Microplastics are widespread in seas and oceans, and their harmful effects on many different marine animals are well known. However, we know relatively little about the microplastics in our freshwater rivers, streams and lakes. We still don’t know exactly where they come from, where they end up – and crucially – what damage they can cause if they get into food chains.
Until now, plastic fragmentation had largely been attributed to processes such as sunlight or wave action, which can take years or decades. But it turns out a tiny shrimp-like creature can do the same job much faster.
I am a researcher who specialises in microplastics in the environment. In my latest study, colleagues and I have shown that microplastics (plastic pieces smaller than 5mm) in freshwaters are being broken down into even smaller nanoplastics (smaller than one micrometre, at least five thousand times smaller in size) by a type of freshwater invertebrate animal, and that this may happen much faster than previously estimated. Our results, newly published in the Nature journal Scientific Reports, highlight the role of biological fragmentation of microplastics, which has been understudied so far.
The animal in question is a 2cm-long crustacean, the freshwater amphipod Gammarus duebeni. This specific species lives in Irish streams, but it belongs to a bigger group of invertebrates that are common in both freshwater and the oceans around the world. Our finding therefore has big consequences for how we understand the environmental fate of microplastics.
Our first experiments had been carried out to understand the potential negative effects (if any) of microplastics in the amphipods. However, some surprising early results led me to run new experiments focused on gathering evidence to show that microplastics were being fragmented biologically – by G. duebeni themselves.
In order to find out about this, I exposed the amphipods in the laboratory to a certain type of microplastics that have a specific colour dye. I then dissected the digestive tracts of the amphipods and visualised them under a fluorescence microscope, which is able to track the dyed-microplastic in animal tissue.
We then concluded that Gammarus duebeni is able to fragment microplastics into different shapes and sizes, including nanoplastics, in less than four days.
We were able to track such fragmentation because the microplastics that we used were originally “microbeads” with a perfect spherical shape. Any plastic with irregular shapes therefore must have been fragmented by the animals, and nearly 66% of the microplastics found in the guts had indeed been fragmented in this way.
Remarkably, the proportion of smaller plastic fragments was highest when the amphipods were “purged” in the lab in a clean environment with no plastics but with their food. This finding indicates that biological fragmentation could be closely related to the feeding process
We also ran some quality control checks, several side experiments to make sure that the plastic was indeed being fragmented by the amphipods and not some other source, and that we were accurately visualising the fluorescence particles.
Microplastics in the food chain
Why does this matter? We already know that microplastics can accumulate in the gut of seabirds and fish, and our current understanding is that the smaller nanoplastic particles could even penetrate cells and tissues where their effects could be much harder to predict.
Therefore the finding that such a common animal can rapidly produce vast numbers of nanoplastics is particularly worrying. Since the crustaceans we looked at are eaten by fish and birds, any nanoplastic fragments that they produce may also be entering the food chain.
For example, scientists at the University of Cardiff recently showed for the first time that microplastics had been transferred up the food chain in a river, from small invertebrates through to dippers, the only songbird that can swim underwater. They looked at dipper regurgitates and faecal pellets from both adults and chicks and found microplastics in all of them.
We still don’t know exactly what effect this microplastic transfer will have on the birds, especially in the early stages of their lives. But our results on the biological fragmentation of microplastics will help us to understand the role that animals can have in determining the fate of plastics in our waters.
Alicia Mateos Cárdenas is a Postdoctoral Researcher at University College Cork. This article appears courtesy of The Conversation and may be found in its original form here.
