3. Algae
This one isnt an animal, but a plant. It probably wont kill you, but even so you would probably rather do without it. Its not even the large seaweeds that you have to be worried about, like the box jellyfish its the tiny ones, the little plankton algae you need to watch out for. Algae produce all kinds of nasty poisons. The strange thing is, youre not likely to get directly poisoned by the algae unless you take a big drink of seawater its eating seafood thatll do it. Well, sometimes just being near a poisonous algal bloom is enough. Every year, massive algal blooms occur. Depending on the type of algae, youll get different types of poisoning. One of the more nasty ones is brevetoxin. This one doesnt necessarily need to be ingested as itll spread just fine through the air, and breathing issues have been recorded previously in lifeguards working close to the blooms. Even nastier is a poison produced by another algal species called domoic acid. Symptoms include nausea, vomiting, brain damage and death. Thankfully, only 4 fatalities have been recorded from over 100 cases. Not so thankfully its incredibly difficult to diagnose algal poisoning so numbers are probably far higher. Blooms of harmful algae can happen pretty much anywhere in the world, and surprisingly, theres no antidote to either poison.