Animals help pollinate and disperse seagrasses

Two recent studies reveal the role of marine creatures in pollinating seagrass flowers and dispersing their seeds!

Male turtlegrass flower with invertebrate.
Photo from article by  Brigit van Tussenbroek
on the World Seagrass Association blog

Tiny worms and crustacea visit the flowers of Thalassia testudinum while fish, terrapins, and birds may help disperse seeds of Zostera marina. Does the same kind of thing happen on our seagrass meadows? So much more to learn and discover!

Some reefs can do well in murky water

A new study has established that Middle Reef -- part of Australia's iconic Great Barrier Reef -- has grown more rapidly than many other reefs in areas with lower levels of sediment stress. Unlike the clear waters in which most reefs grow, Middle Reef grows in water that is persistently 'muddy'. The sediment comes from waves churning up the muddy sea floor and from seasonal river flood plumes.

Middle Reef from above the water. (Credit: University of Exeter)

Singapore's reefs also grow in waters murky with sediments! The photo of Middle Reef above looks very much like the reefs we have in Singapore, below.

Living reefs at Terumbu Pempang a submerged reef
near Pulau Semakau

Today, it was also reported that the world's northern-most reef had been discovered in Japan in murky water too.

Here's more about what scientists think about why Middle Reef is growing more rapidly than reefs in clearer waters in the Great Barrier Reef.

Why do fishermen keep fishing despite poor catches?

A study of traditional fishermen in Africa found that "fishermen in the more vibrant and developed economies were less likely to give up their trade -- despite having more economically fruitful opportunities open to them"

Fisherman laying fish traps at Pulau Sekudu off Chek Jawa.
Fishing with traps and nets is very regularly
encountered on Singapore shores.

Although subsidies might play a part, researchers also suggest that "fishers often have an occupational attachment, job satisfaction, family tradition, culture, and a sense of identity, which makes them reluctant to stop fishing -- even when it would be an economically rational decision." The researchers also highlight that "It is important to understand why and when fishers will leave a fishery, as the creation of parks, management restrictions, and ecological disasters require that fishers change or leave their fishing practices."

Seagrass meadows may be oldest and largest organisms on earth

A seagrass species found in the Mediterranean is possibly the oldest and largest organism, reaching up to (15 km) wide and may be more than 100,000 years old.

Posidonia oceanica by M. San Felix from LiveScience.com

Wow! I wonder how old our seagrass meadows are?!

Sea cucumber poop good for reefs

Sea cucumbers could help buffer reefs from ocean acidification due to climate change.

A sausage-like string of sea cucumber poop, seen on Pulau Semakau.

A recent study found that sea cucumber poop raises the pH level of the water, thus countering the effects of ocean acidification. While their ammonia waste fertilises and provides nutrients for coral growth. As they eat sand, they also release dissolved calcium carbonate, a key component of corals.

Sea slugs help humans get smarter!

Studying sea slugs, scientists may someday be able to design ways for humans to improve long-term memory!

The Spotted sea hare (Aplysia oculifera)
is seasonally common on our shores.

Scientists have been studying the brain of Aplysia since the 1960s, and the animals have revealed many secrets of learning and memory in humans. The sea slug's central nervous system is relatively simple, with only 10,000 neurons, compared with the approximately 100 billion found in humans. Moreover, Aplysia neurons are large and easily accessible.

All about Ovulids of Singapore!

Wong Hoong Wei's awesome paper (pdf) on our fabulous false cowries has been published on the Raffles Museum website as an ebook. Ovulids are snails that live on sea fans and other reef animals, and are perfectly camouflaged on their colourful hosts.

This is a great resource for these fascinating snails! Not only a checklist with detailed descriptions, but also lots of interesting facts and wonderful photos!

What can we learn from dead corals?

A recent study of dead corals suggests that we have seriously underestimated the biodiversity of the world's coral reefs!

The brown bottom half of this coral colony is still alive,
while the upper half covered with scum is dead.

The scientists studied dead corals because "live corals defend themselves from being inhabited by other invertebrates". But once a coral dies its structure becomes covered with algae, sponges, crustaceans, worms, molluscs and other creatures.

Biodiesel from a seashore tree?

This pretty seashore tree is being considered as a source of biodiesel. Although the tree is widely planted in many of our seashore parks, wild trees are rare and it is listed as Endangered in Singapore.

 

The seeds of Mempari (Pongamia pinnata) have long been used traditionally. Although poisonous, an oil extracted from the seeds (called Pongamol or hongay oil) was used for lighting, to manufacture soap and candles, and in medicinal uses. The tree is considered an attractive source of biodiesel because it has a higher yield of oil compared to jatropha. It can also grow on marginal arid or semi-arid land and is a nitrogen-fixing tree, which means that it helps fertilize the soil.

