View source

[[Category:FAQ]] [[Category:PTAGIS]]

A PIT tag implanted in a Columbia Basin steelhead released from Ringold hatchery in April, 2005, and subsequently detected at Bonneville Dam in May, 2005, was recovered almost two years later, in April, 2007, from a sooty shearwater chick on a small island in the far south of New Zealand.

==What do we know about the PIT-tagged fish?==
[[Image:RINH-BON.jpg|thumb|200px|Satellite image of the Columbia Basin in the U.S. Pacific Northwest, showing the location of Ringold hatchery (RINH) and Bonneville Dam (BON).]]On September 9, 2004, a PIT tag (hex code '''3D9.1BF203BEFA''', integer code '''985120024448762''') was implanted in a 73mm steelhead (''Oncorhynchus mykiss'') at Ringold Hatchery (46.5138&#176; N, 119.2583&#176; W), located in Washington State, U.S.A., on the Columbia River 567 kilometers from the Pacific Ocean.  This fish was one of approximately 95,000 Ringold hatchery steelhead PIT-tagged in 2004 by researchers from NOAA-Fisheries as part of a smolt transportation evaluation funded by the U.S. Army Corps of Engineers.

PIT tags are normally not recorded when fish are allowed to exit volitionally from Ringold Hatchery.  However, PIT tag detectors were temporarily installed at the hatchery outfall to monitor the 2005 release, and this tag was automatically recorded as the fish left the hatchery on April 14, 2005.  The tag was detected again about three weeks later, on May 4, 2005, as it passed through the juvenile fish bypass system in the second powerhouse at Bonneville Dam (45.6439&#176; N, 121.9415&#176; W), 234 kilometers from the ocean on the Columbia River.  There were no further detections or direct observations of this PIT tag until it was recovered in New Zealand almost two years later.<BR clear="all">

==Who found the PIT tag, and where was it recovered?==
[[Image:Big_Moggy_Island.jpg|thumb|200px|Satellite image of New Zealand, showing the location of Big Moggy Island/Mokonui, one of the Titi Islands west of Stewart Island/Rakiura.]]
The PIT tag was recovered on Big Moggy Island (Mokonui to the Maori), located at 167.405&#176; E, 47.145&#176; S in the far south of [http://en.wikipedia.org/wiki/Image:New_Zealand_map.PNG New Zealand].  Mokonui/Big Moggy Island is one of the [http://www.oikonos.org/images/titi_island_map.jpg Titi Islands], situated around Stewart Island/Rakiura.  The Titi Islands are generally uninhabited by humans, but are home to huge breeding colonies of the [http://en.wikipedia.org/wiki/Sooty_Shearwater sooty shearwater] (''Puffinus griseus''), known locally in New Zealand as [http://en.wikipedia.org/wiki/Titi/Muttonbird_Islands muttonbirds], or [http://nzbirds.com/birds/titi.html titi].

Dale Whaitiri, a Maori [http://en.wikipedia.org/wiki/Muttonbirding muttonbirder], found the tag in late April, 2007, while she was processing a sooty shearwater chick.  Fortunately, Dale works in the fishing industry and recognized the small glass capsule as a PIT tag, even though the [http://www.hallprint.com/1399/index.html Food-Safe PIT tags] used in New Zealand fisheries research are different than the style of tag used in the Columbia Basin.  Dale sent the PIT tag to the University of Otago's [http://www.otago.ac.nz/titi/default.html titi research team], who in turn passed it on to fisheries scientists at the National Institute of Water and Atmospheric Research ([http://www.niwascience.co.nz/ NIWA]).  The NIWA scientists were able to read the PIT tag, and they contacted [http://www.digitalangelcorp.com/ Digital Angel, Inc.] (DA), the tag's manufacturer.  Roger Anderson at DA identified the tag as one that was sent to the U.S. Army Corps of Engineers for their fisheries research in the Columbia Basin.  Roger forwarded the tag code on to PTAGIS, where it was correlated with the Ringold steelhead marking and release events and subsequent detection at the Bonneville fish bypass.  PTAGIS relayed this information back to the interested parties in New Zealand.  PTAGIS also notified Doug Marsh, the Principal Investigator at NOAA-Fisheries responsible for the Ringold tagging/release activities, of the recovery of the tag on Big Moggy Island.

