BOGOTA, Colombia

Seamen who regularly sail across the Pacific Ocean coastline of South America are not surprised to see hundreds of large vessels brightly lit up like football stadiums.

They are fishing ships, which turn on powerful lights at night to attract giant squid in large numbers.

Their presence in international waters near Exclusive Economic Zones (EEZ) of different nations has alarmed environmental authorities in Ecuador, Peru, Colombia, Chile and Argentina, who are watching their fish stocks under a threat from intensive fishing activities.

Having depleted fish stocks in domestic waters, the fleets of many industrialized nations are now moving into territorial waters of low-income countries to meet the growing demand for seafood, according to a study published by the Overseas Development Institute.

“The vessels, most of them Chinese, operate in international waters, outside 200 miles of the EEZ of Peru, Chile and Ecuador, reaching the boundaries of the Galapagos,” said Eliecer Cruz, Latin American manager of Island Conservation, an organization that works to prevent island extinctions. “Any given day you can see up to 300 boats in the high seas.”

This is not the first time the ships have been detected. In August 2017, Ecuadorian authorities captured the Fu Yuan Yu Leng 999, a Chinese ship with 300 tons of fish illegally caught in the Galapagos. More than half of the catch were hammerheads and threatened silky sharks.

Ecuadorian President Lenin Moreno then formed a team to protect the Galapagos and maritime resources. But countries have little scope of action because vessels are careful not to leave international waters.

After drugs and arms trafficking, illegal fishing -- activities by foreign vessels without permission in waters under the jurisdiction of another state -- is the third most lucrative illegal activity in the world, according to a 2020 study by mongabay.com.

One out of every five fish traded in the world comes from illegal fishing -- an average of 26 million tons per year. It is a business that brings in up to $23 billion in annual profits, says the UN Food and Agriculture Organization (FAO).

But illegal fishing is not the only threat to fish stocks, marine ecosystems and the livelihoods and food security of more than 3 billion people who rely on fish for critical animal protein, Cruz told Anadolu Agency.

Overfishing is also a threat.

Cruz says that overfishing, catching too many fish at once, is difficult to control because it is not done under legal circumstances. It is a challenge for authorities to track fish origins and the amount caught.

“Overfishing endangers the breeding population, which becomes too depleted to ever recover,” he said.

Due to widespread overfishing, a third of the world's fish stocks is exploited unsustainably, according to the FAO.

Fishing vessels can spend six to eight months on the high seas because large cargo ships with refrigerated capacity receive cargo from fishing vessels and return to the country of final destination with the loot.

Tankers provide fuel to fishing vessels which allows them to stay there for months, according to Cruz.

Operations are carried outside the EEZ, which is why authorities cannot prevent the activities.

“Countries put their coast guards in front of these fishing fleets to prevent them from entering the EEZ of each country, but that does not solve the problem,” said Cruz.

Although the use of radar is helping to combat clandestine activities, the Global Fishing Watch, an international nonprofit organization, warned that many companies turn off their satellite systems to avoid being traced.

And turning off the signals may be a red flag indicating that the vessel is hiding illegal activity from regulators.

Cruz said that although more and more countries are demanding that each vessel carry a satellite monitoring system to know where fleets are, additional efforts are needed to take care of the sea's resources.

“We are not aware of the damage we are doing to the sea. Maritime conservation is an issue of food sovereignty, which poses a risk to humanity,” said Cruz.