The sign to the right says "Caution - Blue Bottles." That would be the blue bottle jellyfish:
They came in the two nights ago. There are thousands and thousands washed up on shore. Here's just one, with one of it's very long tentacles:
If a tentacle attaches itself to a human, it releases a poison (through the use of nematocysts), and if you continue to rub the skin after the tentacle has been removed more poison or venom will be released. If you are stung, it is best to wash the area without touching. A cold pack should be used to relieve the pain. If stung, please consult a doctor immediately. No fatalities have ever been reported within Australia or New Zealand from the sting of a blue bottle.
Update: In response to Sara on Facebook, who wrote:
Apparently the quickest and most effective relief from the pain is to pee on the affected area, unless you have a bottle of vinegar handy.
Well you know, Sara, we've discussed just that. Christine has extensive history with blue bottles, and has long talked about how they used to put vinegar on the wounds left by them. Or peed on them if you didn't happen to bring your vinegar along to the beach. But that is done no more, according to our inquiries. Today they recommend washing thoroughly, then applying ice - which will lead to the pain lasting only some hours.
Basically, they don't know jack all what to do, and they just keep coming up with different things every decade or so.
Here's another good closeup, showing the blue bottle's "crimped" edge, giving it what Christine said was a "samosa" look:
After they've been beach-bound for some time, they shrink to a still beautiful "bottle cap" (my definition) stage: