The river insects have rights
It is hard to fathom the amount of different chemicals that enter our rivers, lakes, groundwater and coasts every day. The sources of these chemicals are varied and are linked to our activities. The chemicals include pharmaceuticals, herbicides, cleaning agents, pet care chemicals, antibiotics, petroleum compounds and many more. The majority of chemicals are in very low concentrations. Some have a long residence time and others have a very short half-life and disappear from the environment very quickly. Monitoring programmes don’t include all chemicals. That may be because toxicology studies don’t show a health risk, their likely occurrence is low or they are not yet added to the list of priority and emerging chemicals.
Today in the Guardian newspaper a report showed that highly toxic insecticides that are used on cats and dogs to kill fleas are poisoning rivers across England. An important impact of chemicals on the waters is that invertebrates or insects in the water are affected which in turn impacts the organisms that rely on them for food. One chemical is fipronil and a toxic breakdown product of the pesticide was found above allowable levels. While these chemicals have been found at poisonous levels other chemicals exist at low levels and in a cocktail. Effects of these are yet unknown. The impact of chemicals that are considered not to have health impacts for human health, may be having a wider effect on biodiversity. The organisms in freshwater play a really important role in the whole ecosystem life and therefore should be protected. However, it is a huge challenge to try to measure all chemicals in every water. New methods are needed to determine the effects of chemicals on water – these are called effect based methods. These can tell if the water is causing some toxic or other chronic effect on the life in that environment. This comes back to everyone trying their best to cut down on the use of chemicals for whatever purpose. In the case of pet treatments as highlighted in the article, perhaps the applications of chemicals could be reduced to when they are needed rather than over using.
Cover image:  Remington C.R. (1979) Insecta. In: Paleontology. Encyclopedia of Earth Science. Springer, Berlin, Heidelberg. https://doi.org/10.1007/3-540-31078-9_75