• Wednesday, Mar 03, 2021
  • Last Update : 09:26 pm

Seagrass 'Neptune balls’ sieve millions of plastic particles from water

  • Published at 10:44 pm January 16th, 2021
seagrass fibers
This undated handout photograph released on January 14, 2021 by the University of Barcelona shows plastic-rich balls of seagrass fibers beached in Mallorca Island. AFP

The swaying plants may collect nearly 900 million plastic items in the Mediterranean alone every year, according to researchers

Underwater seagrass in coastal areas appear to trap bits of plastic in natural bundles of fibre known as "Neptune balls," researchers said.

With no help from humans, the swaying plants -- anchored to shallow seabeds -- may collect nearly 900 million plastic items in the Mediterranean alone every year, they reported in the journal Scientific Reports.

"We show that plastic debris in the seafloor can be trapped in seagrass remains, eventually leaving the marine environment through beaching," lead author Anna Sanchez-Vidal, a marine biologist at the University of Barcelona, told AFP.

This accidental cleanup "represents a continuous purge of plastic debris out of the sea," she added.

Add pollution control, then, to the long list of services that seagrass provides -- for ocean ecosystems, and the humans that live near the water's edge.

There are some 70 species of marine seagrass, grouped in several families of flowering plants that -- originally on land -- recolonised the ocean some 80 to 100 million years ago.

Growing from the Arctic to the tropics, most species have long, grass-like leaves that can form vast underwater meadows.

They are more than just pretty, however.

They play a vital role in improving water quality, absorb CO2 and exude oxygen, and are a natural nursery and refuge for hundreds of species of fish.

They are also the foundation of coastal food webs.

1,500 bits per kilo

By anchoring shallow waters, they help prevent beach erosion, and dampen the impact of destructive storm surges.

To better understand the plastic bundling capabilities of seagrass, Sanchez-Vidal and her team studied a species found only in the Mediterranean Sea, Posidonia oceanica.

In 2018 and 2019, they counted the number of plastic particles found in seaballs that had washed up on four beaches in Mallorca, Spain, which has large seagrass meadows offshore.

There was plastic debris in half of the loose seagrass leaf samples, up to 600 bits per kilo of leaves.

Only 17% of the tighter bundled seagrass fibre known as Neptune balls contained plastic, but at a much higher density -- nearly 1,500 pieces per kilo of seaball.

Using estimates of seagrass fibre production in the Mediterranean, the researchers worked up an estimate of how much plastic might be filtered in the entire basin. 

The oval orbs -- the shape of a rugby ball -- forms from the base of leaves that have been shredded by the action of ocean currents but remain attached to stems, called rhizomes.

As they are slowly buried by sedimentation, the damaged leaf sheaths form stiff fibres that intertwine into a ball, collecting plastic in the process.

59
Facebook 57
blogger sharing button blogger
buffer sharing button buffer
diaspora sharing button diaspora
digg sharing button digg
douban sharing button douban
email sharing button email
evernote sharing button evernote
flipboard sharing button flipboard
pocket sharing button getpocket
github sharing button github
gmail sharing button gmail
googlebookmarks sharing button googlebookmarks
hackernews sharing button hackernews
instapaper sharing button instapaper
line sharing button line
linkedin sharing button linkedin
livejournal sharing button livejournal
mailru sharing button mailru
medium sharing button medium
meneame sharing button meneame
messenger sharing button messenger
odnoklassniki sharing button odnoklassniki
pinterest sharing button pinterest
print sharing button print
qzone sharing button qzone
reddit sharing button reddit
refind sharing button refind
renren sharing button renren
skype sharing button skype
snapchat sharing button snapchat
surfingbird sharing button surfingbird
telegram sharing button telegram
tumblr sharing button tumblr
twitter sharing button twitter
vk sharing button vk
wechat sharing button wechat
weibo sharing button weibo
whatsapp sharing button whatsapp
wordpress sharing button wordpress
xing sharing button xing
yahoomail sharing button yahoomail