M.Ed., Stanford University
Winner of multiple teaching awards
Patrick has been teaching AP Biology for 14 years and is the winner of multiple teaching awards.
A biome is a type of ecosystem with similar life forms and environmental conditions. Biomes can be affected by factors like rainfall, humidity and latitude. Aquatic biomes are often classified into freshwater ecosystems (lakes, rivers and ponds), salt water ecosystems (seas, oceans and coral reefs) and wetlands (marshes and swamps).
If you met somebody new and you want to kind of know where they came from you might ask them "so what town do you come from?" and if they rattle about some name you never heard of you might ask them "what is that like?" They said "oh it's a suburb of Chicago or it's a big city kind of like New York" You'd automatically know a lot about the environment that person grew up in, the kind of things that you would expect to find there.
In ecology they don't talk about cities or towns they in stead talk about what are known as biomes. A biome is a type of the ecosystem and a lot of times the term biome and ecosystem are used interchangeably and it's based on the type of environmental factors you may have such as in on land things like rain and temperature and as well as the kinds of organisms that are found there. With the aquatic biomes you are not so concerned about soil types so much as things like fresh water versus salt water. Now there is lots and lots of different kinds of biomes within this group and I'm not going to go through every single kind just like you wouldn't want me to go through every kind of city in town but instead I'll kind of highlight some of the key ideas that are used to categorize them and then I'll go through the different areas that you'll find fresh water and salt water environments.
So the fresh water biomes would be things like lakes and ponds, rivers you also will see a merging between fresh water and salt water where you have what's called estuary that's where rivers starting to spread out and merge with the ocean or sea. Salt water environments are typically things like seas and oceans and you'll find very different biomes in places like a coral reef versus what is known as a whale fall where you'll find a dead whale at the bottom of the ocean and a bunch of organisms living of for that. Now in kind of a weird kind of merging between terrestrial and aquatic biomes you'll find things called wet lands which includes things like bogs, marshes, swamps etcetera.
If we take a look at the zones that you'll find typically in a lake you'll see things like Litteral being used and the Litteral region is the part that is closest to the shore where it's underwater but you'll still often find plants growing up and still able to reach the surface. While the Limnetic or Photic zone is where you are past that but you are still in the area where light can penetrate as opposed to the Profundal or Aphotic zone which is too deep for water to get. Now you sometimes see references to what is called the Benthic and that's just the soil that is around the bottom of the lake. So this is Benthic all the way to there to the deep water zone.
Now you'll see some of the same terms appear when you're talking about oceanic zones but it gets a lot more squishy and there is a lot of different terms here that kind of overlap with each other. For example the Photic zone again is where light can penetrate and the Aphotic zone is where light can't but there is all these other overlapping areas because you'll have what is known as the Intertidal zone and that's where you have parts that are exposed during low tide but covered up by water during high tide. You again see that reference to Litteral region especially when you are talking about shallow seas and then there you get into what is called Pelagic that's the open water, the point at which you start going "oh no I'm a little bit far away". And I start thinking about sharks.
Now I have already discussed the Photic and Aphotic, the Neritic zone that is where if you've ever gone out into the ocean you are actually still over the continent it's not until you passed what is known as the continental shelf because in tectonic continents are actually pieces of land that are above on top of the plates that are on the bottom of the ocean, so this continental shelf is where those two tectonic plates and you'll have the Neritic zone being this part here as opposed to the true oceanic zone which is once you pass that and you will over sudden see the bottom of the ocean starts plummeting rather rapidly, now again the Benthic refers to that layer of sediment that is along the bottom but once you are pass the Neritic zone into the oceanic you start talking about the abyss or the abyssal plane which is what you find way at the bottom of the ocean in that open area and that is the kind of weird areas where scientists are still doing a lot of study because it's only recently that we've been able to get there to examine those sorts of regions.