A year ago your editors were in Hawaii (enjoying 30°C temperatures nearly every day 🙂 ). One of the places we visited was the Hawaiian Islands Humpback Whale National Marine Sanctuary on Maui which has informative displays and daily presentations about not only Humpback whales, but other marine creatures seen around the islands. Website
As can be seen on the outdoor display board near the breakwater enclosure (click for full view), these include Spinner, Spotted, Rough-tooth and Bottlenose dolphins, Pygmy killer, False Killer and Pilot whales, Green Sea Turtles and Hawaiian Monk seals.
The major threat to marine creatures in Hawaii, as it is around NZ, is plastic waste floating in the ocean, nearly all of it having come via currents from Third World countries that don’t care about it, but some also gets discarded from fishing and other vessels. The pic below shows a sampling of what NOAA (National Oceanic and Atmospheric Administration) has extracted from the sea.