Size matters to Whale Sharks

Spring is the auspicious season of a new year, with flower blossom, bluebirds singing in the trees and probably parrots squawking “Kung Hei Fat Choy” to their owners. With all the monumental work and unswerving efforts of local NGOs and advocacy groups for environmental conservation, Aquameridian comes to realize that hope exists only if the level of protection for Hong Kong waters is increased in order to preserve the habitats for a diversity of marine species. That’s why Aquameridan forged ahead with the agenda and caused Hong Kong South Hope Spot to birth in 2022, which is a scientifically special place identified by Mission Blue as vital to the health of the ocean.

The largest marine protected areas in Asia

The designated Hope Spot, in excess of 41,700 hectares, includes areas of South Lantau, Soko Islands, South Lamma, Aberdeen, Po Toi and Cape D’Aguilar. It covers almost 26% of total 164,062 hectares of Hong Kong waters, according to 2022 geographic data from Hong Kong Lands Department, which is the largest marine protected areas (MPA) in Asia thus far.


A significant reason for Hong Kong South Hope Spot is that many pelagic species travel through this migratory channel all year round. One of them is whale shark, an endangered and largely depleted species on IUCN Red List as well as a protected species in CITES. They migrate south of Hong Kong in summer and subadults occasionally venture into local waters. Therefore, the size of Hong Kong South Hope Spot matters a lot to the survival of this world’s largest fish.


Sighting of whale sharks in Hong Kong

Nature strikes a healthy balance

As previously mentioned, seagrass meadows, also known as “blue carbon”, helps create a healthy marine ecosystem as they are responsible for storing up more than 10 percent of all carbon buried annually in the sea, twice as much as the world’s rain forests if calculated by per unit area. Paradoxically to say, important as they are to green turtles as food source, if all the seagrasses are eaten by sea turtles or other marine mammals, it will cause horrendous loss of coastal barriers against storms and bring devastating impacts to our climate![1]Worry not, here comes our seagrass defender – sharks!

Sharks know where to find their preys. They often patrol and rove around seagrass beds to look for food like green turtles. The fear of sharks will keep these grazers away from devouring all seagrasses. Sharks are the best allies of seagrasses to maintain a healthy marine ecosystem. What’s more, they act as a helping hand to marine researchers to discover the world’s largest seagrass system in The Bahamas just a month ago!

[1] Sharks: Meet the seagrass protectors.  National Science Foundation: USA.                   

Whale sharks are docile mammals known from Hong Kong waters. Yet attacks from whale sharks, regardless of provoked or unprovoked are rarely reported. In fact, swimming in Hong Kong is pretty safe as there are shark prevention nets employed across 39 beaches. As long as you do not swim alone, at dawn or at night; or enter the waters with bleeding or open wounds, the chances of encountering or getting attacked by sharks can be reduced. However, if a large fish or shark-like object is sighted in vicinity, it is advised to leave the waters as quickly and calmly as possible and follow the instructions of lifeguards. Worse off, dial 999 for emergency.[1]

[1] Safety Advice on How to Avoid Shark Attack.  Swimmers’ Handbook: Leisure and Cultural Service Department of Hong Kong



6 shocking truths about Whale Sharks

How then, you may ask, could you tell whale sharks apart from the rest of the species if you really spot a big fish? Let’s get acquainted with whale sharks with the facts here:


  1. They are not whales
  • Green sea turtles are not green; whale sharks are not whales. Never judge an animal by its name again. The name of whale sharks comes from the fact that they are as large as whales. They are the largest fish and shark species in the ocean. A full-grown can reach up to 20 meters long and weighs 20 tonnes (almost twice the size of a KMB bus!)


  1. They are like vacuum cleaners
  • Whale sharks have an extremely wide mouth up to a metre across with over 3,000 tiny teeth inside. They are fed on plankton including krill, jellyfish and crab larvae, which are strained from the water through their gills. However, when they eat, they won’t bring a bloodshed but sweep through the waters like a vacuum cleaner as they neither bite nor chew their food.


  1. They have fingerprints
  • Whale sharks have a distinctive pattern of white spots and stripes against a dark bluish-grey background. Like fingerprints to humans, these patterns are unique to individual whale sharks, which are helpful for marine researchers to record their populations.


  1. They have wild but secret sex life[1]
  • Male whale sharks have two claspers (similar to a penis but two!) near the pelvic fin, which are absent in females. When a female shark is ready to breed, she is supposed to send out pheromones or chemical signals to alert any males nearby. However, mating occurs most often in deep or muddy seas. During mating, they involve in a handful of biting and thrashing and wrestling. A male shark will swim beside or beneath a female shark to mount her from multiple angles, then turning upside down and have one of his clasper spread, transferring his sperms into the female for her eggs to be fertilised.[2]


  1. They are generally harmless
  • Whale sharks are filter feeders and non-aggressive. That’s why they are also called “gentle giants”, playful and curious. Snorkellers can swim with these giant fish without real risk, apart from the chance of an unintentional blow from their large tail fins.



  1. Their major enemy is humans[3]
  • Whale sharks are slow swimmers. They travel at a speed of no more than 4km per hour. Because of their bulky size and habit of swimming at the surface, it makes them easy to get killed or injured by fishing, boat strikes or plastic rubbish. More sadly, they are constantly hunted by humans for its flesh, liver oil, cartilage and fins, which have become increasingly popular for use in shark-fin soup. Aquameridian’s Anti Shark Fin Campaign has been working with local restaurants to have shark fin soup removed from their menu and has gained a massive success.

[1] Attempted Whale Shark Mating Caught on Camera for the First Time in History.  (2019, June 25).  Live Science: UK.

[2] How do Sharks Mate?  (2022, November 1).  A-Z Animals: US.

[3] 11 Interesting Whale Shark Facts.  (2021, May 27). PADI Media Group:US


You have the power to change

Apart from saying no to shark fin soups, it is critical to reduce demand by changing attitudes. There are encouraging signs that shark-fin soup consumption is declining and several dozen airlines and hotel chains have stopped serving it. In 2012, the Chinese Government even banned it at official functions.

Today is the day you can be part of our Anti Shark Fin Campaign and help us do more! However big or small your gift is, it will go directly to preserving sharks in Hong Kong South Hope Spot and around the world. Click here and donate to join forces with us.