The streamer line needs to protect baited hooks from seabirds. This means that the streamer line should be positioned in such a way that streamers are flapping, in an unpredictable fashion, above the area in which the baited hooks enter the sea, so that seabirds are deterred from attempting to take bait from the hooks. In order to achieve this, even during crosswinds, it is expected commercial fishers will have to make adjustments to the configuration of the streamer line as conditions change.

Streamer lines should be made of line that is as light as practical and sufficiently strong.

It is generally recognised as best practice to maximise the aerial extent of the streamer line, because this maximises the area in which the baited hooks are protected from seabirds.

In order to maximise aerial extent, it is necessary to create tension in the streamer line. Towing an object on the terminal end of the streamer line is viewed as a preferred option for creating tension (and is required in some cases). The object could be a cone or buoy, a section of heavy rope, or any other object that creates sufficient drag to maintain the streamer line’s aerial extent. Tension in the line can also be created by doing 1 or more of the following:

In order to be effective at scaring seabirds away from the line of baited hooks, the streamers should not become tangled, either with each other or with the streamer line. In order to prevent streamers from becoming tangled,—

To ensure streamers are visible to birds, streamers should be made of brightly coloured fluorescent rubber or plastic tubing or other material that is resistant to damage from ultraviolet light. Bright colours such as red, yellow, orange, and pink are most effective during day setting. For night setting, the streamers should be of a colour that contrasts with the surroundings. Colours such as blue and green are less likely to be effective because they are less likely to be highly visible to birds.

A mixture of long and short streamers should be used. Long streamers (long enough to reach the surface of the sea) should be spaced at 5-m intervals along the aerial extent of the line. Long streamers that are hanging in the water can be prone to tangling. Although it is important that streamers are present to deter birds from taking baited hooks all along the part of the line that remains above water, fishers may not wish to have long streamers the whole way down the line because the far end of the streamer line will frequently be in the water. Short streamers may be used on the in-water portion of the line to increase drag.

Short streamers (of at least 1 m in length) should be spaced at 1-m intervals along at least the aerial extent of the streamer line. Short streamers may extend along the entire length of the line, including the in-water portion, as this may help create drag and increase the aerial extent. Short streamers should be made of a material that creates an erratic flapping movement. Weak links (breakaways) should be incorporated into the in-water section of the line to limit safety and operational problems if lines become tangled.

If the streamer line that is in use breaks or is damaged, it should be repaired or replaced before any further hooks enter the water. For this reason, a complete additional streamer line should be carried as a spare.

Vessels are encouraged to use a second streamer line at times of high seabird abundance or activity. If 2 streamer lines are used, the streamer lines should be deployed on opposing sides of the main line of baited hooks.

Surface longlines should be weighted to sink the baited hooks rapidly out of the diving range of feeding seabirds. Weights will shorten, but not eliminate, the zone behind the vessel in which birds can be caught.

Lead weights (such as safety leads or Lumo Leads) are recommended for surface longline weighting. (Information about Lumo Leads is available at http://www.fishtekmarine.com/lumolead.php)

Scientific studies have demonstrated that a surface longline weighting configuration with more mass close to the hook is more likely to reduce seabird mortalities because it sinks the hooks faster and therefore reduces seabird attacks on baits.

Initial and final sink rates are important for reducing seabird catches (fast initial rates reduce bait visibility near the surface and fast final rates reduce accessibility at deeper depths). In order to maximise both sink rates,—

Long leaders (2 to 4 m long), even with very heavy weights, have initial sink rates that are very slow due to the lag created by the long leader.

The mass of the weight depends on fishery risk to seabirds. Recent advice of the advisory committee for the Agreement on the Conservation of Albatrosses and Petrels suggests that lead weights of more than 60 g should be used where the risk to seabirds is—

Surface longline weights can fly back when the line is under tension at hauling. The safety of surface longline weighting may be improved by taking the following actions: