1. Cycles in Aquatic Ecosystems
Science 10

2. Aquatic Nitrogen Cycle
Nitrogen in an aquatic ecosystem in introduced in two main ways:
Run off – nitrogen compounds from land ecosystems will enter waterways and provide nitrogen to the ecosystem
Cyanobacteria (blue-green algae) – completes nitrogen fixation in an aquatic ecosystem
The remainder of the process is almost identical to the land based nitrogen cycle

3. Eutrophication & Algal Bloom
Fresh water ecosystem
extra nitrogen results in a larger growth of surface plants
Underwater plants do not have enough light to complete photosynthesis
Decomposer populations explodes, reducing oxygen in the water
Consumers die due to reduced resources
Marine ecosystem
Extra nitrogen will lead to an algal bloom (huge increase in algae population)
As algae die, they sink into colder waters and the decomposers work to break down the algae
The decomposers increase in population and use the available oxygen
Consumers die due to reduced resources

4. Carbon Cycle in Aquatic Ecosystems
The cycle is similar in an aquatic ecosystem, with a few variations
Carbon dioxide is dissolved from the atmosphere into water (forming carbonic acid)
Aquatic plants obtain the carbon from carbonic acid to perform photosynthesis
Additionally, a great deal of carbon is stored in shells as calcium carbonate; this can help to form sedimentary rock

5. Draw
Create a diagram to show how the carbon cycle works in an aquatic ecosystem
Highlight the differences between a terrestrial and aquatic system