We could do the following:

-Learn About the Ocean. One fairly simple thing we can do is to learn more about the oceans. ...
-Reduce Ship Strikes. ...
-Reduce Entanglement in Fishing Gear. ...
-Reduce or Eliminate Trawling. ...
-Limit Low and Mid Frequency Sonar. ...
-End "Scientific" Whaling. ...
-Stop Burning Fossil Fuels. ...
-Support Organisations That Help Whales.