GLOBAL VOICES OF SCIENCE:
Mangroves, Fishponds, and the Quest for Sustainability Jurgenne H. Primavera*

An insight of how aquaculture has impacted the mangrove ecosystem in the Philippines and the need for scientists to share their knowledge with the public and decision makers so that existing plots of mangroves can be preserved.

An excerpt of the article...

Mangroves at Risk
Aquaculture ranks as a phenomenal success story in global food production. In 1975, when I joined the SEAFDEC/AQD, aquaculture contributed 8% to the overall yield of the world's fish harvest; now it provides more than one-third of the yield of the world's fisheries. Total aquaculture production in 2003 was 54.8 million metric tons, valued at $67.3 billion in U.S. dollars. More than 90% of this output comes from Asia, where aquaculture has its origins.

As with land-based agriculture, all of this aquatic food production and economic activity has come with environmental problems and social conflicts. Foremost among these is the loss or modification of habitat in places where aquafarmers clear mangroves for ponds and where they install cages or pens above seagrass beds and coral reefs. Other environmental effects include the loss of bycatch (unwanted fish and invertebrate species) during the collection of wild "seed" used for stocking in ponds and of adult brood-stock for hatcheries, introduction of exotic species, spread of parasites and diseases, interactions of escapees from ponds or pens with wild populations, misuse of chemicals and antibiotics, salinization of soil and water, and coastal pollution. Many of these ecological impacts of shrimp aquaculture have brought along social problems, among them privatization of public lands and waterways, the decline of open-sea fisheries, rural unemployment, and social disruption.

Even the seemingly reasonable assumption that aquaculture is an efficient way to produce new protein is undermined by the dependence of shrimp, salmon, and other cultured aquatic carnivores on raw fish and on fish meal and oil in pelleted feeds. Careful calculations indicate that some cultured species actually are net consumers of fish...

For the whole article please visit the Science Magazine

It’s my turn to blog! Feeling guilty bout letting Amanda and Zhong Ning blog for me for the past entries…

Our participation in the oratory competition last Saturday was indeed a unique yet fruitful experience. The 5th Scholastic Environment Fund (SEF) Student Forum and Oratory Competition on the Environment 2005 was jointly organized by SEF and St Andrew’s Junior College in a bid to provide opportunities for the younger generation to think across disciplines and sharpen their verbal skills in the process. The theme for this year is “Green Cities: Plan for the Planet!” and teams were instructed to identify a pertinent environmental issue and after detailed analysis, present their possible solutions in front of a panel of judges.

Our presentation title was “Mangrove Conservation & Reforestation”, as this was closely interwoven with our RS and could be done in accordance with Leadership Service Learning (LSL), killing 3 birds with a single stone. The main issue that we strived to repeatedly emphasize upon is the disappearance of mangroves by highlighting the fact that the mangrove forest cover in Singapore has dropped from 13% in the 1820s to only 0.5% of total land area today (Ng & Sivasothi, 1999). But this problem is not exclusive to Singapore alone. On a global level, mangroves once covered three-quarters of the coastline of tropical and subtropical countries but today less than 50% of mangroves remain (Singapore Zoological Gardens Docents, 2000).

The backbone of our presentation was also to drive home the importance of mangrove awareness and how such knowledge may be beneficial by putting it in the context of the recent Boxing Day Tsunami. Mangroves could have saved numerous lives and reduced a significant amount of damage by acting as barriers, absorbing some energy of the giant waves. In this case, our embarking on this project would serve as a platform for the application of newly-acquired knowledge in situations free from restriction by boundaries.

In relation to Tsunami-hit areas, the key note speaker of the event, Mr Peter Kenny from the International Baccalaureate Organisation gave a short speech-cum-presentation earlier that morning as part of the opening ceremony of the competition. In his presentation, he shared his experience initiating a number of projects throughout Asia Pacific in relation to the tsunami disaster. We were also introduced to the “schools to schools” project, which was set up in an attempt to assist school communities in affected regions. The project aims to establish long tern cross-cultural links between local and foreign schools and staff alike and lend a hand in providing immediate and direct support.

