Freshwater Biology

Bacteria Freshwater bacteria can be cool, but they can also be harmful Bacteria love warm, wet environments –Many freshwater locations are perfect Harmful bacteria in freshwater environments can infect humans

Bacteria How do they get there? –Many bacteria come from animal feces (poo) and earth around the water source –Bacteria can come from infected swimmers –Can also come from infected animals –Strong or large amounts of rain will definitely wash bacteria into the water source Bacteria can enter humans through inhalation, digestion, and open wounds

Bacteria While there are plenty of helpful bacteria in freshwater environments, but many of them can cause harmful symtoms for swimmers; –Cough, rash, diarrhea.. And EVEN DEATH! So.. –Don’t swim if pregnant –Don’t swim if you’re old (Mr. B)

Freshwater Fish Physiology –Freshwater fish must be able to diffuse water through their gills (to eliminate impurities) –Freshwater fish must be able to hold onto salts with a large kidney –Freshwater fish release large amounts of urine –Freshwater fish have to have enough scales to reduce diffusion, fish that loose too many scales will die

Freshwater Fish Migration –Potamodromous –Oceanodromous –Diadromous Anadromous Catadromous 1% of all fish are able to live in both salt and fresh water Freshwater fish can withstand.05% salinity

Freshwater Fish Freshwater fish are much more readily adaptable than saltwater fish –This is because their environments are usually always changing There are more freshwater fish in rivers and streams than in lakes 42% of known fish species live in freshwater

Freshwater Mammals Freshwater mammals include not only cetaceans (river dolphin), but land animals as well Freshwater mammals often have large tails (Ex. Beavers, manatees, etc.) to aid them in swimming Many freshwater mammals have fur (lots of it) to keep them warm

Freshwater Mammals Why do they need fur? –Freshwater environments are often colder than salt water environments so they need insulation What do they eat? –Crustaceans, other fish/animals, freshwater vegetation

Freshwater Mammals Freshwater species are often used as indicator species for scientists –Scientists can study the population size around a water source to determine if the ecosystem is healthy Freshwater mammals are also endangered by the same things as saltwater mammals; –Sewage, boating accidents, stupid people