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Four parts of the tori-pole were tested for their effectiveness in reducing the incidental catch of albatross in the Japanese southern bluefin tuna (Thunnus maccoyii) longline fishery.  Observer data were used to test: 1. bird line material, 2. streamer material, 3. bird line length and 4. pole height above sea surface.  The effectiveness of tori-poles in reducing albatross interactions increased with a longer bird line, but there was no difference in the effectiveness between the different bird line materials, type of streamer material or pole height above the sea surface.  

Interaction risk between the endangered Antipodean albatross (Diomedea antipodensis antipodensis) and fisheries was assessed by combining satellite-tracking data of individuals with data from AIS vessel tracking, as well as oceanographic data to determine how physical ocean features shape high-risk interaction zones. Hotspots for interactions ranged from 25°S to 40° S, varied seasonally, and were significantly higher in May-August and among juveniles. Interaction risk was also greatest where thermal fronts occur. Regional Fisheries Management Organizations could extend current bycatch mitigation measures to include fishing groups between 25 and 30°S to cover seasonal hotspots for juvenile and females. 

At-sea and on-shore trials were conducted to test the safety and effectiveness of an alternative line weight for pelagic longlines called the Safe Lead.  This new line weight is designed to reduce danger to the crew in the event of a bite-off by sliding down or off the line.  At-sea trials were conducted in South Africa and indicated that dangerous fly-backs, a result of a bite-off, were reduced when the Safe Lead was used. During these trials, only 4.2% of Safe Lead fly-backs reached the fishing vessel, compared to 73.3% with traditional leaded swivels.  On-shore trials indicated that the degree of slippage of the Safe Lead off the line was dependent on the distance from the Safe Lead to the hook and the tension on the line. When the Safe Lead was placed within 2m of the hook, it slid off the line under all four tension treatments. Safe Leads appear to be both a cost effective and operationally simple alternative to traditional leaded swivels.

Four types of tori-lines (long streamer, light streamer, hybrid streamer and modified light streamer) were tested for their ability to reduce seabird bycatch on commercial longline fishing vessels in the north Pacific Ocean.  Two experiments were undertaken 1) determine the frequency of bycatch of Laysan albatross (Phoebastria immutabilis) for each tori-line and 2) determine mean rate of attacks for tori-lines.  In experiment 1, the mean number of seabirds appearing and the catch per unit effort (for seabirds) was not statistically different between the four tori-lines.  In experiment 2, seabird attack rates (Laysan albatross and shearwater) were not statistically different nor were bycatch rates of Laysan albatross among the four tori-line types.

Experiments were conducted aboard pelagic longline vessels in the western North Pacific to determine the effectiveness of paired tori lines in reducing seabird bycatch.  Paired tori lines (PT) were compared against single tori lines (ST) during these tests.  The most abundant species of bird attacking longlines was the Laysan albatross (Phoebastria immutabilis) (90.2%).  There was a significant difference in the mean number of albatross and shearwater between ST and PT deployments, with the mean number of birds being lower with PT deployments.  PT deployments reduced attacks by albatross by 47.8% and few attacks occurred within 75 m of the stern.  However when ST were deployed, albatross attacked from 25 to 200 m of the stern.  The number of secondary attacks was significantly lower when PT were used compared to ST, with PT deployments reducing secondary attacks by 43.4%.  In addition, no statistically significant difference in the distribution of secondary attacks between port and stern were found when ST were used but statistical differences were found during PT deployments.

The use of blue-dyed bait (both squid and fish) as a means to reduce seabird interactions with pelagic longline fishing gear was tested during Japanese longline fishery survey cruises off South Africa in the Southern Ocean.  The incidental catch of seabirds was lower for both blue-dyed squid and fish baits compared to non-dyed baits. The catch per unit effort (CPUE) of albatrosses decreased when blue-dyed squid and fish baits were used during all years of the study. The CPUE of petrels was lower during two years when blue-dyed bait was used.  The CPUE of the target southern bluefin tuna (Thunnus maccoyii) was also reduced during all three years when blue-dyed bait was used, except in 2003 when blue-dyed fish bait was used.  A second experiment testing the use of tori lines and blue-dyed bait (both types) resulted in no interactions with seabirds.

The use of blue-dyed bait (both squid and fish) as a means to reduce seabird interactions with pelagic longline fishing gear was tested during Japanese longline fishery survey cruises off South Africa in the Southern Ocean.  The incidental catch of seabirds was lower for both blue-dyed squid and fish baits compared to non-dyed baits. The catch per unit effort (CPUE) of albatrosses decreased when blue-dyed squid and fish baits were used during all years of the study. The CPUE of petrels was lower during two years when blue-dyed bait was used.  The CPUE of the target southern bluefin tuna (Thunnus maccoyii) was also reduced during all three years when blue-dyed bait was used, except in 2003 when blue-dyed fish bait was used.  A second experiment testing the use of tori lines and blue-dyed bait (both types) resulted in no interactions with seabirds.

Several seabird bycatch mitigation techniques were tested aboard distant water tuna fisheries in the South African EEZ.  Two types of bird scaring designs, light lines with short streams and  hybrid lines with a mix of streamer lengths were compared to unweighted branch lines. In addition, unweighted to weighted branch lines, as well as  night versus day setting with a combination of bird scaring lines were tested for their effects on seabird avoidance and targeted fish catch rates.  A total of twenty seven seabird species were observed, but white-chinned petrels (Procellaria aequinoctialis) were the most common seabird observed and had the highest seabird mortality rate in the study. Albatross (black-browed (Thalassarche melanophris), yellow-nosed (Thalassarche chlororhynchos) and shy (Thalassarche cauta)) also suffered high mortality rates while stealing bait from the petrels.  Other common surface foraging species included cape petrels (Daption capense). Hybrid lines did appear to reduce sea bird attacks, but the results are not conclusive because the birds could still attack the line at points not protected by the bird scaring lines.  Sets made at night caught far fewer seabirds (0.439 birds/1000 hooks vs. 2 birds/1000 hooks) and catch rates were 18 times higher on the unweighted compared to weighted branch lines (1.07 birds/1000 hooks and 0.06 birds/1000 hooks respectively). The weighted and unweighted branch lines did not affect targeted fish catch rates.