A major part of his presentation consists of slides with thought-provoking pictures that illustrate the people’s just-barely-tolerable circumstances. There was one photo that was particularly memorable- a picture of a meagre pile of papers on a shelf allocated to a class of 40. Indeed, a picture speaks a thousand words. I doubt that even a well-crafted speech could beat this real-life picture in highlighting the insufficient resources and grossly inadequate conditions of pupils in Tsunami-hit regions that were once devastated by the waves.

Though in the end we only attained a Silver Award, I felt that what was most valuable was not the title at the end of the day, but the opportunity to learn from the presentation of others and be informed of the other efforts put in for the environment, for the single common goal of all those present at the competition. (So yeah, Zhong Ning, don’t take it too hard.) If not for this competition, or should I say, more of an interactive discussion, I would not have realized how many people in Singapore have been harbouring ideas of conserving and protecting Mother Nature’s gift to mankind.

Upon reflection, this competition could have been better prepared for if we hadn’t procrastinated during the June holidays as we overestimated the amount of time we had on hand. As a result, the few days before the competition were chaotic. On a final note, we would like to thank Mr Lim for sacrificing his after-school hours to help us out till the wee hours and not forgetting his humour that kept us awake…

[edit] Ada, I'm SOSOSO proud of you :) [/edit]

The Star Online > Lifefocus

Tuesday August 30, 2005

Harsh reality for tsunami-hit nations

By TAN CHENG LI

Scientists have, for years, shouted themselves hoarse about the wonder role that mangroves play in defending coastlines from erosive waves. Few heard them though, leading the world to lose half of its mangrove cover in the last 50 years to aquaculture ponds, coastal development and agriculture.

In the aftermath of the Asian tsunami, however, mangroves suddenly gained newfound respect among governments which once thought nothing about allowing the clearing of these coastal forests.

Tsunami-hit nations are now planting mangrove trees along coastlines to create “greenbelts” or vegetated strips of land, in the hope of preventing further erosion of damaged shores as well as to shield them from future giant waves.

The mass of tangled roots of mangrove trees is what makes this coastal forest so effective in buffering strong waves.

Some of these schemes, however, may prove futile.

In the dash to revegetate coastlines, ill-designed replanting projects have emerged. This concern was raised by scientists at a symposium organised by the International Society for Mangrove Ecosystems in Kuala Lumpur last week.

Dr Faizal Parish, director of the Global Environment Centre, observes that unsuitable tree species and planting sites, coupled with wrong planting techniques, have led to poor survival and growth of seedlings.

“With governments pressured into replanting, not enough study is being done to determine suitable sites and tree species,” he says.

In Aceh, Sumatra, where the worst coastal devastation occurred, Parish saw sites where mangrove seedlings were just shoved into the ground, and in open areas facing strong waves. As expected, many were washed away.

He says seedlings should have been grown in nurseries for three to four months to sprout roots and leaves before planting, to ensure better survival. He also saw seedlings planted in neat, straight rows – which offer little resistance to swift water flow. To do the job, trees should be randomly planted.

In one project in Aceh, Parish says Rizophora (bakau) seedlings were sourced from Java although good stands of this species exist on the east coast of Sumatra. It took 18 days for the seedlings to reach Aceh, by which time 60% had perished.

Most replanting schemes favour the Rizophora species – simply because seedlings are abundant and easily collected. But Rizophora may not be the right species to grow, according to forest ecologist Dr Noraini Mohd Tamin.

“They require sheltered sites but most of the damaged coasts are open and face the sea,” says the former Universiti Kebangsaan scientist who also found poor regeneration in several replanting sites that she visited in Banda Aceh.

The costly replanting mistakes of Aceh are being repeated in Malaysia. Parish and Noraini say seedlings planted in April in Kuala Muda, Kedah, where the tsunami had inflicted the most damage to the country, are not growing well and have low survival rates. The planting exercise costs RM60,000.

Like in Aceh, Rizophora seedlings were just pushed into the muddy earth, and in straight lines. “This works only if you are planting in the Matang mangrove (in Perak). This is a mature forest, so the bigger trees will shelter the seedlings,” explains Noraini.

