Somehow an electronic tag from a steelhead salmon in Oregon ended up in New Zealand, possibly carried by a sooty shearwater.
The tiny device was noticed by Maori hunter Dale Whaitiri on Mokonui Island, one of the Titi Islands (New Zealand). Shearwaters nest in burrows among tree roots on the island, and are known locally as Titi or Muttonbirds. The tag was recorded two years earlier as young steelhead smolts were passing the Bonneville Dam, on the Columbia River – 10,170 km from Mokonui!This seems quite likely, since shearwaters undertake amazing migrations. Every year, they complete a round trip of 39,000 miles, between their breeding grounds in New Zealand and wintering area in the northern Pacific. They may spend more time wandering than confined to a particular location.
Scientists think that the fish may have been eaten by a shearwater that was scavenging fishery wastes behind a processing vessel in the north pacific. Steelhead Salmon are not a commercial species, but they are sometimes accidentally taken as by-catch. Alternatively, the fish may have been predated as it passed below one of the large shearwater flocks that frequent the mouth of the Columbia River.