The sea grass is disappearing

The health of the natural environment is being undermined, here is another excellent example - the marine equivalent of the tropical rain forests

The species of plants collectively called seaweed belong to the group of flowering plants, at some point a number of flowering plants "left" the land and adapted to life in water - the salty ocean water and brackish or fresh water in streams, rivers and lakes.

Much has been written and written about the damage and destruction of coral reefs, a short time ago I wrote about here The damage to shell reefs, like the oyster reefs, so also the seagrass meadows do not get the attention they deserve.

Over 30% of seagrass areas have been lost since measurements and tests began (at the end of the 19th century). According to a new study, the loss of seaweed "pillows" is accelerating and increasing, the study was conducted by marine biologist Prof. Gary Kendrick from the University of Perth in Australia and was published in the Proceedings of the National Academy of Sciences (PNAS).

According to Kendrick "about 110 square kilometers of seagrass meadows are lost every year". The measurements began in 1879, when seagrass areas were measured at about 11,600 square kilometers. Since then, about 3,500 square kilometers have disappeared in those areas. According to estimates, there were approximately 160.000 square kilometers of seagrass areas in the world (at that time), of which approximately 50.000 square kilometers were destroyed.

Since 1980, the rate of disappearance of seagrass meadows has increased from 7% before 1940 to 9% or more. For the purpose of the study, Kendrick and his team examined seagrass meadows in 215 sites on beaches around the world. In North and South America, on the Caribbean coast, in East Asia, in Southwest Asia, on the coast of Europe, on the coast of the Mediterranean and on the coast of Australia. In all the places examined there was a significant decrease in the seagrass areas.

Various causes of damage to the seagrass meadows: direct physical damage such as: dragging of fishing nets, dispersion of floating materials due to construction and development, more and more people are moving to the seashores and the effect on the seagrass is immediate and negative. But the first culprit in the loss are nutrients (nutrients), mainly nitrates, which reach the sea in sewage and through the irrigation of agricultural fields from which seep water saturated with fertilizers. The nutrients (fertilizers) stimulate the growth of algae that grow over or on the seagrass and prevent sunlight from reaching the grass, which like any plant needs sunlight to live.

The loss of seagrass meadows can be compared to the loss of equatorial forests, since the grasslands fix similar amounts of carbon dioxide (COXNUMX) to the amounts fixed by the equatorial forests, at the same time as the loss of equatorial forests, coral reefs, mangrove forests, oyster reefs, The oceans and seas are vast areas of seaweed.

Seaweed together with bacteria that eat about 75% of it forms the base of the food pyramid in the sea, the remaining 25% is eaten directly by turtles, fish, crabs, shellfish, geese and ducks, manatees and others.

The meadows are essential for the survival of fish that live in the coral reefs, many of the reef fish as well as the fish of the open sea begin their lives in the seagrass beds, which creates a close connection between living systems and the flora in the coral reefs and in the seagrass meadow. The loss of the grasslands directly affects (negative impact) fishing and human health due to the deterioration of the entire marine environment. Seaweed is a coastal barrier against damage from waves and is also a filter that removes the toxins that are discharged into the sea by industry.

It turns out that the farther you get from developed areas, the less damage to the seaweed. Ports, industrial facilities. Agricultural fields, urban settlements, all these turned out to be factors that damage the seagrass meadows and cause their loss.

The publication of Prof. Kendrick's survey inspired many researchers to raise their voices for the protection and preservation of seagrass meadows, which, despite the lack of public interest, are one of the bases for a healthy environment. According to the researchers "seaweed is a marker and sentinel for the health of the coastal and marine environment, the loss of seagrass is a warning call to the state of the environment.

However, it turns out that the seagrass meadows can be restored by reducing the polluting discharges, in Western Australia a preventive action was taken - starting in 1970, the amounts of waste water from industry and agriculture were reduced and the seagrass meadows on the beaches regenerated and grew. That is, despite the dismal situation, much can be done, to correct, prevent and restore the situation and bring the sea meadow to its natural state.

For a statement from the University of Western Australia