Threat to marine powerhouse: doom and gloom for seagrass
YOU don’t need to be whisked away to an endless field of flowers or a garden to watch flowering plants bloom.
Remarkably, the same wonder of nature occurs underwater in seagrass gardens or meadows.
Dubbed “Flowers of the Ocean”, seagrasses have been around since the time of the dinosaurs, and are unique flowering plants that have evolved to live in marine habitats.
Growing in shallow sheltered areas along coastal regions around the world, they can flower, pollinate and even produce edible fruits.
But unlike terrestrial flowers which inspire swathes of romantic poetry and art, seagrass ecosystems remain marginalised and misunderstood.
Not as visually attractive as coral reefs or as visible as mangroves, they are reported to be one of the least charismatic of coastal ecosystems.
Yet seagrass is a marine powerhouse. It’s the world’s third most valuable ecosystem (after estuaries and wetlands).
While seagrasses account for less than 0.2 per cent of the world’s oceans, they’re responsible for 10 per cent of the carbon stored in the oceans annually, and they are up to 35 times for more efficient at sequestering carbon than rainforests.
Alarmingly, close to 30 per cent of the world’s seagrass meadows have already been lost, with an estimated 110 square kilometres of seagrass lost annually.
The region with the highest proportion of sites declining? Southeast Asia. At the same time, this region has the highest diversity of seagrass species and habitat types found anywhere else in the world.
UNSUNG ECOLOGICAL HEROES
The richest coastal marine resources in Southeast Asia are found in Indonesia, the Philippines and Malaysia.
The Power of the Three — coral reefs, mangroves and seagrass — make up the rich biodiversity in this region. However, it’s widely considered that coral reefs are the most popular, mangroves the most disturbed and seagrass the least studied.
“The knowledge about seagrass is low amongst the public and decision makers, and this ecosystem remains ignored on conservation agendas,” according to Benjamin Jones, director and co-founder of Project Seagrass, a UK-based environmental charity dedicated to advancing the conservation of seagrass through education, influence, research and action.
There are common misconceptions about seagrasses, he says, mainly the confusion between seagrass and seaweed.
The former belongs to a group of plants known as angiosperms (flowering plants).
“It (seagrass) has flowers, it has seeds, it has roots and it hatches through sand, not a rock. So a seagrass is a true plant; a seaweed is not.”
Seagrasses grow when completely submerged and pollination is aided by water. They’re able to withstand the forces of wave action and tidal currents, and have adapted to survive in salty waters in mostly sand or mud sediments. Seagrass roots pump oxygen into the sediment, and they rely on light to convert carbon dioxide and water into oxygen and water.
There is a bit of a debate as to how many species of seagrass there are, but studies point to around 60-70 species all over the world and there are clear trends of seagrass loss in all areas of the world.
Not only are seagrasses crucial to food security and alleviating poverty, they serve as nursery grounds for many species of commercially important fish and shellfishes, protect shorelines, are an essential food source for dugongs, green turtles and manatees, and provide natural protection against climate change.
Moreover, seagrass meadows offer non-consumptive services such as educational, recreational and tourism benefits and opportunities. This ecosystem is also inextricably linked to many cultural traditions of coastal communities.
Basic information seagrass distribution in Southeast Asia is still lacking, with 18 of the world’s 60 seagrass species and 33 per cent of all seagrass areas have been identified in this region where millions depend upon marine resources for their livelihoods and diets.
Jones contends that while Southeast Asia is a global biodiversity hotspot for seagrass, to what extent they’re declining is still unclear.
“We know what their threats are and we know they’re in a bad state, but how much of them are we losing?”
But it’s not all doom and gloom for seagrass meadows in the region. ‘Hope spots’, Jones mentions, are appearing on the map too.
RALLYING FOR SEAGRASS RECOVERY
One such ‘hope spot’ is located in Indonesia, a country that has experienced 30 to 40 per cent loss of seagrass beds in the last 50 years, with as much as 60 per cent around Java.
While natural variabilities such as storms and tsunamis contribute to seagrass decline, another study indicates that up to 90 per cent of seagrass in Indonesia has been extensively damaged and degraded over the past five years due largely to human activities such as coastal development, land reclamation and deforestation as well as seaweed farming, overfishing, poor water quality/sedimentation and garbage dumping.
On the island of Kaledupa in Wakatobi National Park, Sulawesi, researchers have worked together with locals to bring about change for the seagrass beds. Started in 2012, the Wakatobi Seagrass Programme is a collaborative research initiative led by scientists Leanne Cullen-Unsworth and Richard Unsworth, and supported by Cardiff University and Swansea University.
Jones is part of the team that have that been working on addressing threats through a bottom-up approach of community-level and action.
“Communities there are pioneering methods that Western and conservation scientists can only dream of,” he enthuses, referring to the integration of local ecological knowledge which helped identify sedimentation as a focal threat that needed to be dealt with.
Local non-governmental organisation, FORKANI, the project’s community partner, is pivotal in inspiring this change. It proposed the idea to provide fruit trees to land owners living adjacent to river beds. Because of mangrove destruction and terrestrial run-off, the trees serve to repopulate the riverine systems, increase water retention and reduce impact on seagrass.
To date, they have planted 6,000 trees along seven river beds. Moreover, once awareness was raised on the importance of seagrass to their livelihoods and nutrition, seagrass education was later incorporated into local school curriculums.
