Marine Life & Conservation
Microplastics on the menu of Manta Rays and Whale Sharks
Plastics pollute Indonesian feeding grounds of plankton-feeding ocean giants…
Plastic pollution has a tremendous impact on marine life – and reef manta rays and whale sharks are not spared from it. These large filter-feeders swallow hundreds to thousands of cubic meters of plankton-filled water every day, and with it, tiny plastic pieces from broken down carrier bags and single-use packaging, a new study has found.
Marine biologists from the Marine Megafauna Foundation, Murdoch University (Australia) and Udayana University (Indonesia), estimated the amount of plastic particles present in the waters off Nusa Penida (Bali), Komodo National Park and East Java in Indonesia and, based on that, calculated how many pieces reef manta rays and whale sharks might be ingesting. These shark species sieve nutrient-rich water through their gills as they swim.
As manta rays and whale sharks spend a lot of time feeding in inshore surface waters where trash commonly aggregates, the researchers used a plankton net to trawl for plastics in the top 50 cm of the water column. They also counted any debris visible at the surface from the boat.
Elitza Germanov on boat – Marine Megafauna Foundation
Lead author Elitza Germanov, a researcher at the Marine Megafauna Foundation and PhD candidate at Murdoch University, said: “With time, plastics break down into smaller pieces called microplastics that large marine filter feeders might accidentally scoop up because they float among their prey.”
“Manta rays and whale sharks can ingest microplastics directly from polluted water or indirectly through the contaminated plankton they feed on,” she adds.
Plankton microplastics sampling – Marine Megafauna Foundation
The collaborative study, which is published today in the journal Frontiers in Marine Science, found that reef manta rays may ingest up to 63 pieces of plastic per hour of feeding in Nusa Penida and Komodo National Park. Whale sharks, which seasonally aggregate in Java, could be ingesting up to 137 pieces per hour.
Thin and bendable films from single-use bags and wrappers as well as hard fragments were the most prevalent plastics (over 50% combined). Of all plastic recorded, around 80% were small pieces of less than 5mm, so-called microplastics.
Manta ray poo and vomit also tested positive for plastics, which means that plastics are easily ingested when filter feeding and likely expose the animals to toxic chemicals and pollutants found in plastics while in their digestive system. These toxic substances can accumulate over decades and alter the hormones that regulate an animal’s metabolism, growth and development, and reproductive functions. Larger plastic particles can block nutrient absorption and cause damage to the digestive tract of animals.
Microplastics in manta poo (c) Elitza Germanov et al 2019
Neil Loneragan, Professor of Marine Ecology and Conservation at Murdoch University said: “It is difficult to assess how much plastic manta rays and whale sharks actually ingest because conventional methods used to study animal diets, such as stomach analysis, are unsuitable for threatened species like these.”
Manta rays and whale sharks are globally threatened species facing extreme pressures from overfishing. They are often caught incidentally in nets or become entangled in fishing lines.
Manta with plastic in Indonesia – Elitza Germanov, Marine Megafauna Foundation
Indonesia is currently ranked as the second worst plastic polluter in the world and many neighbouring countries within the Coral Triangle are among the top 10. This study found that plastic abundance was up to 44 times higher during the rainy season, with the largest seasonal effect observed in Nusa Penida.
Dr. I. Gede Hedrawan, an Indonesian plastics researcher from Bali’s Udayana University and an author on this study, said: “The seasonal variability in plastic pollution shows what a difference it would make to clean up river beds before the rainy season begins.” Local authorities could also prohibit any waste disposal in areas around water sources.
“We welcome Bali’s recent ban on single-use plastic bags, straws and take away containers, although the law is yet to reach its full effect and spread to smaller businesses,” he says.
Trash on beach Indonesia – Elitza Germanov, Marine Megafauna Foundation
It is vital to understand the effects of microplastic pollution on ocean giants since nearly half of the mobulid rays, two thirds of filter-feeding sharks and over one quarter of baleen whales are listed by the IUCN as globally threatened species and are prioritized for conservation. Previous studies found that baleen whales may swallow microplastic particles in the thousands every day.
“We now know that, through exposure to toxic substances, plastic contamination has the potential to further reduce the population numbers of these threatened animals because they reproduce slowly and have few offspring throughout their lives,” Germanov concluded.
As plastic production is projected to increase globally, future research should focus on coastal regions where pollution overlaps with the critical feeding and breeding grounds of these ocean giants. Many areas such as the Nusa Penida Marine Protected Area and Komodo National Park are biodiversity hotspots with significant marine tourism.
Trawling microplastic – Marine Megafauna Foundation
The field research was supported by the Ocean Park Conservation Foundation, PADI Foundation, Foundation FortUna, Mantahari Oceancare, Arenui Boutique Liveaboard, Current Junkies Liveaboard, Happy Days yacht, Scuba Junkie Komodo, and Wunderpus Liveaboard, and was carried out under a RisTek-Dikti (Indonesian Ministry of Research) permit.
The study by Elitza Germanov et al., titled ‘Microplastics on the menu: Plastics pollute Indonesian manta ray and whale shark feeding grounds’ is published in the journal Frontiers in Marine Science on 19 November 2019 and is available here: https://www.frontiersin.org/articles/10.3389/fmars.2019.00679/full
For further details, please see www.marinemegafauna.org or follow them on Twitter, Facebook and Instagram. For information about regional projects, follow the Marine Megafauna Foundation’s Southeast Asia Facebook page.
The Ocean Cleanup, the global non-profit project, has removed a verified all-time total of ten million kilograms (22 million lbs.) of trash from oceans and rivers around the world – approximately the same weight as the Eiffel Tower.
