Whether you like lobsters or not (as food or as a species), they’re important for the marine life. Sadly, if microplastics are left alone without any solution, these crustaceans might not last long. According to a new research, microplastic fiber pollution in the ocean impacts larval lobsters at each stage of their development.
A study published in the Marine Pollution Bulletin reports that the fibers affect the animals’ feeding and respiration. What’s worse, they could prevent some larvae from reaching adulthood. This species is said to be immortal, but I don’t think not having larvae grow will be okay.
“In today’s ocean, organisms are exposed to so many environmental factors that affect how many make it to the next stage of life. Lobsters play a fundamental role in the Gulf of Maine ecosystem as well as the state’s economy, and it is important that we understand how pollutants impact their development,” said Paty Matrai, a study author and senior research scientist at Bigelow Laboratory for Ocean Sciences.
There are four developmental stages that young lobsters must go through in order to reach adulthood. Researchers found that the physiology of each stage determined how the animals interacted with plastic fibers.
Now, since very young lobsters don’t consume those plastics, the fibers plague them by accumulating under the shells that protect their gills. In experiments where the larvae were exposed to high levels of fibers, the youngest larvae were the least likely to survive.
The older lobster larvae, which are more agile and active, didn’t accumulate fibers under their shells. But this is not a good thing either, since they ingest the particles and keep them in their digestive systems.
Surely when they have reached adulthood and are roaming in the ocean, it will be problematic because plastics leach chemicals which can be toxic to the marine life.
“Plastic particles have been found in almost every animal in the ocean. If an animal can fit something in its tiny little piehole, it’s probably going to — and that can have repercussions for the animal and potentially for the food web,” said David Fields, another study author and a senior research scientist at Bigelow Laboratory.
Microplastics and marine life
There are a lot of sources that carry microplastics to the ocean, such as wastewater. However, they can also be created in the ocean when larger materials degrade. Plastics float at the surface, and the sunlight exposure can break them down into small particles.
It doesn’t matter if the level of microplastics are low or not, because they can still bring problems to the animals that encounter them. Some animals are more likely to face any fibers, since microplastics tend to float at the ocean’s surface, therefore the ones inhibiting surface waters like larval lobsters come into contact with them more often than not.
“Even relatively low levels of plastics can be harmful for the animals that encounter them, and where an animal lives in the water column can amplify the problem. A lobster larva that eats a plastic fiber is just like us eating a candy wrapper — it’s not great, but it will probably just pass though. But if all you’re eating is candy wrappers, it’s certainly going to have other repercussions for your health,” Fields said.
Ocean acidification and rising temperatures have already made things hard for lobsters and other animals in the ocean. Given this fact, researchers are interested in how microplastic pollution affect them now and in the long run. Therefore, they’re also planning on conducting future experiments to know how the marine life is impacted when they’ve got three factors challenging it at the same time.
When I find out about things like these, there’s a part of me that believes humanity’s getting better at preserving our planet and environment, but at the same time some part of me also thinks that the future is bleak. But anyways, on to another piece of news about microplastics.
Highest level of microplastics on seafloor ever found
I’ve seen plastic on the seafloor (sort of) on EVNautilus’ YouTube channel, so it’s not that surprising for me when I first saw the headline. An international research project has found the highest levels of microplastic ever recorded on the seafloor, with up to 1.9 million pieces in a thin layer covering one square meter.
The research was conducted by The University of Manchester (UK), National Oceanography Centre (UK), University of Bremen (Germany), IFREMER (France) and Durham University (UK). It showed that deep-sea currents act like a conveyor belts which transport tiny plastic fragments and fibres across the seafloor.
These currents can accumulate microplastics in certain areas that the researchers call ‘hotspots’. The microplastic hotspots appear to be the deep-sea equivalents of the so-called ‘garbage patches’ formed by currents on the ocean surface.
“Almost everybody has heard of the infamous ocean ‘garbage patches’ of floating plastic, but we were shocked at the high concentrations of microplastics we found in the deep-seafloor. We discovered that microplastics are not uniformly distributed across the study area; instead they are distributed by powerful seafloor currents which concentrate them in certain areas,” said Dr. Ian Kane of the University of Manchester, who is the lead author of the study.
The journey of microplastics
Fibers from textiles and clothing are usually the main culprit of these microplastics. Domestic waste water treatment plants can’t effectively filter these and that’s why they can enter rivers and oceans without a hitch.
Once they reach ocean, these fibers either settle out slowly, or can be transported rapidly by episodic turbidity current (fancier term for powerful underwater avalanches) that travel down to the deep seafloor.
In the deep sea, microplastics are readily picked up and carried by continuously flowing seafloor currents that can preferentially concentrate fibers and fragments within large drifts of sediment. Hence the hotspots.
That’s not the end of the journey, though. Deep ocean currents still carry nutrients and oxygenated water. This means that the hotspots can also house important ecosystems that can consume or absorb the microplastics, which is bad, basically.
But the bright side is, this study provides the first direct link between the behavior of these currents and the concentrations of seafloor microplastics. Additionally, scientists can predict the locations of other deep-sea microplastic hotspots as well as direct research into the impact of microplastics on the marine life, thanks to the findings.
The researchers collected sediment samples from the seafloor of the Tyrrhenian Sea and combined them with manmade models of deep ocean currents as well as detailed mapping on the seafloor. In the laboratory, microplastics were separated from sediment, counted, and analyzed to determine the plastic types.
“It’s unfortunate, but plastic has become a new type of sediment particle, which is distributed across the seafloor together with sand, mud and nutrients. Thus, sediment-transport processes such as seafloor currents will concentrate plastic particles in certain locations on the seafloor, as demonstrated by our research,” said Dr. Florian Pohl from the Department of Earth Sciences, Durham University.
sources
https://www.sciencedaily.com/releases/2020/07/200707083958.htm
related note: https://www.sciencedaily.com/releases/2020/04/200430150213.htm
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