It appears, from the zoomarine.pt site, that there is a daily bus departure from the Pestana Dom Joao II at Hotel D. João II (bus stop) 9.25 to Zoomarine.
There also appears tp be a bus at 09:05 and 11:05 to Slide and Splash.
http://www.slidesplash.com
Much cheaper than taxis.
I am sure the hotel reception can provide more info.
