Passive Integrated Transponder Antenna Research Articles

The potential of flat‐bed passive integrated transponder antennae for studying habitat use by stream fishes

Abstract – Describing habitat use by stream fishes is important from both basic ecological and fisheries management points of view. The most widely used methods of measuring habitat use vary in degree of effort required, level of intrusiveness and in the level of spatial and temporal resolution. In this paper, we describe a remote monitoring technique that can provide detailed and continuous data on habitat use of individual fish in the field. The technique is based on the passive integrated transponder (PIT) system, in which a newly developed flat‐bed antenna is placed on the stream bottom and simply requires a PIT‐tagged fish to swim over it. We present data obtained from work using this new technology on brown trout (Salmo trutta) in stream enclosures, in which we describe habitat use and temporal patterns of movement by individuals and relate such data to growth rate and sex of the individual fish as well as to pool depth and time of day. In addition, we describe the range of applications of the flat‐bed PIT‐antenna as well as the advantages and disadvantages of using the system.NOTE

Use of a flat-bed passive integrated transponder antenna array to study the migration and behaviour of lowland river fishes at a fish pass

The suitability of fish pass designs currently installed in rivers for non-salmonid species is poorly known, particularly in terms of their efficiency. The use of an automated flat-bed passive integrated transponder (PIT) antenna array to study the behaviour of fish at a Denil pass on the Yorkshire Derwent, North East England, is described. The array comprised four flat PIT antennae, each connected to a detector unit. Two antennae were positioned at the downstream end of the fish pass, and two at the upstream end. Each detector unit sent interrogation signals, received transponded signals from tags, and stored the data in a memory chip. Efficiency of the upstream detectors was validated as near 100% using tagged brown trout ( Salmo trutta) introduced below the detectors and observed to swim past them. Between 22 May 1998 and 23 June 1998 a total of 284 fish, comprising 11 species with a combined length range of 9–95 cm, were PIT tagged and released downstream of the fish pass. Continuous recording between 23 May 1998 and 31 August 1998 demonstrated the effectiveness of the PIT array at this site, for recording entry to, and successful exit from the pass. A total of 160 separate entries from 36 different fish were recorded at the downstream detectors, and six fish successfully exited from the top of the pass, giving a pass efficiency of 16.7%, based on the proportion of different fish which passed. Overall 12.7% of tagged fish entered the pass, comprising chub ( Leuciscus cephalus), dace ( Leuciscus leuciscus), roach ( Rutilus rutilus), perch ( Perca fluviatilis), bleak ( Alburnus alburnus) and brown trout.

A flat-bed passive integrated transponder antenna array for monitoring behaviour of Atlantic salmon parr and other fish

A flat-bed passive integrated transponder antenna array for monitoring behaviour of Atlantic salmon parr and other fish

A flat‐bed passive integrated transponder antenna array for monitoring behaviour of Atlantic salmon parr and other fish

A system for monitoring automatically the movements of individually identified small fish in natural habitats is described. The system incorporates novel flat‐bed antennae to detect the passage of miniature passive integrated transponders.

The effect of mouthpieces on the flow of water through a submerged short pipe

To help achieve effective longitudinal river connectivity, evaluation of the efficacy of fishway use by upstream-migrating fishes is needed. Larinier super active baffle (SAB) fishways are relatively cheap retrofit fish passes, suitable for low-head barriers, widespread in Europe and the most commonly fitted technical pass in Britain. Their suitability for non-salmonids, however, is poorly quantified. The efficacy of a 15% gradient SAB fishway and effects of flow regime and water temperature were tested for European river lamprey (Lampetra fluviatilis) using passive integrated transponder (PIT) and acoustic telemetry at a Crump weir on the River Derwent, Northeast England. In migration season 2013–14, over a wide range of flows, 90.1% of 350 tagged lamprey entered the fishway. One fish (0.3%) of those that entered the pass ascended successfully, even though measured water velocity was within laboratory-measured performance conditions for this species. Of 29 acoustic-tagged lamprey that visited the weir over the same period, four (13.8%) ascended it directly, during elevated flows. These data suggest that high turbulence and/or the physical characteristics of baffles may inhibit lamprey ascent of the pass. In migration season 2014–15, we tested the effect of adding studded modular plastic tiles adjacent to the fishway wall, employing PIT antennas separately interrogating the entrance and exit of each of the main fishway and tile routes. 85.8% (169) of 197 tagged lamprey entered the fishway, of which 72/169 (42.6%) entered the tile entrance. Passage efficiency of entrants was 7.1% (12/169), all of which used the tiled route. Reduced local flow velocity in combination with increased availability of resting habitat within the tiles may have facilitated increased passage. Although fishway passage efficiency increased after placement of the modular tiles, it remained half that measured for direct weir passage, both of which are inadequate for connectivity restoration. Quantitative tests of studded tiles placed on the sloping downstream weir face by comparison to control conditions may be more effective and are needed. This study demonstrates the importance of carrying out full-scale field tests to supplement possible solutions developed under laboratory conditions.