Bluewater Magazine Issue 121

All seafarers know it is considered bad luck to kill an albatross. These and other seabirds inhabit many of the same waters as tuna and billfish, especially in temperate latitudes and play a key role in the marine ecosystem. They also help ‘show the way’ to feeding fish, helping anglers get the bite. Unfortunately, seabirds are occasionally hooked or entangled by commercial and recreational fishers resulting in serious injury or death.

The good news is that Australian fishers and researchers have taken the lead developing measures to dramatically reduce the amount of seabirds killed during commercial tuna fishing. This article explains the history of seabird mitigation in the Eastern Tuna and Billfish Fishery (ETBF) and how using line weights and other measures when fishing for tuna can prevent seabird deaths.

The last thing that any commercial or recreational tuna fisher wants is a seabird attacking their bait or otherwise getting caught. They lose bait, equipment gets damaged, and time is wasted as lines get hauled in and reset. It doesn’t just impact the fishers though, seabird numbers are also affected. Seabird populations are often slow to recover from fishing impacts, especially in larger species such as albatrosses, which only lay one egg each season. Many species are listed as vulnerable or endangered, including 19 out of 21 species of albatross.

Twenty years ago, the number of seabirds caught in the ETBF each year was in the hundreds. Today, that number has been reduced to almost zero, thanks to the use of a few simple preventive measures.

Seabirds are often attracted to line and hook fishing, as they attempt to catch and eat the bait. To protect seabirds and assist in the recovery of their population, the Australian Fisheries Management Authority (AFMA), working with industry and researchers has implemented several strategies in the ETBF to minimise the chance of any bird becoming hooked.

Firstly, all pelagic longline fishing vessels are required to carry and deploy a bird scaring line, otherwise known as a ‘tori line’, which is set directly above their normal fishing lines. The tori lines have coloured streamers attached that act as a physical and visual barrier between the birds and the baited hooks.

Not discharging fish waste during line setting is the second requirement. Fish waste that is thrown overboard while the longline is being set can increase the attraction of seabirds to the boat. It can also make them associate the vessel with food, and act more aggressively around fishing gear.

Another requirement is the weighting of the branch lines stemming off the main longlines. The use of specific weights takes the baited hooks below the surface of the water and out of the seabirds’ reach as quickly as possible, so they are unable to catch the bait.    

To make sure these strategies are working, trained observers collected data on the number of seabirds caught for every 1000 hooks deployed in the ETBF region. The dedicated collection of this seabird interaction data started in 2003 and continues each year, although observers have now been replaced with electronic monitoring cameras.

The data shows that the number of seabirds caught or interacted with has decreased steadily from almost 60 birds in 2003, to just 6 in 2015. In some years that number has gone right down to 0, a huge improvement! AFMA aims to maintain these low rates of seabird interactions, though there is still more work to be done.

While Australia is already considered a world leader when it comes to minimising the impact of longlining on seabirds, AFMA and industry continue to research and trial new ideas to help reduce the numbers even further. Some of the trials conducted in Australia have included an underwater chute, which sets the longline directly under the water, preventing seabirds from reaching the lines (and hooks) at all as they are deployed.

Following on from trials over the last 15 years, an improved underwater bait setter is currently being developed through the collaboration of several companies and the Australian Government’s Australian Antarctic Division. If underwater setting can be implemented it should further reduce the number of seabirds caught in all longline fisheries.

Seabird interactions occur during all types of commercial and recreational fishing. Understanding and implementing the latest and most effective ways to reduce these interactions looks after the ecosystem and ensures a better fishing experience for all.

To find out more about seabird conservation efforts in and around Australia you can visit AFMA’s website at afma.gov.au or the Australian Antarctic Division’s website at antarctica.gov.au.