Coral-killer seaweeds and fishes that eat them

Seaweeds can contain chemicals that harm corals, and a study has for the first time identified these chemicals. These chemicals can prevent young corals from growing and can make adult corals ill. Thus making it difficult for reefs to grow and recover.

One of the seaweed-eating fishes found on our shores,
a rabbitfish is caught in a driftnet found on Tuas, Sep 2011.

Seaweeds are usually controlled by seaweed-eating fish. Thus overfishing of such fish can affect the health of reefs.

Sharks and anti-virus compound for humans

A compound initially isolated from sharks shows potential as a unique broad-spectrum human antiviral agent, a recent study found.

A shark caught in a driftnet laid on Cyrene, a reef in Singapore.

"I was interested in sharks because of their seemingly primitive but effective immune system. No one could explain why the shark was so hardy," said the study's lead investigator. The study also answered this longstanding mystery of how sharks, which have a very primitive immune system, can so effectively fight the viruses that plague all living creatures.

Will there be any dugongs 100 years from now?

Professor Helene Marsh, the leading authority on dugongs, gave a public lecture on "Challenge of conserving dugongs in our region". 

She outlined some aspects of the rather dire situation that dugongs face today. Dr Elizabeth Taylor also shared about Singapore's wild dolphins.

Moon snail eats crab!

Moon snails have been observed to hunt fast-moving soldier crabs in Australia!

In Singapore, we do have soldier crabs (Dotilla sp.) and moon snails (Family Naticidae) living near one another on our sandy shores too. It's time to observe whether our moon snails also hunt these crabs!

How much plastic might fishes eat?

About 12,000 to 24,000 tons per year, for fish in the intermediate ocean depths of the North Pacific.

Floating plastic trash is common on all our shores.

A study of the "Great Pacific Garbage Patch" found plastic waste in more than 9% of the stomachs of fish collected there.

Floating sea seeds suggest new non-toxic ship skins

It's amazing what can be learnt from seeds floating in the sea! Biofouling is a big problem for shipping. All kinds of marine life quickly settle on any hard surface left in the sea for some time. These growths make the ships less streamlined and affect speed and energy consumption, not to mention eventually corroding the surface.

All kinds of floating seeds seen on Changi Beach.

Biofouling is usually kept at bay by painting surfaces with toxic paints. But scientists are recently developing a non-toxic surface based on seeds which float in the sea, free of fouling for long periods.

Stony stare of a chiton

Eyes made of rock crystal that can distinguish shapes! This is among the findings of a recent study of the eyes of a chiton, a strange snail with a coat of mail.

A large chiton sometimes seen on Singapore's shores.
Not all chitons have eyes though.

Why rock? The hard aragonite that comprise the eyes is extremely resilient. Chitons are constantly pummeled by waves in the intertidal zone. "If their eyes were made of protein" — which is the case for humans and most other animals — "they would get worn right away," said the author.

Blobs in the sea help us understand human health issues

These blobs are related to us humans! Ascidians belong to the same larger group as vertebrates and studying them can help us understand human health issues. These animals are commonly seen on our shores.

Botryllus schlosseri is a type of sea squirt.
(Credit: Anthony W. De Tomaso)

Recent studies of the small sea squirt may ultimately help solve the problem of rejection of organ and bone marrow transplants in humans, according to scientists at UC Santa Barbara.

Mangroves, seagrasses 'lock up' carbon: IUCN report

Mangroves, seagrass meadows and other coastal wetlands remove carbon from the atmosphere and lock it into the soil, where it can stay for millennia.

Rare Beccari's seagrass growing at mangroves of Kranji Nature Trail.

When these are destroyed, huge amounts of carbon are released. “For the first time we are getting a sense that greenhouse gas losses from drained and degraded coastal wetlands may be globally significant and that drained organic-rich soils continuously release carbon for decades” says a spokesman for the report.

Aquaculture: where does the fish poop go?

A recent study found that relatively high concentrations of dissolved waste from fish pens do not consistently dilute immediately.

Fish farms just off the Chek Jawa boardwalk and jetty.

"This study suggests that we should not simply assume 'dilution is the solution' for aquaculture pollution," said one of the authors."As the aquaculture industry grows, so will the number of pens that create pollution," another author added. "The models that we developed for this study can help regulators determine how waste from proposed fish farms might impact the waterways and coastlines both near and far from the pens."

Why does fish waste matter?

Mangroves: the "most carbon rich forests in the tropics"

Mangroves store more carbon that almost any other forest on Earth!

Mangrove forest at Kranji Nature Trail

A recent study found that mangroves store up to FOUR times more carbon per acre than most other tropical forests around the world. How do mangroves do this?