There are 4 expansions for Zoo Tycoon 2.
They are:

● Marine Mania®
● Endangered Species
● Extinct Animals
● African Adventure

All of these expansion packs can be also found in Ultimate Collection!

3 expansion pack trials are free for download at:

● link

You can also download additional animals
and patches at link

If you don't know how to make waterfalls,
or need some useful links, read some more articles
that i wrote.

Oh!Also, there are some cool things that you unlock by solving missions:

Unlockable     How to Unlock

African theme     five game challenges...