Despite their detection, the project team is quick to emphasize that their relative concentrations are low.

Relative to other freshwater samples, microplastics in Okanagan Lake are quite low (as compared to Lake Ontario, for example). Similarly, relative to marine environments, Okanagan Lake is also quite low (as compared to Pacific Ocean datasets, for example). We are encouraged by the relatively low values but we caution that this is a preliminary study. More work is needed to identify point source origins as well as mitigation solutions.

Freshwater results

The freshwater team discovered that microplastics were present in all five sampled locations of Okanagan Lake. In total, about 2.75 grams of plastic were collected across all five sample locations. (out of a total of 155,000L water filtered across all sample sites). The greatest concentration of microplastics was collected below the William R. Bennett bridge and yielded 1.1009g.

Microplastic morphology (fragments, fibres, and films) was highly varied, randomized, and did not follow a distinct pattern. Visual analysis revealed that fragments were the most abundant morphology of microplastic collected, although some fragments mimicked the appearance of fibres. With that being said, film-type plastic was the most distinguishable of the samples but least commonly found due to the ease of degradation and resultant varying sizes.

Fragments were collected at four of five locations, with abundance being greatest in the area south of the William R. Bennett Bridge. Fibres were collected at all locations, with the greatest abundance appearing in the region of the lake south of the Mission Creek outflow. Films were collected at three of five locations, with the area north of the William R. Bennett Bridge and the area south of it yielding the greatest number of films.

Wastewater results

The wastewater team discovered that microplastics were present in both influent and effluent samples. Influent is the water coming into the facility, pre-treated; effluent is what goes out after it has been filtered, processed, and treated.

Based on visual observation, most recovered particles appeared to be microfibers. Some plastic films, fragments, and particles that appeared like microbeads were also observed. The most identified colours of the particles were red, blue, black and clear. Other colours observed included yellow, purple, green and pink colours were also observed.

There may have been some contamination while processing samples that would have impacted data results. For example, during sample collection, plastic bottles and a plastic water pump were used, which could lead to plastic particle shedding and contamination into water samples. Similarly, synthetic clothing worn during collection and analysis could impact samples.

The source of contamination could also be environmental: previous studies have suggested that plastic particles can remain in the air for between one hour and 6.5 days.

What are the solutions?

There are many actions we as individuals can take to prevent more microplastics from entering our freshwater ecosystems.

• Get involved with local beach, stream, or neighbourhood cleanups, to remove plastics and other trash from entering storm drains or waterways.
• Remember to pack out what you pack in when visiting a beach, hiking,  or camping.
• Limit your use of single-use disposable plastics like bags, cutlery, takeout foam food packaging, and straws.
• Consider your garment choices: synthetic clothing sheds microplastic fibres each time you wash them; transition to cotton or other natural fibres. Buy second-hand or on consignment to save on new material production (and save money!).
• Install or invest in microplastic-capturing devices for your washing machine. (e.g. Lint Luv-r, Filtrol, Cora Ball, or Guppy Friend).

Speak up for our water

In addition to individual actions, there are many ways to collectively let our elected officials and business owners (large and small) know that we care about clean, freshwater ecosystems:

• Let your local government officials (Mayor and City Council; MLA; MP) know that you care about clean water and that you support more research into microplastics in your area.
• Support the Government of Canada’s declaration of plastics as a toxic substance.
• Support legislation to ban or remove harmful or excessive amounts of disposable plastics such as bags, straws, and take-out packaging.

We have an opportunity to prevent further, widespread contamination in the lake, as well as to create hope and opportunity for mitigation solutions to be developed.

When we think of plastic pollution, most of us imagine the ocean with images of sun-bleached or barnacle-covered laundry baskets, fishing debris, or other detritus. We may recall that one photo of the albatross that was going around, with its belly full of plastic. Or, we see what looks like a blue soup: clear ocean water with small, floating bits swirling about, the occasional plastic bag wafting into view.

We imagine marine examples because those are what has captured the public eye with myriad documentaries, photos, videos, and research projects taking place at sea or along our coastlines.

Microplastics in the freshwater environment are still considered to be a contaminant of “emerging concern” that is to say, we still don’t know much about them!

Plus, microplastics in freshwater are a lot harder to see with the naked eye…maybe that’s why they’re called microplastics! 😉

Why is it important to understand microplastics in freshwater?

Because we don’t know much about this issue, we also can’t assess the risk they pose to both aquatic life and human health. But risks they do pose! Microplastics – whether they are primary or secondary – are composed of plastic, made from petroleum with a whole slew of additives (phthalates, bisphenol-A, among others). They (and plastic pollution generally) also have the ability to soak up toxins from their surroundings, in addition to being physically damaging (even in organisms as small as phytoplankton). This toxin-soaking can have a “bioaccumulation” effect where toxins are accumulated as they advance up trophic levels (for example zooplankton ingests microplastics, which are then ingested by a small fish, then a larger fish, and then finally a fish we humans might consume).

In order to manage any risk, we have to know something about the issue and that requires two things: data and regular monitoring. As Kennedy Bucci and Chelsea Rochman suggest in their recent paper, ‘Microplastics: a multidimensional contaminant requires a multidimensional framework for assessing risk:

…microplastic pollution exists as a complex and dynamic mixture of particles, that varies over temporal and spatial scales.

Bucci and Rochman, 2022

They advocate for a multi-disciplinary approach to assessing microplastic risks and instead of simplifying the process, to actually incorporate all of what makes microplastics complex – it is in that complexity that connections can be made.

Resources

There is much to learn about microplastics in freshwater and the research just keeps on coming. Besides the two papers we’ve cited above, here are a few more that informed our own understanding, to help get you started learning more.

• Blair, 2017 – “Micro- and Nanoplastic Pollution of Freshwater and Wastewater Treatment Systems”
• Vermaire et al 2017 – ‘Microplastic abundance and distribution in the open water and sediment of the Ottawa River, Canada, and its tributaries’
• Claudia Campanale, et al 2020 – ‘A Practical Overview of Methodologies for Sampling and Analysis of Microplastics in Riverine Environments’
• Cox et al 2021 – ‘Distribution, abundance and spatial variability of microplastic pollution on the surface of Lake Superior’