Invasive species (Put HW on your desk while you answer this in your notebook)  Why are species like cane toads a problem? After all, lots of species have high population growth rates and high carrying capacities.  In other words, what’s wrong with a species that grows so quickly?  Discuss, be ready to share.

Basic terms – “native” and “invasive”  What is a “native species”? Discuss, be ready to share.  Native Species: Lives in an ecosystem without having been distributed there by humans.  What is an “invasive species”? Discuss.  Invasive Species: NOT native to an ecosystem Introduced to the ecosystem by humans Causes harm to the ecosystem, human health, or our economy.  Note: not all non-native species are invasive

Why should you care?  How do you think invasive species can cause damage to the economy or the environment? Discuss.  Economy Devastates key industries - seafood, agriculture, timber, hydro-electricity, and recreation (boating, fishing…). Costs Americans billions of dollars a year  Environment Impact/harm nearly half of all endangered or threatened species Lowers biodiversity

Why does biodiversity matter?  What is biodiversity? Discuss.  Biodiversity = #of species in an ecosystem  “Stable” ecosystems have relatively constant biodiversity over time  How do invasive species affect biodiversity? Discuss  Invasive species can decrease biodiversity  less stable (big problem) Invasives “do better” than native species, sometimes driving them to extinction  Invasive species can decrease productivity  fewer resources for human (e.g. food, pharmaceuticals)

Why do invasive species do so well?  Working with your neighbor, share information on species you discovered while doing your homework from last night.  Brainstorm a list of characteristics that invasive species must generally have in order to “do better” than native species You could verbally “invent” an invasive species with these characteristics if it helps…  Example: All invasive species are well-adapted to the climate of the ecosystem they “invade”.  Be ready to share.

Factors affecting population growth (or, why invasive species do so well)  Competition Better able to compete for resources like food, shelter, space (higher birth, lower death rates)  Predation Have no/few predators (incl. parasites/diseases) or can easily avoid them (lower death rate)  Reproduction Are able to quickly produce high numbers of successful offspring (high birth rate!)  Abiotic factors Well adapted to the climate /conditions of the new ecosystem (higher birth, lower death rates in the ecosystem they “invade”)  Immigration and Emigration Often continue to arrive in large numbers – because of humans or their own dispersal (immigration), and tend to stay put once in the new ecosystem (no emigration)

Examples  The following species are invasive in Washington State (or may be soon) Could a few of you share what you learned (give one example)? Record brief descriptions of each of the invasive species covered in the next few slides or shared by students Don’t record if you already recorded information about the species for homework.

Brazilian Elodea  Historically sold in pet stores, gets dumped in water bodies (streams, lakes, etc)  Grows VERY quickly. Chokes out native plants. Blocks passage of native salmon  Illegal to buy/sell in WA  (It’s in our jars! I’ll dispose of it carefully.)

Zebra Mussel  Reproduce VERY quickly  Filter out nutrients from freshwater rivers, lakes, harming native species  Grow so fast that native species are crowded out  Clog water intakes, hydroelectric dams - $$$  Not in WA, yet?

 Left in zebra mussel-infected waters for a “few months”…

Atlantic Salmon  Native to eastern US  Escape from “fish farms” (aquaculture) on west coast  Last sighted in 2000?; still a concern  Why a concern? Bring “sea lice” to wild, endangered salmon populations Can kill juvenile salmon…

Nutria  Live in marshy areas, though not yet well established in WA  Breed very quickly in Louisiana population went from 20 to 20 million in two decades!  Eat tremendous amounts of food – degrading wetlands and removing food for native species Can cause destroy dikes, dams, cause flooding.

Invasive species in the Pacific Northwest: Tunicates (sea squirts)  Lives in the Puget Sound, displaces native mussels, clams and oysters Has abundant food (filter feeds) No predators Reproduces quickly Well adapted to climate

Himalayan Blackberry  Evergreen shrub with thorns and edible fruit Found throughout WA Shades/outcompetes native species Lowers biodiversity

English Ivy  A woody evergreen vine or shrub, English Ivy is found throughout Washington state Grows and spreads very, very quickly Can crowd native plants Reduces animal foraging Very hard to remove from an ecosystem

Eurasian Milfoil  Common in freshwater ecosystems throughout North America Spreads very rapidly Crowds out native plants No predators

Purple loosestrife  Common in wetlands throughout the US Crowds out native species, eliminating food sources for many aquatic (often endangered or threatened) birds Destroys wetland habitat Cannot be killed by an pesticides, no known predators State law requires landowners to control it!

Cane Toads – a Review  Think back to the Cane Toad video. Take out your notes if you need a refresher.  Working alone, list reasons explaining why Cane Toads are such a successful invasive species in Australia. Specifically refer to what we just discussed in class.