Aquatic Habitat Lakes and Oceans Lecture 15

Factors Influencing Lake Dynamics Hydrology Geology Morphometry Base chemistry Biology (food chain) Human activity

Human Impacts on Lakes Alter hydrology Increase nutrients Increase sediment Alter vegetation

Water Quality Determined by: Combinations of: Alkalinity Phosphorous Dissolved Oxgyen Nitrogen Temperature Dissolved & suspended solids chlorophyll iron calcium algae macrophytes Morphometry fish

Water Quality Classifications Measured by Phosphorous in parts per billion

Lake Productivity Through Time

Eutrophic Conditions

Natural Eutrophication geologic time (thousands of years) natural sedimentation delivered by streams the lake gradually shallows phosphorous is in the sediments - taken up by macrophytes the lake turns into a marsh, and eventually a forest To set back the successional clock, the lake must be dredged

Cultural Eutrophication Human generation P in water Increased algae & macrophytes No change in depth Improved only by decreasing nutrient input

Seasonal Changes in Habitat Water is the most dense at 4 degrees C

Habitat Scale Macrohabitat: Temperature, DO Mesohabitat: estuaries, littoral zones Microhabitat: fish occupied location

Habitat Management in Ponds & Lakes (video of plant control)

Habitat Management in Ponds & Lakes Nuisance plant control Water level manipulations Artificial spawning structures Cover aeration

Ocean Habitat and Fish

Zones of Habitat in Ocean Benthic realm: all those areas in direct contact with the bottom. (shelf, upper slope, lower slope, abbysal, hadal zones) Pelagic realm: independent of the ocean bottom, open water habitats. (epipelagic, mesopelagic,bathypelagic, hadopelagic)

Habitat Management in Oceans Decrease pollutants Prevent shoreline development Add artificial reefs

Nutrient Source?