What aquaculture experts tell me about the world’s fastest-growing food source.
- Nigerian catfish are bred so densely you can walk across their ponds.
- “In an urban environment, why not use a rooftop to grow fish in a couple of recirculating ponds?”
- China grows grass carp in quantities equal to the catch of the entire U.S. fishing fleet.
- “Everyone’s working hard to reduce the use of fishmeal and fish oil in feed, and to fool the fish into thinking they are eating what they want.”
- All the tilapia we eat are male, with females forced that way early in life.
- “Many agricultural landscapes are becoming more saline and facing more seasonal inundation from the sea. There’s a big opportunity for aquaculture explicitly to be part of a planned transition that can not only recover but actually dramatically increase the value of these landscapes.”
- Shrimp lack an immune system.
- “In Africa, the sooner we move past small-scale aquaculture, the better. It’s a dead duck.”
- Eight miles off Panama’s Atlantic coast, cobia destined for plates in the United States fatten up in high-tech cages.
- The world needs to grow 30 million more tons of fish each year by 2050: “We mostly know how, but is there a will to do it?”
Photos courtesy WorldFish.
Commissioner Mary Griffin of the Massachusetts Department of Fish and Game and CRWA scientist Elisabeth Cianciola release shad larvae into the Charles.
In spring the U.S. Fish and Wildlife Service grabs adult American shad from the Merrimack River for spawning in tanks at its fish hatcheries in North Attleboro, MA and Nashua, NH. Last week, a Fish and Wildlife truck arrived at Charles River in Waltham with a huge tank filled with a few hundred thousand week-old larvae, each about half the size of a penciled eyebrow.
Shad are the largest member of the herring family and can grow to maybe eight pounds. Present in huge numbers in east-coast rivers, they were easy targets as they swam upstream from the sea to spawn, and they were crucial food fish for native Americans and then early European settlers.
But their range narrowed as dams were built, and like other local fish they were hit further by overfishing, pollution and loss of habitat. A decade ago shad were just about gone from the Charles and the Merrimack.
Both rivers had been painstakingly cleaned up, however. They offered fishways in their lower reaches. And effective technology for propagating shad fry was in hand, as shown by successful restocking programs in Chesapeake Bay and the Delaware River.
So the Fish and Wildlife Service joined with the Massachusetts Department of Fish and Game to begin bringing shad back in 2008. The partners now work with the Charles River Watershed Association (CRWA) to stock up the river with two or three million larvae annually.
This year, they were pleased to find that in a sample of adult shad in the Charles, most came from the restocking program.
“I’m really happy to return this part of the Charles River to wildlife,” CRWA executive director Robert Zimmerman told the small crowd gathered on the river bank just before the release. Nicely written up in a Boston Globe story, the event was a festive occasion, especially for the sunfish who soon lined the shallows for their best lunch of the summer.