A massive fire broke out at the Port of Beirut on Thursday, incinerating a warehouse full of tires and oil within the port’s free zone. The same area was heavily damaged in the ammonium nitrate explosion that leveled the central port area and the adjacent waterfront on August 4. According to Lebanon’s civil defense agency, […]
Over the course of the past five days, the Australian Maritime Safety Authority arranged a medical intervention for an injured aboard a freighter in the Indian Ocean. On Saturday evening, the Spliethoff tweendecker Dolfijngracht called for assistance while under way about 1,000 nauical miles off the coast of Western Australia. A crewmember had sustained serious […]
The naval forces of the US and Bahrain recently staged a joint force training exercise which showcased the interoperability between coalition warships operating I the Arabian Gulf. Coalition Task Force Sentinel executed combined exercise Sentinel Shield supporting Sentry and Sentinel patrols in the coalition’s area of operations. The guided-missile destroyer USS John Paul Jones and […]
DSV Belgium has solid experience in the transport of pharmaceutical products for different customers. With a pharma hub based at Brussels Airport a lot of experience and know-how has been built up over the years. Last weekend, the forwarder handled one hundred million mouth masks, an important milestone for its Belgian organisation that has put […]
The U-Freight Group (UFL), with its considerable involvement in eCommerce logistics, says that the latest statistics showing that global e-commerce sales hit $25.6 trillion in 2018 are a further vindication of its decision to enter this sector of the international freight market several years ago. The latest available estimates, up 8% from 2017, were recently […]
The UK government’s new post-Brexit tariff regime will result in both winners and losers. The new regime is set to replace the European Union’s Common External Tariff from the end of the Brexit Transition Period on December 31, 2020. The UK’s commitment to the ongoing Brexit process and ending the UK’s transition from EU membership […]
Astral Aviation has increased its intra-African network with cargo freighters during the pandemic. While there has been a reduction in capacity to, from, and within Africa, which has been caused by a stoppage of passenger flights and limited frequencies on freighter aircraft, Astral Aviation continues to operate cargo freighters from its Nairobi hub to 13 destinations […]
The National Transportation Safety Board (NTSB) has released a Marine Accident Brief about an accident that occurred on April 15, 2019, involving the towing vessel DeJeanne Maria which struck the end of a submerged dredge pipeline while pushing two spud barges to the Gulf of Mexico. The incident occurred on the Mississippi River in Pass […]
With close to 100 daily cargo flights operated to a destination network spanning more than 65 cities across six continents, Emirates SkyCargo is delivering essential supplies and commodities to people around the world. The air cargo carrier is currently operating 11 Boeing 777 freighter aircraft, each with a capacity to transport about 100 tonnes of […]
Best known as a leading passenger airport serving Germany’s most populated federal state North Rhine-Westphalia, Düsseldorf has become transformed into a vital distribution point, during the COVID 19 pandemic, for medical equipment and other life-saving goods, mostly from China. Gerton Hulsman, managing director of cargo operations, reports that the handling teams are working hard to […]
Operators can continue to use pilots and other crew members who have unable to comply with certain training, recent experience, testing, and checking requirements due to the COVID-19 outbreak in support of essential operations. Additionally, this Special Federal Aviation Regulation (SFAR) provides regulatory relief to certain persons and pilot schools unable to meet duration and […]
Emirates SkyCargo has expanded its weekly scheduled cargo flight operations to cover 75 destinations across six continents. Through its wider reach, Emirates SkyCargo is able to transport essential commodities and other urgently needed cargo more rapidly across the world, allowing exporters and importers across markets to benefit from direct access to widebody cargo capacity. Some […]
Global commercial aviation charter company Albion Aviation Group is reporting that it is seeing a considerable uptake in its professional cargo broker training courses from the current global pandemic crisis and surge in charter demand. “We have completed a number webinar courses for a whole of host of companies, looking to manage their own cargo […]
The First DP2, Twin-Hulled SOV in the World, NB72 Groene Wind met the Sea on September 29. 2020 in Yalova, Turkey. The Groene Wind will be directly chartered to Siemens Gamesa Renewable Energy for the maintenance of the Rentel and Mermaid & Seastar (known as SeaMade) offshore wind farms in Belgium. This is the first DP2, […]
Callan Marine is serving as the prime contractor to the Texas Department of Transportation for a maintenance dredging project located at the Bolivar Ferry Terminal, in Galveston, Texas. Work began in May and is estimated to be complete in late July 2020. The project consists of the removal of 600,000 cubic yards of material and […]
Network Airline Management and TAAG Angola Airlines are pleased to announce the renewal of their long-term freighter aircraft contract by an additional 12 months, sealing an ongoing partnership for the foreseeable future. Operating a regular weekly scheduled service from Liege, Belgium, to the capital of Angola, Luanda, Network Airline Management provides a Boeing 747-400F aircraft […]