Yuba River Relicensing (P-2246)

YCWA Fish Behavior and Hydraulics

Study 7.11a –Radio Telemetry Study of Spring- and Fall-Run Chinook Migratory Behavior Downstream of Narrows 2 Powerhouse

Phase 1.Telemetry Desktop Assessment – September 23, 2013

Task: Compare acoustic and radio telemetry options for tracking fish behavior patterns as migrating adult Spring and Fall Chinook salmon (some possibly ESA listed) move from Daguerre Point Dam through the Narrows 2 pool. Provide estimation of most effective strategy to address stated study objectives from Study Plan 7.11a.

The Fish Behavior section of Study 7.11 addresses the need for more detailed information regarding the behavior of Chinook salmon migrating up the Yuba River to the Narrows 2 Powerhouse than was collected during a previous radio telemetry study (RMT, 2012). The current study objectives are outlined below and are followed by a comparison of various telemetry technologies and an evaluation of each as a potential tool for addressing the stated objectives.

Stated Study Objectives

  1. Evaluate coarse scale behavioral trends of migrating adult Chinook between Daguerre Point Dam and the Narrows 2 Powerhouse including travel time and residence time. Regress quantitative data against measureable environmental variables including flow regime, depth, and seasonally variable temperature. Use qualitative data to describe general trends in behavior patterns.
  2. If client determines that more precision is desired than afforded by previous observations, acquire fine-scale 2D (or 3D) positioning data using acoustic or radio telemetry sufficiently precise to spatially map behavior patterns of migrating Chinook in the vicinity of the Narrows 2 tailrace pool. Quantitative variables produced will include residence time, travel time, nearest approach calculation, zones of avoidance. Regress qualitative data against measureable environmental variables including flow regime, depth, and seasonally variable temperature.

Challenges to Successful Fish Tracking

Most technologies for tracking the movement of live fish in bodies of water involve the use of sound waves propagating through the water (or air) from a transmitter inside a fish to a receiver some distance away. Transmitters emit a coded ping at a specific rate and on a specific frequency, which the receiver array (listening only to that frequency) decodes and stores as a valid detection of that fish each time it ‘hears’ the fish ping. The detection range, or the maximum distance at which the receiver(s) can decode the transmitter, is a function of the power level of the transmitter, the sensitivity of the receiver, and the interference caused by the acoustic environment. There are several potential aspects of an aquatic environment that can cause interference, or otherwise attenuate or mutate a transmitter’s signal: entrained air which causes a non-uniform medium for sound propagation as well as excessive acoustic noise; presence of a thermocline which causes differential speed of sound within an array; presence of acoustically reflective surfaces which cause multi-path interference; and/or ambient noise interference at the same frequency as the coded transmission. As a general rule-of-thumb, the more powerful the transmitter and more sensitive the receiver, the more robust the system is to these disturbances. At the Narrows 2 Powerhouse facility and immediate area below Englebright Dam, environmental conditions that include periodic entrained air, shallow water, large stream-bed substrate, surface reflection, and ambient powerhouse noise pollution are expected.

In basic presence-absence telemetry, a series of successful detections by a receiver within a given time frame is considered evidence that the fish is present in the environment. Even in acoustically noisy environments, enough successful (non-sequential) detections may be recorded to provide definitive evidence of the fish’s presence even if the receiver does not record each ping. This type of telemetry creates a time-stamped binary dataset—at time x, fish either was (1) or was not (0) present in the array. These data can be used to calculate relative time-of-arrival (TOA, the first detection of a transmitter in an array), residence time (RT, the duration of transmitter detection within the detection range of the array), travel time (TT, time between detections at subsequent arrays), etc.

More advanced 2D and 3D acoustic telemetry systems are significantly more sensitive to environmental interference because they rely on simultaneous detections of a single ping by multiple receivers. In order to acoustically triangulate the location of a transmitter, the differential in TOA between receivers (measured in seconds, s) is multiplied by the speed of sound in water (m s-1) to get a distance measurement (meters, m). To triangulate a 2D position, at least three distance vectors (hence three simultaneous receiver detections) are required-- 3D positions require a minimum of four. When environmental factors such as entrained air or multipath prevent or distort simultaneous detections of a single ping on multiple receivers, the resulting position estimate may be imprecise, or impossible to resolve without excessive error.

