You do not have to have a special degree to work with orca.
If you want to become an orca researcher and are thinking about studying for a Bachelor of Science (BSc) degree at university, then biological science subjects like Marine Biology or Zoology will stand you in good stead to pursue a scientific career working with killer whales. If you already have a degree and are thinking about taking your academic career to the next level by gaining a Master of Science (MSc) degree and/or doctorate (PhD), you can seek a course which will allow you to further specialise in studying marine animals and specifically orca.
There is also another career path that you can choose to take if you want to work with orca. You can begin by volunteering with a research, conservation or education project.
You can also combine both an academic career with gaining voluntary experience outside of university. Both practical and academic routes have their advantages and disadvantages. However, they are both as equally beneficial when pursuing a career working with orca!