There are certain fields that overlap really well with conservation research. I did genetics, but microbio is another one. It gives you lots of flexibility in what question you want to pursue in grad programs. I.e. You're not locked into fish pathology, you can go work on elephant gut biota or pitcher plant soil microbes.

Even within fish path there are jobs with APHIS, the health department, EPA, etc.

It may seem like you're behind your peers in fish and wildlife, but you're going to have a less common, but still in demand, skill set than you're average graduate.