Retrieval of lost gear
Figure 1 shows the general arrangement for retrieving lost fishing gear.
The FAO Code of Conduct for Responsible Fishing implies that owners and skippers should make reasonable attempts to retrieve lost fishing gear. Equipment can be lost at sea for several reasons such as bad weather, poor seamanship, rock obstructions, etc. Various methods of recovering gear, particularly when surface markers have been lost or active gears have separated from the vessel, are described below. Under current practices, the amount of time and effort spent retreiving gear is related to its value, the probability of recovery and the opportunity cost in continuing fishing.
Knowing the exact location of lost gear greatly enhances chances of recovery. Close to shore this can be achieved by using landmarks; artisanal fishers are skilled in this method. Further offshore, defining the exact position of the fishing gear could be a problem, though the recent emergence of inexpensive GPS systems means that in most cases the position can be known - and recorded.
Rod creeper used onboard.
The typcial recovery method consists of dragging an implement (a "creeper") designed to snag the gear along the sea bottom until the gear is found. With light gear, such as traps and lines, the effect of tide and/or wind on the vessel is sufficient to generate a dragging motion. Where there is little or no wind or tide, the vessel must use power to drag the creeper slowly along the sea bottom. Too much tension on the creeper wire should be avoided as the lost line or trap attachments could break. In this respect, when there are very strong tides, the vessel must tow the creeper slowly against the current.
With heavy gear, the creeper operation can be much more active; the vessel's power can be used to a greater extent and a far higher tension can be kept on the creeper wire. In such cases a weight must be connected to the wire some distance ahead of the creeper to ensure that good ground contact is made and that the creeper moves horizontally. Monitoring the tension in the wire carries out the creeping operation. Successful contact with the gear is indicated by an increased tension. Recently, growing concerns over the accumulation of lost fishing gear has led governments to embark on clean-up operations using specially-developed creeping gear.
Plate creeper used onboard.
Another method of retrieving fishing gear or any other item lost on the sea bed is to use a different type of fishing gear (generally trawls). Although this may not be as effective as creepers, the cost of lost fishing is, to a certain extent, avoided. However, the vessel must fish in the same area as that in which the gear was lost. Attachment of the creeper to the toes of the net increases the chances of snagging lost gear.
If the problem requires remedial action, a clean-up operation can be introduced. For example, such programmes have already been initiated by the Canadian and Norwegian authorities using special equipment. One simple method used on relatively clean ground is to sweep the area with a trawl net. Even if recovery is not complete, the damage done to set nets and/or traps would be sufficient to ensure that ghost fishing does not continue. This system should not be used on or close to reefs or in very shallow water. In the latter case it could cause danger to the vessel and its crew.
Horseshoe creeper used onboard.
Ghost nets in deep waters
According to reports, ghost fishing is particularly problematic in deep water. In deep waters there are fewer currents to distort and reduce the effective fishing area of the net, no sunlight to degrade the materials, little growth of algae on the net and no other form of fishing (e.g. trawling or danish seining) to accidently recover the gear. This means that lost or abandoned fishing gear gradually accumulates until the problem becomes very acute. A set net lost at a depth of 200 meters on the continental slope can ghost fish for years after its loss (unseen and unreported). This probably causes far more environmental damage than a driftnet washed up on a beach in North America or Europe, which can then be identified (and dealt with).
Chain creeper used onboard.