Tilapia and shrimp farms

While in Cox's Bazaar, as I mentioned before, I got to tour a tilapia hatchery and shrimp farm. Ibrahim's grandfather started both businesses years ago and they are very lucrative. The first day, we visited the hatchery where they have breeding pairs of tilapia (which lay their eggs in their mouth and the eggs need to be hand-harvested one fish at a time when they're at the right incubation stage). Here are the ponds with the breeding pairs: The sticks are holding up nets which keep 300 females and 100 males in each long section.

After harvesting the eggs, they go into incubation tubes to hatch. Here's the continuous flow of water--the eggs are in the large clear tube and the water circulates through the mesh. The eggs in the net are unfertilized eggs which float and then are rinsed off.
Here's a close up of the eggs-you can see the fish embryos and yolks (the yellow part)
Once they're out of the egg sacs, they're put in a slightly larger bin to absorb the yolk sacs: Here, the white spoon is a rice-serving spoon for scale:
Then once they're a bit bigger they're transferred again to a larger bin:
And finally one more larger pool before shipping off to other tilapia farmers to raise. A few days after this (I think around 25 days after they hatch) they're ready to sell.
Once they're to this ~30 day stage they will expose the ones they want to grow for food to a male hormone to turn them all male so they will grow and develop faster. Apparently it only takes one small dose and then they're more profitable.
The same day we also walked around the shrimp hatchery, where they have a similar process of breeding pairs and eggs and babies they sell to other shrimp farmers. Unfortunately, it's the wrong season and it was just in its summer upkeep phase. Cleaning, changing filters, repainting, etc.

The following day I was lucky enough to visit the tilapia farm where they also raise tilapia to adult stages to sell for food. At this farm, they raise shrimp in the same pools to help with the water chemistry/biodiversity of the system. I was told early on in their business development they experimented with high-density shrimp and tilapia raising separately and that led to disease, water quality issues and pollution. Here is a pool of small tilapia feeding--click on the photo to see a larger version.
The guys who were showing us around brought a net and pulled up a couple medium-sized shrimps:
These were really medium sized! They showed me a couple HUGE (the size of small lobsters) shrimps in formaldehyde jars that go for lots of $$.
The water here is a combination of fresh well water and salty river/delta water to get the right salinity. Tilapia can tolerate a large range of salinity and shrimp also like some salt to reproduce.
Of course, with any large farm, there are pests--while we were walking they noticed a small snake eating a fish and so the head engineer used the proper tool--a stick to whack it and kill it:
There are 16 families that live in various places around the huge farm to keep an eye on things, make sure poachers don't come in, tend the sheep that keep the weeds down (I didn't get any photos, but there are mostly only goats in Bangladesh, but apparently the goats don't like the open spaces of the fish farm and the salty water, so they have sheep instead ). Here's a photo of a couple of kids that live there--I took the photo because the kid in the front has a sizeable knife and he's slicing palm fronds for something. He's about 4 or 5. He was also hauling pitchers of water back and forth for his family while we were having lunch.

Which brings me to one of the best parts of the day: lunch! We sat under the shady palm trees in the breeze and had fresh coconut water to drink and then fresh shrimp three ways: fried w/ the legs still on--so crunchy and good! Curry type 1 and Curry type 2. Lots of rice of course. It was SO TASTY! I don't even love shrimp all that much, but I can easily say this was some of the best I've ever tasted--and I knew how fresh it was!
There are a lot of workers and people around--it was many many acres. Here's a shot of a few of them as we were leaving in the boat:
And here are slightly related photos of local guys with the catch of the day:
This next guy saw me taking photos of the other guys and elbowed his way in and insisted on holding two fish while I took his photo.
I'm not sure about the fish on the left (maybe hilsha, which is very tasty and the national fish of Bangladesh), but the one on the right is called pomfrit and is served fried--really good flavor, but like all fish here, FULL of an insane amount of bones.
I really enjoyed touring these facilities--they're huge operations that take a lot of technical expertise as well as labor to keep going! I used to work in a fish toxicology lab in undergrad and was hatching baby fish in my aquarium in California, so it was interesting to see another similar system. A note to my science peeps: Mr. Khan is looking for skilled chemists, engineers, agriculturalists and biologists!
I will post some more photos of our boat ride out to the island where the fish farm was--I got a lot of great shots of fishing/pirate boats!