WORLD SEAGRASS DAY – HEALTHY SEAGRASS, HEALTHY PLANET

Destruction of natural ecosystems has become a common topic in today’s world. Lately, the destruction of seagrass and its restoration has been a trending topic in Sri Lanka.

The world loses 110km² of seagrass annually. Sri Lanka also has a considerable area of seagrass that was destroyed. In such a backdrop, creating awareness of seagrass and initiating conservation programs is essential.

We celebrated Word Seagrass day 2023, on the 1^st of March, for the first time. In 2022, the United Nations General Assembly decided to commemorate World Seagrass Day yearly.

The theme of world seagrass day 2023 was “Healthy seagrass, Healthy planet.” The UN resolution highlights the urgent need to raise awareness at all levels and promote and facilitate actions for the conservation of seagrass and contribute to their health and development, bearing in mind that enhancing ecosystem services of the sustainable development goals.’ here Archived

Seagrasses are the only flowering plant in the marine environment. The appearance of seagrass is similar to terrestrial grass types, and they have true roots, stems, leaves, flowers, and seeds, just like a typical plant. Seagrass is grown in shallow, salty, brackish water, from tropical to the Arctic circle. They are most common in oceans near the equator.

Seagrass grows as a population to create seagrass meadows. A seagrass meadow is one of the most critical ecosystems in the world. Seagrass meadows have higher productivity and provide a wide range of shelter and food for marine fauna species.

Healthy Seagrass, Healthy Planet

A healthy planet is a planet that is not polluted, not harmed, and not damaged.

With the higher productivity mentioned above, the seagrass ecosystem is the ocean’s most important and productive ecosystem. Seagrass has higher biodiversity with a wide range of fauna. There are even smaller animals like shrimp to larger species like scotoplanes. Seagrass meadows supply these animals with much-required shelter and food. Also, marine animal species use seagrass meadow areas as nurseries to protect their eggs and larvae.

Seagrass beds stabilize the bottom of the ocean. This is because their root system extends both horizontally as well as vertically. Therefore, it can stabilize the ocean bottom from soil erosion with the waves at the bottom of the sea.

Seagrass sometimes acts as a filter capturing fine sediments and particles in marine waters. This increases the water clarity of the area. Also, seagrass meadows remove up to 50% of marine bacteria that are hazardous to humans.

Oceans are the primary source of the world’s oxygen. Three main sources provide oxygen gas in the ocean. They are plankton, seaweed, and seagrass. So, seagrass is one of the main sources of oxygen in the world.

There are economic values to seagrass beds as well. They are good tourist attraction points and important for the fisheries industry. Most fish and other marine animals live in these areas, attracting tourists and fishermen.

Seagrass in Sri Lanka

Sri Lanka is an island surrounded by water near the equator. So, the seagrass bed density around Sri Lanka is high. As a result, seagrass beds can be easily found in Sri Lankan coastal areas, ranging from North, South, Southwest, West, and Northwest coastal areas.

About 12 species of seagrass can be found along the Sri Lankan coastline. In addition, the Puttalam lagoon has an extensive seagrass meadow, which in the early and mid-1990s covered approximately 24% of the total lagoon area.

Also, there is high productivity as well as high species diversity in these areas. Click here to find out more about seagrass diversity in Sri Lanka.

Threats to Seagrass meadows

The Climate Fact Checks team contacted Dr. P.B.T. Pradeep Kumara, senior lecturer at the University of Ruhuna, Faculty of Oceanography and Marine Geology. He mentioned that “the main threat to the seagrass community around Sri Lanka is illegal fishing gear which harms the bottom of the ocean. Though this damaging fishing gear is prohibited in Sri Lanka, still in the Northern parts of the country, they are being used. Some Indian fishing boats visiting the Sri Lankan oceans are mostly responsible for this.”

These fishing gear clutched to the bottom of the ocean and dragged forward along the ocean floor by the boats. Fishing gear like these are primarily used to capture bottom-feeder fish and organisms, such as sea cucumbers, at the bottom of the ocean.

