Drones and the fight against ghost gear
Fourth Element x ARRI
Aerial Recon and Recovery Initiative, or ARRI, is a project dedicated to the study of abandoned, lost, and discarded fishing gear (ALDFG) and its impacts on marine ecosystems. They use aerial surveying via drone, coupled with action by local recovery and recycling teams, marine conservation organisations and dive centres, to restore coastal marine environments.
Ghost gear – what is it, and why do we care?
We know troublingly little about the true extent of lost fishing gear in our oceans. There is no estimated figure on the amount of ghost gear currently in the oceans; none that are considered accurate, at least. However, we estimate that fishing gear results in a loss of up to 30% of some fish populations and causes approximately 650,000 marine mammal deaths every year. The nylon used in gillnets is extremely strong & does not break down for hundreds, if not thousands, of years.
It’s important to realise that there is zero benefit to a fisher when they lose a net. This is central to our work; we collaborate with the fishing community, we don’t blame them.
To understand this a little better, let us explain the technical term for ‘ghost gear’, otherwise known as ALDFG: Abandoned, Lost or Discarded Fishing Gear.
Abandoned – gear that has become stuck at sea during deployment or at an irretrievable depth on the seafloor, and gets left behind;
Lost – when a deployed net or trap moves from its deployment location, so when the fishers return they cannot locate it;
Discarded – gear that is brought back on board but is found to be damaged. With no means of compensation for the material and no use for fishing, fishers may just throw it overboard.
ALDFG can be deadly to marine wildlife. Nets can envelop coral and snap off branches, break entire colonies or suffocate them completely. Small fish use the mass of nets as shelter in the vast ocean. This attracts larger predatory fish, which then become trapped within the nets. This in turn attracts much larger predators – at this point, you end up with sharks, rays and turtles becoming entangled, the lines cutting into their skin, stopping sharks from breathing and turtles from feeding. This most often has a sad end.
Researchers Kat and Sol observed this first hand in the Maldives. Kat discovered an Olive Ridley turtle caught in a mass of nets during a drone survey (the first time this has been done). The turtle received urgent veterinary care but still sadly succumbed to its injuries & died that night.
Why do we use drones?
In recent years, drones have become an increasingly popular and democratising tool in conservation and science in general. Until recently, aerial surveys would be conducted by plane or helicopter which are incredibly expensive, and therefore inaccessible to small conservation groups. Now, we’re able to cover kilometres of landscape at higher resolution than via satellite.
With drones, we cover wide survey areas in short periods of time, and require limited resources. The data provides us with information about biodiversity, habitat classification and encroachment of human activities. In terms of ghost gear, we are able to detect nets, lines and traps, and pinpoint their locations with extreme accuracy, producing GPS coordinates, which allows us to locate and retrieve them in-water, quickly and efficiently.
Drones also allow us to monitor wildlife to help shape more effective conservation strategies, and are far less invasive than other methods – meaning we can watch animals behaving as they would naturally, without disturbing them through our presence in the water. By using drones, we’ve been lucky enough to observe a pod of dolphins using a jellyfish as a ‘football’, a turtle snacking on a jellyfish (jellyfish don’t seem to be having a good time of it out on the reef!), schools of mobula interacting with eagle rays and reef sharks hunting together.
This is where our project comes in…
Aerial Recon and Recovery Initiative, or ARRI, is a project dedicated to the study of abandoned, lost, and discarded fishing gear (ALDFG) and its impacts on marine ecosystems.
We use aerial surveying via drone, coupled with action by local recovery and recycling teams, marine conservation organisations and dive centres, to restore coastal marine environments. We are extremely passionate about ocean conservation, cultivating relationships with local communities and researchers, and implementing long-lasting locally-managed solutions.
The ARRI Team: Our team consists of conservation ecologist and PhD Candidate Tania Kanchanarak, marine and shark biologist Kat Mason M.Sc., and conservation technologist Sol Milne, PhD. We are ecologists focused on studying Thailand’s marine environment using innovative technologies, and developing capacity to protect it long-term.
With support from Experiment Foundation, we spent 2.5 months of 2023 on Koh Phangan, Thailand carrying out our initial ALDFG surveys. It became apparent early on that the team were justified in their hypothesis that the coastlines were heavily impacted – over 200 pieces of gear were found around just the one island. We also spent a good amount of time SCUBA-diving, snorkelling and kayaking the coastline, and whilst we were saddened to see the state of many of the reefs, we were also surprised by just how well some of the corals and fish communities were doing.
The development of local capacity for long-term research and monitoring are vital to this project. We are proud to be partnered with COREsea, a research and education centre based on Koh Phangan, with research manager Victoria Fahey M.Sc. and marine biologist Lauren Blau, B.Sc. We are also working with passionate conservationist and diver Big, from Phangan Sea Guardian, a local conservation organisation, to recover ALDFG identified through our drone surveys.
We are ever-inspired to continue our work in the region, and in May 2023, the ARRI team was selected as one of eight projects to receive the GGGI and Ocean Conservancy’s Small Grants Award. This enables us to expand on the research within Koh Phangan, to see how the accumulation of ALDFG changes throughout the seasons and to implement a recovery system; collaborating with local conservation organisations and dive centres to remove the gear via snorkelling, freediving and SCUBA-diving. ARRI will also implement this on neighbouring island Koh Tao.
We have been working with Global Ghost Gear Initiative since 2019 on various projects shedding light on the scale of ALDFG globally and developing creative methods to mitigate this issue. Sol Milne began work in this field in 2019 with GGGI and Myanmar Ocean Project, using drones and an ROV to survey reefs in the Myeik Archipelago to uncover tons of submerged gear. This impressed upon Sol the ecological devastation caused by ALDFG, and he has since been working to combat this, on projects in Greece, Jamaica, Trinidad and Maldives, the latter where he began working with ARRI co-founder Kat Mason studying ALDFG, plastic and marine megafauna on Maldives’ coral reefs. Sol’s colleague from university, Tania is a Thai citizen, and spent much of her childhood in Koh Phangan, Thailand. She saw first-hand the impacts of ghost gear and witnessed the degradation of her local reefs. Together, the idea was formed to create a project studying ALDFG around her home island, and the impacts this was having on the marine ecosystem.
We are now working towards implementing an all-encompassing method from start to finish – from the initial surveys to pinpoint ALDFG locations, to in-water recovery, to recycling within Thailand. We aim to train Thai researchers to carry out ALDFG drone surveys multiple times per year, work with local organisations and dive centres to remove and recover said gear, and create a supply chain to clean, transport and sell this gear to recycling centres on mainland Thailand. We hope that the local communities of these islands will continue to work together to protect their marine ecosystems for future generations.
We are incredibly excited and grateful to be working with and supported by Fourth Element; an organisation that has always been aligned with marine conservation efforts. Fourth Element plays a crucial role in combatting ALDFG as a member of the Global Ghost Gear Initiative (GGGI). Their support of GGGI has enabled research, technology development and ALDFG removal projects. Through their platform, Fourth Element raises awareness surrounding ALDFG. Their Ocean Positive range was conceived as a result of recycled nets and other discarded waste, and they encourage their customers to take action to reduce their own impact on the oceans. We’re looking forward to using our new Fourth Element equipment for our next field season of beach surveys and ALDFG recovery dives.
Thank you to Fourth Element for your support in our research. We can’t wait to see where the next stage of our project takes us.