31 August 2008

What are Coral Reefs?

Coral reefs are one of the most biologically diverse marine eco-systems on the Earth! Many think that corals are plants, but they are actually animals.

A coral reef is composed of a calcereous exo-skeleton secreted by billions of tiny animals called polyps. Millions of polyps grow on top of the limestone remains of former colonies to create the massive reefs. It takes years for some corals to grow even one centimetre! They range in size from a pinhead to a few feet in length. Amazingly, these tiny animals form the only natural structure visible from space.

Each polyp lives in a symbiotic relationship with a type of algae, zooxanthellae, that gives the coral its colour.

Read more at: http://www.nature.org/joinanddonate/rescuereef/explore/facts.html

The Coral Reef Ecosystem

The coral reef ecosystem is a diverse collection of species that interact with each other and the physical environment.They are perhaps one type of ecosystem that is neglected more than any other and is also one of the richest in biodiversity. That is why it is very important to protect these natural treasures.

Coral reefs create homes for many different types of animals, from crabs to fishes to turtles! They are like giant cities for marine life. Each and every species of animal in the reef relies on others to keep it alive, so you can imagine what will happen if the reefs are wiped out!

Ocean Threats

Coral reefs are being degraded by an accumulation of stresses arising from human activities and examples of these activities include:
Over-Fishing - There is an increasing demand for food fish and tourism curios, which resulted in over-fishing of not only deep-sea commercial fishes, but key reef species as well! The over-fishing of certain species near coral reefs can affect the ecological balance and biodiversity of the reefs. From subsistence level fishing to the live fish trade, inadequate fisheries management is forcing the decline of fish stocks.
Pollution - Pollution causes the damaging of reefs worldwide. The disposing of litter or unwanted items on beaches, in the sea or near storm drains can damage coral reefs when transported by rivers into coastal waters.
Corals are also affected by climate changes.

Coral Bleaching - This occurs when symbiosis between corals and their symbiotic zooxanthellae breaks down, resulting in the loss of the symbionts and a rapid whitening of the coral host (thus the term "bleaching"). This is actually a stress response by the coral that can be caused by various factors. But the more severe and frequent cases are caused by the rising of the sea surface temperature (SSTs).If the temperature decreases, there is a chance that the corals can recover; but if it persists, the whole colony could be wiped out.

The impacts from coral bleaching are becoming global in scale. They are also increasing in frequency and intensity. Mass coral bleaching generally happens when temperatures around coral reefs exceed 1o C above an area's historical norm for four or more weeks. Sea surface temperature increases have been strongly associated with El NiƱo weather patterns. However, light intensity, (during doldrums, i.e. flat calm conditions), also plays a critical role in triggering the bleaching response. If temperatures climb to more than 2o C for similar or longer periods, coral mortalities following bleaching will increase.

Other causes such as coral disease can also cause the deterioration of coral species. Most diseases occur in response to the onset of bacteria, fungi, and viruses. However, natural events and human-caused activities may exacerbate reef-forming corals' susceptibility to waterborne pathogens.

The Crown of Thorns Starfish(COTs) is a voracious coral reef predator. Populations of the COTs have increased since the 1970s and large outbreaks of starfish can occur wiping out huge tracks of coral reef. Few animals in the sea are willing to attack the spiny and toxic crown-of-thorns starfish, but some shrimp, worms and species of reef fish do feed on larvae or small adults. The decline of these predators, through over-harvesting and pollution, is one factor contributing to the rise in the population of the starfish.

How Fast Are The Reefs Disappearing?

Coral reefs are home to 25 percent of the world's marine fish species, and cover 1 percent of the Earth's surface. But they will be soon destroyed if we do not try to save them. Did you know that around 30 percent of the world's coral reefs are already damaged, some irreparably? At the present rate, by the year 2050, 70 percent of the world's reefs will have disappeared!

Coral reefs in the Indo-Pacific region - where 75 percent of the world's reefs live - are now being destroyed at a rate of 1 percent a year. That doesn't sound like a lot, but it is actually twice as fast as the rate of destruction of tropical rainforests!

