Oil spills in the ocean affect both the aquatic environment and the frequency of volcanic eruptions. immigration rates. economy. frequency of earthquakes.

Hello There! ^_^ 

Your question: Oil spills in the ocean affect both the aquatic environment and the .

Your  Oil spills in the ocean affect both the aquatic environment and the economy.

The answer is economy.
Hope this helps!

The answer may be "economy".

Hope this helps !

Photon