Monitoring fish can take countless forms when it comes to approach and methodology.  At FISHBIO, we offer a unique range of automated fisheries monitoring solutions that are tailored to meet your specific project needs. While we work with many different technologies and maintain close relationships with many vendors, we do not exclusively associate with one specific solution. Why? We feel there are a number of effective solutions, any of which may be the most appropriate depending upon your needs.

Below is a summary of different automated monitoring solutions that include: PIT Telemetry, Active TelemetryUnderwater Video, Vaki Riverwatcher, and ARIS or DIDSON Camera. We provide information on the benefits of each system and what instances each is most applicable. Our team specializes in each of these solutions and is happy to further discuss particular options or any questions you may have (Contact Us).

CharacteristicsPIT TelemetryActive TelemetryUnderwater VideoVaki RiverwatcherARIS Camera
Start-up Cost$ to $$$$ to $$$$ to $$$$ to $$$$$$
Monitor fish behaviorIndirectlyYesYesIndirectlyYes
Estimate population sizeYesYesYesYesSomewhat
Uniquely identify individual fishYesYesNoWhen combined with PITNo
Requires fish handlingYesYesNoNoNo
Identify to speciesYesYesYesYesYes
Can detect and measure fish sizeNoNoSomewhatYesYes
Can monitor smaller fishYesYesYesSomewhatSomewhat
Mobile or actively track fishYesYesNoNoYes
Can be solar poweredYesYesYesYesYes
Works in turbid waterYesYesLimitedYesYes
Requires natural light or lightingNoNoYesSometimesNo
Works in deep waterNoSometimesNoNoYes
Requires a narrow opening to channel fishNoNoYesYesNo
Works in brackish or saltwaterLimitedSometimesYesYesYes

PIT Telemetry

Pro’s:  With small inexpensive tags and affordable detection stations, you can monitor numerous fish of many lifestages across a great distance.  PIT tags do not require a battery and last for decades.  The technology is excellent for monitoring movement, survival, and other large population metrics.

Limitations:  Tags are identified at monitoring locations, making mobile or active tracking more challenging.  Unique skill is required to monitor areas greater than 4 feet in depth.

When it comes to tracking fish, tremendous advances in technology have occurred over the last decade. PIT tags provide many advantages over traditional methods for marking or tracking fish. A PIT tag is a small radio transponder that contains a specific code, which allows individual fish, as well as amphibians, reptiles, birds and even rocks, to be assigned a unique 10 or 15 digit alphanumeric identification number. Unlike acoustic tags that actively send out a signal, they are “passive” and do not require a battery. Rather than the tag transmitting a signal, the tag scanner (or reader) sends out a radio frequency and when a tag is within range of a detection station, it will relay the identification code back to the receiver. The lack of a battery is the greatest advantage of the PIT tag since it allows for the production of much smaller tags that can be used on smaller organisms, which will last the life of the fish.  There are two types of PIT technology, half duplex and full duplex. While we have an affinity towards the benefits of half duplex, we provide complete service for either.

The detection stations can be placed in many different scenarios that can range from a natural stream channel to a culvert or diversion.  Antennas usually detect in depths of 4-5 ft and up to 80-100 ft of channel width.  We’ve made small, large, and even mobile antennas.  Call it our most towering achievement: as a testament to their ingenuity and skill, our team succeeded in constructing two of the largest PIT tag antennas in the world.  We designed, fabricated, and deployed PIT antennas in two hydroelectric diversion tunnels in two northern California streams. The two freestanding arrays measured 12 feet and 14 feet tall, respectively, and their performance was remarkable considering the conditions in which they were deployed. The PIT tag antenna arrays were used to monitor fish entrainment in two diversion tunnels that experienced flows as high as 12.1 feet per second, and discharges as high has 1,072 cubic feet per second. The arrays exceeded expectations by monitoring 99% of all flows diverted through the tunnels at an efficiency greater than 90%.

Active Telemetry

Pro’s:  Radio or acoustic telemetry offers the ability to directly track individual fish in 1, 2, or 3 dimensions.  Transmitters can have significant detection ranges and can be actively mobile tracked.  Monitoring stations are small and can be quickly deployed in the river without the need for a large custom antenna.  Moderate sized transmitters can be paired with sensors to provide additional measurements (e.g. temperature, depth, oxygen).

Limitations:  Tags can be expensive.  The monitoring time is based on battery life of each individual tag.  Smaller tags are available, but have relatively shorter operational life.

Active tracking using radio or acoustic telemetry offers an advance method to individually identify and monitor the movement of each tagged fish.  These systems are capable of monitoring in large rivers, lakes, and even the ocean.  Transmitters are either placed through the mouth into the stomach of adult fish, attached to the outside of the fish, or surgically inserted (primary option for smaller fish). Fish can be detected in great distances at fixed monitoring locations or can be actively monitored with mobile monitoring.  Radio telemetry can also allow for general location identification from low elevation aerial flyover surveys.  Radio and acoustic telemetry each have their own benefits.  Radio telemetry performs better than acoustic telemetry in noisy (aerated), shallow, freshwater environments.  Acoustic telemetry works best in deeper, less aerated waters—also in marine conditions as well.

There are a number of studies that can be addressed with this technology.  These studies can include predation studies (tracking predator, prey, or both), behavior studies in and around areas of interest, migratory studies investigating the timing and pathway fish choose, and these are just a few potential options.  Our team offers a suite of experience working with radio and acoustic telemetry.  We can provide an analyses of which system will best suit your project and what would be required to successfully obtain the data you need.  We are experienced with all major telemetry providers and provide an unbiased assessment as to which technology is most appropriate.

