Feedlots of the sea

Ocean fish farm near SerbiaFish farming is growing at 9% per year.

? a freshwater farm in Serbia produces 80,000 carp.

The director of a fish farm in Hawaii says, “Farming the oceans, instead of chasing down wild fish, is the only sustainable way to meet the world’s rising demand for seafood.”

Others say fish farms will reduce genetic quality and pollute – becoming unmanageable “feedlots of the sea”.

About 1 billion people rely on fish directly. And about a quarter and a third of the world’s fish are converted to animal feed each year.

A ship lifts a ton of wild fish an hour but the hunt requires a major policy overhaul in order to preserve species and the environment. Nevertheless, an extra 40 million tons of seafood per year is needed by 2030. Will we float 1,000s of extractive ships or install 1,000s of new fish farms?

China sells 70% of the world’s farmed seafood. The USA is well behind other nations while Congress is hamstrung over how to stimulate current plans for a $5 billion offshore aquaculture industry.

Worrying many, the waste produced when thousands of fish eat and excrete together in a small patch of the sea is equivalent to discharging untreated sewage. On the other hand, if farms are correctly located and their excess nutrients and nitrogen carefully diluted, nearby waters can support an improved ecology.

Farming in deep water with highly separated facilities may be a better approach, but a new system of international cooperation is required.
[Environmental Science & Technology]