Microplastics as a physical growth substrate for freshwater algal species
Conference Year
January 2020
Abstract
Humans interact with plastics every day in commercial and domestic uses. In 2017, 348 million tons of plastic were produced. Microplastics (<5mm) form when larger pieces of debris break down from photodegradation and weathering processes. The abundance of microplastics and their characteristics make them hard to recover, resulting in accumulation in aquatic ecosystems. While the negative interaction between microplastics and marine mammals, birds, and reptiles has been widely documented, there is an increasing body of research on smaller-scale interactions between microplastics and microorganisms. Evidence from several studies suggests microplastics can act as physical substrate for algal growth. Most of these studies, however, have been conducted in laboratory conditions, so it remains unclear how microbes interact with plastics outside of a controlled environment at realistic concentrations. The purpose of this study was to determine how microalgae interact with microplastics in lake ecosystems, and specifically if microplastics function as a physical substrate for algal growth.
Water samples were collected from surface water (2 m) near three Combined Sewage Outflows (CSOs) on Lake Champlain. Samples were dyed using Nile Red in acetone before being low-pressure vacuum filtered membrane filters. Microplastics and attached microalgae were quantified using fluorescence microscopy.
The results from this research will contribute to the growing but largely unexplored topic of microplastics pollution. More importantly, the conclusions will contribute to our understanding of how microplastics enter aquatic food webs. As microplastics sink through the water column, fish and other species cannot distinguish them with viable sources of food. More so, when plastics sink, they become difficult to recover from lake sediments. The results could be used as valuable information for researchers investigating food webs, particularly zooplankton and fish, which eat algae. Understanding the implications of microplastics on biota will inform management and policy decisions and prevent further harm to the environment.
Primary Faculty Mentor Name
Mindy Morales-Williams
Status
Undergraduate
Student College
Rubenstein School of Environmental and Natural Resources
Program/Major
Environmental Sciences
Primary Research Category
Food & Environment Studies
Microplastics as a physical growth substrate for freshwater algal species
Humans interact with plastics every day in commercial and domestic uses. In 2017, 348 million tons of plastic were produced. Microplastics (<5mm) form when larger pieces of debris break down from photodegradation and weathering processes. The abundance of microplastics and their characteristics make them hard to recover, resulting in accumulation in aquatic ecosystems. While the negative interaction between microplastics and marine mammals, birds, and reptiles has been widely documented, there is an increasing body of research on smaller-scale interactions between microplastics and microorganisms. Evidence from several studies suggests microplastics can act as physical substrate for algal growth. Most of these studies, however, have been conducted in laboratory conditions, so it remains unclear how microbes interact with plastics outside of a controlled environment at realistic concentrations. The purpose of this study was to determine how microalgae interact with microplastics in lake ecosystems, and specifically if microplastics function as a physical substrate for algal growth.
Water samples were collected from surface water (2 m) near three Combined Sewage Outflows (CSOs) on Lake Champlain. Samples were dyed using Nile Red in acetone before being low-pressure vacuum filtered membrane filters. Microplastics and attached microalgae were quantified using fluorescence microscopy.
The results from this research will contribute to the growing but largely unexplored topic of microplastics pollution. More importantly, the conclusions will contribute to our understanding of how microplastics enter aquatic food webs. As microplastics sink through the water column, fish and other species cannot distinguish them with viable sources of food. More so, when plastics sink, they become difficult to recover from lake sediments. The results could be used as valuable information for researchers investigating food webs, particularly zooplankton and fish, which eat algae. Understanding the implications of microplastics on biota will inform management and policy decisions and prevent further harm to the environment.