On the center make dunkleosteus quite the pest when trying to gather silica pearls or other deep water resources. If one is provoked by combat or getting too close other dunkleosteus will come to attack you from very far away and it is almost impossible to escape once they swarm you or your tame.
Make a stone or metal box underwater, two walls high and three or more walls wide. They flee if you use any narcotic arrows or tranq darts so avoid those when kiting one into the box. Once inside, they cannot escape through a gap one wall thick or high.