Aquatics

Aquatic Habitats Lentic Lentic –Standing water habitats (lakes, ponds, wetlands) Lotic Lotic –Moving water habitats (rivers, streams)

Classifying Aquatic Habitats Oligotrophic Oligotrophic –Aquatic ecosystem with low nutrients –Usually, clear, cold, fast moving, hard bottom, low nutrient soil, low algae

Classifying Aquatic Habitats (continued) Eutrophic Eutrophic –Aquatic ecosystem with high nutrients –Usually warm, slow moving, turbid water, high nutrient soil, lots of algae Mesotrophic Mesotrophic –Middle/medium nutrients

Zones of a Lake (surface) Litoral Litoral –Shoreline and shallows –Fluctuates –Breeding grounds and protection Limnetic Limnetic –Open water in middle of the lake –Can be deep water or may be shallow –Little interaction with land

Zones of a lake (light) Photic Photic –Area that light reaches –Plants –Emergent Vegetation –Submergent Vegitation –Algae Aphotic Aphotic –Light doesn’t reach Benthic Benthic –Bottom of lake –Benthos is dead decaying muck –bubbles Pond vs Lake Pond vs Lake

Zones of a Lake (Temprature) Epilimnion Epilimnion –Upper layer –Usually warm Hypolimnion Hypolimnion –Lower Layer –Usually cold Thermocline Thermocline –Line between hypolimnion and epilimnion –Water usually doesn’t mix between the two layers Turn Over Turn Over –Complete mixing of the thermolayers –Cold on top, warm on bottom

Living Conditions D.O. D.O. –Dissolved Oxygen –Low temp=High DO –Moving Water=High –Cold Pop Turbidity Turbidity –How cloudy the water is –High Temp=High Turbidity –Moving Water=High Turbidity –Warm Coffee Secci Disc Secci Disc –Used to Measure turbidity Trout Streams of SE MN vs NE MN Trout Streams of SE MN vs NE MN Channeling Mississippi Channeling Mississippi Eutrophic vs Oligotrophic Eutrophic vs Oligotrophic

Winter Kill Freeze Out/Winter Kill Freeze Out/Winter Kill –Fish in lake die because of lack of oxygen BOD (Biological Oxygen Demand) BOD (Biological Oxygen Demand) –Increases slightly in the winter because of algae death not fish breathing Bacteria eat algae in eutrophic lakes Bacteria eat algae in eutrophic lakes No Oxygen exchange with air because of ice No Oxygen exchange with air because of ice Shallow eutrophic lakes are the most susceptible Shallow eutrophic lakes are the most susceptible

Pollution Pollutants can turn an Oligotrophic lake to a Eutrophic lake Pollutants can turn an Oligotrophic lake to a Eutrophic lake –Ammonia, Phosphorus and nitrogen –Farms, lawns, raw sewage Run Off Run Off –Impermeable surface (roads and driveway) –soil run off (farms, and construction) Thermal Thermal –Power plants

Riparian Habitat Riparian Zone Riparian Zone –Transition zone between an aquatic habitat and a terrestrial habitat –High diversity –Important to both ecosystems

Altering aquatic ecosystem Benefits of Dams Benefits of Dams –Electricity –Recreation –Water supply –Reservoirs Drawbacks of Dams Drawbacks of Dams –Loss of Riparian Habitat –Fluctuation of river down stream –Build up of sediment –Stopping corridors –Thermal pollution Hydroelectricity Hydroelectricity –Good or Bad?

External Fish Anatomy

Internal Fish Anatomy

The End