In the early 1980s, around 40 percent of the region's reefs hosted live coral -- today it is just 2 percent. Now do you see how disastrous the situation is?

Conservation Efforts

What have people done/plan to do to protect the coral reefs? Here are some examples:
The Nature Conservancy - Their coral reefs project around the world ensure that support for designing and creating resilient marine protected area networks in the Asia-Pacific region, known as the Coral Triangle. They also ensure that the staghorn coral restoration efforts in the Florida Keys will be monitored.
Caribbean Nations Launch Challenge - This will accelerate the marine conservation in the region with the aim of protecting 20 percent of the region's marine and coastal habitat by 2020.
Rainforest2Reef - It is developing a program to work with local communities on the use of more environmentally friendly techniques and materials. Through these efforts, we are beginning to help local communities become stewards of their coastal and marine environment as well as the rainforests.
A few of these type of organisations in Singapore include:
Nature Society (Singapore) (NSS) - This organisation is dedicated to the study, conservation and enjoyment of the natural heritage in Singapore, Malaysia and surrounding region. It organises special awareness and conservation campaigns, to raise national conservation issues, such as the protection of Singapore's Natures areas.
Singapore Underwater Federation (SUF) - This organisation conduct activities such as underwater cleanups, the installation of courtesy mooring buoys and environmental seminars.
Raffles Museum of Biodiversity Research - This organisation conducts intertidal walks and does research on marine life.
Tropical Marine Science Institute - This organisation is centre of excellence for research, development and consultancy in tropical marine science as well as environmental science.
Underwater World Singapore - It has sought to raise public awareness on marine conservation issues via educational exhibits and signage information, enriching educational programs, outreach assembly talks for schools and various ongoing conservation projects with other partners and institutions.

How You Can Help?

Everyone can help in the conservation of coral reefs! Here are some things that you can do:

Educate yourself about coral reefs and the creatures they support. With enough knowledge, you can help others understand the fragility and value of the world’s coral reefs.

Make sure that sewage in you living area is correctly treated. Excessive nutrients in waste water can negatively impact coral reef ecosystems.

Don’t use chemically enhanced pesticides and fertilizers. Although you may live a long way from a coral reef ecosystem, these products end up in the watershed -- the area that drains to a common waterway, such as a stream, or a lake, and ultimately, the ocean.

Be an informed consumer. Only buy marine fish and other reef organisms when you know they have been collected in an ecologically sound manner.

Recycle. This helps keep trash out of the oceans and also out of landfills where it can have an adverse impact on the water quality of our rivers and oceans.

Conserve water. The less water you use, the less runoff and waste water eventually find their ways back into the oceans.

Carry away the trash that others have left behind. Beach litter poses a significant threat to the health and survival of marine organisms, which can swallow or get tangled in plastic containers, plastic bags, Styrofoam boxes, and other debris.

Report dumping or other illegal activities. Help be the eyes and ears of the reef!
Consider visiting a coral reef on a vacation. Spend some time enjoying the beauty of one of the world’s treasures while helping to preserve it for future generations.

Do not touch the marine life. Take only pictures. Keep your hands away from the reef, as the marine life can hurt you and you will also damage the delicate coral animals. Stay off the bottom because disturbed sediments can smother the corals.

Respect local guidelines when you visit a reef. Help keep coral reefs healthy by respecting local customs, recommendations, and regulations.

Stay informed regularly. Find out about existing and proposed laws, programs, and projects that could affect the world’s coral reefs.

Support organizations that protect coral reefs. Your support can make a big difference! E.g., You can go for intertidal walks at our Singapore islands, participate in the coastal clean-up efforts, go for talks, volunteer etc.

Spread the word. Share your own excitement at learning the value and importance of coral reef ecosystems. This gets everyone involved!

Our Coastal Cleanup Efforts - 31st August 2008

Today, Yi Xi and I went to the beach to pick up litter. We found lots of stuff! We found styrofoam, plastic bottle caps, bottles, balloons, a slipper, a lot of rice and macaroni and even a full pack of fries!

We picked up a lot of litter from the beach.

There was a lot of styrofoam on the beach...

... together with yoghurt bottles... ...plastic bowls...
... empty cigarette boxes...

