Illegal fishing vessels sail our seas everyday. We know they are out there, we just don’t know how to catch them all.
Their presence has profound influence on the overexploitation of fish stocks, food security, and bycatch of threatened species. However, our oceans are vast and our global politics messy. To combat this, scientists from the Centre d'études biologiques de Chizé have turned to some high flyers for help: albatrosses.
It’s been known for some time these birds love to follow a ship; they’ve been featured in poems as signs of good luck or, if slain, bad luck. Now, they are being equipped with state-of-the-art loggers to become “Ocean Sentinels” to help thwart illegal activity.
The albatrosses allowed the researchers to estimate “the proportion of non-declared fishing vessels operating in national and international waters of the Southern Ocean.” In international waters, they found that more than one-third of vessels had no operating Automatic Identification System (AIS) and could not be identified. For national Exclusive Economic Zones (EEZs), that number was lower on average but still exists.
"In the oceans, the surveillance of fisheries is complex and inadequate, such that quantifying and locating nondeclared and illegal fisheries is persistently problematic," the team write in the Proceedings of the National Academy of Sciences.
"This study shows that the development of technologies offers the potential of implementing conservation policies by using wide-ranging seabirds to patrol oceans."
Albatrosses cover large swathes of the ocean surface: 22 million square kilometers (8.5 million square miles) when 50 individuals are rigged in a radar detector, GPS antenna, and an antenna to send data to satellites. The loggers weighed roughly 0.46 to 0.93 percent of the bird’s total body weight, well below the 3 percent recommended limit. Albatrosses are highly attracted to fishing vessels, detecting them up to 30 kilometers (18 miles) away, "making them particularly suitable patrollers of the oceans."
However, it does take a bit of time to equip the birds with loggers. "As often with work on wildlife, it takes long, long days of waiting, that a couple finally shifts over their nest: a partner finally comes back from the sea, and takes over the incubation duty," study author Julien Collet told IFLScience. "Then we can equip the one that is about to leave at sea. On average each couple does that every 9 days, so even if you can monitor 100 nests with your binoculars, you expect only 2 or 3 on average in a day.
"Sometimes it's the rush and they are all shifting at the same time, and it takes good preparation to make the most of it. The good thing for us is they are really kind birds, rarely aggressive, easy to work with."
Almost 170 bird patrols were tested between November 2018 and May 2019 in the Southern Indian Ocean at Crozet, Kerguelen, and the Amsterdam Islands. The Ocean Sentinels checked whether vessels had an AIS signal or not. If they didn’t, the logger still detected the radar from the boat, which the sailors need to navigate. If the radar signal doesn't match the position of registered AIS vessels, the vessel is possibly involved in illegal activity.
During the 6-month period, more than 100 million AIS locations were obtained. This includes information such as date, latitude, longitude, ship name, identity of International Marine Organization (IMO) number of the vessel, nationality, call sign, speed, and type of vessel.
The feathery flyers recorded 353 vessels but more than 28 percent had no AIS signal. In international waters, this percentage increased to nearly 37 percent. There are many reasons for why this may be, but most of them are illegal, such as fishing without a license, transferring illegal catch to other vessels, or navigating outside their designated range.
"Attraction differed between species, age, and vessel activity. Fishing vessels attracted more birds than other vessels, and juveniles both encountered fewer vessels and showed a lower attraction to vessels than adults," write the team.
The researchers hope further study and observations will help government officials locate illegal vessels and investigate suspicious activity.
"Boat detections are relayed through satellite in near real-time (1-2h delay), and in our study it was directly communicated to French enforcement authorities," said Collet. "Then it is their call if they have the logistics to intervene with nearby patrols, in case of undeclared operations. They have patrols present, and these can not monitor large areas at a given time, so having extra pairs of smart, wing-propelled eyes can help! Fisheries can be very lucrative, so it's in everyone's interest to prevent illegal fishing there: legal fishermen, authorities, fish, birds... This is for national waters. In international waters, it gets all the more complicated to intervene. But describing the extent of the issue is a first step."