I am just about to start my final year of a zoology degree in which I am predicted a first, I want to start a phd next year when I finish so when should i start looking to apply?

It varies but in my university the department asked for students interested in pursuing a PhD to get in touch with them around March. The best thing to do would be to ask your academic supervisor, but if my university is anything to go by it won't be until the new year before they start thinking about applications.

I should say that as zoology will be dealt with under a different research council (I'm under the ESRC, zoology I would guess might come under the BBSRC) that it could be earlier depending on when their application deadline is.

i would keep an eye out on sites like new scientist etc from when you return, a few places i contacted early or knew about were willing to speak before xmas especially if they state on the webpages etc feel free to contact reguaring projects, as if you get in early it can be useful. most advertised places begin in march, though beware often they are already filled (and advetised because they have to) so start looking early!