Successful First Field Season for Microplastics Research Team
Searching for Microplastics in New Brunswick rivers
ECAB Lab researchers travelled the province during the summer months to collect samples from New Brunswick rivers in search of microplastics. Microplastics are very small pieces of plastic found in the environment. Their presence in aquatic and terrestrial habitats are thought to pose a threat to wildlife, and the effects on the ecosystem are just starting to be understood.
Postdoctoral Fellow Dr. Andrew Labaj and a select team of summer students collected water and sediment samples from over 90 sites throughout the Saint John watershed. Five rivers, the Kennebacasis, Nashwaak, Tobique, Oromocto and Saint John, were sampled as part of the field campaign, which occurred between June and September of 2019.
Collection site along the Saint John River
Sampling points near WWTPs along the Saint John River watershed
Sampling sites were chosen to account for various pollution scenarios. These included:
background (minimal impact) levels of microplastics,
wastewater treatment plant (WWTP) upstream,
WWTP downstream, and
intermediate (between WWTP, near farms or human settlements or otherwise at regular intervals along the rivers).
At most sites, a large mesh net was used to filter 10,000 to 20,000 litres of water and collect microplastics. At sites where the net could not be deployed effectively, a pump and generator setup were used to draw ~5,000 litres of water through the net. Mussels, which occur commonly in rivers, were also gathered from many of the sites. Analyzing the microplastics found within these filter feeding organisms may help reveal the linkages between microplastic sources and the aquatic food web.
Freshwater mussel in the Saint John River
Collecting a freshwater mussel
Pipe from WWTP discharging into a river
Sampling sites were chosen by the research team with the help of representatives from the Kennebecasis Watershed Restoration Committee, the Nashwaak Watershed Association, and the Tobique First Nation. These groups also provided assistance with sampling efforts and field logistics.
The ECAB research team, which included students Amber LeBlanc and Casey Doucet, benefited from the help of Canadian Army divers. The dive team helped collect sediment samples and mussels from sites near the main discharge of the CFB Gagetown / Oromocto, NB main wastewater treatment plant. The Mt A researchers were thankful for help from the divers, who were able to obtain samples that would otherwise have been impossible for them to access.
The first field season has now wrapped up and the real work is set to begin. Dr. Labaj, LeBlanc, and Doucet will spend months working in the lab to process and analyze the samples. Results will be used to map the distribution of microplastics along the Saint John River watershed. The information generated will also help clarify the role that land use, wastewater effluent, and population density play in microplastic pollution.
This research is just the starting point to better understand the ecological impacts of microplastic pollution in NB waterways. Establishing the baseline level of microplastics in the watershed will help determine changes in microplastics over time, assist in studying effects on aquatic organisms, and inform future decisions on how to deal with plastics in the environment.
Using a manta net to filter microplastics
Sediment samples were collected at each site by the research team
In search of mussels