To complete its mission of ridding the oceans of plastic, The Ocean Cleanup uses a dual strategy: cleaning up the Great Pacific Garbage Patch (GPGP) to remove the plastic already afloat in the oceans, while stopping the flow of plastic from the world’s most polluting rivers.
Through cleaning operations in the GPGP and in rivers in eight countries, the cumulative total of trash removed has now surpassed ten million kilograms. This milestone demonstrates the acceleration of The Ocean Cleanup’s impact, while underlining the astonishing scale of the plastic pollution problem and the need for continued support and action.
While encouraging for the mission, this milestone is only a staging point: millions more tons of plastic still pollute our oceans and The Ocean Cleanup intends to continue learning, improving and innovating to solve this global catastrophe.
This announcement comes as governments from around the world meet to continue negotiations to develop a new legally binding instrument to end plastic pollution at INC4 in Ottawa, Canada. Representatives of The Ocean Cleanup will be in attendance and the organization will be urging decision-makers to collaborate towards a comprehensive and ambitious global treaty which addresses plastic at all stages of its life cycle and in all marine environments worldwide, including in areas beyond national jurisdiction.
It is encouraging to see that the need for remediation is reflected in the various options for potential treaty provisions. It is essential that the final treaty contains clear targets for the remediation of legacy plastic pollution, and reduction of riverine plastic emissions.
Tackling plastic pollution requires innovative and impactful solutions. The treaty should therefore incentivize the innovation ecosystem by fostering innovations that make maximal use of data, technology and scientific knowledge – such as those designed and deployed by The Ocean Cleanup.
‘After many tough years of trial and error, it’s amazing to see our work is starting to pay off – and I am proud of the team who has brought us to this point.’ said Boyan Slat, Founder and CEO of The Ocean Cleanup. ‘While we still have a long way to go, our recent successes fill us with renewed confidence that the oceans can be cleaned.’
The Ocean Cleanup was founded in 2013 and captured its first plastic in 2019, with the first confirmed catch in the GPGP coming soon after the deployment of Interceptor 001 in Jakarta, Indonesia. After surpassing one million kilograms of trash removed in early 2022, the non-profit project has since progressed to the third iteration of its GPGP cleaning solution, known as System 03, and a network of Interceptors currently covering rivers in eight countries, with more deployments set for 2024.
About The Ocean Cleanup
The Ocean Cleanup is an international non-profit organization that develops and scales technologies to rid the world’s oceans of plastic. They aim to achieve this goal through a dual strategy: stemming the inflow via rivers and cleaning up the legacy plastic that has already accumulated in the ocean. For the latter, The Ocean Cleanup develops large-scale systems to efficiently concentrate the plastic for periodic removal. This plastic is tracked and traced through DNV’s chain of custody model to certify claims of origin when recycling it into new products. To curb the tide via rivers, The Ocean Cleanup has developed Interceptor™ solutions to halt and extract riverine plastic before it reaches the ocean. Founded in 2013 by Boyan Slat, The Ocean Cleanup now employs a broadly multi-disciplined team of approximately 140. The foundation is headquartered in Rotterdam, the Netherlands.
For more information, visit: theoceancleanup.com and follow @theoceancleanup on social media.
Marine Life & Conservation
Steve Backshall to headline Shark Trust’s flagship event: For the Love of Sharks
Join a host of amazing, shark loving, speakers including Steve Backshall and the Shark Trust team for an evening celebrating shark conservation at the Royal Geographical Society in London this November.
Date: 29th November 2024
Time: 6-10pm
Location: Royal Geographical Society, London
Tickets: https://www.sharktrust.org/Event/flos24
The event will be a celebration of all things shark. Those lucky enough to get hold of tickets will hear from engaging guest speakers with a passion for sharks.
The line-up includes (*subject to change if unforeseen circumstances arise)
Steve Backshall: One of television’s busiest presenters, BAFTA award-winning wildlife expert Steve has been passionate about the wild world ever since he was young.
Steve’s impressive TV career has taken him all around the world, investigating a wide array of species and environments. Steve has filmed over 100 hours of children’s wildlife programmes with the BAFTA award winning Deadly 60 franchise and recently, with Sky Nature, for his new series ‘Whale with Steve Backshall’. He has been a patron for the Shark Trust for 10 years.
Simon Rogerson: is a photojournalist specialising in natural history, diving and the sea.
He is editor of SCUBA magazine, the official journal of the British Sub-Aqua Club. Simon started his career as a crime reporter but gravitated towards his ‘less depressing’ interest in underwater exploration, joining the staff of DIVE magazine in 1999. In 2005 he was named ‘Editor of the Year’ in the PPA’s Independent Publishing Awards. Simon also works as a freelance writer, contributing frequently to the Sunday Times and Telegraph, in addition to BBC Wildlife, Esquire, and a host of international diving magazines. He is the author of a book, Dive Red Sea, published by Ultimate Sports. Now based in Berkshire, Simon has been a Patron of the Shark Trust for 20 years.
More speakers to be announced soon. Head to the Shark Trust website to learn more.
The evening will also allow guests the final chance to see the Oceanic 31, shark art exhibition. Some of the artwork will be auctioned/raffled at the event, while the rest will be auctioned online to raise money for the Shark Trust Oceanic Programme.
For the Love of Sharks is an evening with something for everyone who is interested and fascinated by sharks. Join the Shark Trust, their Patrons, Trustees and Staff, along with a host of supporters for this celebration of shark conservation.
For more information or to buy a ticket: https://www.sharktrust.org/Event/flos24
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