Overfishing at sea can lead to a(n)

Overfishing at sea can lead to an extinction. 
Overfishing is a serious problem, it affects lot of marine species, at every water corner of the Earth. If the fishing is not controlled strictly it leads to extinction of the marine wildlife, lot of species have already been extinct, thousands are on the verge of extinction. Also, the extinction of a single species makes big problem in the ecosystem, removing lots of species has huge impact on lots of ecosystems that are connected and the consequences are irreparable.

2cool and cold temperature unless its an ever green tree 

Answer volcanic outgassing;