Positioning in two dimensions using radio telemetry operates on generally the same principle, except that the relative distance from transmitter to receiver is measured by differential signal strength at TOA. Signal strength can be used as a proxy for distance and a triangulated position can be estimated. Environmental factors such as deep water that can attenuate the transmitter signal strength (especially if the effect is not uniform across receiving antennae) may result in imprecise (if any) position estimation. So far, this technique has been used on a very large scale to triangulate general movement of large animals in marine environments (Cooke et al., 2013) and is probably not precise enough for the environment of interest here.

The general robustness of available radio and acoustic telemetry technologies (described below) to environmental conditions and environmental interference areexplored below and in Table 1. Generally, radio telemetry is more robust to entrained air, shallow water, and acoustically reflective surfaces, while acoustic telemetry is more suited to conditions of deep water andsome ambient powerhouse noise, or where incognito deployments are desired (Cooke et al., 2013). However, it is often the case that the ambient noise environment and any potential interference on a given transmission frequency are not known until feasibility testing is performed.

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Table 1. Summary of the various technologies used for tracking animals in freshwater with a brief summary of strengths, limitations, and common applications in fish and wildlife tracking applications. After Table 1, Cooke et al., 2013.

Technology / Summary of technology and techniques / Strengths / Limitations / Applications
Acoustic telemetry; manual tracking / Uses a transducer to convert electrical energy to acoustic energy that is detected by an underwater hydrophone / Deep water (> 20 m) / Hydrophone must be submerged in water / Some applications in FW
Animals usually tracked by boat using bearings and triangulation / Ineffective in shallow or turbulent water / Mostly for fish, some use with alligator, FW mammals and elasmobranch
Not suitable for transmitters with long pulse interval (time between pulses) / Interference from macrophytes and noise (for example, boats, entrained air)
Acoustic telemetry; fixed stations / As above / Can be deployed as gates, grids, or arrays to monitor animal movements for long periods, including under ice / Generates large datasets / Widespread use in FW
Autonomous or cabled hydrophones and associated loggers store time-stamped data when tagged animals enter reception zone. / multiple station can provide precise two or three-dimensional tracks of animals / Requires significant post-processing and analytical efforts (can be challenging to recover data with some systems) / Mostly on fish, some use on mammals that move between marine and FW environments
Some systems provide real-time data transmission / Interference from macrophytes and noise (for example, boats, entrained air)
Radio telemetry; manual tracking / Emit electromagnetic energy in the radio frequency range (usually in the VHF band between 30 and 300 MHz) / Shallow water (<10 m) / Deep water (>15 m) / Fish and other taxa, especially amphibious species (for example, basking turtles, amphibians, some mammals)
Signals detected by antennas (aerial or underwater) and a receiver (some have logging capability) / Low-conductivity (<500 μS/cm) / High conductivity
Tracking can occur from boat, vehicle, air, foot / Relatively inexpensive / Sensitive to localized interference
Functions in moving water and through ice as well as on land and in air / Antennas visible, thus can attract vandals / Widespread use in FW
Radio telemetry; fixed stations / As above / Suitable for long term deployments / As above / Widespread use in FW
Fixed stations with multiple antennas detect and log tags when in the vicinity of an antenna / Not possible to obtain precise two-dimensional positions (mostly presence or absence in a given location)
Most often deployed in riverine systems to detect migration / Sensitive to localized interference

September 23, 2013Page 1 of 14

Radio Telemetry Options

Radio telemetry works by the emission of electromagnetic energy in the radio frequency by the transmitter (VHF band between 30-300 MHz). This system has traditionally been effective for monitoring not only the movement of fish, but also terrestrial wildlife because the signal propagates through air as well as water. For fish tracking, radio telemetry is most effective in shallow water with low conductivity. High conductivity (> 500uS) can cause signal disturbance, while deep water (>15 m) attenuates the signal to the point where detection range is significantly diminished (Cooke et al, 2013) and deep-water habitat use by study fish may be underestimated (Freund et al., 2002). Generally, radio telemetry for fish allows collection of animal behavior data without introduction of data-loggers into the aquatic environment. Radio transmitters have good longevity and can be tracked easily over vast distances with mobile antennae. When deep water, high conductivity, or substantial noise interference are expected, opting for a transmitter with maximum signal power may help improve detection range (Peters et al., 2008).

