Fisherman shows Dr Eknarin Rodcharoen the crab larvae ready to be released, picture by Sara Barrento

Larvae in, crab out? A story about crab restocking

We are in Thailand, we are at the Fishery Association of Sating Phra. In the next three hours we will see: 1) fishermen coming with their crab catch; 2) fishermen releasing crab larvae in the hope of enhancing their stock; 3) fishing boats and their fish catch; but that is another story.

I am not sure if it works, but they are doing it. Maybe it gives them peace of mind and they do it. Maybe the crab eggs they count (2.000.000), the crab larvae numbers they release (4.000.000) are accurate.

Maybe the larvae will survive, maybe the artificial reef made of coconut and local materials helps these crabs grow and come back once again to be fished by these fishermen.

Maybe … but I just don’t know. It is the first thing they show us. They show us the berried female crabs. They show us the larvae. They are proud.

Fishermen at the Fshery Association of Satingphra (Songkhla Province, Thailand) show us the larvae and the berried females, pictures by Sara Barrento
Then they show us the traps; the illegal trap that they don’t like — they are not proud.

I need to draw some of my questions on the sand — they are patient, and I am ignorant of Thai language and of their ways. I try to find out how many females they get the eggs from; they say 200… And I keep on asking: do you release larvae every week, every month, whenever you catch berried females? What is the best season, time of the day, moon cycle to release the larvae? I make some more rough drawings on my notebook — my questions are many, too many

Drawings in sand; notes in my notebook, pictures by Sara Barrento

But they are happy to talk and to share their catch — they invite us for lunch. Nearby there is an oil platform. It is too close - it is on their fishing grounds. They get to be compensated.

Dr Sara Barrento and Dr Eknarin Rodcharoen having lunch with the fishermen. Picture taken by Siriwan Yeng OkBetong, who was also having lunch and doing some translation.
While the rice boils, and crabs cook, the fisherman releases the larvae. Then we eat the parent crabs on the hope that the larvae will soon come fully grown in the shape of an adult crab.

Below is the full story in images, as I saw it

This story in images, video by Sara Barrento

You are reading a short series of factual stories about aquaculture and fisheries in Thailand— this is the second of five stories. I use storytelling to facilitate conversations about aquaculture, fisheries, and all the other industries along the way. If you are an educator you can use this site in blended learning — see below learning objectives, suggested activities and further reading.

You can contact me through LinkedIn.


PREVIOUS STORY: The small scale fishermen community in Songkhla coastline, Thailand| NEXT STORY: growing is not the solution — quality is

Learning objectives

  • To define restocking and stock enhancement
  • To discuss the advantages and limitations of restocking

Suggested activities

  • Find out the name of this species
  • Describe the life cycle of this species
  • How could you answer some of the questions raised?
  • Find out about the restocking program of another species of your choice? Is the information more complete than in this example? If yes, explain what type of information is provided?
  • How can we monitor the success of a restocking program?
  • Do you think it is important to study the genetic population of this fish stock?

Further reading

Scientific papers
  1. Restocking and stock enhancement of coastal fisheries: Potential, problems and progress

2. Stock enhancement or sea ranching? Insights from monitoring the genetic diversity, relatedness and effective population size in a seeded great scallop population (Pecten maximus)

FAO Report: Feasibility of stocking and culture-based fisheries in Central Asia