Development of a double-breakaway pass-through PIT-tag antenna system for flood-prone rivers

Abstract

Pass‐through passive integrated transponder (PIT) antennae are often used in river and stream habitats to monitor the movement of aquatic species. Where these habitats are prone to high flows containing suspended debris, traditional pass‐through antennae designs are particularly vulnerable to damage which can be time consuming and expensive to repair and lead to extended gaps in data collection. We designed and tested a novel pass‐through half duplex (HDX) antenna system that allows the antenna loop to (1) break away from one river bank under predetermined strain and (2) split into two separate cables, thereby shedding entangled debris that could otherwise damage or dislodge the antenna system. After break away events, our system can be rapidly reconnected and redeployed without the need for personnel to enter the water, reducing maintenance time and costs while minimizing gaps in data. In locations where pass‐through antennae are prone to flood damage, this system offers distinct advantages over traditional designs.