The Nationa Animal Health Service (Senasa) now has a new tool to halt illegal sail fishing. A three-year-old law has banned catching and selling the fish.

But despite this, commercial fishermen have continued the practice, aided by the fact that, cut up into pieces and frozen, the meat is often passed off as that of legal species, including tuna.

But a year ago, the Pronature organization donated sophisticated equipment to Senasa to allow officials to analyze fish at the market and identify sailfish meat, through DNA.

Before the new tool, according to La Nacion, veterinaries had to depend upon a simple visual inspection at the market. But once cut up and the distinctive fin discarded, the flesh was easily passed off as legal fish.

(Sailfish are also sought on the high seas by sport fishermen, but today’s sport fishing boats all follow the “catch and release” technique in which the fish is hauled to the boat, photos taken, then then freed to fight another day.)

In the last year and a half, two national commercial fishing companies have tried to export some 15,000 kilos (more than 35,000 lbs.) of sailfish labeled as other species, reported the paper.

But, thanks to the new equipment, they didn’t get away with it. All it needed was a five cubic centimeter sample of flesh for the DNA scan.

Hector Mendez, legal director for the National Fishing Institute (Incopescar) told La Nacion that two criminal cases are on court dockets right now, one for a confiscation of 7,000 kilos of sailfish in April of 2011 and 8,000 kilos confiscated in Limon in a container last July.

Mendez added that the fine for selling illegal sailfish is about 9 million colones.

Why sailfish were declared of sport and tourism interest in 2005 is clear: while illegal sailfish goes for 1,400 colones per kilo on the street as food, the University of Costa Rica calculates that the live fish in the sea is worth 3,000 colones per kilo to sport fishermen and their employees–and it survives to thrill with its spectacular leaps when hooked.