarios, as well as SSD (Species Sensitivity Distribution) studies. These tests can be carried out at standard temperature, but also for different temperature ranges.

Acute tests with non-standard invertebrates

We have experience in conducting acute tests (e.g. 48 h, 96 h) for various zooplankton organisms and macroinvertebrates:

Insects

• Mayflies (e.g. Habrophlebia lauta, Serratella ignita, Cloeon dipterum, Habroleptoides confusa)
• Caddisflies (e.g. Hydropsyche siltalai, Sericostoma spec. )
• Stoneflies (e.g. Leuctra spec., Siphonoperla spec.)
• Phantom midges ( Chaoborus crystallinus)
• Water bugs (e.g. Notonecta spec.)

Crustaceans

• Aquatic isopods (Asellus aquaticus)
• Amphipods (e.g. Gammarus pulex, Crangonyx pseudogracillis)
• Cladocerans (e.g. Chydorus sphaericus, Daphnia longispina)

Chronic tests for lethal effects

To investigate longer-term lethal effects, we successfully established test procedures with mayflies (e.g. Habrophlebia lauta, Cloeon dipterum) over at least 21 days.

Chronic tests with sublethal endpoints

Currently, we have developed test protocols to investigate the feeding rate and the developmental rate of Cloeon dipterum,  which are currently in a test phase.

Plankton communities

• We have experience in conducting experiments with already developed, natural phytoplankton species communities and zooplankton communities to study acute effects caused by pesticides. These experiments can be conducted under controlled conditions in the laboratory or under natural conditions as small enclosure experiments e.g. in mesocosms. The duration of the experiments is 21 days.

Mesofauna species community

We have developed a test protocol that allows us to investigate acute effects on mesofauna communities in soil. This approach can be used as a screening procedure for the initial assessment of effects on collembolans and oribatids and as a preliminary test for selecting the appropriate test item concentrations for higher-tier TME studies or field studies.

Our aim is to reproduce the ecological requirements of the test species in our laboratory systems as well as possible and thus to minimise the stress level for the test organisms. We strive to establish new approaches for further relevant species or communities in order to support a more realistic risk assessment.

Currently, there is no uniform standard for the implementation and evaluation these testing approaches. In order to ensure that the test results are highly informative, we are continuously improving the methodology used for effect evaluation.