Jones adds: “Women go out on seagrass beds during low tide to collect invertebrates to feed their families and to sell on a daily basis. Fishermen understand that the substantial decline of seagrass affects their catch and food source. They’re the voices that need to be heard in the fight to preserve seagrass ecosystems.”
SAVING DUGONGS AND THEIR SPECIALISED DIETS
Humans are not the only ones reliant on seagrass ecosystems for food. Dugongs (Dugong dugon) are the world’s only vegetarian marine mammal and can consume up to 40kg of seagrass a day.
Also known as “sea cows” because of their tendency to “graze” on seagrass, dugongs can only survive in specific areas with healthy seagrass ecosystems.
Therefore, dugong and seagrass conservation should go hand in hand, as well as the mainstreaming policies and planning for this endangered species with their habitats needing to be national and regional priorities.
Endangered in Malaysia, it is estimated that there are only 40 to 50 dugongs left in Johor, mainly around Sibu and Tinggi islands and their adjacent waters.
Dugongs are also found in Sabah, where around 20 to 30 dugongs were recorded around Mantanani, Bangi and Mengalum islands, and in Sarawak, in the waters of Brunei Bay, Lawas.
Dr Leela Rajamani, a marine conservation biologist from Universiti Sains Malaysia, has been researching on community understanding and management of dugong and seagrass resources in Johor and Sabah.
She cites her studies as using interdisciplinary methods such as marine biology, ecology, anthropology and sociology in looking at conservation problems.
She stresses on community involvement in protecting dugongs and their seagrass habitats, and that education is key in transforming their involvement into conservation action.
Says Leela: “The older males and females seem to know about the dugong from seeing it themselves or the seeing the animals stranded on the shore. The younger people do not know much about these animals because they’ve never seen it. Using the local knowledge and anecdotes, communities on these islands are aware that the presence of dugongs on seagrass beds which they call Rumput Setu (Enhalus acoroides) and Rumput Ketam (Halophila sp.) make these plants healthier.”
Leela states that the main threats on Malaysia’s seagrasses are mainly coastal development and sedimentation.
She created focus groups to engage and educate members of the community, fishermen and resort operators on the loss of seagrass along the coastline and how this will have a negative impact on marine animals, especially dugongs.
She also met with the oldest residents in the village to collect oral histories on dugong origin stories and myths, and to use these stories to link cultural values of locals with this charismatic species.
“In most of the stories about dugongs, they’re ‘originated’ from humans — consequently the communities regard this animal with respect. They also recognise that when dugongs are around, it’s easier to get fish and other catch as the environment is thriving with sea life. For this reason, they don’t disturb dugongs or other animals like turtles as a sign of respect.”
Dugongs are protected under the Fisheries Act 1985 and the Fisheries Regulations 1999 (Control of Endangered Species of Fish) for Peninsular Malaysia and Federal Territories of Labuan, Wildlife Protection Ordinance 1998 and the Wildlife Conservation Enactment 1997 for Sarawak and Sabah.
The Johor state government is in the process of gazetting the area between three islands off Mersing as a Dugong Sanctuary but Leela argues for the creation of Seagrass Marine Protected Areas (MPA). Seagrasses are usually included in MPA management plans for the sake of inclusion without any real thought on why it should be included.
“There are no reasons not to have seagrass protected areas. I can still remember the first time I went to a seagrass meadow and saw the flowers, and thought, wow! They’re not well-understood and there’s still a lot more to discover about seagrasses and its inhabitants like the dugongs, turtles and seahorses,” says Leela.
It is this same fascination with seagrasses that are driving efforts around the region to save these habitats.
Since more than 30 years ago, scientists have reported the need to stop the degradation of seagrasses and to step up protection and management of this vulnerable ecosystem.
In spite of the ample evidence accumulated on their threats, benefits and biology, the urgency hasn’t reverberated enough.
“The biggest challenge is that we simply don’t know where they are, how much they are and how much we’re losing. People do get behind initiatives that want to change things, and it’s really about education, education and education,” remarks Jones. But a little bit of technology also can’t hurt.
Project Seagrass launched the ‘Seagrass Spotter’ this year — a free database which allows for citizen scientists around the world to participate in the conservation effort instead of a handful of researchers.
Accessible with a mobile phone, anyone can upload a photo of seagrass and key in basic information such as the shape of the leaves, the location, etc. There have been 27 species uploaded within the app from 54 countries so far.
Jones explains that there’s no other global citizen science programme like Seagrass Spotter, and showcases how science can be translated into what communities and marine natural resource managers and decision-makers can use.
“It’s entry-level, anybody can use it and anybody can get involved. It was designed initially as a tool to get people to visit seagrass meadows and learn about these sites. But now it’s evolved to mapping them through pictures globally and serves as a free database for management agencies and a tool to streamline data collection for seagrasses.”
With less than 500 scientists studying seagrasses around the world, there’s a need to increase the local capacity of researchers, teams and managers. Seagrasses has never been on the big players’ table.
Getting seagrasses acknowledged on the main stage is central to efforts for the protection and conservation of seagrasses in this region and worldwide.
A petition by the international seagrass research and conservation community is underway to call on the United Nations to declare a World Seagrass Day.
Exposed only at low tide, the loss of seagrass meadows have gone largely unnoticed, but this doesn’t mean we need to submerge our appreciation for these amazing marine habitats.
Benjamin Jones and Dr Leela Rajamani were interviewed at the recent 5th International Marine Conservation Congress in Kuching, Sarawak, Malaysia.
source: NEW STRAITS TIMES