In some cases, however, it is beneficial to restrict the detection range of the receiver in order to more accurately determine the position of transmitters. Since radio waves attenuate so rapidly in water, the loss of both transmitter signal strength and underwater antenna range corresponds to greater accuracy of positions, though more antennas may be required to cover a given study area (Beeman et al, 2004). Beeman et al (2004) found that detection range of a standard 150MHz transmitter on an underwater dipole antenna was between 4-7 meters. The use of a more powerful tag in the Narrows 2 assessment on adult Chinook behavior (no tag-burden concerns with adult salmon relative to smolts) may increase this range. An underwater array of antennas with smaller detection radii would allow for more fine-scale presence-absence mapping in the vicinity of the powerhouse structure, however, this technique would be a grid-analysis, not a 2D triangulation system.

Various vendors supply radio telemetry equipment, though there were no commercially produced underwater antennas found currently on the market. Beeman et al (2004) provide specifications on the construction of various types of underwater antennae and a review of their detection efficiency in a range test (Figure 1). Radio telemetry is well suited to mobile fish tracking and presence-absence surveys.Some researchers have used aerial radio telemetry for rough 2D telemetry (Cooke et al., 2004). Radio technologies suitable to address the study questions presented here are described below. It should be noted that groundwork needs to be done prior to the selection of equipment frequency to establish the conditions of the ambient noise floor--the background level of electromagnetic noise from the sun, electric power lines, generators, boats, etc., below which no transmitter signals could be differentiated from noise by the receiving antenna (Sisak and Lotimer, 1998).

Figure 1. Cross sections of a standard (A) and armored (B) dipole antenna constructed from schedule 40 PVC, stainless bolds and fasteners, and dielectric-stripped Belden model 9311 coaxial cable (After Beeman et al, 2004, Figure 1).

Lotek Wireless

SRX-400-600 Radio Receiver + MCFT2 Coded transmitters

  • Designed for telemetry applications that involve autonomous data collection.
  • Unit can store unique code data from up to 7 antennas (250k records).
  • Built into a weather resistant/ waterproof case for protection.
  • Requires external power source (10-18 VDC) or rechargeable batteries.
  • Appropriate for presence absence studies, determining residence time, etc.
  • Use of Yagi style directional antenna necessary for directional positioning (not available from Lotek).
  • Compatible with Lotek MCFT2 coded transmitters (up to 521 unique codes). Rapid PRI, extended tag life allows long duration of tracking in long-lived or far-journeying species.
  • When used with a rapid antenna switching system (FAS-7), transmitter location relative to array antenna positions can be estimated using W30_CodeLog. Resolution of signal strength for computation of position is 0.25dB.
  • Data output includes: date-time, pulse rate, frequency, signal strength, antenna ID.

Advanced Telemetry Systems (ATS)

ATS- R2500CD Receiver-Data logger + F1820 Model esophageal implant transmitters.

  • Radio frequency receiver and data logger in one unit
  • Detects coded ID tags
  • One antenna port, PC USB connection. Antenna can be switched to up to 8 antennas. Use of Yagi style directional antenna necessary for directional positioning (also available from ATS)
  • Rechargeable batteries for autonomous remote deployment (8 hours operation). External 10-18V DC power source required for longer term deployments.
  • Appropriate for presence absence/ passage studies, determining residence time and rough 2D positioning relative to array antennae.
  • Data output includes: date-time, pulse rate, frequency, signal strength, antenna ID.

Custom Underwater Fixed Telemetry Array

Dipole antenna, Armored dipole antenna, etc.

