Maybe fisheries should get some kayaks or a shallow water dinghy and shadow the people who look like they'd be likely to take undersize crabs. They are going to break whatever rules are in place if they have 150 undersize crabs between 4 people.
I won't even take take just sized crabs unless we are having a really, really quiet day and I simply cannot see why people would want undersized ones. Would be way too much work for little joy.

Edit: reading the article, if 95% of crabs are undersized still then I don't have a problem with extending the closure but still think fisheries need to start profiling crabbers and targeting them.

The size of the crabs at the moment make it a total waste of time crabbing now. However you still see people out wading and using drop nets taking very small crabs and not returning them in a good condition to survive and as soon as possible.

Result a lot of crabs never get to reach a good size and full of meat.

January would be my choice of crabbing season start, more bigger crabs.

 While I have been out chasing whiting on the flats recently I have seen many people taking undersize crabs and it makes my blood boil. After wading the flats for a few hours at a time I have a good idea of how many size crabs are NOT there. I have reported it many times but it continues in this same spot and I am yet to see a fisheries officer there. You often hear the conversation between the crabbing party go something like " did you bring the measure? no I thought you had it" then they continue to just fill the tub.