Commentary

Smart drum lines, not so smart, Sea Shepherd Australia urges the NSW Government to reconsider their use

Thursday, 26 Nov, 2015

Commentary by Allyson Jennings - NSW Apex Harmony Coordinator

Tiger shark caught on drum line in Western AustraliaTiger shark caught on drum line in Western AustraliaThe NSW Government has announced that as a part of its $16 million shark management package that a trial of smart drum lines will be implemented off the NSW North Coast in two locations: Ballina and Coffs Harbour. Drones will also be trialled off Coffs Harbour. The smart drum lines will be in place 24 hours a day, 7 days a week.

Ballina and Coffs Harbour are both popular holiday destinations for domestic and international travellers. With both located near the ocean, they make for great places to take advantage of water based activities such as swimming, surfing and scuba diving.

The Solitary Islands Marine Park off the coast of Coffs Harbour extends from Coffs Creek north to the mouth of the Sandon River. The Solitary Islands are a well known scuba diving spot due to its incredible marine biodiversity of tropical, subtropical and temperate species including clown fish, blue tangs, nudibranchs, turtles, sponge gardens, rays and home to two aggregations of critically endangered grey nurse sharks.

They are also two locations which are subjected to intense weather systems particular low pressure systems, storms and Ballina in the past has been subjected to the remnants of tropical cyclones from Queensland. Both locations are also high energy in terms of wave activity and currents.

While the government cannot completely reduce the risk of human-shark interactions it is disappointing that the NSW Government has chosen to ignore the concerns raised within the Cardno review about smart drum lines, concerns from various scientists, stakeholders and the general public. The local communities of Ballina and Coffs Harbour have been largely kept in the dark with these drum lines and very little community consultation has taken place.

It also seems despite NSW DPI Fisheries frequently stating that any device or initiative implemented in terms of shark mitigation must be scientifically robust and have considerable independent testing, they have largely ignored their own statements.

Additionally, the smart drum line trial will not be subjected to an environmental impact assessment or scrutinised under other environment legislation including the federal Environment Protection and Biodiversity Conservation Act which raises serious concerns about their potential impact on the biodiversity of the two chosen locations and also to beach safety.

So what do we really know about these smart drum lines and the potential effects they may have on marine life? Not a great deal.

Smart drum lines have only been used in one location globally, Reunion Island off the coast of Madagascar. Essentially they are a standard drum line much like the ones used in Western Australia during the cull and also with the current shark control program in Queensland. The only difference is that they have a GPS device attached to the drum line which sends a signal to whomever has been assigned the role to check the lines once it has been trigged by an animal becoming hooked.

It is also important to note that since smart drum lines were implemented in Reunion Island in 2014 there have been 2 fatalities this year.

And as proven with the Queensland Shark Control program where over 84000 animals have been caught on the drum lines most of which are bycatch, it is clear that there is no discrimination between species caught.

There are numerous unanswered questions surrounding these drum lines which need to be addressed and made public.

There has been no significant indication of what the government wants to achieve with the roll out of smart drum lines. We do not know how long they plan for the trial to go for.

Are they for beach safety or research purposes? If they are for research purposes, will the data be publicly released?

What effect these drum lines will have in terms of beach safety is largely unknown.

In order for tagging to cause a positive impact for beach safety, thousands of sharks need to be tagged. Thousands of sharks being tagged means a lot of money needs to be spent given on average a satellite tag costs approximately $10,000 to install and maintain. An acoustic tag around $500-3000. These tags also have a life of around 10 years.

There are also costs associated with ensuring a boat is within close proximity to the drum lines, with anything standby or overtime generally costing more money especially if the drum lines are to be in place 24 hours a day.

There is a possibility of transmission failure of trigger signal and GPS. Animals snared on the drum lines need to be removed within a 2hr window to ensure maximum survival. However it is important to note that some marine species are susceptible to high mortality regardless of the 2 hour window such as dolphins, turtles and some shark species such as hammerheads and makos which can suffer from low oxygen stress.

Marine biology expert Dr Daniel Bucher from Southern Cross University has expressed concerns regarding the 2 hour window for animal removal and on any given day, it can be difficult to navigate a boat offshore in Ballina due to sandbars and the shallow depth of the water. This poses significant risk of an animal dying a slow and inhumane death on the drum line before it is removed.

There is also the potential for animals snared on the drum line to attract other predators. In Reunion Island, there have already been incidences of animals caught on the drum lines alive being mauled to death by other predators. This highlights a risk for the ocean using public if more sharks are attracted to an area due to an easy feed. How is this providing beach safety to ocean users?

Humpback whales. Photo: Allyson JenningsHumpback whales. Photo: Allyson JenningsIf a protected species is caught on the smart drum line such as a green turtle or grey nurse shark, will the trial be stopped? What are the trigger points for this trial and if tripped will they be immediately be addressed? Based on NSW DPI's track record with addressing trigger points with the shark meshing program, there does not appear to be a lot of promise. In 2013, a juvenile humpback whale died in a shark net off Mona Vale in Sydney. The report into this incident still has not been published.

Furthermore, the Cardno review also stated that the capture rate on smart drum lines is generally low, so why is the NSW Government spending so much tax payer money on a program which potentially has very little effect in terms of shark mitigation. Sharks are highly mobile animals as indicated by research conducted by CSIRO with white sharks in particular travelling hundreds of kilometres in a day.

CSIRO estimates that the east coast population of white sharks is approximately 1000 individuals, potentially half are breeding females. The smart drum lines thus far have been largely ineffective against target species such as white sharks, tiger sharks and bull sharks.

It is also critical a task force is established to oversee the management of sharks in New South Wales. This issue needs to be addressed across the state and have input from various stakeholders including emergency services, local governments, beach safety providers, aerial patrols, environmental groups and government officials to ensure transparency and accountability. Currently, NSW DPI Fisheries oversee shark management. They do not have to report to anyone and therefore do not have to make any research or activities public. This raises the questions of are the ocean using public being protected as effectively as possible and is the marine life being given enough protection especially when it comes to endangered and critically endangered species such as grey nurse sharks and green turtles.

The management of sharks in New South Wales will not be solved by one government body nor will there be one solution which fits all situations across the state. Sea Shepherd Australia stands ready to assist the NSW Government where possible to ensure the management of sharks in New South Wales is constructive, minimises risk of human-shark interaction and ensures the biodiversity of our ocean is maintained.

Sea Shepherd Australia will not support lethal methods of managing sharks when many other non lethal options are available or close to commercial availability including Shark Spotters, aerial patrols, Eco Shark Barrier, Clever Buoy, personal protection device loan schemes and others. There are too many unanswered questions surrounding the use of smart drum lines that we urge the government to reconsider their use. The ocean using public deserve effective solutions to minimise the risk of interacting with sharks not the same mistakes being repeated again when it comes to the management of sharks. Our ocean wildlife deserves as much protection as well so future generations can enjoy the beauty our oceans provide.

In an age where so much technology is at our disposal we do not have to chose between both, we can do both.

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