1. Woods Hole Oceanographic Institution
Marking gear location
Mark Baumgartner
Woods Hole Oceanographic Institution

2. Ropeless (buoyless) fishing
Taking away the end line and buoy requires the functions of these components to be replaced:
Function 1: Retrieval of the gear
Lift bags (variable buoyancy)
Bottom-stowed rope
Function 2: Marking the location of the gear

3. Ropeless fishing and gear conflict
NMFS Concept Paper on ropeless fishing (Nov 2010):
Problems with gear conflicts are the main reason why buoy lineless fisheries are not being conducted on a broad-scale basis. Any unmarked fixed gear would be susceptible to being towed through by mobile gear fisheries (bottom trawl, scallop dredge, etc.), and set over by other fixed gear and vice versa. Therefore, in order to encourage buoy lineless fishery operations, … gear conflicts would need to be addressed.

4. One approach:
Have fishermen mark the location of the gear on a plotter or other system when they deploy, and then share those locations with other fishermen
Pros: Relatively cheap, solutions exist today
Cons: (1) Fishermen are not keen to share fishing locations, (2) most fishing boats not equipped with satellite communications, (3) can be manipulated, and (4) unhelpful for gear that has moved (e.g., by a storm)

5. Acoustic approach
Acoustically mark the location of each trap (singles) or the ends of each trawl
Enable the trap/trawl to report its position to fixed or mobile fishermen
Enable the trap/trawl to report its owner’s registration/permit information to enforcement
Enable commercial chart plotters to display the positions of acoustically marked fixed gear
Acoustic modems

6. Acoustic approach (continued)
Pros: (1) Reports only to ships that are nearby, (2) reported locations are associated with gear that is actually on the sea floor, (3) allows recovery of gear moved after deployment (e.g., in a storm), and (4) can take advantage of acoustic communications already needed to trigger retrieval
Cons: Potentially expensive (at least initially)
Acoustic modems

7. Technology
Acoustic modems allow data to be passed through water via acoustical waves the way cell phone modems allow data to be passed through air via radio waves
Proven technology with several commercial manufacturers: Teledyne Benthos, Nortek, EvoLogics, Sonardyne, and AquaSeNT
Propose to use modems on traps and on ships to acoustically “mark” location of on-bottom gear

8. Trap deployment Trap modem w/GPS Lift bag GPS satellite constellation
Note: trap not to scale

9. Trap deployment
GPS satellite
constellation

10. Ship with surface modem

11. Data sent from ship to trap: Date/time Position of ship
Ship identifier
Data sent from trap to ship:
Public data
Last known position of trap (GPS/ranging)
Private (encrypted) data
Last surface date/time
Fisherman’s registration number
Unique device identifier
User-designated identification number
Sensor data (e.g., trap occupancy)
Emphasize that the trap only responds to sounds, it is not emitting sound. It also keeps track of a ship’s identifier, and after communicating with a ship, will not communicate with it again after some blackout periods, such as a half hour. This does not apply to the trap owner’s boat, who can communicate with his traps anytime.

12. Data Warehouse Fisherman Enforcement Regulators Trap modem data
(public and private)
Data warehouse (cloud) operated by
Private company
Fisheries commission
Government

13. Trap recovery

14. Gear that moves from its deployment location
Locations in the data warehouse can be used to alert fishermen of…
The fact that their gear has moved
The new location of their gear
System can greatly reduce lost gear, time spent looking for lost gear, and costs
Can significantly reduce ghost gear

15. Your trawl #29 has moved. It was detected by a ship 5 hours ago at 41 18.43 N, 70 36.22 W
???

16. Development
Acoustic modems are commercially available, but development is required to
Incorporate retrieval trigger mechanism
Incorporate GPS and self-localization capability
Communication and data protocols to ensure interoperability (e.g., JANUS)

17. Development (continued)
WHOI is working on this…
Incorporated WHOI Micromodem-based trap modem in 2 retrieval systems (SMELTS lift bag, WHOI spooled rope)
Will incorporate GPS this winter
Developed methodology for self-localization
Plan to demonstrate these capabilities for fishermen and regulators
Provide open access to methods and software

18. Commercial acoustic modem
Development (continued)
Cost depends on design and demand
Units
Cost per unit 1
$18,000 10
$9,000
100
$4,500
1,000
$2,250
10,000
$1,125
100,000
$563
1,000,000
$281
WHOI trap modem
Commercial acoustic modem
Engineering rule of thumb: As production increases by a factor of ten, cost goes down by a factor of 2

19. Thank you! Acknowledgements Funding: Island Foundation
Your trawl #29 has moved. It was detected by a ship 5 hours ago at N, W
Thank you!
Acknowledgements
Funding: Island Foundation
Lift bag: Richard Riels (SMELTS)
Spooled rope: Tim Werner (NEAq)
Useful discussions: Jim Partan, Keenan Ball (WHOI)