.. bottle caps... ... bottles...
... lighters...
... a sponge...

... and even balloons!
Look at the amount of rubbish we collected!

I encourage all of you to do your part not to throw rubbish into the sea and to actively participate in coastal clean up projects.

Rubbish Statistics

Around 100 million tonnes of plastic are produced in the world each year! 10 percent of that ends up in the sea. That is equivalent to 10 MILLION TONS of rubbish!

Look at this poor turtle. Animals tend to mistake rubbish for their prey (e.g. jellyfish) and choke on them! It is estimated that around 1 million sea creatures die from choking on plastic!

This all happens because people are littering. We should spare a thought for the animals and dispose of our rubbish appropriately.

30 August 2008

International Whale Shark Day

Today is International Whale Shark Day! Whale sharks are the largest fish in the ocean, some with a length of 18m! Despite their size and name, they are actually plankton eaters.

28 August 2008

Pulau Semakau 17 Aug 08 (Part 1 - Intertidal Walk, Corals)

On 17 Aug 08, I woke up at 3am to get ready for our trip to Pulau Semakau. My mother had signed us up for an intertidal walk organised by the Raffles Museum of Biodiversity Research. What we saw was really unbelievable! This affirmed our belief that we need to save the reefs!

Look at all the hard and soft corals spotted! Are they fabulous? Would you have imagined that they can be found along Singapore's shorelines?

Pulau Semakau 17 Aug 08 (Part 2 - STARS)

One of the highlights was seeing the knobbly sea star (Protoreaster Nodosus). This is probably the biggest sea star in Singapore based on body width, as it can grow to about 30cm wide.

This sea star apparently feeds on micro-organisms on seagrass or sediment surfaces. However, it is known to feed on soft corals, sponges, clams etc. when in captivity. But they are not known to survive long in captivity, which suggest that the latter may not be their preferred natural diet.

We also saw a cushion star (Culcita novaeguineae). They feed on corals.

We saw several species of sea stars too. The below are sand-sifting sea stars (Archaster typicus) in a shallow tidal pool, including one pair which is mating!

Pulau Semakau 17 Aug 08 (Part 3 - Sea Cucumbers)

We saw lots of sea cucumbers that day! Not all can be eaten :) This sandfish sea cucumber (Holothuria scabra) is the one often served in Chinese restaurants. They must be probably treated to remove their toxins before they can be consumed.

This ocellated sea cucumber (Stichopus ocellatus) has very striking colours and has lots of "eyespots" on its body, which are basically dark papillae surrounded by a white ring.

Pulau Semakau 17 Aug 08 (Part 4-Flatworms and Nudibranchs)

We also saw many invertebrates along the shoreline! Examples include this Acanthozoon flatworm:

These flatworms are very fragile and tear easily, so handling them is a delicate task. The good news is, they can regenerate their lost body parts.

We also saw this funeral nudibranch (Jorunna funebris). "Nudibranch" means "naked gills" as their gills (the flowery structures on their backs) are exposed, not in their body like most other marine animals.

Just like snails, Nudibranchs are hermaphrodites. This means that they have both male and female reproductive systems. The above Glossodoris nudibranchs (Glossodoris atromarginata) are actually mating!

We were lucky enough to spot a swallowtail headshield slug (Chelidonura pallida). The swallowtail headshield slug has a well-developed "headshield", which is used to plow beneath the sand surface and helps prevent the sand entering the mantle cavity. These slugs feed on tiny flatworms living on coral reef substrate.

Pulau Semakau 17 Aug 08 (Part 5 - Crabs)

Can you spot the hairy crab in this picture? Hairy crabs are masters of camouflage, as they are coloured and textured just like a lump of seaweed.

This is probably a carnivorous crab, as it has sharp pincers and not spoon-shaped ones. It is actually getting ready to attack as it had sensed our presence.

Pulau Semakau 17 Aug 08 (Part 6 - Noble Volutes)

We also spotted 2 noble volutes (Cymbiola nobilis) laying their eggs. Noble volutes are sea snails, but they are fierce predators and kill their prey by smothering them with their foot.