<br clear="all">

==How did the tag end up in New Zealand?==
[[Image:sootyShearwaterTracks650.jpg|thumb|200px|Monitored annual migration paths of tagged sooty shearwaters.]]
It's almost certain that the PIT tag was carried to Big Moggy Island in the [http://www.earthlife.net/birds/digestion.html crop] of an adult sooty shearwater, which then regurgitated the tag along with the rest of the crop contents while feeding its chick.  The host fish met its demise somewhere in the North Pacific, but exactly where and when will never be known.  The [http://www.fish.washington.edu/research/highseas/known_range.html ocean ranges] of Columbia Basin salmon and steelhead and the [http://www.pnas.org/cgi/reprint/0603715103v1.pdf migratory paths] of sooty shearwaters overlap across the entire width of the North Pacific.

[[Image:steelhead_trout_distribution.jpg|thumb|200px|left|Migration range of North American steelhead in the Pacific Ocean.]]
According to a [[Media:NOAA_NZ_recovery_press_release.pdf|press release]] issued by NOAA-Fisheries, ''"The most likely scenario is that the young salmon was caught and consumed by an adult sooty shearwater at the mouth of the Columbia River some time in the summer of 2005. The tag then remained in the bird's stomach for over 16 months until it was regurgitated to feed young chicks early in 2007."''

Another possibility is that the tag was scavenged from the remains of the mature steelhead.  Shearwaters are too small to prey directly upon and consume adult steelhead (or even large smolts), but they often follow commercial fishing vessels and feed on discarded bycatch and offal.  In fact, the well-documented diving abilities of sooty shearwaters can result in their [http://www.int-res.com/articles/meps/158/m158p249.pdf entanglement] in gill nets and other gear deployed by these fishing vessels.  The PIT tag may have been embedded in the entrails of the steelhead and consumed by the shearwater.  If this were the case then there may have been a much shorter interval between the time the PIT tag was consumed and when the shearwater returned to New Zealand to breed.

<br clear="all">

==External Links==
PIT Tags
*[http://www.ptagis.org PTAGIS - The Columbia Basin PIT Tag Information System]
*[http://www.digitalangelcorp.com/ Digital Angel, Inc.] - Manufacturer of PIT tags and detection equipment used in the Columbia Basin
*[http://www.hallprint.com/1399/index.html Hallprint's Food-Safe PIT Tags] - Manufacturer of PIT tags common in New Zealand


Titi Islands
*[http://www.otago.ac.nz/titi/default.html Kia Mau Te Titi Mo Ake Tonu Atu (Keep the Titi Forever)]
*[http://www.oikonos.org/projects/titi.htm The Rakiura Titi Restoration Project]
*[http://en.wikipedia.org/wiki/Titi/Muttonbird_Islands Titi/Muttonbird Islands]
*[http://en.wikipedia.org/wiki/Rakiura Stewart Island/Rakiura]


Steelhead Migration Range
*[http://www.fish.washington.edu/research/highseas/known_range.html Ocean Ranges of Pacific Salmon and Steelhead - North Pacific Anadromous Fish Commission]
*[http://www.pac.dfo-mpo.gc.ca/species/salmon/salmon_facts/steelhead_e.htm Steelhead facts - Department of Fisheries and Oceans,  Canada]


Sooty Shearwater Biology and Migratory Behavior
*[http://www.pnas.org/cgi/reprint/0603715103v1.pdf Migratory shearwaters integrate oceanic resources across the Pacific Ocean in an endless summer; Shaffer ''et al.'', 2006; Proceedings of the National Academy of Sciences of the United States of America]
*[http://polaris.nipr.ac.jp/~penguin/polarbiosci/issues/pdf/1992-Shiomi.pdf Feeding Ecology and Body Size Dependence on Diet of the Sooty Shearwater, ''Puffinus griseus'', in the North Pacific; Shimomi and Ogi, 1992; National Institute of Polar Research (Japan)]
*[http://www.int-res.com/articles/meps/158/m158p249.pdf Determination of migratory dynamics of the sooty shearwater in the Pacific using stable carbon and nitrogen isotope analysis; Minami and Ogi, 1997; Marine Ecology Progress Series]
*[http://www.seaturtle.org/tracking/?project_id=229 Satellite Tracking of Sooty Shearwaters in the California Current, 2007] (data from 2006 are available [http://www.seaturtle.org/tracking/?project_id=147 here])


Articles in the Popular Press
*[[Media:NOAA_NZ_recovery_press_release.pdf|Press release from NOAA-Fisheries regarding the PIT tag recovery]]
*[http://news.bbc.co.uk/2/hi/science/nature/5242360.stm BBC News, 8 August 2006] - ''BBC'' article on the sooty shearwater's migration
*[http://www.npr.org/templates/story/story.php?storyId=5626692 NPR, 8 August 2006] - ''Day to Day'''s take on the same topic