Things that go bump in the night can get really interesting by the next morning, too. Don't let the kiddies play with the road kill. I know, it sounds like restating the obvious, but it isn't. Well, wear shoes while you stroll along looking for agates to wash up. Stepping on a stingray will make it mad and it will sting ya good.
Jellyfish can be a major hazard, especially for the young.
By all means explore the tide pools, but leave the animals that live in it alone. There is a world of difference in 'touching' and 'looking'. Never take a live shell away from the beach. Look, enjoy, and then leave it alone. Oh, BTW, don't ignore the shark warning signs either.