Sea weed invasion - threatened marine life - Seeker's Thoughts

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Sea weed invasion - threatened marine life

A new species of seaweed discovered is killing large patches of coral on once pristine reefs and it is rapidly spreading across one of the most remote and protected ocean environments on earth.

The latest study from the University of Hawaii found the seaweed id spreading more fatly than anything researchers have been noticing in the North-western Hawaiian Island, a nature reserve that stretches more than, 1,300 miles which are about (2,092km) north of the main Hawaiian Island.

Study findings

According to the study published in the journal PLOS One. Scientists say, that the algae easily breaks off and rolls across the ocean floor like tumbleweed, covering nearby reefs in thick vegetation that outcompetes coral for space, sunlight, and nutrients.

 Researchers say – this is severely destructive seaweed which has high potential t overgrow entire reefs.
In 2016, official researchers were doing a routine survey of Pearl and Hermes Atoll when they found small clumps of seaweed they had never seen before.
In 2019, they returned to find algae which had taken over the huge area if the reef- in some areas covering everything as far as they could see- with seaweed nearly eight inches 20cm thick.

And everything underneath of it was dead.

According to the researchers - The area was mostly devoid of huge schools of tropical fish and other marine life that usually cruise the vibrant reef, and fish that typically what algae were not grazing on the new seaweed.

After diving along the outer reef of the 15-mile they found the seaweed in varying densities and depths.

Scientists said the actual coverage area can be much larger than documented because they couldn’t survey many other sites during their brief visit.

Researchers noticed seaweed were as big as several football fields, and the algae could dramatically alter Pearl and Hermes Reef and threaten the entire Hawaiian archipelago if it spread.

Hawaii’s main island has several established invasive seaweeds, but cases in the northwest are rare.

What is this new species of seaweed?

When researchers studied the seaweed’s DNA to find out its origin but they figured it is a new species of red algae they named Chondria Tumulosa.

These algae can spread in various ways. It produces tumbleweed-like clumps that move around the immediate area but also generates spores that could be traveling much greater distances.

Seaweeds were described as simple plants that grew in the sea. Seaweeds play an important role in marine ecosystem/ as the first organism in marine food chains, they provide nutrients and energy for animals – either directly when fronds are eaten, or indirectly when decomposing parts break down into fine particles and are taken up by filter-feeding animals. 

Beds of seaweed provide shelter and habitat for scores of coastal animals for all or part of their lives. 

They are important nurseries for many commercial species as the rock lobster, paua (abalone), and green-lipped mussel.

They are simple in structure, usually consisting of a holdfast that anchors to a surface, and a blade which may be divided into fronds. Some of the larger seaweed have a flexible stalk or stripe connecting the blade to the holdfast.

 Unlike plants, seaweeds do not have roots or internal tissues to conduct water. They absorb minerals and gases directly from seawater through the surface of their blades.

Seaweed group

Seaweed can be grouped into three types, based on color green, red, or blown. They all contain the light-absorbing pigment chlorophyll, which is necessary for photosynthesis. Brown and red seaweeds have additional pigments that enable them to photosynthesize at the depth where little light penetrates. 

These extra pigments mask the green color of chlorophyll. Brown seaweeds can be yellow-brown to dark olive. Red seaweeds have the greatest range of tone- pink to purple, red, and brown to nearly black.

Why and how seaweed is getting invaded?

In 2018 Thousands of tons of prolific seaweed called “sargassum” invaded the pristine beaches of the Caribbean. In Mexico, the turquoise waters and clear, smooth sand of the touristy Mayan Riviera turned into a brown mess.

The sight of sargassum – a type of brown algae—and its smell scared tourists away, and the local ecosystem started to suffer greatly.

The country’s navy to lead the beach-cleaning effort and to prevent the sargassum from reaching the coast. In June, the situation was so bad that the southeastern state of Quintana Roo – home of the tourist destination of Cancun – declared a state of emergency.

Sargassum invasion could damage the coral reefs in the Mexican Caribbean

According to the researcher – Rosa Rodriguez Martinez, Sargassum repeatedly arrived in 2015, 2016, 2017, and 2018 on the beaches. It has been impacting water quality, because of dying the areas near the beach right after that corals began to die massively because of diseases.

A whole giant belt of sargassum has already formed in the Atlantic that goes from Africa to the Gulf of Mexico. 

They also did the nutrient analysis, confirming that the Amazon River discharge is influencing the seaweed’s growth, as well as the upwelling [cold and nutrient-rich water rising from deeper parts of the ocean to the surface] that occurs on the east coast of Africa. Climate change and eutrophication surely have something to do with it.




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