There are many hazardous organisms in the intertidal. Be sure that whenever you walk in the water wear covered shoes with good soles. When you are walking on algae-covered rocks, you need to be careful because algae are very slippery and it is easy to fall. When you are looking for organisms, be sure to not touch brightly colored ones, especially red ones, or ones that look dangerous. Most brightly colored organisms are poisonous. Do not stick any part of your body in crevices because there may be something hazardous in it, like an eel for example. Stay away from sea cucumbers. Although they dont look dangerous, they are capable of squirting out guts that can cause irritation on the skin. That is basically all you have to look out for. Be sure not to touch anything that looks like it can cause harm. Whenever you visit a site, be sure to have a first aid kit ready, just in case you need it.
Dont step on coral or any habitat that you see animals living in. you also should not pick up any sponges, cone snails, or anemones. Especially if any of them are red. Red means stop, except if it is red algae, then its all right, so dont worry. You might not want to pick up any sea urchins either because they might poke you and it hurts. You can touch some of them, but not the big black ones. Those are called wana, and they will sting you, so be careful.
Another thing you should never do in the intertidal is stick any part of your person into a hole. Many dangerous things like wana, sea anemones, big fish, poisonous cone shells, and eels live in holes in the intertidal, and putting a part of your body into it can result in the loss of it. A few people in our groups have come across these organisms and have not had the most pleasant experience. When visiting the intertidal, always be aware of where you step. There are many kinds of algae in the intertidal and they can make the rocks very slippery and that can make you fall if you arent careful.