Death of aquatic animals disorganizes ecological chain and ends up affecting cultivated pollinating bees such as soy
Contamination and death of fish by microplastics may not only decrease the availability of this food, but also affect the production of cultures of great importance for Brazilian agriculture.
The warning was made by, professor at UNIFESP (Federal University of São Paulo), Diadema campus, in a lecture during the September 2-13 in Santos, on the coast of São Paulo.
“The problem of fish intake by fish is no longer analyzed in isolation and their environmental impacts will be evaluated in an integrated manner, because aquatic and terrestrial ecosystems are connected.”Disse semensatto.
Fish are natural predators of dragonfly larvae (Anisopera), who live in the water, explained the researcher. In turn, these winged insects are predator of some species of flower pollinating bees and fruits of great economic importance.
Thus, the contamination and death of fish by ingestion of microplastics can cause the increase in dragonflies to aquatic ecosystems and, consequently, increased predation and decreased population of how soy (Glycine max), the coffee (Coffea), the beans (Phaseolus vulgaris L.) and orange (Citrus sinensis).
“To increase plant production, it is necessary to protect fish [contra a contaminação por microplásticos]because nature is connected ”affirmou semensatto.
Omnipresence in water
Derivatives of the degradation of larger objects, such as bottles and bags, microplastics travel long distances and became ubiquitous in the environments. “Bottle caps, for example, last 100 years and, during this period, go through aquatic environments, affecting various organisms of different sizes”said the teacher.
To the tiny water flea (Daphnia magna) is not immune to contamination by microplastics. Researchers have identified the presence of nanoplastics within this species of microcrustacean, which measures a maximum of 5 millimeters (mm) and feeds on suspension organic matter, such as microalgae, bacteria and debris, acting as a common filter organism in freshwater bodies. Therefore, it is widely used as an environmental sample bioindicator for ecotoxicological tests.
“Laboratory analyzes revealed the presence of up to two nanoplastics inside these organisms, which can be derived from bottle caps or detached from a fiber”Disse semensatto.
According to the researcher, the chemical and physical characteristics of microplastics change along the journey through aquatic environments, which makes it difficult to identify original polymers through current spectroscopy techniques, employed for substance identification.
Exposure to Ultraviolet Radiation (UV), water and other environmental factors induces the degradation of microplastics and, consequently, changes in the color and physical structure of these materials, allowing you to increase your surface area and the release of even smaller particles: called nanoplastics.
During a ongoing research project, the researchers collected at the mouth of the Amazon River a type of fiber whose end has been fragmented over time, release some potential nanoplastics. “This shows how a single fragment can multiply in countless others, each with its own chemical and physical ‘history’. This is a tragedy”evaluated Semensatto.
Moving fossil fuel
In the researcher’s evaluation, treaties and agreements on climate change mitigation should take into account the production chain and the life cycle of plastics, as these themes are directly related.
“Plastics can be manufactured from renewable sources, but 99% of the polymers we use today are derived from fossil fuels. Therefore, plastics are moving fossil fuels.”evaluated.
In early August, representatives from 184 countries gathered in Geneva, Switzerland, for the 5th session of the Intergovernmental Trading Committee to elaborate a legally binding instrument (in which signatories have to comply with the agreement) to face plastic pollution. The negotiations, however, ended without consensus.
“The discussion about plastic pollution is moving very slowly and it is necessary to advance”affirmou semensatto.
With information from.
