How marine biologists are using elephant seals as nature's 'artificial intelligence'

Elephant seals are being used as nature's artificial intelligence to monitor the health of the oceans -- especially the little-known "twilight zone," an ecosystem abundant with fish that could soon be targeted by commercial fisheries, researchers told ABC News.

Marine biologists at the University of California Santa Cruz have tagged thousands of northern elephant seals with smart sensors that can measure anything from physical environmental characteristics -- like temperature of air or water -- the salinity of the ocean, location and how deep the seals are diving, according to a paper published in Science on Thursday.

The sensors are also equipped with video and audio so researchers can get a sense of what the marine mammals are seeing and hearing.

In a modern world of super computers that analyze data and perform tasks, elephant seals with these sensors can behave in a similar manner and naturally gather valuable observations about the ocean along their natural migratory route, the researchers said.

Unlike other fully aquatic marine mammals, elephant seals are available to researchers for a large part of the year when they come onto land along their migratory routes, Roxanne Beltran, the study's lead researcher and an assistant professor of ecology and evolutionary biology at the University of California Santa Cruz, told ABC News.

Thousands of seals come ashore at the Año Nuevo Natural Reserve in California twice a year to breed and molt, the annual event in which they replace their fur.

It is currently peak breeding season for the elephant seals. Those gatherings offer a boisterous scene, Beltran said.

The females are fighting each other to protect their pups from one another. The males, attempting to mate with them, are competing with other males for those females and space on the beach.

"It really is a really rowdy group during the breeding season," Beltran said.

The researchers are especially interested in studying the adult females as they get pregnant and give birth.

"They come back year after year in order to give birth," she said.

After breeding season is over, the seals will embark north on a short foraging trip that lasts about 2.5 months, Beltran said. After they return to molt, they depart again for a 7-month migration into the Northeast Pacific Ocean.

"They make it halfway to Japan and back, which is a pretty extraordinary feat for for a marine mammal," Beltran said.

During the first migratory route, the elephant seals seek out the transition zone between two ocean fronts, where there is a lot of food available in the form of fish and squid, Beltran.

In the longer migratory route, each seal is making something like 75,000 foraging attempts. The researchers know this because the sensors are have onboard processing algorithms that captures every time the seal lunges its head to get fish or opens its mouth to chew and swallow the fish.

"The sensors can give us a whole ton of information about where the seals are going, how deep they're diving, how successful they're being, which environmental metrics are predicting their success," Beltran said.

During the migratory route, the elephant seals enter the "twilight zone" -- also known as the mesopelagic zone -- a layer of the ocean that extends from about 656 feet to 3,280 feet below the ocean's surface that is abundant with fish, Beltran said.

Since the ecosystem is an untouched resource, fisheries have begun to express interest in extracting fish from the twilight zone, Beltran said.

"But because the mesopelagic is so deep, and in particular, so far from the coast, we don't yet have the technology available to fish those resources in a way that is cost effective," she said.

If pilot fisheries were to go up in the region, it could have reverberations all across the ecosystem -- including for the elephant seals that rely on the plentiful fish to sustain themselves.

Northern elephant seals were once thought to be extinct due to commercial sealing in the 1800s, but a small population survived in Mexico and the population began to steadily increase in the early 1900s, according to NOAA Fisheries.

Today, there are about 350,000 seals along the west coast of the U.S., Mexico and Canada.

They are the perfect specimens for studying the ocean because they are far-ranging, deep-diving and reliably return to the colony, Beltran said. They also provide a lot of information on biological productivity in the ocean, because they put on a lot of mass during the foraging trips.

A long line of professors at UC Santa Cruz have been studying elephant seals since the 1970s, which has provided enough observations to tell a complete story of how the health of the ocean has fared through the decades, Beltran said.

During that time, the marine biologists have been pioneering the use of the miniaturized technology that can be carefully glued to animals

They have amassed more than 350,000 observations on about 50,000 seals since the research began.

"The reason this paper is so useful in terms of its biological and ecological insights and potential management applications is that that program was able to continue for so long," Beltran said. "There really hasn't been a more important time to continue long-term monitoring programs and support for science."