CALLAO, Peru – The ocean off Peru boasts the world’s richest fishing grounds, but Taurino Querevalu is returning to port empty again after a hunt for Peruvian anchovy, cursing his empty nets.

Querevalu’s frustrated search for the silvery fish reflects a growing global demand for the protein-rich fish meal, and oil, into which nearly all of Peru’s anchovy catch is converted. It also reflects unremitting cheating by commercial fleets on quotas and other regulations designed to protect the species.

Not only has overfishing of the Peruvian anchovy, or anchoveta, battered the industry that makes Peru the world’s No. 1 fish meal exporter, it has raised alarm about food security in a nation that had long been accustomed to abundant seafood.

The drop in the anchoveta population has over the years affected the food chain, as stocks of hundreds of bigger fish and marine animals that eat it have also thinned.

It is “the most heavily exploited fish in world history,” according to the U.N. Food and Agricultural Organization.

Peru’s government ordered deep cuts in what the country’s commercial fleet could catch in October after anchoveta stocks plummeted. While the small fish reproduce rapidly, their overall population is now less than half its volume a decade ago, said Patricia Majluf, a top Peruvian marine scientist.

The government slashed the permitted commercial catch by two-thirds and set rules meant to put more fish on tables in a country whose rural areas are afflicted by child malnourishment.

Yet the commercial fleet has continued to cheat, said Paul Phumpiu, Peru’s vice minister of fisheries.

“They have no social conscience,” he said Monday in announcing new fines of nearly $3 million on companies for illegally harvesting more than 18,000 metric tons of juvenile anchoveta during the three-month fishing season that ended Jan. 31.