Bio-indicators are the investigators of the ecosystem, always looking for clues to pollution. Imagine a mushroom, intent on revealing the reactivity of the soil! Thanks to them, we can check up on the environment and make sure it is fine, just like a doctor does with his patients.
Bioindicators and environmental monitoring
Bio-indicators are living organisms that help us assess the health of a natural environment. They react to environmental changes in predictable ways, making them valuable tools for monitoring air, water and soil quality.
Thanks to them, we can detect changes in ecosystems at an early stage and take timely action to mitigate negative impacts. They also help us identify sources of pollution and assess the effectiveness of remediation measures.
For example, lichens, a combination of algae and fungi, are very sensitive to air pollutants such as sulphur dioxide and hydrocarbons, making them useful for monitoring air quality.
Algae in water may indicate the presence of excess nutrients or toxic substances, while terrestrial plants detect soil contamination by heavy metals.
Animals, as bioaccumulators, reveal the presence of chemicals in the environment, even if they have been dispersed for a long time.
Bees indicate pesticides, earthworms monitor soil quality, amphibians signal pollutants in water and birds reflect the health of entire ecosystems.
Microorganisms, such as bacteria and fungi, are very effective indicators.
Coliform bacteria assess the quality ofdrinking water, nitrifying bacteria signal the presence of nitrogen compounds, fungi indicate soil health.
Operating mechanisms
To understand how bio-indicators respond to environmental changes, we can measure several parameters. These organisms react through a range of responses that can be physiological, biochemical or behavioural.
Physiological changes in plants are abnormalities in growth, leaf colouration or flower and fruit production when they are exposed to air pollutants or soil contaminants.
One of the biochemical mechanisms is bioaccumulation, which indicates the concentration of chemicals accumulated in the tissues of organisms, such as heavy metals.
Animals then may manifest alterations in behaviour, reproduction, feeding, migration or general health in response to toxic substances or changes in environmental conditions.
Despite its many advantages, the use of bio-indicators also presents limitations and challenges. The inherent variability of species can introduce uncertainty into the interpretation of results.
Furthermore, external factors such as climate fluctuations or competition for resources can influence bio-indicators independently of the presence of pollutants.
Bioindicators, case studies and potential
In some regions of Italy, bees have been used to monitor the presence of pesticides and heavy metals. By analysing honey, pollen and the bees themselves, researchers obtain detailed information on the presence of contaminants in the environment.
This method has been successfully used to identify areas with high levels of pollution and to monitor theeffectiveness of policies to reduce pesticide use.
In Germany, butterflies have been used to monitor biodiversity and habitat quality. A study in North Rhine-Westphalia assessed theimpact of agricultural practices on biodiversity by observing butterfly populations in agricultural and natural areas.
The results showed that sustainable agricultural practices promote greater butterfly diversity than intensive agriculture, providing valuable data to promote practices that support biodiversity conservation.
These tools, together with technological innovations, offer enormous potential for protecting the environment and promoting sustainable development. Bioindicators could be used in new contexts, such as monitoring air quality in urban environments or assessing the impact of microplastics in marine ecosystems.
Play for the Planet