  • Antennae are made by stripping a section of coaxial cable of the dielectric and copper shielding to allow conduction of electricity. Various configurations are possible depending on deployment methodology and whether detection range is more desirable in horizontal or vertical direction (dipole has greater horizontal detection range while armored dipole has greater detection in the vertical plane) Beeman et al., 2003).
  • Fixed array allows collection of quantitative data relative to residence time and travel time, and depending on the detection range, more precise estimates of position.
  • Most effective if deployed as a series of “check points” in a narrow, defined region.
  • Antennae can communicate as switched antennas on commercial aerial tracking systems (above).

Acoustic Telemetry Options

Acoustic telemetry is more suitable for fine-scale behavioral studies than radio telemetry. Autonomous data loggers deployed throughout the study area can collect fine-scale information on fish passage behavior. Acoustic tags generally have very short code lengths (e.g. JSATS is only 32 bits) which make their detection systems robust to signal fragmentation in some ranges of ambient noise. Acoustic receivers are often small and easy to deploy in autonomous locations, and will run independently on battery power for weeks to months. There are varying degrees of user-friendliness, user capacity to manipulate settings, ease of data download, and precision of telemetry capabilities. Below, various systems for two or three dimensional tracking of fish are compared based on detection range, logistical ease of deployment and servicing, robustness to noise interference, and estimated precision of position estimates. Acoustic telemetry options are described by vendor.

Lotek Wireless

MAP System, WHS 3150 + ALPS positioning software

  • Small code length makes MAP system robust in noisy environments (reduces partial signal) and high frequency may be robust to low frequency noise.
  • Autonomous (un-cabled) 2D telemetry and presence absence monitoring.
  • Accuracy of 2D positioning depends on stability of array, but can be within feet.
  • Available software, ALPS, allows user to estimate 2D positions and filter presence/absence data
  • Available pressure sensors in transmitters allow addition of z dimension (depth) to 2D positions.
  • Field-based data extraction is possible via a wet RS422 cable
  • Battery life is 50 – 150 d. depending on model. Lithium batteries can be changed easily.
  • Minimum tag size for 200 d. study with short PRI (5 s.) is 16 x 62 mm. (shorter PRI is possible).
  • Receivers can be used individually (with Bluetooth ™) as mobile tracking devices.
  • Data management is user-friendly, with software built in to query and organize data.

JSATS System, WHS 4000 + ALPS positioning software

  • Cost efficient receivers are small, simple, and lightweight.
  • Small code length makes JSATS system robust in noisy environments (reduces partial signal). (high frequency may be robust to low frequency noise)
  • Autonomous (un-cabled) 2D telemetry and presence absence monitoring
  • Accuracy of 2D positioning depends on stability of array, but can be within feet.
  • Available software, ALPS, allows user to estimate 2D positions and filter presence/absence data
  • Onboard SD memory card must be removed to extract data (not always practical in-field)
  • Battery life is 100 d. with two lithium batteries. Unit must be opened to change batteries.
  • Transmitters are designed for small fish. Maximum tag life achievable for decent telemetry is 118 d at a PRI of 5 s.
  • Receivers can be used individually (with Bluetooth ™) as mobile tracking devices.

MAP 600 System + ALPS positioning software

  • Robust in noisy environments due to short code length
  • Cabled requires a minimum of 6 hydrophones to achieve 3D positioning.
  • 2-3 Dimensional telemetry resolution is sub-meter.
  • System requires a dedicated power source on land and constant interface with a computer.
  • Array is localized (maximum cable length is 600m) for telemetry. P-A monitoring would require supplemental equipment located downstream.

Vemco Acoustic Monitoring

VR2 69 kHz + Vemco Vue software

  • Small, easy to deploy, affordable
  • Long battery life (15 months) allows undisturbed deployment during extended studies
  • Bluetooth ™ capability makes wet data download possible in the field, though receivers need to be retrieved to connect Bluetooth ™ reader-chip.
  • Low frequency (69 kHz) may be robust to high frequency noise
  • In-field firmware and software updates allow for the systems to be updated as new versions are available from Vemco.
  • Suitable for presence- absence surveys with long detection ranges relative to high frequency/ short wavelength transmitter signals.
  • Tag life is tailored to monitoring goals. PRI is generally long for monitoring.

Vemco Positioning System (VPS) with VR2- receivers