Otter dung reveals secrets of missing sturgeon in B.C. river

A studyof the places where river otters poop along the Nechako River is helping conservationists understand how the sleekmammal's appetite forwhite sturgeon is hamperingefforts to savethe endangered fish species.

Cale Babey, a UNBC graduate student, becameacquainted with dozens oflatrine sitesfrequented by the fish-loving Lontra Canadensis, as he spent two years searchingthrough their deposits of spraint (otter feces).

Babey was looking for small identification tags from juvenile white sturgeon released by a Vanderhoof hatchery, and he found plenty of them.

"We had had some preliminary evidence that this predation was going on," Babey told Daybreak North host Carolina de Ryk.

"We now have evidence of over 1,000 sturgeonbeing eaten by otters in the Nechako,"he said.

The findings werepublishedin a paper by Cale and co-researchers in the Oct. 5 Journal of AppliedIchthyology.

For his research,Babey passed a handheld device similar to a grocery storescanner over theotter dung. He was lookingfortiny one-centimetrepassive integrated transpondertags thatidentify each fish with a unique code.

When an otter eats a fish, it often swallows thetag, then excretes itin its spraint.

In response to the findings on river otter predation of the hatchery sturgeon, Babey saidthe Nechako White Sturgeon Recovery Initiative is working on strategies toincrease post-release survival.One possibility is to growthe juvenile fish in the hatchery for an extra year.

Although the white sturgeon are a critically endangered species (and the river otters are not),Babey says the carnivorous weasel relatives are not to blame.

"I think it's not quite fair to look at them as sort of the villain here,but as the predator, and what's an expected predator and prey interaction," Babey said.

"Otters are doing what otters do. Eat fishand eat a lot of fish."

To hear the full interview with Cale Babey on CBC Radio One's Daybreak North with Carolina De Ryk, tap the link below:

With files from Daybreak Northand Deborah Wilson