This practice causes massive damage to the ecology of the ocean floors. This practice deeply harms the seagrass meadows. The roots and rhizomes of the seagrass do not expand to deeper soils in the ocean bottom. So, using this gear, the roots and rhizomes easily get removed.

According to Dr. P.B.T. Pradeep Kumara, the other threat to seagrass is damage caused by tourism. Tourists dive into visit seagrass meadows and tamper with these sensitive ecosystems. There have been times when these activities removed seagrass from its root.

Also, urban runoff, plastic, and polyethylene reaching the ocean bottom harm seagrass meadows.

Climate change is the leading natural cause that threatens seagrass beds. But Dr. Pradeep highlighted that there is no noticeable harm done to seagrass beds in Sri Lanka due to Climate Change. He added that this might be due to the need for more research evidence.

But according to him, there are several ways in which climate change can damage seagrass. With global warming, the temperature of the ocean can be changed. Usually, seagrass can be more commonly found in warm seas than in cold areas. But with temperature raging, seagrass communities can also spread towards the northern and southern hemisphere ocean areas. But due to the rise in temperature in equatorial seas, seagrass can also be threatened.

The chemical properties of the ocean change with climate change; for example, ocean acidification is a prominent impact of climate change. This can directly impact the health of seagrass beds.

Protection of seagrass community

According to Dr. Pradeep, specific and straightforward legal action has yet to be taken to protect Sri Lankan seagrass. But there are few legal actions which are supporting seagrass protection circuitously. Some of the shallow ocean areas in Sri Lanka are legally prohibited for tourists, locals, and fishermen to visit due to their natural value. Most of these areas consist of seagrass ecosystems.

“Legally minimizing human intervention is the best way to protect seagrass around our country.” Added Dr. Pradeep.

However, much improvement is required in the law, which needs to be developed by authorized parties and consultants to protect seagrass in the country.

In addition, there needs to be more awareness among the general public regarding the importance of seagrass ecosystems.  In reality, only a handful of Sri Lankans know the numerous benefits of seagrass ecosystems. Although some people are aware of its existence, they need to be more informed about its conservation.

According to Dr. Pradeep, only a few Sri Lankans, including deeply concerned local citizens, non-government organizations, and subject-related experts, are trying to protect local seagrass beds. Hence, he mentioned how vital it is to broaden the awareness among the public about this topic, and this needs to start at the grassroots level for optimum results.

Is there a dark side to seagrass?

Typically, seagrass is considered a very precious gift of nature. But rarely, there can be a few minor level drawbacks with seagrass.

When seagrass dies, it settles down at the bottom of the sea. To decompose these deposits, the biological oxygen demand increases. This limits the oxygen available for other organisms living in the ecosystem.

In addition, higher seagrass density controls the light’s penetrating to the sea bottom, which limits the productivity of other photosynthetic organisms at the sea bottom.

Is there a difference between seagrass and seaweed?

Dr. Pradeep Kumara mentioned that very often, people confuse seagrass and seaweed. Many people think they are the same and there is no difference between them. But that is not true.

Seagrass is the only type of flowering plant in the ocean. It consists of roots, stems, leaves, flowers, and seeds. Their structure is similar to typical flowering plants, which can be found in the terrestrial environment.

But seaweed has a different structure. They are non-flowering and are not considered plants.  Seaweed instead is introduced as algae. Their structure has holdfast instead of root, blade instead of leaves, and stipe instead of the stem. There are no flowers or seeds. But mostly, there can be a round structure named float to float the seaweed at a suitable level from the sea bottom.

But both seagrass and seaweed produce oxygen by photosynthesis. But only seagrass can build such a great ecosystem in the marine environment.

Products with seagrass?

Dr. Pradeep said that in some countries, there are mattresses made with seagrass. They are introduced as an eco-friendly product for good and healthy sleep compared to mattresses made of other materials. And also, some people, including Sri Lankans, prepare baskets, mats, and bags with seagrass leaves. But those industries have died down in Sri Lanka at the moment.

It is crucial to sustainably extract these resources and give them value so people would try to conserve them.

-With inputs from Mihiri Saparamadhu –