In the beginning of June, scientists spilled bitum - a viscous liquid that is extracted from sand in some regions of the country and transported in ducts - in a limited surface of the Experimental Lakes from the International Institute for Sustainable Development (IISD-ELA). The objective of the study was to help protect future freshwater ecosystems from oil spills.
In a large test tube, installed in the lake where the research station was constructed, the scientists are studying the physical, chemical, biological and toxicological impacts from bitum in freshwater organisms - from the plankton to the frogs and fishes.
Until recently, this type of experiment had been made only in laboratories, where it wasn't possible to imitate the real world. It's the first study of its kind made in Canada - an opportunity to answer questions that can help to protect the lakes of the country, like what happens when bitum is spilled in freshwater ecosystems? Where does it go to? And what is the safest and most efficient cleaning process (does the technique have to be different from the one used in conventional crude petroleum spills?)
During the weeks prior to the intentional spill, dozens of students worked putting sand into sacks. They transported the material in trucks and quadricycles on a trail that leads to the lakes. And, after they unloaded the material, they carried the sacks to the docks, where they were put on ships.
"It's like a low-cost crossfit", joked Sonya Michaleski, a student from Manitoba University.
Sam Patterson, a post-grad student, explains his role: to get water from the compartments before and after the spill of diluted bitum. Afterwards, he has to put forest frog eggs into the treated water to see how the exposure affects their development.
Most of the data collection happens during this summer and fall, before the lake freezes. The subsequent analysis will be shared first in academic essays before being released for the public.
The IISD-ELA is a research station known for making experiments in lakes. In previous studies, they contaminated the lakes with phosphorous, cadmium, mercury and synthetic estrogen, which is used for making contraceptives. Before that, they have never used oil.
The experiment - called the Boreal, an acronym for Boreal Lake Oil Release Experiment by Additions to Limnocorrals - will not cover the whole lake. Small compartments restrict the oil spill area, and four extra containment measures are being added to avoid the contamination of the whole lake, explains scientist Vince Palace, research chief from IISD-ELA.
Even so, the smaller spill area will provide the scientists with a much better idea regarding how the bitum behaves and affects the environment than what they are capable of analyzing in the laboratory.
"In the laboratory, there are technical problems related to the difference in scale with the real world", says Bruce Hollebone, chemical analyst from Environment and Climate Change Canada and collaborator with the Boreal experiment.
"It's nothing like using miniatures of ships, where you can test, for example, how a channel works in a smaller scale. You can't do the same with oil spills because there are a lot more factors involved, and all of them change the different rates when you increase the scale."
"The Boreal gives us the opportunity to work with scales close to that of the real world... And it offers a good notion of what happens in these natural environments."
Also, one of the most studied topics is the spilling of oil in the oceans. And, even in research studies done in freshwater, Hollebone warns: "There are few that study boreal ecosystems."
The Boreal Forest is a biome with cone trees, granite rocks, swamps and lakes.
"Half of Canada is a boreal ecosystem", added Hollebone.
How an oil spill affects this and other ecosystems became a controversial topic in the topic, mainly after the government had announced the recent nationalization of a pipeline project that ends in the Pacific Ocean.
Many transport systems, including pipelines and railways, load off oil into the boreal ecosystems in Canada. According to Hollebone, in the last decade, there were many spills in the forests and swamps. And, when dealing with the spills, "we are not sufficiently knowledgeable to deal with them", he said.
One of the challenges is the high viscosity of the bitum, even when diluted in lighter oil fractions that allow them to flow more easily through the pipes. When spilled, it behaves in a very distinct way in freshwater and oceanic systems, explained Diane Orihel, from Queen's University, in Ontario, one of the leaders of the Boreal project.
Among other topics, the researchers want to investigate for how long the diluted bitum will float in freshwater ecosystems, how fast the lightest component will evaporate, the actual amount that composes the end sediment and the speed of entrance and build up in the food chain.
To track the path of the bitum, the scientists will work in teams - each will evaluate the effects of the compound in the ecosystems, basing themselves in different categories, like air, water, sediments, periphyton communities and animals like forest frogs and fishes.
Following that, they will calculate the mass of the policyclic aromatic hydrocarbons (PAHs) - a family of chemical substances found in organic materials, like oil, which have cancerous agents - in each section.
The team will also examine the organisms that integrate the local community and compare themselves before and after the spill. What kind of bacteria, phytoplankton, zooplanktons, aquatic invertebrates and insects exist? How many of each? And how bitum affects their survival capacity, reproduce and provide food for the other species that eat them?
Translated from: https://g1.globo.com/natureza/noticia/2018/08/14/como-um-derramamento-intencional-de-oleo-pode-ajudar-a-proteger-o-meio-ambiente.ghtml
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