All tanks for captive orcas consist of hard concrete surfaces, which is something that is unnatural for all orcas; even those who beach themselves on flat surfaces to hunt sea lion pups in Argentina, as they hunt on sandy beaches. By including some soft surfaces, pools for orcas could be improved. However, many orcas in captivity are prone to biting on their tank structure's surfaces which may severely damage softer surfaces. To combat this, their environment could be made sufficiently complex so the orcas are less likely to interact with the softer surfaces in this way. Thick rubber blocks embedded into the poolside walls, where no edges are free to be chewed on, could provide a more interesting, less harsh and more tactile surface than concrete or tiles.
To help reduce stress and promote mental welfare, quiet shaded areas, where the whales could withdraw to rest, would provide them with an area to retreat from the public and also help with reducing tensions between group members. To create a more desirable resting area, cooler water could be maintained at the bottom of these withdrawal pools.
If large boulder substrates were added, this may provide a relaxing and stimulating area for the whales to be in. However, if substrates are not carefully selected, they could be swallowed by the whales or chewed, causing damage to the teeth and gut. To simulate rubbing beaches, large, smooth, roller-bearing surfaces, similar to those used on production lines, could be carefully installed into the pool floor or walls for the whales to rub against.
Photo: Kevinma255 (Flickr)