How to catch Mud Crabs (Scylla serrata)

So you’ve developed a hunger for these tasty little crustaceans called crabs and want to get out and catch your own. (I guess they aren’t particularly little when you are trying to get them out of the crab traps!) The following article details the best methods that I have found for catching mud crabs, or if you will, “How to catch crabs”. You might go grabbing using different methods, and I am not an expert, but these techniques have helped me to get the best results.

Crab fishing can be a family oriented sport or activity. After the first time that you go crabbing with your children you’ll hear them on the weekends cry out to you, “Let’s go Crabbing!”

Local laws and regulations

Before you can begin your crabbing adventure you must check your local laws and regulations on catching crabs. This is important as each district, state or country has their own set of laws and guidelines on catching crabs.

These rules usually govern what type and sex of crab you are allowed to catch, how many you are allowed to keep to take home, how big the crab has to be before you can keep it, how many traps you are allowed to use and what identification your traps must have.

It is important to follow these rules no matter how tedious or ridicules they seem. They are there to protect the species to ensure there will be sustainable quantities in the ecosystem. The rules are also in place to ensure that there will be plenty of crabs in the future for people to catch.

Australian laws (in the state of Queensland) on catching crabs permits you only to keep male mud crabs which are greater than 15cm (6 inches) across the back. You are only allowed to have four traps (locally known as crab pots) per person on board your vessel and these pots have to have your name, address and phone number clearly labeled on the crap pot and also its float.

If you are interested in Queensland laws on catching crabs you can follow this link to read more.

About Crabs

The main objective on how to crab is that you have to think like a crab. I don’t mean you have to get down on your haunches and scurry around on the floor sideways. What I mean is you have to think like a hungry crab that is always wary of predators and you also have to know about their movements.

Crabs move about more during the safety of night than in the day, so it’s best to leave your crab traps out over night if possible.

Female crabs feed heavily during the summer months after they have mated to ensure they have enough energy to hatch their offspring. Therefore you will catch more female crabs during this time.

With the onset of winter female crabs leave the river systems and estuaries to hatch their offspring. Therefore during this time you will catch more male crabs.

If you are interested in the full sexual reproductive cycle of the mud crab you can follow this link to read more.

Equipment

If you want to catch a crab you’ll best need to use or borrow a boat. You can throw crab traps or crab pots in from the bank but you will be limiting yourself to the places you can put your traps. Also these places that are easily accessible from the creek bank are where everyone will be crabbing from, so your catch will be little if none. In Australia crabbing from the bank can also prove to be fatal. This is due to the fact that the crocodile can follow your movements on the bank, remember where that human activity occurs the most and attack when you least expect it. If you are interested in a recent casualty from crabbing off the bank please follow this link.

You will need some good crab traps. There are a lot of varieties, shapes and sizes on the market for example they are available in round, square, pyramid, collapsible and net types. Queenslanders (in Australia) were able to use traps called Dillys but have since been banned. These were like a basket that sat flat on the sea floor, crabs made their way to the centre to get to the bait. When you lifted the rope which attached the float to the trap the basket would scoop the crabs up.

I use the small, round and collapsible type as shown in the photo below. I use these because they are cheap to replace if they get lost or stolen and they don’t take up much room in my boat when I am setting or retrieving the pots. These crab traps or pots are available from most good fishing stores. BCF in Australia usually have huge quantities in stock.

Bait

Being successful when fishing for crabs has a lot to do with the bait you select. The most successful bait that I have found is whole fish frames. These frames are from fish that I have caught and filleted. I freeze the frames for when I next intend to go crabbing. These fish frames include the tail, backbone and head of the fish and are approximately 30cm (12 inches) long as a minimum.

If you don’t have your own fish frames the next best thing I could think of is mullet heads from a fishing bait store. I would then use bones from a butchers store as a last resort.

I know crabs are like little scavengers eating from the sea floor but I’d be more inclined to try to catch them on the foods that they are used to. I have been more successful this way.

I have heard of crabbers using baits like pierced cat food tins, road kill, chickens, pigs heads and even whole Kangaroos. If I were a crab I’d know which food I’d go for but ultimately this choice is up to the individual.

 Moon Phases and Tides

From my experience moon phases and tides have little to do with the success of catching crabs. For me it has more to do with baits and seasons.

Typically we are told to go crabbing on a half moon phase. This is when there is little run in the tide. I’d say this would be the best time to go crabbing as the crabs will move around further to find food. They won’t be affected as much by the currents caused from the run in the tide (change in tide height).

I would still go crabbing on full moon or new moon, possibly tending more to the new moon. This is because on a new moon the night is darker and as a crab I’ll be more protected being out of the moonlight. The only reason I’d skip crab fishing on full or new moon phases is if the weather/winds are great for getting out to catch some fish on the reef.

I also talk about moon phases and tides in the following paragraph.

Where do I catch crabs?

In the tropics you will catch mud crabs in the estuary, in the creeks or on the mud flats. You might have more luck on the mud flats than in the creeks as most crabbers target creek locations. On the mud flats you will also catch the smaller blue swimmer crab (note that these crabs have different size and possession limits).

You will be able to crab during full or new moon phases on the mud flats as the large change in tide height will have less affect as it does in the creeks. As you could imagine a creek is like a gutter of the mangrove estuary system. During a full or new moon phase these narrow and deep creeks/gutters have quite strong currents. The crabs won’t enjoy coming out in these strong currents and you may even lose your crab trap as they will get carried away and out to sea.

 The Ugly Side of Crabbing

The ugly side of crabbing is when other crabbers or fishers check your crab pots or worse they steal your crab pots. (Regular crabbers call this activity - Share Farming) Although this is an illegal activity there is little you can do to prevent it from happening. I have had pots raided and stolen on a couple of occasions. When this happens, you immediately feel like going out and doing the same to other pots in your surroundings. You can't do this and you shouldn't do this. You shouldn't lower yourself to the raider or thief's level.

To try and prevent crab pot theft try these pointer:

• Crab in areas which are hard to access or are in remote areas.
• Put your crab pots out at sunset and collect them on sunrise.
• Don't go crabbing in school holidays or other public holidays.

• Camouflage your crab pot floats.

• If you see another boat in the area, "guard" your pots until they leave.

There are usually only a few "rotten eggs" who spoil this fun past time for others. If you know of anyone who has stolen crab pots or from crab pots it is an illegal offence an you should report them. Contact CrimeStoppers (in Australia)

You may have overheard your friends bragging about the extra crab pots that they "found". You may have seen your friends return home from crabbing with extra crab pots.

Please do the right thing and report it to your local authorities.

Crab pots have become relatively cheap and you would think that crab pot stealing should reduce however as the population grows I doubt this activity will lessen.

It's up to all of us to ensure crabbing remains a fun activity for all.