hi my name is Mary penro and I'm an adun professor of biology and today we're going to be talking about keystone species versus indicator species a keystone species is a species that has a huge impact on the environment even though its population numbers may be kind of low much like a keystone in an arch helps support the entire Arch a keystone species if removed from the ecosystem can cause a collapse one example is the California sea otter the California sea otter was almost haunted to Extinction when that happened scientist and fishermen started to see a collapse in this ocean environment you see sea otters are one of the only organisms that eat sea urants well sea urchins eat kelp no sea otters the sea urant population exploded and started to eat all of the kelp so what's the big deal well kelp actually provides a place for protection as well as spawning for fish so as the sea otters disappeared so did the fish luckily sea otters were brought back and the ecosystem off the coast of California are doing much better our next example is indicator species an indicator species is a species that whether absent present or in relative abundance tells scientists a little something about what's going on in the ecosystem one example are lyans lyans are extremely sensitive to things like sulfur dioxide and ozone if these things are in the air you can tell because the lyans won't be doing so good and possibly be absent from areas that they used to be in so that can tell scientists that there's probably an air pollution problem in that area now even though every species has an inherent right to live on our planet some species are just a little bit more important to the health and vitality of an ecosystem than others thanks for watching and if you want to learn more about this subject click on the link below or if you want to learn more biology feel free to click on any of the links around me and please rate comment and subscribe to this Channel or maybe if you have ideas for more videos send us an email at requests mahalo.com thanks for learning