Autotrophs
There are two main autotrophs in the area of the Bruny Island neck, the two main autotrophs around the neck are algae and phytoplankton. There are two types of algae each with several different species, they are micro-algae & macro algae. The two types are different in a couple of ways, the main difference is micro algae is microscopic and macro algae isn't and the other main difference is macro algae prefers rock. Although there are two types of algae micro algae is the only type around the neck. phytoplankton and micro algae play a huge role in the ecosystem because they are the only two autotrophs in the ecosystem which means if one disappears the first order heterotrophs lose half they’re food which could have devastating affects later on down the food chain. |
First Order Heterotrophs
I found four first order heterotrophs with gastropods, bivalves, Amphipods and Zoo-plankton being them. The reason why I have only four is to stop the pyramid from having 100 different ones so clams, oysters, mussels, scallops, and other shell families in the ecosystem were classified as bivalves. All four types of first order heterotrophs eat both phytoplankton and micro algae but not every second order heterotrophs eat all first order ones with amphipods and zoo-plankton barely being eaten but gastropods and bivalves being rather popular, but even though some don't get eaten they each play a vital role in keeping the food web stable. |
Second Order Heterotrophs
There are a few more second order heterotrophs and these are all fish except for the crab, each of these second order heterotrophs play a vital role because they are pretty much all get eaten by all order’s above except for the southern right whale which doesn't get eaten at all, so with most of the second order being eaten by levels above and crab being extremely high on the menu it also plays a crucial role in the food chain for the levels above. |
Third Order Heterotrophs
There are 7 third order heterotrophs with them being Flathead, squid, pike, trout, flounder, Australian salmon and Atlantic salmon (farm escapes) . Each of the fish in this order have a wide variety of food they eat with most of them eating all second order Heterotrophs and some eating first order heterotrophs with most liking gastropods and bivalves, so the role of the third order heterotrophs is to keep eating so the number of lower orders don't get out of control making to many second order heterotrophs which would eat all first order heterotrophs resulting in nonfood for the higher order heterotrophs. |
Fourth Order Heterotrophs
There are 3 fourth order heterotrophs they are Fur Seals, Bottle Nose Dolphins and barracuda. Each of these 3 organisms eat the same food which is pretty much anything of reasonable size, so basically all second and third order heterotrophs. They’re role in the food web is the same as third order heterotrophs in just not letting population get out of hand which could create to many fish with hardly anything to feed on in comparison. |