Tuna as scarce as estimated

2001/11/15 Elhuyar Zientzia

• Biologia

In the last 25 years the number of flying tuna in the sea has declined uninterruptedly. In the western Atlantic Ocean, the current presence of cimarrones is 90% lower than in 1970. Overfishing is the main cause of decreased tuna. Tuna is a highly prized and expensive fish compared to traditional tuna. It is the largest and most expensive of all types of tuna. A brown can reach about 500 kilos and its meat is highly appreciated in Asian markets.

To redirect the number of tuna it is necessary to reduce the fishing of this fish, but researchers believe that it is useless to prohibit this fishing in some areas if in others the catch continues. Maroons are very fleeting fish. Some tuna breed in the Gulf of Mexico, but then reach the Italian coast. Another is the case in the Pacific, where tuna lay eggs in Japan and soon after they are in Mexico.

Therefore, to better understand the nature and customs of cimarrones, researchers at Galveston University of Texas will use otoliths. Otoliths are small bones that form in the ear of the fish. These small bones grow with fish and each year a new layer of bones grow around the otolith. As in tree trunks, analyzing the size and characteristics of the reared ring each year, researchers hope to learn more about the places of residence and the habits of tuna, and then, with this information, begin to take breeding measures.