Archival Tag Summary
In terms of size and function, this device is very different from other NMT tags. The
Archival Tag is a device which is attached to or implanted in a large highly migratory
pelagic fish, such as a tuna or billfish, to keep a "sailing log" of its
travels over a
period which may span seven years. When the tag is recovered, it will provide daily
positions for the entire time the tag is out, along with a detailed time series of
temperature, depth, and light data for a portion of that time.

The tag is housed in a stainless steel cylinder 16 mm in diameter and 100 mm long,
and is normally implanted in the animal's body cavity or muscle. A flexible
measurement stalk of 2mm diameter extends through the skin and trails in the water to
measure external temperature and light intensity. Experience with tuna shows that the
tag and its Teflon (TM) stalk lacks the irritation or infection normally seen with
percutaneous tags, and that the stalk surface remains free of fouling.
Data from recovered tags may be down-loaded in compact binary form via an ordinary
computer, then translated into printable form by software supplied with the read-out kit.
For further information contact Dr Phil Ekstrom, ekstrom@nmt-inc.com, or the NMT
main office.

- Northwest Marine Technology, Inc
- P.O. Box 427, Ben Nevis Loop Road, Shaw Island, Washington 98286
- Telephone (360) 468-3375 Fax (360) 468-3844