Comparing Littoral and Pelagic Zooplankton Communities in the Lakes of Maine
Document Type
Event
Department
Environmental Science and Policy
Abstract
Zooplankton communities are efficient algae grazers, and play a key role in the aquatic ecosystem’s food web as consumers as well as prey. Within a lake there are two zones of interest: littoral and pelagic. The littoral zone is where the water is shallow enough that sunlight can penetrate to the bottom and support rooted aquatic plant growth. The pelagic zone is deep enough that sunlight only supports microscopic plants (phytoplankton). We conducted zooplankton net tows from both zones in eight lakes throughout the state of Maine in July 2021. Using microscopy to identify and count the collected zooplankton, I will compare zooplankton community differences in littoral versus pelagic zones. Specifically, I ask the question: how do pelagic and littoral communities differ in species population and abundance? While results are likely to vary from lake to lake, I expect to see a general trend of larger species in the littoral zone and smaller species in the pelagic zone. I expect to see differences in population and abundance in these two sites because the littoral zone has physical structure including rooted macrophytes and the bottom substrate that the pelagic zone does not. It has been hypothesized that these structures provide refuge from predation for large zooplankton. In addition, there are some families of cladocerans (e.g. Sididae) that are often found around structure but infrequently at the deep hole.
Comparing Littoral and Pelagic Zooplankton Communities in the Lakes of Maine
Zooplankton communities are efficient algae grazers, and play a key role in the aquatic ecosystem’s food web as consumers as well as prey. Within a lake there are two zones of interest: littoral and pelagic. The littoral zone is where the water is shallow enough that sunlight can penetrate to the bottom and support rooted aquatic plant growth. The pelagic zone is deep enough that sunlight only supports microscopic plants (phytoplankton). We conducted zooplankton net tows from both zones in eight lakes throughout the state of Maine in July 2021. Using microscopy to identify and count the collected zooplankton, I will compare zooplankton community differences in littoral versus pelagic zones. Specifically, I ask the question: how do pelagic and littoral communities differ in species population and abundance? While results are likely to vary from lake to lake, I expect to see a general trend of larger species in the littoral zone and smaller species in the pelagic zone. I expect to see differences in population and abundance in these two sites because the littoral zone has physical structure including rooted macrophytes and the bottom substrate that the pelagic zone does not. It has been hypothesized that these structures provide refuge from predation for large zooplankton. In addition, there are some families of cladocerans (e.g. Sididae) that are often found around structure but infrequently at the deep hole.
