A new study revealed that new tracking and observing technologies are giving marine conservationists a fish-eye view of conditions, from overfishing to climate change, that are contributing to declining fish populations. Charles Greene, Cornell professor of ocean sciences and lead author of the study, opined that until recently, scientists provided fishery managers only such limited data as stock counts and catch estimates.
It is informed that new advances in miniature sensors and fish-tracking tags, ocean observing systems and computer models are providing much more information about the environmental changes and how fish are responding behaviorally and biologically to such changes, thereby enabling better modeling to predict fish populations. This helps researchers making more informed recommendations for strategies to address falling fish populations.
Greene states that obtaining real-world data is essential. He added that many of the commercial fish populations in the world are pretty highly depressed. For instance, the Atlantic bluefin tuna fishery, which can garner more than $15,000 per fish, is managed as two separate stocks, one in the Eastern Atlantic basin, with a breeding ground in the Mediterranean, and another in the western basin, with a breeding ground in the Gulf of Mexico.
It is told that both stocks are not sustainably harvested, and the western population has declined by roughly 90 percent over the last 25 years, despite strict quotas. This project known as Tag A Giant (TAG) uses an implanted tag in the tuna to record external pressure, internal and external temperature and ambient light, though the tuna must be recaptured to recover these data. The tags help researchers estimate geo-locations and track each fish’s daily movements.
Greene said that new TAG data have revealed that as tuna grow, they swim all over the Atlantic, and that the fish from the two stocks commingle. Past failure to account for this mixing of the two stocks has led to unsustainable management practices, especially for tuna originating in the Gulf of Mexico.