“Kuala Muda is an exposed site. So seedlings are smothered by beach deposits and are easily dislodged as they lack roots. Mangroves grow best in protected estuaries and bays.”

Students helping to plant mangrove seedlings in Balik Pulau, Penang, in March.

Noraini notes that people are cashing in on the demand for Rizophora seedlings. Prices have hiked from 50 sen each last year to RM3. She says the Avicennia mangrove species are more suited to exposed coasts but they are hardly used for replanting because seedlings are not easily available since this species does not fruit year-round. In fact, Avicennia trees would be more suitable for Kuala Muda since they grew there originally. Villagers had, over the years, felled the trees as well as Nipah palms found there.

“Everyone wants to be seen doing something after the tsunami. But if the planting is not planned and done properly, some seedlings will not grow,” says Noraini.

In erosion-prone coasts, she says replanting must be combined with installation of wave breakers. Otherwise, seedlings will be swept to sea.

Post-tsunami replanting in Balik Pulau, Penang, also suffers from poor seedling growth, says mangrove scientist Dr Ong Jin Eong.

“For effective rehabilitation, you must plant the correct species, understand the hydrodynamics of the place and determine the site,” says the retired Universiti Sains Malaysia lecturer. “Scientific studies on the functional physical and ecological processes involved must be carried out before more good money is poured into badly thought out so-called mitigation projects.”

Ong believes money will be better spent saving an intact forest rather than rehabilitating a degraded one. “You can never recreate the original. This is expensive and you don’t get what you want.”

Tan Kim Hooi, senior researcher at the Maritime Institute of Malaysia, concurs.

As replanting projects are risky and involve taxpayers’ money, he says there should be proper assessment and planning.

He says many replanting projects with Rizophora apiculata and Rizophora mucronata in exposed coastlines in Asia have failed. In fact, both species are not commonly found in the natural environment of Penang and Kedah coastlines and yet, are being used in coastal rehabilitation efforts.

“We are living in the shadow of Matang’s success. The planting of R. apiculata there has been so successful that people think we can plant this species anywhere along the coast,” says Tan. On the contrary, both Rizophora species can tolerate only a narrow range of environmental conditions – specifically estuarine areas with brackish water and heavy rainfall. Matang has these conditions but not the coastlines.

Tan also questions the need to replant. “The immediate action should be to protect existing stateland mangroves which are about 100,000ha and subjected to various development threats. There is no point replanting while at the same time, we are losing these stateland mangroves.”

Planted in neat rows in the highly exposed coast of Kuala Muda, Kedah, these mangrove seedings are unlikely to survive strong waves that pummel the shore.

Indeed, with mangroves being a rarity – they cover a mere 0.04% of Earth’s surface and 0.12% of its land area – we should conserve whatever mangrove that remains. This is cheaper too.

In Malaysia, it costs RM15,000 to replant one hectare of mangroves. The government has identified 4,016ha of degraded mangroves requiring rehabilitation at a cost of RM110mil. Some 151ha have been replanted so far.

Ultimately in the long-term, Parish says nations have to review their coastal development plans to include a “zero development” zone of 200m to 500m width, and turn it into a greenbelt consisting of mangroves, casuarina trees or mixed crops.

Many tsunami-hit countries are finally implementing such rules, which existed but were never enforced.

“The tsunami was a wake-up call for many,” he says.

But there is no quick fix. Parish points out that a stable greenbelt can form only in five to 10 years. “So we need sustaining action. That means designing a long-term programme now.”

In the rush to maintain and create greenbelts, however, the role of other coastal ecosystems in shielding shorelines should not be ignored.

Dr Sundari Ramakrishna, director of Wetlands International Malaysia Programme, asserts that coastal peatlands, beach dunes, coral reefs, mud flats, seagrass beds and tidal flats can also do the job.

These habitats deserve attention and protection too.

