Finally, the lowest zone is exposed only during minus tides those below average low-water mark with purple urchins, sea cucumbers, many-rayed sea stars, and bull kelp proliferating.
(the lowest zone; is exposed; T:only during minus tides; T:Finally) (bull kelp; proliferating; )
the lowest zone bull kelp
is exposed proliferating
T:only during minus tides T:Finally