Underwater Monitoring

Pro’s:  Excellent long-term monitoring solution to count and identify fish.  Modern high-resolution images allow for identification of relatively small fish and provides an excellent visual log of fish condition.  Cameras are significantly smaller in size, inexpensive, and can provide wide-angle imagery in a number of applications.

Limitations:  Underwater videography requires somewhat clear water and light.  These challenges can be mitigated for with custom lighting and contrasting backdrops.  Automated software handles processing most detections, but some review is required.

While underwater cameras have been around for decades, the technology continues to improve, miniaturize, and reduce in cost.  Today, cameras are reliable, higher resolution, and require less power than ever before.  The viewable range is incredibly wide, allowing for a much broader or wide-angle camera perspective. When paired with motion-detection software, the level of accuracy and automation is astounding.  What’s more systems can be remotely powered with solar energy.

We use underwater cameras in many different aspects of our work.  Recently, we developed a specific camera system for monitoring smaller fishes (see our camera construction movie). The unique camera system consists of an underwater High Definition video camera with infrared vision, underwater infrared and white LED lights, a stainless steel camera tunnel, and computer operating motion detection software. We selected a camera lens with a 160-degree viewing angle, and designed the stainless steel camera tunnel to eliminate all “blind spots” that fish could potentially pass through undetected. We also created a false ceiling for the camera tunnel that can be raised or lowered to ensure the whole interior of the tunnel is submerged relative to a change in river flow. This is important because using motion detection software requires eliminating as much “background noise” as possible, such as bubbles, surface water turbulence, debris, or shadows.  The system has been deployed to monitor juvenile fishes successfully and offers and excellent automated solution.

Vaki Monitoring

Pro’s:  Excellent for enumerating total population counts without ever handling a fish. Works well with large juvenile to adult fishes.  Operates in murky water.  Can automatically log a scanned silhouette, digital picture, and fork length when a fish passes.

Limitations:  Requires a narrow passageway, like a weir or fish ladder.  Less appropriate for smaller fishes.  When relying only on the scanner system, unique species morphology assists in species identification confidence.

Vaki Aquaculture Systems Ltd. in Iceland has developed an electronic fish counting system, the Riverwatcher, which was designed for use in fish ladders and other fish ways, but works nicely with a fish counting weir. The base unit operates on a 12-volt power supply and is ideal for remote applications in conjunction with a battery and solar panel. The basic Riverwatcher consists of an in-river scanner unit and a control unit housed in a weatherproof enclosure on the bank of the river. The scanner consists of two plates mounted vertically in an aluminum frame with an opening 12 inches wide and 22 inches high. When a fish swims between the scanner plates the infrared beams are broken and a silhouette image of the fish is generated. Riverwatcher units can also be set up in conjunction with a digital camera recording video or still images. The data (silhouette, size, date, time, speed, water temperature and digital images) are sent to the control unit where the information is stored.

FISHBIO has used the Vaki system for over a decade in many river systems.  Often times these applications are in conjunction with a river weir.  We fabricate the weir, install the Vaki system, and maintain the overall operation throughout a monitoring season.  We then remove the entire weir and Vaki after the season is complete.  Our team is willing to provide any level of service on your project from end-to-end implementation or simply helping you to setup your system and training your team to maintain it.  We are a North American representative for Vaki and can help provide additional information upon request.

ARIS or DIDSON Monitoring

Pro’s:  Collects high-resolution video of fish behavior in all riverine conditions—light, dark, murky. Works best with large juvenile to adult fishes.  Software tools allow for analyses of imagery, such as image enhancement and onscreen measurements.

Limitations:  Collects a large amount of data and requires significant hard disk space.  Video content must be reviewed and analyzed.  Doesn’t work as well in noisy or aerated conditions.  The units are also expensive.

Based on Dual-Frequency Identification Sonar (DIDSON) technology, the ARIS is the most cutting-edge hydro-acoustic sampling method available today. The ARIS camera can produce near-video-quality imagery in high turbidity and zero-light conditions because the camera uses sound waves instead of light waves to “see” underwater. Sophisticated software created by Sound Metrics Inc. not only processes the echolocation data into a visual image, but also allows the camera user to retrieve range and size information from the footage with a simple click of the mouse. We’ve used both ARIS and DIDSON technology in our research at FISHBIO.  We’ve produced a video reviewing the latest camera and detailing one of our new mobile mounts.  We also have an example video of how we’ve combined standard video with the ARIS.

With the ability to capture details as small as a few millimeters, and view targets at a range of up to 40 meters, the ARIS is an incredibly powerful tool with nearly unlimited applications, judging from our experience. Our team at FISHBIO has already used this camera for a variety of different projects, including estimating adult salmonid escapement, observing fish behavior in relation to operational changes at a hydroelectric facility, determining the effects of invasive aquatic plants on salmon migration, and assessing the effects of habitat mitigation features on juvenile salmonid abundance. Of course, all of these projects would not be possible without the innovative camera mounts constructed by our FABLAB. We now have a number of custom mounting systems at our disposal that enable us to control the depth, pan, tilt, and roll of the camera, whether on shore or on a boat. This combination of tools allows us to acquire the most accurate and effective data in any setting.

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