Impact of the tsunami The Dec 26 tsunami left behind extensive environmental damage across the region. It totally changed coastal landscapes and ecosystems. The impact include: Loss and degradation of mangrove and seagrass beds Silting and degradation of coral reefs Change in tidal flats and coastal lagoons Uplifting of the seafloor in some areas Turbid coastal water Scouring of coastline Inland deposition of sand Salination of coastal land Impact on fisheries The role of mangroves during the tsunami Reflect and resist tsunami energy, thus reducing the inundation depth and area. Trap driftwood and other debris, thus reducing human injuries and property damage. Prevent people from being washed out to sea. Reduce erosion of beaches and sand dunes which also act as barriers to tsunamis.

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© 1995-2005 Star Publications (Malaysia) Bhd (Co No 10894-D)
Source: http://thestar.com.my/services/printerfriendly.asp?file=/2005/8/30/lifefocus/11872997.asp&sec=lifefocus

Even though our RS is on biology, physics comes into good use, occassionally.

Newton's 1st Law:
An object at rest will remain at rest unless acted upon on an external net force.

Newton's 1st Law redefined:
Ada at rest will remain at rest no matter how large the external force is.

Application:
Ada moves at the speed of light.
[Note: Mass increases when approaching speed of light.]

Fret not, ADA!
We've been doing work all day :)

The next entry shall be evidence.

P.S ADA TEO. IS NOT ALLOWED TO AMEND ANYTHING ABOVE. THANK YOU FOR YOUR COOPERATION :D

with love,
AMANDA AND ZHONGNING.
(much credits to Isaac Newton, Albert Einstein, and a certain Mr Patrick.)

It's Zhong Ning blogging for Ada this time round. Why? She doesn't know how to blog. Cool huh? So now, I shall be doing this round's reflections until we teach her how to blog.. (Or maybe get her the “Dummies Guide to Blogging )

Honestly speaking, this entry is one week late. Nonetheless, I think reflections can be done any time, though it is best done as soon as the activity is completed.

Hmm...well, I entered Sungei Buloh in the same way as the week before, though it was more disastrous this time round. First of all, I woke up late, and so, in my rush, I forgot to bring along the measuring tape, TWIST TIES, and goodness knows what other stuff. Hence, I have resolved to pack my bag the day before, and ALWAYS list out the things I have to bring along for each meeting.

According to reliable sources (i.e. Amanda), I will be dead the next round I forget something. Anyway, after confessing to an irritated Ada and (I think) an exasperated Mr Lim, some improvisation was done. (Habits of the Mind come in useful here I suppose..."Creating, imagining, innovating" and "Thinking flexibly")

The tidal level was taken to be as mentioned in the tide table, and as for the twist ties, raffia string replaced them temporarily. Since the person at fault was me, I was naturally the one to run back to the visitors' centre to get raffia. After some chiding from people around the topic of "you are suppose to bring your own twist ties. It is not our responsibility to provide you with string", I eventually managed to secure some raffia string to tie the hypocotyls to the bamboo after applying some more HoM ("Gathering data through all senses"??). Ok, HoM don't really work here. After all, I was remorseful.

So after these hiccups, we finally started securing the hypocotyls to the bamboo. This round was fun since we did planting in the rain! =D That was enjoyable, though I doubt anyone was in the mood to “赏雨”. Well, despite the morning's work being done, the raffia string had to be either replaced or secured further by proper twist ties. That basically meant that we needed to go back to do the tying one more time.

We went back today. (and Amanda continues, with occasional protests from Zhong Ning.)

We started early in the morning. The meeting time was 7.30 a.m. (I know we are nuts, nobody gets up that early to do RS. I mean who would even bother bout RS that much :b) but Zhong Ning was late (as usual) [Comment from ZN: I am not late AS USUAL. It's just today!]. Reached SBWR at around 8.00 a.m. to meet a highly annoyed (as usual again) Ada, and proceeded to Kranji Extention to start work.

Ada and I had our dads with us, so with adult supervision and aid, all we had to worry about was attaching the twist ties properly. Ada's dad helped with cutting the twist ties. Pardon my failing memory, I think they were about 15cm long.

