New research pinpoints ‘blue corridors’ for highly migratory fish —

New analysis has pinpointed 4 high-traffic areas within the Pacific Ocean that ought to be thought of of excessive precedence if conservation efforts centered on giant pelagic fishes corresponding to tuna, blue marlin and swordfish are to achieve success.

By finding out the tendency of fish to return to their hometown to breed — an idea referred to as philopatry that’s usually, and falsely, thought to use solely to salmon species — and pairing such information with catch distribution maps and tagging and genetic sequencing research, researchers at UBC’s Sea Round Us initiative recognized the tentative migration routes of 11 tuna and different giant pelagic fish within the Pacific Ocean and decided that sure areas ought to be thought of as of ‘excessive’ and ‘very excessive’ precedence in relation to sustaining their populations.

“We utilized the idea of philopatry to the actions extracted from tagging research of species such because the near-threatened Pacific bluefin tuna and the heavily-fished yellowfin tuna, and we additionally mixed this info with the hyperlinks between populations inferred from genetic research. This allowed us to determine tentative annual migration cycles,” stated Veronica Relano, a doctoral candidate with the Sea Round Us and lead writer of thestudy that presents these findings.

“The attention-grabbing factor is that after we in contrast our proposed migration routes and the mapped catch information from 1950 to 2016 accessible on the Sea Round Us web site, we discovered many coincidences. Clearly, the accuracy of those routes is strengthened by contemplating philopatry, though they’re nonetheless tentative,” she stated.

After analyzing the seasonal migration paths of every of the 11 fish species individually, the researchers superposed them and observed that a number of species and populations of those giant pelagic fishes use the identical migration routes.

“These high-traffic areas, two of that are in northeastern and central sections of the Pacific Ocean and two within the southwestern and central sections, ought to turn into components of blue corridors, that are routes the place strict fisheries administration measures or partial bans of business fishing should be enforced to permit for elevated connectivity of habitats and thus permit populations of marine species to keep up themselves,” stated Dr. Daniel Pauly, co-author of the examine and the Sea Round Us principal investigator.

“However earlier than organising any protected space to help the rebuilding of diminished fish populations, you will need to take into account your entire physique of information accessible on the migrations and actions of various species. That is what we got down to do with this examine. Our findings recommend through which areas such efforts can be simpler, however as acknowledged in our title, the closed migration cycles we suggest are tentative, and thus it could be good if different researchers got down to check their validity,” he stated.

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