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