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The importance of ocean meadows

An in-depth look into the importance of protecting and conserving seagrass, by marine conservationist Shaha Hashim.

17 December 2020, MVT 09:18
"Seagrasses are flowering plants that adapted to survive underwater 100 million years ago. Just like plants on land, seagrasses photosynthesise and release oxygen as a by-product". PHOTO: MATT PORTEUS / OCEAN CULTURE LIFE
17 December 2020, MVT 09:18

I remember my first experience of seagrass very well. I was living on a reclaimed island called Hulhumale’ at the time, a five-minute boat ride from the capital city of Male’. The island had been built to make space for an increasing population at the city centre, but in the process, it destroyed the once thriving reef that it was built on top of. I knew I had a very slim chance of seeing healthy corals. Still, I wanted to venture underwater to get up close with its inhabitants, to disappear into their world.

I surveyed the shoreline. I could just about make out dark patches in the sea on the northern side of the island. I struggled over broken rocks and discarded construction material and finally plunged myself waist deep into the water. With plans already underway to reclaim the island further, this swim was my only chance to witness what lay beneath the waves at this particular spot.

I started to swim. Having seen stingrays swimming in the silty lagoon from the shore, I was a little apprehensive - growing up we were told that the ocean was a dangerous place. After a few minutes I reached the dark patches I had spotted earlier. As I drew closer, I started to make out what was in front of me. It was a densely vegetated underwater meadow, a forest of long green grasses swaying back and forth in the water, dancing amongst the rays of sunlight. I was mesmerised.

"IUCN estimates that seagrasses are responsible for storing about 15% of the total carbon stored in the ocean. Furthermore, they can bury that carbon in the seabed 40 times faster than tropical forests bury it in soil". PHOTO: MATT PORTEUS / OCEAN CULTURE LIFE

I started visiting this patch more often and with each visit came a new surprise. Pairs of ribbon eels swam freely in the water flaunting their bright blues and yellows. Schools of bumphead parrotfish cruised by without taking any notice of me. Fevers of juvenile stingrays lazed on the sandy patches in the afternoon sun. Yellow coral gobies checked me out from behind branches of staghorn corals. Patches of very healthy rose-like corals glinted in the sunlight and small fish that I had never seen before on coral reefs were spotted sheltering amongst the seagrasses.

I felt like I had stumbled upon a well-kept secret. At that time, in the Maldives, seagrasses were considered ugly and both Maldivian people and tourism businesses actively destroyed them. Some resorts would cover seagrasses with tarp to suffocate them while others would remove them laboriously by hand or with tools. This didn’t sit well with me. I couldn’t understand how anyone could think these beautiful places merited being destroyed. Surely seagrasses served a purpose?

I discovered that seagrasses are flowering plants that adapted to survive underwater 100 million years ago. Just like plants on land, seagrasses photosynthesise and release oxygen as a by- product. Smithsonian Institute estimates that just a hectare of seagrass can produce 100,000 litres of oxygen a day.

A thick, vibrant bed of seagrass - a haven for marine life. PHOTO: MATT PORTEUS / OCEAN CULTURE LIFE

Seagrasses are found on all continents, except Antarctica. To date, more than 70 species of seagrasses have been recorded. Soberingly, a study by the University of California found that almost 15% of these are now considered threatened due to habitat loss and degradation, driven by rapid development and pollution. Seagrasses are thought to be one of the most rapidly declining ecosystems in the world. It is estimated that 29% of global seagrass has been lost and if trends continue, another 20-30% could be lost in the next 100 years.

In the Maldives, seagrasses are found in shallow lagoon areas between the low-tide mark of the island and the coral reef which protects the island. They are not found uniformly across the country, but it is not understood why this is. Maldivians often confuse seagrasses with seaweed. Seaweeds are a type of algae that do not have flowers or veins and are not specialised to absorb nutrients like seagrasses. In recent years, seagrass areas are believed to have expanded in the Maldives. Scientists put this down to high nutrient input from sewerage outfalls and restricted water flow due to coastal modification projects. Like any other land plant, they grow stronger and faster when nutrients are present, providing an essential function in cleaning up the water column.

"Seagrass beds have long been deemed unsightly by resorts in the Maldives, blemishes that need removing in order to maintain the archipelago’s picture-perfect reputation. Now, campaigners for the Resilient Reefs Project are rapidly changing that reputation by revealing the importance of seagrasses for local marine life and global carbon capture, as well as the positive impacts they can have on the tourism industry". PHOTO: MATT PORTEUS / OCEAN CULTURE LIFE

Seagrasses can also help protect coral reefs and humans from disease. In Indonesia, a study led by Cornell University (US) found that reefs bordered by seagrass meadows had 50% less bacterial pathogens capable of causing disease in humans and marine organisms. Seagrasses are home to a huge numbers of marine species that depend on them for food and shelter. A study by the National Centre For Sustainable Coastal Management in India discovered that a single hectare of seagrass can house as many as 100,000 fish.

