Cease or prohibit line fishing
Overall effectiveness category Awaiting assessment
Number of studies: 1
Background information and definitions
Commercial line fishing is catching fish using the relatively simple equipment of a cord (fishing line) attached to a hook. Commercial lines vary in construction material and thickness and range in configuration from a single line with several hooks to hundreds or even thousands of hooks attached to one main line (longline) in groups via shorter lines. Hooks are baited with animal or synthetic substances to attract the fish and can be deployed anywhere in the water column or on the seabed depending on the habit of the species being targeted. Although a less destructive fishing technique compared to some others, line fishing can lead to over-fishing, particularly in shallow coastal waters where intensity can be high. In addition, longlines can be responsible for high levels of unwanted fish catch as well as incidentally capturing other marine animals and birds. The control or elimination of line fishing in an area may help reduce fishing pressure and unwanted catch and mitigates the effects of removal of target species and sizes.
Supporting evidence from individual studies
A site comparison study in 2006–2011 of four coral reef sites in a marine protected area in the Indian Ocean, South Africa (Maggs et al. 2013) found that two to seven years after closing a zone to offshore line fishing and all other vessel-based fishing (including spearfishing), there was a higher abundance and larger size of four coral reef fish species, compared to two adjacent zones where boat-based line and spear fishing was permitted. For all years, individual catch rates of four of four species were higher inside the zone closed to line fishing and other vessel-based fishing than in the zone permitting offshore line and spear fishing: slinger Chrysoblephus puniceus (3.1 vs 0.8 fish/angler/h), Scotsman Polysteganus praeorbitalis (1.2 vs 0.3 fish/angler/h), poenskop Cymatoceps nasutus (0.4 vs 0.2 fish/angler/h) and yellowbelly rockcod Epinephelus marginatus (0.6 vs 0.1 fish/angler/h); and average lengths were higher (slinger: 293 vs 240, Scotsman: 415 vs 359, poenskop: 417 vs 380, rockcod: 495 vs 435 mm). The Pondoland Marine Protected Area (800 km2) was designated in 2004 and has a central ‘no-take area’ (400 km2) closed to all offshore (vessel based) exploitation and two adjacent controlled fishing areas where offshore line fishing and spearfishing are permitted. No commercial fishing, such as trawling or long-lining, is permitted anywhere in the protected area. From April 2006 to June 2011, quarterly research angling was conducted at two sites in the no-take zone and two in the nearby exploited zone (6 h angling in each zone) at 10–30 m depth. Data were analysed for four species depleted by line fishing.Study and other actions tested