6 Legs Unhealthy Stream Invertebrate Invertebrates example essay topic

Outline for a report Aquatic Invertebrates Used to Classify Stream HealthEcosystemAll things contained in an environment Water (input and output) ClimateDaylightPlant life Clear Cutting Clear Cutting seriously effects all aspects of an ecosystem Maine is, per capita, the most heavily logged state in the continental U.S. Why Clear Cutting is UsedSimpleCreates a uniform forest to harvest in 40 years or so Easy to replant Cheap to Maintain (pesticides) Clear Cutting Impacts on Streams Clear Cutting seriously effects stream ecosystems The effects of clear cutting can be felt on stream ecosystems for up to 60 years The First Five Years After a Clear Cut This time period is actually beneficial in most aspects of stream animal (vertebrate and invertebrate) health The increase in CWD creates resources for life Nutrients good for aquatic species increase Nitrogen levels increase 40 times Potassium levels increase 11 times After Five Years The negative effects of clear cutting begin to be felt Increase in fast growing vegetation catches nutrients Increased solar radiation leads to increased water temperatures With no protection, water temperatures drop drastically at night After Five Years (continued) Packed soil and new vegetation lead to increased water input Leading to higher peak flows and washing out CWD and boulders (habitats) The stream widens and becomes shallower Overall homogenization of the stream occurs Second Growth After 30-40 years, second growth forests develop The stream ecosystem stabilizes Stream Invertebrates Stream invertebrates have adapted to the harsh stream environment Mayflies are flattened from top to bottom, allowing them to swim fast in low current areasBlackflies produce a substance to attach themselves to rocks when the current is strong Many aquatic insects have tarsal claws used to attach themselves to rocks to avoid the current Identifying Stream Quality with Stream Invertebrates These adaptations have led to species that easily survive in polluted streams and those that don " streams can be classified by the types of insects in them There are 3 different categories of aquatic invertebrates when referring to stream health Invertebrate Body Parts Healthy Stream Invertebrates Invertebrates that live in a healthy stream are classified as Group One Taxa Healthy streams contain high biodiversity Some examples are... Stonefly 1/2 to 1.5 inches long 2 tails 6 legs with hooked tipsCaddisflyUp to 1 inch " Shell" made of mud sticks or small rocks 6 hooked legs Different Caddishly "Shells " Riffle Beetle 1/4 inch long 6 legs Oval body covered with tiny hairs Mayfly 1/4 to 1 inch long 2 or 3 tails 6 large hooked legs Often confused with the Stonefly Moderately Healthy Stream Invertebrate Invertebrates that live in moderately healthy streams are classified as Group Two Taxa Moderately healthy streams support a lower number and diversity of species Some examples are... Crayfish Up to 6 inches long 8 legs, 2 claws Dragonfly 1/2 to 1 inch long Light colored 6 legs Damselfly 1/2 to 1 inch long Large eyes 3 large tails, 6 legs Unhealthy Stream Invertebrate Invertebrates that live in an unhealthy stream are classified as Group Three Taxa Unhealthy streams support a very low species count and diversity Some examples are... Aquatic Worm 1/4 to 2 inches long Thin, worm like bodyMiteVery Small Looks like a spider May have up to 8 legsBlackfly Larva Up to 1/4 inch long One end of body wider than the other Suction pads on either end Leech 1/4 to 1 inch long Brown, Slimy body Suction pads at ends Accuracy of this approach Classifying streams by invertebrates is not always accurate Pockets can develop that contain healthy stream species in an unhealthy stream Often, though, it is a good indicator of how healthy the stream is.