Failing Fisheries:The Fate of Food Choices

The first large-scale assessment of Earth's marine ecosystems suggests that today's fishing practices are leading to empty oceans.

First it was orange roughy. Then Atlantic cod. Chilean seabass is next in line. One by one, our seafood favorites are dropping off dinner menus across America. It's clear to marine biologists that decades of destructive trawling, hooking, and netting has taken a toll on many fish populations. Yet, getting an overall picture of ocean health has been nearly impossible-until now. Scientists have come up with the first model to assess marine ecosystem health on a global scale. And its first snapshot is murkier than ever.

Daniel Pauly from the University of British Columbia and colleagues divided the planet's surface into about 260,000 square cells, each about 30 miles on a side. Then, starting with the North Atlantic, they assembled information from the cells ranging from water temperature and depth to who eats whom along the food chain and combined this with catch reports across the seas to estimate the effects of the fisheries on species throughout the basin.

The team found that only one-third of the high-level predators that swum the North Atlantic in 1950 remain today. And worse, our appetites have turned to their prey, further complicating their survival. While the model is far from perfect, it is gaining widespread support, and hopes are high that it may one day help bring the orange roughies, the Atlantic cods, and the Chilean seabasses back to our oceans-and menus.

Shrimp trawl catch, primarily composed of juvenile fish, benthic invertebrates and other bycatch, Texas. Photo: Norbert Wu

 

Left: Giant bluefin tuna (Thunnus thynnus) are harvested at a 1200 year old tuna fishery, Sardina, Italy. Photo: Norbert Wu
Right: Blue sharks (Prionace glauca) caught by shark fishermen, threatened by overfishing to supply high demand for fins and flesh. Photo: Norbert Wu

Manta ray (Mobula lucasana) caught in a gill net.
Photo: Norbert Wu