Blue Swimmer Crabs: How and Where to catch them in Western Australia

The Blue Swimmer Crab (Or often known as the Blue Manna) is a dinner table favourite for many fisherman on the west coast. Found all along the coast, these powerful swimmers are both a fun and tasty catch.

Blue Manna crab caught while fishing in Busselton
A male Blue Manna Crab caught in Busselton, Western Australia

How to Catch Blue Swimmer Crabs

There are a number of techniques used to catch blue swimmer crabs.  These include drop nets, scooping or if you’re feeling a little adventurous then freediving is an option.

Drop nets are a popular and probably the easiest way to catch blue swimmer crabs.  Whether you’re fishing off a boat, a jetty or off the shore drop nets can be used as a method to catch them.

Method 1: Drop nets

When using them off the shore, be sure to throw them to the deeper water in the area you are fishing as the crabs may spook easily and may not want to enter the net if the water is too shallow.  

Catching blue manna crabs at Busselton
Catching Blue Swimmer Crabs in a drop net, Busselton Western Australia

The best way to throw the nets is like a frisby as this keeps the net horizontal and when it hits the water it has a better chance of sinking and laying on the ocean or estuary floor level.  

If you’re crabbing from a boat then the usual approach is for your nets to be released in a line relatively close to each other.  Note, it’s always good to ensure your floats are marked with your initials or are of similar appearance so you can easily identify which ones are yours.

You can secure the baits within the nets by either a mesh cage or a bait clip.  If you’re using a somewhat mushy bait (such as sardines) then a mesh cage will be better as the crabs will pick the bait apart quickly. Additional to this, fish such as blowies can quickly demolish your bait or even birds like shags can dive down and steal the bait.

However, if you’re using a tougher bait such as chicken necks or meat this can be secured to the bottom of the net with a bait clip.

What is the best bait to use in crab nets? 

Fish baits are known to attract the crabs quicker due to the oily nature of fish, however the likes of chicken necks will last longer and are more durable. Common baits used include fish heads, fish frames, chicken necks, chicken wings, salted or brined pilchards, bullock spleen or lamb. 

Personally, I use spleen on bait hooks as it’s durable and has produced some great results in the past.

Method 2: Scooping

Scooping for crabs is another great technique used to catch them.  This involves walking through the shallow waters of estuaries, inlets or shorelines to find the crabs.  Once located you can then use the wire scoop to well, you guessed it – scoop the crab out of the water!

Video by Two pirates fishing and outdoors

This can be a fun activity to do with friends and families as you get to walk through enjoying the scenery whilst on the elusive hunt.  When you find a crab this is where the fun starts especially if it manages to get away.  If this happens its not long until everyone is hopping around wondering where the crab has gone and who might get nipped!

If you are scooping one thing you’ll need to think about is where to store your crabs when you catch them?  Alot of people usually tow some type of bucket or esky behind them via a rope.  This way your hands are free to focus on scooping.

One word of caution, when you’re out scooping for crabs, always be cautious of the environment you’re in and in particular the tide movements.  If you’re scooping in an incoming tide the level of water around you can quickly increase and sometimes it can become too deep to get back to shore.

Method 3: Free diving

Free diving or snorkelling for blue swimmer crabs is great fun.  This isn’t for everyone, especially if you’re not a good swimmer though for those that are great at snorkelling it’s definitely worth a go. 

If you do try it some thick gloves (such as welding gloves) can help avoid getting nipped.  Also a weight belt can also assist with keeping you deeper in the water whilst trying to grab the crabs.

Free diving for blue manna crabs off Port Coogee, Western Australia

There are a number of bays and areas where you can free dive for crabs. Personally, I love taking my two sons free diving in Geographe Bay.

Kids swimming in geographe bay busselton

Method 4: Using a hook to catch Crabs

Although not seen often, another method that fisherman use to catch Blue Manna Crabs is a metal hook. As you can see in the below video, you simply place the hook behind the crabs claw and pull it towards you to catch them.

Catching a blue manna crab using a hook

Where to Catch Blue Swimmer Crabs

Blue swimmer crabs can be found all along the WA coastline, both within the estuaries and in the ocean. Below are a few spots were Blue Swimmer Crabs are often caught.

Frequently Asked Questions

Are blue manna or blue swimmer crabs nice to eat?

Yes, blue swimmer crabs are very nice to eat. They have a white sweetish flesh that can be eaten as is or can be used in the likes of a fresh seafood salad or chilli curry. Chilli crab is a popular dish in the west coast!

How to catch blue swimmer crabs?

Methods of catching blue swimmers include scooping, using nets or for the more adventurous free diving for them.

Are they posinous?

No, these crabs are not considered poisonous as the crab doesn’t produce toxins. However, blue mannas can be found in areas where toxic algal bloom events occur (such as the Swan and Canning rivers) hence always ensure to check for any health warnings in the area you are crabbing.

What is the biggest crab that has been caught?

According to the Department of Fisheries the biggest blue manna crab caught was over 1kg.

Scroll to Top