Spider Crabs that is!
Our infamous Spider Crabs are on the march again!
Every year around May or June, Millions of Spider Crabs Congregate around the Shallows off Blairgowrie or Rye as part of the Annual Spider Crab Migration.
Often throughout the year you will find one or two lonesome Spider Crabs in Bass Strait or Port Phillip Bay just wandering around, doing its thing, all alone. But this time of year the otherwise solitary Spider Crabs start appearing together in huge masses, it assumed the mass congregations are the Spider Crabs defense mechanism, providing safety in numbers as they molt their shells.
Congregating in groups of many tens of thousands sometimes even hundreds of thousands, the crabs often spread tens of meters and up to hundreds of meters across the bottom.
It is believed the Spider Crabs congregate en mass like this in a hope to keep themselves safe from predators and prey as they shed their protective shell and their new shell hardens . Often local rays can be seen nearby coming in for a feed, the rays may pick a few stragglers off of the pack, but the sheer volume of these congregations provides shelter and safety in numbers for the now vulnerable Spider Crabs. Sometimes we will see huge stingrays swimming nearby, these creatures are upwards of two meters across and their stomachs bulge out like a basketball, after feasting on the smorgasbord of crabs.
Over the past few years this unique annual phenomena has attracted a huge following globally with news stories appearing across American and European main stream media last year, it has even attracted the interest of the naturalist David Attenborough and the BBC,. However for a large number of Melburnian's the annual spider crab migration is still just one of the many secrets hidden just below the surface of Port Phillip Bay.
If you are a diver already we suggest Melbourne's Spider Crab Migration should be a priority in your bucket list of dives! Especially if you are based in Melbourne there is really no excuse why you would miss this amazing show of nature!
Not a diver yet? We can help you with that too!
At this stage we are tipping the crabs will be around for about a week to ten days and they would be best viewed from about Thursday 8th June (based on conditions and current crab movements). This Queens Birthday Long Weekend would be a good time to try and catch a glimpse of this incredible display. We have divers out daily following the location of the crabs, over the coming week we will be featuring the Spider Crabs on our guided shore dives, assuming they are in a safe accessible place and we manage to keep tabs of their location, Port Phillip Bay is a big place, its surprisingly easy to loose a few hundred thousand Spider Crabs!
Finally if you are planning to jump in the water and make the most of this incredible opportunity to view the Spider Crabs, please dive safely, the crabs are often in places where diving is not permitted or not safe (I.E under the boats in Blairgowrie Marina), if you haven't dived in a while consider a refresher dive or guided dive as part of your experience, view our guided dives here. And respect the crabs, don't harras them!