A man was walking along a deserted beach at sunset A man was walking along a deserted beach at sunset. As he walked he could see a young boy in the distance, as he drew nearer he noticed that the boy kept bending down, picking something up and throwing it into the water. Time and again he kept hurling things into the ocean. As the man approached even closer, he was able to see that the boy was picking up starfish that had been washed up on the beach and, one at a time he was throwing them back into the water. The man asked the boy what he was doing, the boy replied, "I am throwing these washed up starfish back into the ocean, or else they will die through lack of oxygen. "But", said the man, "You can't possibly save them all, there are thousands on this beach, and this must be happening on hundreds of beaches along the coast. You can't possibly make a difference." The boy looked down, frowning for a moment; then bent down to pick up another starfish, smiling as he threw it back into the sea. He replied, "It makes a huge difference to this one!" 

*You don’t have to copy down notes that are in italics* Species at Risk *You don’t have to copy down notes that are in italics*

What is a habitat? The space that a species needs to live and grow Food Water Living space Shelter

There are 4 types of species at risk: An organism that is at the risk of extinction due to threats caused by humans There are 4 types of species at risk: Special concern Threatened Endangered Extirpated And Extinct, though this is not at risk anymore.

Special Concern A species that may become threatened or endangered because of a combination of biological characteristics and identified threats Eg. Polar bear– global warming causes Arctic ice to melt (calving)

Threatened A species that may become endangered unless actions are taken to reverse the factors reducing its population Eg. Humpback whale– commercial hunting/fishing, collisions with ships, lack of food

Endangered A species at imminent threat of extinction Swift fox– loss of habitat in the prairies, poisoned, trapped

Extirpated Extinct in certain regions but exist in other parts of the world Eg. paddlefish– destruction/blockage of spawning grounds, pollution, overexploitation

Extinct Well, you know; not found anywhere on Earth anymore Eg. passenger pigeon-- overexploitation, loss of habitat with disappearing deciduous forests It’s actually stuffed 

The Importance of All Species The disappearance or decrease of a species will effect many other species (up to 30) within their ecosystem Think of a scale; if one side has more mass, it’s unbalanced. Nature will always try to reach an equilibrium, but a disturbance can cause it to fluctuate again. Now think of a 1000-sided scale. With more biodiversity though, the populations will return to its original balance faster as there are more species to counteract the disturbance

For example, in a simple food chain like this, one change can affect every other species. Say humans started sport hunting hawks: Hawk population decreases Snake population increases Mouse population decreases Grasshopper population increases

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