I don't know if you are aiming at the private or public sector but I have a MS in biology and am retired from the field of biology within the Federal government. Before my going to the Interior Department, I worked for a decade doing environmental analysis, risk assessments and environmental documents (in compliance with ESA, NEPA, FIFRA, etc.) for the U.S. Department of Agriculture i(USDA) n one of their headquarters agencies in Washington D.C. Our environmental staff was located within the agency's biotechnology and environmental coordination staff. A good number of our people were Phds but all of the biotech people were lawyers and PhDs.
With your international experience, I would say you would be a good candidate for USDA's Foreign Ag Service (FAS). I was once offered the opportunity of joining FAS while I was serving a temporary duty assignment in South America but I turned it down because I had a young daughter in school at the time. The best thing about FAS is that it had a 20-year full retirement similar to Federal law enforcement. I'm sorry that I can't offer any information regarding FAS hiring procedures. I'm sure Civil Service admissions has all changed since I left.
I wish I could remember all the leads I had for entry-level positions after graduation but a few I recall were:
1. A state game warden (my BS was wildlife management)
2. A state water fowl biologist
3. A reclamation biologist for a coal company doing strip mining.
4. R&D for several pharmaceutical companies.
5. Several Federal agencies who hire biologists (USDA, USDI, EPA, etc.)
Other possibilities for biologists: I used to have to meet with various Congressional staffers on environmental issues. I used to wonder what it would have been like to work as one of those staffers providing biological information to be used in the Congressional decision-making process. I have no idea how one gets those jobs.
Biologists also work in art. Early in my career I was once asked if I would be interested in sketching the insects to be used in the USDA training manual after the instructors caught me drawing the insects for the recognition tests we were to take for our new officer training. Another guy who was a real artist beat me out on that job.
One biologist who became a very successful artist you may know is Gary Larsen, the author of the cartoon series called The Far Side.
Many of his best cartoons contain a biological theme.
Other fields that use biologists include parks, zoos, environmental management companies, environmental analysis contractors, health care providers, natural history museums and on and on. Of course there are hundreds more career areas that use biologists. Each carry with them certain educational and experience requirements.
If nothing else from my ramblings, I hoped I could offer a bit of encouragement. Some folks do make a career of biology.
You sound as though you certainly have the courage to take on real challenges so I wish you the best of luck. Who knows. The next time we hear from you you may be representing the interests of the USDA at the American Embassy at Beijing.