A study just published in the journal PNAS reveals that populations of tuna and tuna-like species have decreased by 60% on average worldwide in the last half century. The most affected are cold-water tunas, such as Atlantic bluefin tuna and southern bluefin tuna, which have decreased by up to 80%. They are large, long-lived species with a high economic value.
But the mackerel, which is usually smaller and with shorter life cycles, has also suffered a marked decline. According to the work, this information is an indication that fishing can be a threat to all kinds of species, regardless of their size.
In the authors' opinion, managing tuna stocks can work, "although with some species, fisheries management needs help. Those with the highest commercial value are the most overexploited. Clearly, there are still economic benefits from illegal fishing for bluefin tunas. , a case in which international trade exceeds fisheries management, which is normally effective, "Nicholas Dulvy, a researcher at Simon Fraser University (Canada) and co-author of the work, told the SINC Agency.
