Status: Draft for team discussion
Column prefix: gear_
Source: David Ruiz Garcia's reference paper (Issue #2), FAO gear classification, ICES terminology
Classify papers mentioning specific fishing gear types. Enables analyses like "which gear types are most studied in bycatch research?" or "are there geographic biases in gear-type research?"
| Column | Label | Search Terms |
|---|---|---|
gear_longline |
Longline | longline, long-line, pelagic longline, demersal longline, bottom longline |
gear_gillnet |
Gillnet/Entanglement | gillnet, gill net, trammel net, entangling net, drift net, driftnet |
gear_trawl |
Trawl | trawl, bottom trawl, demersal trawl, pelagic trawl, otter trawl, beam trawl, shrimp trawl |
gear_purse_seine |
Purse Seine | purse seine, purse-seine, ring net |
gear_seine |
Beach/Danish Seine | beach seine, Danish seine, seine net |
gear_hook_line |
Hook and Line (non-longline) | hook and line, handline, rod and reel, trolling, jigging, pole and line |
gear_trap |
Trap/Pot | trap, pot, fish trap, drumline, SMART drumline |
gear_net_other |
Other Nets | cast net, lift net, scoop net, fyke net, pound net, weir |
gear_harpoon |
Harpoon/Spear | harpoon, spearfish*, spear gun |
gear_survey |
Scientific Survey Gear | research vessel, survey trawl, BRUVs, longline survey, fishery-independent survey, drone survey, UAV survey, ROV, submersible |
| Column | Label | Search Terms |
|---|---|---|
gear_pelagic |
Pelagic Gear | pelagic longline, pelagic trawl, midwater trawl |
gear_demersal |
Demersal Gear | demersal longline, bottom trawl, demersal trawl, bottom longline |
gear_artisanal |
Artisanal/Traditional | artisanal, traditional gear, small-scale, hand-operated |
| Column | Type | Description |
|---|---|---|
gear_target_species |
text | Target species group of the fishery, e.g., "tuna", "swordfish", "shrimp", "shark", "mixed demersal". Free text extracted from paper; standardised during analysis. |
| Column | Label | Search Terms |
|---|---|---|
gear_mit_circle_hook |
Circle Hooks | circle hook, non-offset hook |
gear_mit_brd |
Bycatch Reduction Device | bycatch reduction device, BRD, turtle excluder, TED |
gear_mit_deterrent |
Shark Deterrent | shark deterrent, SharkGuard, shark guard, electropositive, Rare Earth, EPM, LED deterrent, magnetic deterrent |
gear_mit_time_area |
Time-Area Closure | time-area closure, spatial closure, fishing closure, seasonal closure, MPA |
gear_mit_handling |
Handling/Release | safe release, handling practice*, live release, post-release mortality, PRM |
Note: Shark deterrents (previously split across gear_mit_brd and gear_mit_led) are consolidated under gear_mit_deterrent. Deterrents are a subset of bycatch reduction approaches but are distinct enough in the literature to warrant their own column. BRDs retain the physical device meaning (TEDs, grids, escape panels).
- Level 2 vs separate columns: Keep separate. Pelagic/demersal modifiers add gear-specific context that eco_ columns don't capture (a paper might study pelagic habitat but discuss demersal gear).
- Mitigation as sub-category: Keep here under gear. They are gear modifications.
- Survey gear vs techniques: Keep separate schema. See Gear-Technique Comparison table (below) for where they overlap and diverge.
- Target species: Added as free text column
gear_target_speciesrather than splitting gear into fishery-specific buckets. Allows "tuna longline" to be captured as gear=longline + target=tuna. - Coverage: Gear type is mainly relevant for FISH and CON disciplines. ~40-50% of papers won't mention gear at all.
- Drones in survey: Added drone survey, UAV survey, ROV, submersible to
gear_survey.
