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Hydroacoustic Technology, Inc.
  Hydroacoustic Technology, Inc.    
  Acoustic PIT Tag Combination  
 > Ideal for Predation Studies to Identify Tagged Fish Out-of-Water
In recent years, avian predation has been suspected as a significant contributor to the loss of juvenile salmon. Because the potential impact to migrating salmonids was unclear, a combination HTI Acoustic/PIT Tag was created to better understand their consumption by various bird populations.

Piscivorous, colonizing birds can be well positioned to take advantage of migrating fish populations navigating in and around hydropower dams or other human-made structures. In North America and Europe, a few of those predators include the Caspian Tern, the California Gull, and Great Blue Heron. The combined Acoustic/PIT Tag helps shed more light on the sources of salmonid mortality.

The unique combination tag has two features performing two distinctive functions. HTI’s Acoustic Tags emit SONAR “pings” making it possible to track the 2D and 3D movement of fish within a hydrophone array. This details vital fish behavior as it migrates. Embedded in HTI’s Acoustic Tag is a second tag, a Passive Integrated Transponder tag. As small as a grain of rice, it emits no SONAR, requiring no battery. It cannot provide fine-scale behavioral data, however, it can be identified throughout the salmon’s life, even after the fish has died. This serves a second function to recognize presence of a tagged fish at different locations, such as in a bird colony, to better illustrate the impact of the predator/prey dynamic on salmonids.

The combination tag helps reveal the impact of the predator/prey dynamic once the fish has left the water, the acoustic tag battery has expired, or if the fish has left the area. A direct measurement of bird species abundance and relative distribution as it relates to fisheries management practices can increase our understanding of avian impacts to the restoration efforts of salmon.

  Key Features of Acoustic / PIT Tag Combination
Designed for Avian Predation Studies, Helps Quantify Tagged Fish Consumption
Small tag size PIT Combination Available with All HTI Tags
Small tag size High-Resolution 2D or 3D Fish Movement is Tracked by the Acoustic Tag While the PIT Inclusion Allows the Fish to be Identified Out-of-Water or After the Acoustic Tag Battery Expires

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