Changing a job choice

Hi,

We are couple looking to move to Cairns, I currently work in a motorcyle dealership and my partner is a vet nurse.
My partner plans to continue this course of work but I would like to change.... I am currently studying a Marine Biology degree and will have it completed by the time we leave the UK.

I am hoping someone can give me some information on how hard it maybe to change job prospects and try to secure and job with the Marine Biology sector?

And help or info would be great.

Doug & Kate