Critically endangered green and hawksbill turtles feed on seagrasses. Green turtles can eat up to two kilograms of seagrass a day and they tend to return to the same areas to feed. When resorts remove their seagrass meadows for aesthetic reasons, the chances of their guests seeing turtles around the island decreases significantly. Kuredu Island Resort, which has a four-hectare seagrass meadow, one of the largest patches of seagrass of any resort in the Maldives, has a resident green sea turtle population of 76.

“The data we gathered revealed that guests saw more megafauna in the seagrass meadows than on the reefs. Conserving these meadows was good for business". PHOTO: MATT PORTEUS / OCEAN CULTURE LIFE

Many commercially important reef fish use multiple habitats such as seagrass meadows and mangroves at different stages of their life cycle. For fish like groupers, snappers, emperors and parrotfish, these meadows are a haven from predators in their juvenile stages. A study by British seagrass scientist Richard Unsworth found that seagrass meadows provide valuable nursery habitat for more than 20% of the world's largest 25 fisheries.

The draw card though, is the capacity for seagrasses to fight climate change – they absorb enormous amounts of carbon dioxide from the water. IUCN estimates that seagrasses are responsible for storing about 15% of the total carbon stored in the ocean. Furthermore, they can bury that carbon in the seabed 40 times faster than tropical forests bury it in soil, according to a study led by the Institut Mediterrani d’Estudis Avançats, Spain.

Protection of seagrasses in the Maldives is imperative if the country – my country – wants to protect its islands and people. A staggering 80% of our islands are less than a metre above sea level; we are at the frontline of climate change. These magnificent plants can help us protect ourselves. They bind the sediment together, reducing the energy of waves, which is turn reduces erosion.

Buffered by a sandy beach, two green worlds collide - vegetation on land and seagrasses beneath the waterline. PHOTO: MATT PORTEUS / OCEAN CULTURE LIFE

In 2016, I started working for Blue Marine Foundation (BLUE), which is working to get 30% of Maldivian waters protected, and moved to Laamu Atoll to live at Six Senses Laamu, our partner resort. Within the first few weeks of being there I noticed the resort removing some of the seagrass around the island – a practice that was quickly stopped following discussions with the resort’s general manager. With the local seagrasses protected, the Maldives Underwater Initiative team and I got to work with our broader task of making seagrass interesting. We developed education material, snorkelling excursions and got guests involved in seagrass conservation by asking them to record the megafauna they saw on their snorkels or from their over-water bungalows.

The data we gathered revealed that guests saw more megafauna in the seagrass meadows than on the reefs, which made for happy customers. Conserving these meadows was improving business. The resort was also sand pumping ten times less than it was prior to committing to protect its meadows.

The data showed that seagrass could be an asset to tourism, and we wanted to help others realise its value. Before we could tackle this issue, we needed to understand the scale of seagrass removal by resorts in the country. An initial survey of 49 resorts showed that more than 50% of those that had seagrass were actively removing it. This was the catalyst for the #ProtectMaldivesSeagrass campaign. BLUE and Six Senses Laamu developed a social media campaign to encourage other resorts to stop removing their seagrass beds. Within a few months, more than 25% of the country’s luxury resorts had committed to protect more than 830,000 square metres of seagrass across the country. Months later, seagrass conservation was included in the government’s new Strategic Action Plan, the first time seagrass had ever been included in a national planning document in the Maldives. Earlier this year, the Ministry of Fisheries, Marine Resources and Agriculture agreed to work with resorts to collect data on seagrasses around resort islands, in the same way they do for reefs.

Members of the Resilient Reefs Project collect data. PHOTO: MATT PORTEUS / OCEAN CULTURE LIFE

Efforts are now underway to calculate how much carbon the Maldives’ seagrass meadows store. Such data would allow the Maldivian government to include blue carbon ecosystems within its ‘Intended Nationally Determined Contributions’ to the United Nations, a summary of greenhouse gas mitigation offered by each signatory nation of the United Nations Framework Convention on Climate Change. It may also provide new impetus for better seagrass protections.

The seagrass monitoring protocols developed throughout this project have been standardised for use across the country via the Maldives Seagrass Monitoring Network, a collection of seagrass champions who feed data into a national database. Securing nationwide data will build a detailed picture of the diversity, abundance and distribution of seagrasses across the Maldives archipelago, which in turn will help us in achieving protection for seagrass meadows under national law.

Editor's Note: This is a repost of an article originally published in Oceanographic Magazine on Aug 7, 2020.

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