You would probably be most interested in becoming marine biologist. They do quite a bit in the lab, as well as quite a bit out on the land. I will attach some websites that may give you some more insight as to what they do, but I will provide some basic information here for you to take a look at.
** Look at trends, and how the weather systems, as well as the different phenomens such as El Nino, and La Nina affect the trends of the coastlines, and what they are doing to the existence of the marine mammals such as seals, otters, sea lions, dolphins, porpoises, orca and so on.
** Ensure that the shoreline remains clean and an inviting place for marine life to come to as well as to ensure that the garbage is picked up from around this area, as many animals will become injured with things such as pop links, ropes, fishing equipment etc.
** Look for sick and/or injured marine life, and know how to deal with them, and how to coax them into the proper areas i.e. out into open sea, or into the river, or away from areas that might put them into trouble with survival such as urbanization, boats, fishermen, and ones that may become to used to being around humans.
** Look into ways of rehabilitating sick and injured animals, and look at ways that the general public can reduce the impact that they have on the marine mammals, and the other intertidal life etc.
** Depending on some types of biologists, they may also go out and research about the underwater life around corals, and other things that attract animals, and do research on them. Some of them may be required to do things like scuba diving, or taking boats, or rafts etc. into some of these areas, and look for predictions and other type of things that might indicate possible trends, and knowing how to deal with impacts.
** Educating the general public about safe ways of draining dirty water, detergent etc., that will not impact the waters such as streams, and creeks etc.