The otter vs seal vs sea lion was a big issue when I went to Oregon Zoo last year. The seals and otters are next to one another, with a kelp tank in between and a big curve if you're doing the enclosed/underwater viewing vs water level. It was really hot so I stopped and watched the seals several times (seating and AC? yes please). The number of people who thought the seals were otters, despite signage, was unbelievable. A lot of people thought the seals were sea lions, too (I believe they had one lion until a few years ago?). On my last stop I decided I was going to stop trying to politely educate and just enjoy watching the animals. I ended up speaking up again, though, when one mom was telling her daughter to look at the seals and another woman informed her that no, they were sea lions. If you're going to try and correct someone, at least be right!! I explained a few of the differences, which lead to a guy trying to mansplain to me stuff I know but hadn't said because hello, I'm talking to a woman who can't read a sign and is with her toddler, I don't think she gives a **** about minor differences and things that aren't super obvious, like generally brown = sea lion and gray = seal.
During that entire time, there was a toddler who kept standing at the glass and screaming any time the animals came close (which was at least once a minute, given they were swimming mostly in a circle). Turns out her mom wasn't even in the underwater viewing area, she was somewhere else.