Whale sharks are some of the most fascinating creatures roaming our oceans. Known for their impressive size and gentle nature, these majestic beings have captivated marine enthusiasts and scientists alike.
In this blog we dive into the world of whale sharks to uncover their mysteries, behaviours, and the conservation efforts aimed at protecting them!
What are whale sharks?
Whale sharks (Rhincodon typus) are the largest fish in the ocean, with some individuals reaching lengths of 12m (40ft) or more. Despite their size, whale sharks are filter feeders, primarily consuming plankton, small fish, and other tiny marine organisms. Their wide mouths can open 1.2m (4ft) across, allowing them to take in enormous amounts of water and filter out their food.
Unique Features
One of the most distinctive features of whale sharks is their unique skin pattern, which consists of a series of spots and stripes. No two whale sharks have the same pattern, making it possible for researchers to identify and track individual sharks over time.
Habitat and Distribution
Whale sharks are found in warm waters around the world, typically in tropical and subtropical regions. They are known to migrate seasonally to areas rich in food, such as coral reefs, coastal waters, and areas where cold water upwelling supports an abundance of food.
Behaviour and Social Structure
Whale sharks are often seen swimming alone, but they can also be found in small groups, particularly in feeding areas. They often rise to the surface to feed, providing a fantastic opportunity for marine enthusiasts to observe them in their natural habitat.
Conservation Status
Despite their majestic presence, whale sharks face numerous threats. Overfishing, bycatch, ocean pollution, and climate change have all contributed to a decline in their populations. Whale sharks are listed as Endangered on the IUCN Red List, prompting increased efforts to protect them.
Shark Sightings in Seychelles
Over the past few months, the island of Mahé, the largest island of Seychelles and the location of several of WiseOceans Marine Discovery Programmes, has transformed into a breath-taking hotspot for whale shark sightings!
Lucky local and tourists enjoyed often daily encounters with these charismatic creatures. Swimming alongside these magnificent underwater giants has been nothing short of magical, allowing us to witness their serene elegance as they glide through the water and filter food. Each encounter has deepened our appreciation for marine life and reinforced the importance of conservation efforts to protect these vulnerable species. Truly, it has been a dream come true, filled with unforgettable moments that remind us of the beauty of our oceans and the need to protect them!
Megafauna Data Collection
Data collection on whale sharks is a cornerstone of marine research and conservation. As these gentle giants are classified as endangered on the IUCN Red List, the information gathered from field observations helps marine biologists monitor their population trends, behaviours, and health. This, in turn, informs conservation strategies to protect the species. Whale sharks are also highly migratory, meaning they travel vast distances across international waters. By tracking them, researchers can understand their migration routes, feeding habits, and the specific threats they face in different regions. This data is essential in advocating for stronger international protections and creating marine protected areas (MPAs) tailored to the species’ needs.
The data collection process begins with noting environmental conditions, such as sea conditions and, visibility. These factors are recorded to provide context for the encounter. For example, clear water and calm seas might make it easier to observe whale sharks, while rough conditions could alter their behavior. The more we understand how environmental factors affect their movements, the better we can predict when and where to find them, aiding in long-term population studies.
Once a whale shark is sighted, the clock starts ticking! Logging the time of the encounter is crucial because it helps researchers track interaction durations, which can reveal behavior patterns—such as how long whale sharks stay in a particular feeding area or how they interact with boats and people. Observing how long they spend at the surface or in specific areas of the ocean also contributes to our understanding of their feeding and migratory habits.
One of the most important methods for identifying individual whale sharks is through photo identification (photo ID). Each whale shark has a unique pattern of spots on its skin, particularly in the area between the 5th gill and the pectoral fin (as seen in the image below). By capturing clear photos of these patterns on both sides of the shark, researchers can use software like I3S Classic Model to match the images against an existing database of identified sharks. This process allows marine biologists to track individual sharks over time, monitor their movements, and even detect migration across countries.
Thanks to our Seychelles team of Marine Biologists, Raisha and Marielle for this blog!
For more information on our Discovery Programmes, visit WiseOceans Discovery
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