Since there were 3 plots and 3 of us, we took 1 plot each. I think they were rather kind to me [duh! I did the muddiest plot because you ppl were so reluctant!], I got to work on the 'cleanest' sandy area. It was much easier for me, considering my inability to mobilise myself in mud. But anyway, I think I have an innate talent, just undiscovered [haha, like real. wait till you do the middle.] . I didn't have any difficulties moving in the mud today! The url of our blog no longer stands :) [at least for Amanda]

Everything was completed in about an hour and a half. The hypocotyls barely grew - none on the first plot (closest to the trail), 2 on the middle muddy plot, and 1 on the sandy plot, nearest to the waters. 1 hypocotyl was found rotten, and we replaced it with a new one we picked up from the ground.

I can't say the morning was a well-spent one, as all we did was to attach the twist ties to the hypocotyls and supporting sticks. But, at least we got what we were supposed to do done pretty efficiently :) Hopefully the next time we get to our plots, there'd be more measurements to take. I really hope they grow! And then we'll be contributing to the country, by extending the beach coverage at kranji extension by about 50%.

Yes, so Happy Birthday Singapore :D

Zhong Ning & Amanda. (Pictures from Ada to be uploaded soooooon.)

We went back to Kranji extension and finished planting 90 seedlings (mainly Rhizophora apiculata. Hope they'll grow well. if they do, we will have extended the beach coverage of the area by 50% from the shore.

Not bad for a morning's work.

This photo was taken at Pulau Semakau, during a quick transect to assess the biodiversity residing in Singapore's landfill. It is amazing and tough to navigate through the thick net of prop roots. The trees were about 6 meters tall and it is hard to tell where the trunk ends and where the root begins.

Rhizophora apiculata prefers deep soft mud and flooding by high tides. It's red stipules covering the leaves and its short greyish inflorescence stalks distinguishes it from the other members of the genus; R. stylosa and R. mucronata.

Amanda Lim (304)
Lau Zhong Ning (308)
Ada Teo (309)

RS Topic: Mangrove reforestation in Sungei Buloh Wetland Reserve

The mangrove forests all over the world are threatened. The reasons for their rapid destruction range widely from land reclamation and industrialization, to destruction of coastal areas due to uncontrolled development and constructions (Carola Elster, 1999). Pollution and natural disasters also contribute to the diminishing of mangrove forests.

Previously, especially in Southeast Asia, efforts for reforestation were evident, but due to scarce reforestation measures, plantings were mostly carried out by trial-and-error and scientific documentation was the exception. Thus, rehabilitation of various mangrove species, other than the widely researched and experimented species of the genus Rhizophora, was especially difficult, because planting guidelines were incomplete (Elster, 1999). According to Elster’s study on ‘Reasons for reforestation success and failure with three mangrove species in Colombia’, it is important to identify ecological factors that most influence mangrove establishment, growth, and survival under the current conditions in the study area.

Many methods are used in mangrove reforestation which in this context is defined as “the act of bringing a [mangrove] ecosystem back into, as nearly as possible, its original condition, renewing or bringing it back into use” (Field, 1996). There are three case studies that we feel have helped immensely in our understanding of the process of mangrove reforestation, together with its advantages, drawbacks and cost-effectiveness. These studies include JG Kairo et al.’s no the topic of reforestation and management of mangrove systems in East Africa, D.J. Macintosh et al.’s Mangrove Rehabilitation and Intertidal Biodiversity, and Roy R. Lewis III’s on the cost and benefits of successful ecological restoration.

Mangrove restoration has been in the international spotlight due to the increased documentation of “long-ignored ecological and environmental values of mangrove forests” (Kairo et al., 2001). However, without adequate reforestation techniques, many of these projects do not meet their ultimate aim of re-establishment of habitat and functions (Lewis, 2001). For example, Sanyal (1998) has reported that between 1989 and 1995, 9050 hectares of mangroves were planted in West Bengal, India, with only a 1.52% success rate. In view of this, Lewis and Marshall (1997) have suggested five essential steps to ensure the success of a mangrove restoration programme, consisting if understanding the “autecology”, “normal hydrologic patterns that control distribution”, “assessing the previous mangrove environment… that… prevents natural secondary succession”, designing and planning a methodology and only starting to plant if natural secondary succession does not take place.