“Who thought it was a good idea to put a whale in a pool?” Howard Stern recently wondered on his satellite radio program.

The shock jock’s comment hints at just how much public scrutiny of captive orca shows has increased, driven by well-organized animal advocates and written into a new bill to outlaw the practice that was introduced in Congress last week.

SeaWorld—the most famous keeper of orcas, also known as killer whales—responded on Monday by announcing sweeping changes to programs at its flagship San Diego location, including phasing out the “Shamu” orca act.

The developments come amid reports of falling admission to its 11 parks around the United States. SeaWorld’s share prices have also been sliding steadily