1. Acoustic Telemetry Tagging Hillary Sinnott SCM 330 March 12, 2008 Hillary Sinnott SCM 330 March 12, 2008

2. Introduction  Acoustic Telemetry Tagging is used in the ocean to obtain a continuous record of the movement of fish  Its very useful in answering specific, fine- scale questions about the physiology and environment of marine life  It can be conducted two ways, actively and passively using digital tags involving hydrophones, GPS systems and different sensor technology  Acoustic Telemetry Tagging is used in the ocean to obtain a continuous record of the movement of fish  Its very useful in answering specific, fine- scale questions about the physiology and environment of marine life  It can be conducted two ways, actively and passively using digital tags involving hydrophones, GPS systems and different sensor technology

3. Introduction  For both passive and active tagging technology the first step is to attach a “pinger” or acoustic transmitter to a fish  The “pinger” sets off an acoustic pulse of a frequency of about 32-300 KHZ  The pulse is then picked up from a hydrophone near by  For both passive and active tagging technology the first step is to attach a “pinger” or acoustic transmitter to a fish  The “pinger” sets off an acoustic pulse of a frequency of about 32-300 KHZ  The pulse is then picked up from a hydrophone near by

4. Passive Telemetry  Uses a listening station where a hydrophone is mounted  Detects any tagged fish within its range of about 100-1000m and logs the occurrence of these fish  Range of detection is dependent on the output power of the tags and the frequency of the transducer  Common for islands, bays and submarine canyons to use more than one listening station to detect the number and type of fish that travel in the area  Uses a listening station where a hydrophone is mounted  Detects any tagged fish within its range of about 100-1000m and logs the occurrence of these fish  Range of detection is dependent on the output power of the tags and the frequency of the transducer  Common for islands, bays and submarine canyons to use more than one listening station to detect the number and type of fish that travel in the area

5. Hydrophone Arrays  Consists of at least 3 hydrophones  Can be towed behind a ship or placed on the sea floor  Sounds of an animal are received by the hydrophones at different times because the hydrophones are at different distances away from the animal  The “time-of-arrival” of the sound can give information about the distance and direction of the animal  Consists of at least 3 hydrophones  Can be towed behind a ship or placed on the sea floor  Sounds of an animal are received by the hydrophones at different times because the hydrophones are at different distances away from the animal  The “time-of-arrival” of the sound can give information about the distance and direction of the animal

6. Hydrophone Arrays

7. Passive Telemetry  Range in complexity  Some collect extensive data from tags while others simply record when a certain ID tag has been detected  A tag may provide a date and time of detection as well as its depth in the water column  Range in complexity  Some collect extensive data from tags while others simply record when a certain ID tag has been detected  A tag may provide a date and time of detection as well as its depth in the water column

8. Advantages of Passive Systems  Listening stations used for a long period of time  Certain areas can be monitored for years without disruption  General location of a number of individual fish can be monitored and documented at one time  Listening stations used for a long period of time  Certain areas can be monitored for years without disruption  General location of a number of individual fish can be monitored and documented at one time

9. Disadvantages of Passive Systems  Precise location of fish is very difficult to determine without a complex 3-D system  If a tagged fish leaves the covered area it is impossible to detect  Precise location of fish is very difficult to determine without a complex 3-D system  If a tagged fish leaves the covered area it is impossible to detect

10. Active Telemetry  The Active method is in real time  A hydrophone is mounted to a tracking vessel  A sound is released by a sonic transmitter and is then used to follow the fish  Intensity of the signal indicates the distance between the fish and the boat  The Active method is in real time  A hydrophone is mounted to a tracking vessel  A sound is released by a sonic transmitter and is then used to follow the fish  Intensity of the signal indicates the distance between the fish and the boat

12. Advantages of Active Systems  The exact path of the fish through the water can be obtained by a tracking vessel  Other information about the fish and its environment can be encoded by the transmitter  The depth of the water, the waters temperature, the heart rate and tail frequency of the fish and its compass heading can all be accurately recorded  The exact path of the fish through the water can be obtained by a tracking vessel  Other information about the fish and its environment can be encoded by the transmitter  The depth of the water, the waters temperature, the heart rate and tail frequency of the fish and its compass heading can all be accurately recorded

13. Advantages of Active Systems  Method can always know the exact location of a fish  When more sensors are added additional information about the animal and its environment may be discovered  Oxygen concentration of the water  Prey abundance  Interactions between the species and other marine life  Method can always know the exact location of a fish  When more sensors are added additional information about the animal and its environment may be discovered  Oxygen concentration of the water  Prey abundance  Interactions between the species and other marine life

14. Disadvantages of Active Systems  Requires the labor of a crew  Used over a short period of time, from a number of hours to just a few days  Tracking ability is dependent on the endurance of the crew and the sea conditions  Adjustment period of about 4-24 hours for the fish after observation  Requires the labor of a crew  Used over a short period of time, from a number of hours to just a few days  Tracking ability is dependent on the endurance of the crew and the sea conditions  Adjustment period of about 4-24 hours for the fish after observation

15. Active Study  Conducted by the Pfleger Institute of Environmental Research (PIER)  Striped Marlin  Movement patterns, stock structure and habitat preference of the species are not well understood  The large and active fish is a prime target for sport fishing and populations near Latin America, New Zealand and Australia have begun to decline in number  Conducted by the Pfleger Institute of Environmental Research (PIER)  Striped Marlin  Movement patterns, stock structure and habitat preference of the species are not well understood  The large and active fish is a prime target for sport fishing and populations near Latin America, New Zealand and Australia have begun to decline in number

17. Active Study  Since 2000, over 100 pop-up satellite sensor tags have been deployed off the coast of Mexico to find answers  Since deployment sensors have received data leading researchers to focus on day and night activity differences, temperature preferences and diving migration patterns of the Striped Marlin  Since 2000, over 100 pop-up satellite sensor tags have been deployed off the coast of Mexico to find answers  Since deployment sensors have received data leading researchers to focus on day and night activity differences, temperature preferences and diving migration patterns of the Striped Marlin

18. Pop-Up Satellite Sensor Tags

19.  These tags are small devices that represent a combination of archival tags and a satellite transmitter. The tag is inserted with a barb beneath the skin near the base of the dorsal fin, while the tag itself stays outside the animal.

20. Passive Study  Published in the Journal of Environmental Biology of Fishes  Blacktip Sharks  Examined sharks within a coastal nursery to define how individual animals use the habitats during the summer months  A number of acoustic hydrophones were used to monitor the movement patterns of the sharks over 167 days  Published in the Journal of Environmental Biology of Fishes  Blacktip Sharks  Examined sharks within a coastal nursery to define how individual animals use the habitats during the summer months  A number of acoustic hydrophones were used to monitor the movement patterns of the sharks over 167 days

22. Passive Study  Study focused on each animal’s utilization of space and core area within the nursery as well as the length of the sharks excursions out of the nursery  The analyzed data concludes that each shark had a small core area and underwent a “homerange” expansion in the month of July  Also, young sharks remain in the nursery up to six months suggesting that nursery protection is critical to young sharks  Study focused on each animal’s utilization of space and core area within the nursery as well as the length of the sharks excursions out of the nursery  The analyzed data concludes that each shark had a small core area and underwent a “homerange” expansion in the month of July  Also, young sharks remain in the nursery up to six months suggesting that nursery protection is critical to young sharks

23. Conclusion  Passive and Active Telemetry Tagging helps us better understand the behavior of marine life as well as their habitats