Zooplankton
Highlights:
Zooplankton serve as consumers of algae in Cherry Creek Reservoir. In WY 2023, the zooplankton population dynamics were similar to previous years.
Zooplankton are microscopic animals that consume algae and bacteria in the water column. Some types of zooplankton feed on algae, others on other zooplankton, and some take in both plant and animal particles. Larger zooplankton can exert significant grazing pressure on algal cells; however, they are also subject to predation as they are a food source for larger crustaceans, aquatic insects and fish.
Most freshwater zooplankton are part of only three phyla: amphipods, which include both cladocerans (shown in green) and copepods (shown in orange); rotifers (shown in yellow); and protozoa (shown in blue). Cladocerans and copepods are microscopic crustaceans that feed primarily on phytoplankton. These organisms can be an important food source for fish and can also exert grazing pressure on phytoplankton populations when present in high enough numbers. Rotifers are microscopic animals that feed on detritus and smaller organisms, such as bacteria. They can also serve as a food source for larger zooplankton. Protozoans are single-celled organisms that feed on other microorganisms, organic matter, and debris.
The invasive water flea, daphnia lumholtzi, a type of cladoceran, is less palatable to fish due to its spines.
Due to unforeseen delays in late season plankton sample analysis, a more detailed zooplankton evaluation summary will be provided in an amended report later in 2024.
Useful Links
Zooplankton Concentrations and Biovolumes
info_outlineEach point on this graph represents a sampling event. The y-axis represents the concentration (number) and the size of the bubble represents the biovolume (size). The colors represent different zooplankton groups. Use the filters to target a specific group or date. To learn more about a specific data point, hover over it with your mouse.