Gear Interactions & Classification
|Purse seining in the Adriatic Sea, Croatia. Photo by Ulrich Karlowski/Marine Photobank.|
Gear interactions were gleaned from literature searches for each species. For newly split species, we used information from the original species and separated it where possible, usually based on geographic range.
If a species has any sort of known interaction with fishing gear (capture, entanglement, or collision), whether the gear was active or derelict, it receives a Yes for Known Interactions with Fishing Gear. This information comes from onboard observer records and logbooks (e.g. Robertson & Bell 2002), carcass recovery (autopsy reports, band returns, beached carcasses, museum specimens, or animals collected from fishermen), and interviews. In cases where the primary source has been unavailable, the secondary source is cited and its status as a secondary source is noted.
A marked checkbox in a specific gear category indicates that a species has been documented to have interaction with that gear type, but does not necessarily imply mortality. These individuals may suffer mortality and/or injuries, or may have been released alive; a penguin hooked but released alive demonstrates the species’ susceptibility to the gear. These released alive individuals may or may not have sustained fatal injuries.
In some cases, we have indicated that a species has known interaction with fishing gear, but which specific gear type is not indicated. This is usually because the literature does not provide sufficient description of the gear to place it confidently in one category or another. If an interaction could not be allocated to a particular gear category, the headline Yes is retained for the species, and there may be no further information in the subsidiary gear type category boxes; the Gear Notes box may provide additional information in these cases (e.g. fishing nets). Depending on the presentation of data for a given fishery or recovery, sometimes species (often gulls) or gear types are not possible to disaggregate. In these cases, every effort was made to determine whether the gear could be correctly identified to any of the 18 categories established (see below for descriptions of categories). Sometimes this involved ancillary research on the fishery itself. If it was not possible to discern the depth of an executed trawl or longline set, or to disaggregate interactions by species from a fishery using mixed gear, as much information as possible is provided in Gear Notes.
If a species is considered at risk of capture in a particular gear type by an author, but no known captures are cited, this information is retained in Gear Notes but is not indicated for the gear type (for an example, see Sula sula). If the species’s taxonomic group (usually at the genus level) has been documented interacting with gear within a species’s given range (e.g. Larus spp. in the North Pacific), this is also noted in Gear Notes. In some cases, animals (dead and alive) have been recovered with fishing gear still attached to their bodies. For hooks (usually hand line or longline) we only indicated the relevant category if ingestion is indicated by the literature. For some species, impacts include striking fishing vessels; this is usually caused by disorientation due to night lighting. This information is recorded in Gear Notes and is not considered a gear interaction in and of itself because this is not unique to, and not always caused by, fishing vessels.
|Lobster trap, Florida, USA. Photo by Jiangang Luo/Marine Photobank.|
Gear type classifications are based on the FAO International Standard Statistical Classification of Fishing Gear (ISSCFG) Annex M III, 2016 categories but some categories (e.g., the large ISSCFG category 9 called "hooks and lines") have here been further divided to provide greater resolution to fisheries managers with respect to the gear employed and the differential susceptibility of various species. In other cases, where sources rarely or never indicated which gear was used, FAO categories were lumped together. The terms used are discussed below.
|Gear Type||Draft new ISSCFG category||Description|
|Seines||01-02.9||Seines and surrounding nets, including purse and beach seines|
|Trawl-bottom||03.11-03.14, 3.19||Includes otter and beam trawls|
|Trawl-midwater/pelagic||03.21, 03.29-03.9||Includes trawls described as pelagic and those described as "middle depth"|
|Pair Trawl-bottom||03.15||Bottom pair trawls can be operated in very shallow waters (2-5 meters) or at much greater depth|
|Pair Trawl-midwater/pelagic||03.22||Carried out in all depths from coastal to offshore areas|
|Dredges||04||Mechanized and hand dredges|
|Lift Nets||05||Portable, shore, and stationary lift nets|
|Falling Gear||06||Cast nets, falling gear, cover pots|
|Set Gillnets||07.1, 07.4||Anchored nets; mesh may be in midwater or bottom set|
|Drift Gillnets||07.2||Gillnets that are not anchored to the seafloor, but kept suspended by floats and weights|
|Trammel Nets||07.5, 07.6||Most commonly used as stationary gear, but may also be used drifting|
|Traps||07.3, 07.9, 08.1, 08.3-08.9||Includes fyke nets, weirs, encircling gillnets, salmon bag nets|
|Pots/Korean Traps||08.2||E.g., lobster pots|
|Handlines and Harpoons||09.1, 09.2, 09.9, 10.1||Includes pole and line used by recreational and sport fishers|
|Demersal Longline||09.31||Longlines set on or near the seafloor|
|Pelagic Longline||09.31, 09.32, 9.39||Includes South American techniques for dolphinfish known as "surface longlining"(sensu Bugoni et al. 2009); the Australians and U.S. Gulf of Mexico also refer to these as surface longlines|
|Troll and Jig||09.4, 09.5|
|Other||10 excluding 10.1, 99||Hand implements and other gear|