September 13, 2022 — Once upon a time, on the outskirts of Lisbon, villagers threw their doors open to the street whenever they heard the clopping of donkeys laden with baskets of sardines. Every household claimed its share of Portugal’s ocean bounty. But one day in early 1773, the Marquis of Pombal, a statesman who ruled the country much as the prime minister does today, learned that yet another load of sardines had been smuggled across the border into Spain. No more, he declared.

The Marquis promptly founded the General Company of the Royal Fisheries of the Kingdom of Algarve, and a new relationship among the Portuguese coastal communities was forged: The central government in Lisbon would thereafter manage the sardine industry.

If abundance means royalty, the sardine was the queen of the Portuguese coast three centuries ago. An upwelling of cold, highly saline water above the continental shelf here provides abundant nutrients for the phytoplankton and zooplankton that feed a variety of pelagic fish. Schools of sardines in these waters could reach the size of a soccer field and exceed 10 tons.

Today, however, the Portuguese sardine industry has declined significantly, under pressure from waters warmed by climate change, as well as overfishing. Scientific data gathered since the 1900s show that Portugal is a long way away from reaching sustainable populations of the Ibero-Atlantic sardine stock it now shares with Spain. In recent decades, concern for the health of its fish resources led Portugal to join the International Council for the Exploration of the Sea (ICES), an intergovernmental marine science organization that promotes the sustainable use of the oceans.

The Pacific sardine population, which extends from Mexico to the Canadian border with the United States, faces similar challenges. Those fish provide not only fresh and canned food for humans, but also feed marine species such as whales, sea lions, sea birds, and even Chinook salmon.

In 2020, a monitoring campaign by the Portuguese Institute of Sea and Atmosphere (IPMA) and the Spanish Oceanography Institute announced some good news: a sardine biomass inrcrease of around 110,000 tons—the most exciting rise in the past 15 years.

A cause for hope, yes, but not a reason to relax, says Gonçalo Carvalho, director of Sciaena, a nongovernmental organization that encourages sustainable fisheries. To Carvalho, a marine biologist who specializes in policy, the past has shown the dramatic consequences of poorly administered conservation measures. According to ICES data, provided mainly by IPMA but also by Spanish research institutions, the loss of sardines in just 31 years has been colossal. In 1984, sardine biomass measured around 1.3 million tons; in 2015, it was just one-tenth of that.

Read the full article at National Geographic