This research line is looking at developing ecotoxicity tests to identify potential effect of contaminants that are present in the environment and biowaste in very low concentrations over a long period of time.
Copepods are a group of small crustaceans found in the sea and nearly every freshwater habitat, playing a major role in ocean ecosystems. They are the most numerous multi-cellular organisms, at about 80% of the animal mass in the water column community. Copepod means “oar footed”. They are often referred to as the “insects of the sea”, because of their numbers and similar role in food webs as insects have on land. They are the major food item for many other planktonic species, fish, sea-birds and even some great whales. Some species are planktonic (drifting in sea waters), some are benthic (living on the ocean floor), and some continental species may live in limnoterrestrial habitats and other wet terrestrial places, such as swamps, under leaf fall in wet forests, bogs, springs, ephemeral ponds, and puddles, damp moss, or water-filled recesses (phytotelmata) of plants such as bromeliads and pitcher plants. Many live underground in marine and freshwater caves, sinkholes, or stream beds.
The key objective of the project was to assess whether this copepod species is a suitable ecotoxicology model for studying the effects of an organism that is in contact with a small dose of a pollutant over a long period of time. Anais Guyon (visiting French student) successfully conducted a long-term exposure experiment where the copepod (Gladioferens pectinatus) were placed in the presence of non-lethal low doses of the UV blocker benzophenone and the anti-inflammatory drug diclofenac. The time of exposures covered a total of six generations, i.e. from new born to adult stages. At the end of the experiment, Anais found that the copepods had become more tolerant to the chemicals than the non-exposed animals. That demonstrates that the stress from the chemicals led to some level of adaptation. Further experiments will continue around more in-depth investigations with colleagues from Griffith University to further advance our understanding of the subtle effects of micro-pollutants on the health of our environment.
For more information about this project, please contact: Louis.Tremblay@cawthron.org.nz