Some items appear in both the gear schema and the technique taxonomy. This is intentional — they serve different analytical purposes.
| Item | In Gear Schema | In Technique Taxonomy | Rationale for Both |
|---|---|---|---|
| BRUVs | gear_survey |
a_bruvs (MOV) |
Gear: what equipment was deployed. Technique: the analytical method used. |
| Longline survey | gear_survey |
a_longline_survey (FISH) |
Gear: the physical gear. Technique: the standardised sampling design. |
| Acoustic telemetry | No | a_acoustic_telemetry (MOV) |
Technique only — not a fishing gear. |
| Satellite telemetry | No | a_satellite_telemetry (MOV) |
Technique only — not a fishing gear. |
| Trawl | gear_trawl |
a_trawl_survey (FISH) |
Gear: commercial/survey trawl. Technique: when used as standardised survey method. |
| Drone | gear_survey |
a_drone_survey (BEH) |
Gear: the survey platform. Technique: the observation/analysis method. |
| Circle hooks | gear_mit_circle_hook |
No | Gear only — a gear modification, not an analytical technique. |
| Stable isotopes | No | a_stable_isotopes (TRO) |
Technique only — not a gear type. |
| Mark-recapture | No | a_mark_recapture (BIO) |
Technique only — the tagging gear is incidental. |
| Genetics/eDNA | No | a_edna (GEN) |
Technique only — sampling gear is incidental. |
Principle: Gear describes what physical equipment was used in the water. Technique describes what analytical method was applied to the data. A paper can use longline gear and apply CPUE standardisation technique to the resulting data.
New gear types from ISSCFG classification and mitigation devices from BMIS (Bycatch Management Information System) review.
| Column | Label | Search Terms | Threshold | Notes |
|---|---|---|---|---|
gear_dredge |
Dredge | dredge, towed dredge, scallop dredge, clam dredge, oyster dredge, hydraulic dredge | 1 | ISSCFG code 04. Previously absent; relevant for benthic elasmobranch bycatch studies. |
gear_trawl_beam |
Beam Trawl | beam trawl, beam-trawl | 1 | Subtype of gear_trawl. Separated because beam trawl bycatch composition differs substantially from otter trawl. |
gear_trawl_otter |
Otter Trawl | otter trawl, otter-trawl | 1 | Subtype of gear_trawl. Most common demersal trawl type in elasmobranch bycatch literature. |
| Column | Label | Search Terms | Threshold | Notes |
|---|---|---|---|---|
gear_mit_weak_hook |
Weak Hook | weak hook, corrodible hook, designed to straighten | 1 | Hook designed to release large non-target species (sharks, rays) while retaining target species. From BMIS. |
gear_mit_line_weight |
Line Weighting | line weight*, weighted branchline, leaded swivel, sliding lead, lumo lead, sink rate | 1 | Branchline weighting to increase sink rate, reducing seabird and shark interactions. From BMIS. |
gear_mit_setting |
Setting Practice | night set*, deep set*, deep-set buoy gear, side-set*, underwater set* | 1 | Operational modifications to when/how gear is deployed. From BMIS. |
gear_mit_pinger |
Pinger/Acoustic Alarm | pinger, acoustic alarm, acoustic deterrent, porpoise alerting device, PAL | 1 | Acoustic devices attached to nets to deter marine mammals and elasmobranchs. From BMIS. |
gear_mit_illumination |
Net Illumination | illuminat* net, illuminat* gillnet, LED net, net light*, lightstick*, light attract* | 1 | Visual deterrents or attractants on nets. Distinct from gear_mit_deterrent (which covers shark-specific electronic/magnetic devices). From BMIS. |
gear_mit_wire_leader |
Wire/Mono Leader | wire leader, monofilament leader, wire trace, nylon leader | 1 | Leader material affects shark catch and bite-off rates. From BMIS. |
gear_mit_ghost |
Ghost Gear | ghost gear, ghost net, ALDFG, abandoned gear, lost gear, derelict gear, derelict fishing | 1 | Abandoned, lost, or otherwise discarded fishing gear. From BMIS. |
gear_survey: Now also includes "diving survey" and "diver transect" as search terms, covering in-water visual survey methods alongside drone, ROV, and vessel-based surveys.
Rationale: Dredge and trawl subtypes fill gaps in gear resolution identified via ISSCFG cross-referencing. The seven new mitigation columns cover the most commonly studied bycatch mitigation approaches catalogued in BMIS that were not already captured by gear_mit_circle_hook, gear_mit_brd, gear_mit_deterrent, gear_mit_time_area, or gear_mit_handling.
Draft created: 2026-03-10, revised with team feedback Updated: 2026-03-16, added 10 columns from ISSCFG and BMIS review