Aquarium researchers have undertaken a combination of field, captive and lab studies for research. The studies emphasize the effects of changes in types of prey on sea lion condition, health and energy balance. Steller sea lions are larger and have longer flippers. They are very vocal, territorial and aggressive. Sea lions are also able to support themselves on their front two flippers and can pull their hind flippers under their bodies to walk.
Seals have a smaller and sleeker torpedo shaped body.
They rarely vocalize and are quite shy. Seals do not use their flippers to support their bodies and move by sliding or shuffling. Males have a higher mortality rate than females. It is difficult to study Steller sea lions in the wild, because Steller sea lions are extremely skittish, especially in the winter. Scientists are not certain if these rocks are swallowed by accident or if they serve a useful function.