Classification of Lakes “Limnology” – the study of Lakes

Lake size and depth can change over time Lakes can fill in with sediment without human interference. Lakes can be classified by their progression through this process.

Oligotrophic Very Low nutrients Deep lakes – 60-100 feet deep Very Clear water –Secchi reading of more than 12 feet Less plant and animal growth Usually poor fishing but GREAT for scuba diving and swimming

Oligotrophic

Oligotrophic

Mesotrophic Moderate levels of nutrients Some Clear water – Secchi reading of 8-12 feet Moderate plant and animal growth Average Fishing and swimming lakes Some algae and plant growth around the shoreline with open water in most of the lake

Mesotrophic

Mesotrophic

Eutrophic High levels of nutrients Mostly murky water – Secchi reading of 3-8 feet High level of plant and animal growth GREAT fishing Green or dirty looking – plant dominated Lots of sediment in the lake bottom

Eutrophic

Eutrophic

Hypertrophic Extremely high levels of nutrients Algae blooms – Secchi reading of 0-3 feet High level of plant and animal growth Poor fishing, often too much nutrients to support a healthy fish population Overrun with plants and algae, often caused by sewage and fertilizer runoff Smelly water and muck covered bottom

Hypertrophic

Hypertrophic