Finding Nemo in Vain
In the blink of an eye, signs of life have gone. In the last 30 years, we have lost 50% of the world’s corals due to climate change. Coral communities in Hong Kong South Hope Spot, is one of the few marine habitats in the world, that have adapted to and survived the harshest environment. Climate change and rising sea temperatures haven’t affected Hong Kong yet, but one day they soon will.
Hong Kong’s awe-inspiring coral reefs
Coral reef exists in sea temperature from 20-25 degree Celsius in shallow, clear waters. Considered the low salinity and murky water quality caused by the pollution of Pearl River, corals are seldom found on the west coast but mainly in the northeast and eastern shores, as outlined in red from the map above. Out of around 800 coral species world-wide, 84 are documented in Hong Kong waters, more than the entirety of Caribbean Sea.[1]
Distribution of Hong Kong Coral Communities
Northeastern region | – Tung Ping Chau – Kat O – Shelter Island – Chek Chau – Hoi Ha Wan | -brain corals -honey comb corals |
Eastern region | – Sharp Island – Shelter Island – Bluff Island – Sai Kung | -plate corals -bore corals -bowl co |
[1] Coral Field Guide. Agricultural, Fisheries and Conservation Department: Hong Kong.
https://www.afcd.gov.hk/english/conservation/con_mar/con_mar_cor/con_mar_cor_cor/con_
What is coral?
Corals are often mistaken as plants but they are actually living animals. They have tiny arm-like tentacles with stinging cells on the tip to catch their food during nighttime. Inside the tissues of corals are small plants called microalgae, that rely on photosynthesis during the day to create food for themselves. Corals provide algae with shelter, and in return, algae provide corals with oxygen and organic food to grow and thrive. This sort of “You in me, I in you” relationship forms a mutually beneficial partnership named “symbiosis”.[1]
Corals take in many forms and shapes but are generally divided into two categories – soft corals and hard corals (a.k.a. stony corals/ reef-building corals).[2]
Major Differences | Soft Corals | Hard Corals |
Appearance | – 8 tentacles or in multiples of 8 – in the form of underwater plants – soft structure swaying with the tide | – 6 tentacles or in multiples of 6 – in the form of rocks – hard structure like skeleton |
Growth characteristics | – rely on spiracles as spine/stem for internal support – cannot forms reefs – grow faster(2-4 cm a year)
| – create skeletons out of calcium carbonate and eventually becomes rock – can form reefs – grow slower(less than 0.3-2 cm a year) |
Defense mechanism | – use chemicals for defense and spicules for detecting predators | – Polyps can retreat to skeletons for protection |
Habitat | – deep water across the globe | – shallow clear water that allows light penetration |
After two unsuccessful “rescue” operations, the only viable option now is for fishermen to cooperate with conservation efforts to retrieve all gillnets in the Gulf of California, so that the vaquita population can have a chance to recover. However, in 2019, news have reported that vaquitas were still being entangled by fishing nets. This suggested that law enforcement has not been able to effectively prevent these tragic incidents from happening. If vaquitas continues to be entangled by gillnets, they will likely go extinct within two years.
What can you do?
- Write a letter to the Hong Kong government to strengthen law enforcement and increase penalties for the illegal trade of wild and endangered animals (including their body parts) in Hong Kong
- Watch more documentaries and books to raise awareness and discuss related issues with family and friends
- Protect the environment around you, and make some changes in life that can reduce the consumption of the planet’s resources, such as eat less meat and seafood and reduce waste generation.
Mass coral bleaching rings the alarm bell
In 2016 alone, 29% of the Great Barrier Reef, from Lizard Island north through Torres Strait, died of coral reef bleaching, a phenomenon where corals lose their vibrant colors and turn completely white attributed to climate change. Corals survive in a certain sea temperature and if the ocean gets too hot, corals become stressed and expels the colorful micro-algae inside their tissues, leaving a white skeleton behind. Once dead, it takes a decade for coral reef to recover.
The first global mass bleaching event happened in 1998. The second event occurred 12 years later in 2010. However sadly, the third was witnessed 6 years later in 2016. It suffices to say that global warming is spreading at a breakneck speed, to a point that scientists suggested it was not a natural fluctuation of the growth cycle of coral reefs. In this documentary Chasing Corals, scientist showed us the imagery of the disheartening bleaching event within 4 months in Australia.[1]
Coral restoration starts with us
In Hong Kong, two coral restoration approaches are employed by coral advocacy group Coral Academy in degraded coral areas to mitigate population declines of corals, enhance biodiversity and promote reef resilience, including:
1. Sexual propagation – it involves the collection of egg bundles from corals during coral spawning, allowing them to fertilize and develop into larvae/juveniles before out-planting them to the degraded sites.
2. Asexual propagation – it involves collecting, cutting, and culturing hard coral fragments in lab-based coral nurseries for direct transplantation in the reefs.[2]
If you are a diver or snorkeler, follow these three rules:[3]
1. Don’t touch – coral polyps protect themselves and micro-algae from infection with a mucus layer that is home to a rich microbiome, just like your own skin! Touching corals, either directly or accidentally, will damage this protective layer.
2. Don’t chase – coral fishes are sensitive to sound and physical disturbances in the waters. If you see bigger animals like sharks, turtles, and dolphins, keep a distance of at least a few meters from them. Unless they choose to approach you, a closer distance is acceptable but even so, no touching!
3. Don’t feed – the entire food chain can be upended when you change an animal population’s diet and feeding habits. Conditioning animals to expect feeding can also disrupt critical behaviors that they need to survive and make them more vulnerable to ship strikes, intra-species aggression, and disease transmission. Needless to say, don’t join any wildlife feeding tours!
Everything can change in just one split second. Don’t take life for granted. Protect Life, Conserve Nature.
[1] The Issue: coral reefs are vanishing at an alarming rate. Chasing Corals: Exposure Labs.
[2] Restoration of degraded Hong Kong coral habitats using multiple active coral restoration approaches. Coral Academy: Hong Kong.
[3] Why you shouldn’t touch coral, fish or other sea life while snorkeling. (2020, August 28). Tide Trek.