A group of scientists have discovered a shocking sea grass meadow off the Western Australian Coast, which is apparently the world’s largest plant alive.

The researchers have taken specimen from the species – a Posidonia australis, also known as fibre-ball weed or ribbon weed, which is commonly found along the western coast of Australia to test their genetic variations but to their total astonishment, found out that the specimens they took from two places 180km apart were not from two different plants but one single plant!

Being puzzled by this discovery, the scientists have taken a genetic test on the plant to determine a single 4,500-year-old sea grass may have spread over 200 sq km of underwater seafloor – about 20,000 football fields or over three times the size of Manhattan Island.

According to the scientists, a single seed spawned from two different sea grass species, has deposited on a favourable, cosy spot on the seabed of the area known as the Shark Bay at present, and started to nourish and flourish for 4500 years till now. The speciality is that this seed has inherited all the chromosomes of both parent species instead of halving the total number of chromosomes and it has given extraordinary features to the plant, making it strong and resilient.

According to the researches, this single plant has spread over 200 sq km, using rhizomes in the same way that a lawn can spread from its edges by sending out runners. “The existing 200 sq km of ribbon weed meadows appear to have expanded from a single, colonising seedling,” mentions Student researcher Jane Edgeloe, of the University of Western Australia.

It is based on the rate 35cm a year, the rate in which a Ribbon weed rhizomes can normally grow, Rat the scientists calculate the plant to be 4500 years old. The meadow has grown in dense masses; the length of a ribbon of the plant, which is normally 10cm, extends up to 100cm at some places. The scientists state that the resilience of this huge Ribbon weed sea grass can be understood by the way it has thrived through the very challenging conditions that prevail in the area of the Shark Bay; it has found somehow to thrive in the regions with very high salinity as well as at temperatures as high as 30 degree Celsius and as low as 15 degree Celsius.

“They have a versatile growth pattern which contributes to this long life span,” says Associate Professor Kathryn McMahon of Edith Cowan University, an expert on sea grass, although not involved in the Shark Bay research. “They can grow towards nutrient-rich patches to access the nutrient they need, or to gaps in the meadow where there is space for them to grow or away from stressful locations. All of these characteristics mean that if they are in the right place they can persist over long periods of time.”

However the scientists suspect that the plant is largely sterile and thus depends totally on its ability to grow rather than disperse seeds.

Now, since it covers more than 20,000 acres, which is more than the area covered by quaking Aspen trees in Utah, often referred to as the world’s largest plant-covering 43 hectares- Ribbon Weed at Shark Bay can be considered as the world’s largest plant. Most importantly, this sea grass meadow has provided a sanctuary for a wide array of marine species including turtles, dolphins, dugongs, crabs and fish. So it is a must that we do not harm this huge Posidonia australis and imbalance the whole marine eco system of the region.

By Induwara Athapattu