California, Feb. 16 -- A new study by marine biologists reports that seals can essentially act as 'smart sensors' for monitoring fish populations in the ocean's eerily dim 'twilight zone.'

Over the past 60 years, marine biologists at UC Santa Cruz have monitored the behaviour of northern elephant seals that journey to nearby Ano Nuevo Natural Reserve.

With the seals gathering on the beach by the thousands to breed and moult, generations of researchers have been able to amass more than 350,000 observations on over 50,000 seals.

Roxanne Beltran is next in line to lead the project, and her new study being published on February 14 as the cover story for Science reports that seals can essentially act as "smart sensors" for monitoring fish p...