Exploring The Wobbegong Shark: A Dive Into Sydney's Vanishing Species

Peter Letts   Jun 18, 2023

Wobbegong: A Dive into Sydney’s Vanishing Species

A Deep Dive into the Disappearing Wobbegong

Do you know the wobbegong shark, also known as the common carpet shark? This amazing creature, with its camouflage appearance, is one of the fascinating fish of Australia, living in the coastal waters of the Indo-Pacific. It has a flat body and patterns that blend with the sea floor. This guide will discuss wobbegongs, their characteristics, species, habitats, hunting, human interactions, and the future of this fish. Let’s dive in!

Quick Facts

• Wobbegongs are cool, with camouflage and many species.

• Breeding is a 3-year cycle; pectoral and pelvic fins help them ambush prey.

• Conservation is needed to protect the wobbegongs in Sydney’s marine environment for future generations.

The Wobbegong World

Carpet sharks, particularly wobbegongs, have patterned skin and cryptic colouration that allows them to blend in with the sea floor, making them perfect ambush predators. Wobbegongs are commonly found in shallow coastal waters, typically at depths not exceeding 100 meters. They use their features to sneak up on fish, crustaceans and octopuses. With 12 species of wobbegong shark in the world’s oceans, carpet sharks have many cool traits that set them apart from other sharks. We’ll go into their world more by looking at their breeding cycles and habits.

Breeding Cycles and Habits

Wobbegongs breed in July during the breeding season when males are attracted to females through pheromones. The mating process involves the male wobbegong biting the female in the gill area and using a specialised pelvic fin called a clasper to inject sperm into her cloaca. Males bite females during mating to successfully insert their claspers and release sperm, highlighting a natural reproductive behaviour in this species. They have around 20 pups in a litter, but can have up to 37. They breed every three years.

Wobbegong shark pups have a 10% survival rate to adulthood. This is because they face many challenges, including competition for food, predation, and habitat loss. Their predators are sea turtles, larger sharks, and fish. Now that we know about their breeding, let’s look at their characteristics.

Pectoral and Pelvic Fins: Wobbegong Features

One of the most interesting features of wobbegongs is their broad pectoral and pelvic fins and skin flaps around the snout. The second dorsal fin is positioned close to the anal fin, which is a distinct anatomical feature of this species. These help wobbegongs blend in with the sea floor, camouflage themselves and ambush their prey.

This is how wobbegongs thrive in their natural environment; they are truly one of a kind among sharks.

Wobbegong Species

Different species of wobbegong, including spotted wobbegong sharks and ornate wobbegongs, are common in Sydney dive sites. There are 12 species of wobbegongs in total, each with its own characteristics, habitats, and behaviours. The spotted and ornate wobbegongs have camouflage, but each has its own traits.

Let’s take a look at these two.

Spotted Wobbegong

The spotted wobbegong, also known as the shark wobbegong, Orectolobus maculatus or tassel shark, has some cool features, including large lobes on its head. It can reach a maximum length of up to 3 meters. Its pattern is dark saddles, white rings, white o-shaped spots and white blotches. Found along the southern coast of Australia from Queensland to Western Australia. Common in these areas. Spotted wobbegongs are found in coral and rocky reefs, estuaries, seagrass beds, coastal bays and areas with sandy bottoms, so they have plenty of places to blend in and ambush their prey.

Spotted wobbegongs feed on fish, crayfish, crabs and octopuses, they are formidable predators in their environment. Their camouflage pattern is their main anti-predatory adaptation, to hide from prey and potential threats.

The spotted wobbegong is a great example of how well adapted these sharks are to their environment.

Ornate Wobbegong

The ornate wobbegong is a larger species with a more complex pattern of lines, spots, swirls, and large fleshy lobes on its head. It is less common than the spotted wobbegong but has the same great camouflage.

This bottom-dwelling shark is found in tropical waters. Its nocturnal behaviour and diet are similar to those of the spotted wobbegong. Understanding the different wobbegong species gives us a greater appreciation of their unique features and role in their environment.

Wobbegong Habitat and Distribution

Two species of wobbegongs, the spotted wobbegong and the ornate wobbegong, are found in coastal waters of the Indo-Pacific region, in Sydney Harbour, where they live in coral reefs, rocky reefs and seagrass beds. They are also present in the eastern Indian Ocean, where their natural camouflage helps them blend in with the reefs. As nocturnal ambush predators, wobbegongs wait for their prey, using their camouflage to blend in with their surroundings before striking. They are commonly found in southern Australia, interacting with other sharks, making them perfect for studying their behaviour and role in the marine ecosystem. There are also potential occurrences of wobbegong sharks in the South China Sea, although these records are likely inaccuracies.

Rocky Reefs and Seagrass Beds

Rocky reefs, rocky reef bottoms, and seagrass beds are wobbegong habitats, shelters, and food sources. These underwater structures support a wide range of marine life, and wobbegongs are the top predators in their environment.

By living in these habitats, wobbegongs keep the marine ecosystem in balance, so conservation is important.

Southern Queensland and NSW

In the shallow temperate waters of Southern Queensland and New South Wales, wobbegongs are found on the continental shelves, in inshore waters where rock and weed are prominent. The waters of South Wales are particularly significant for the Spotted Wobbegong and other species, providing diverse habitats around Sydney and the wider New South Wales region. These areas are perfect for living in wobbegong, with plenty of food and habitat to hide and ambush unsuspecting prey.

Wobbegongs in these areas are a testament to their ability to adapt to changing environments.

Ambush Predators: How Wobbegongs Hunt

Wobbegongs use a unique hunting technique, their shaggy beard-like projections as lures to attract prey closer before sucking in any prey within their reach. This suction-feeding technique, combined with their camouflage, makes them very effective ambush predators in their environment.

Wobbegongs are nocturnal hunters and interact with other sharks in the area, which makes them perfect for studying their role in the marine ecosystem.

Interactions with Other Sharks

Wobbegongs are not aggressive towards other sharks. They congregate with preferred partners and live peacefully in their environment. Although I have observed a wobbegong lying on the bottom with a Port Jackson shark tail hanging out of its mouth, it is good to understand their interactions with other shark species to understand their role in the marine ecosystem.

By understanding these interactions, we can see the complex relationships between different shark species and the marine ecosystem.

Human Encounters and Safety

Wobbegongs generally do not threaten humans, yet it’s wise to be cognizant of their presence while diving, especially for scuba divers. They possess sharp teeth that can cause severe lacerations if they feel threatened or are provoked. Sometimes, they might nip at divers unexpectedly, without any clear provocation. Adhering to safety measures and guidelines is crucial for a secure and pleasant diving experience with wobbegongs.

Sydney Dive Sites

Sydney dive sites like Kurnell, Bare Island, Voo Doo, Oak Park and Magic Point are perfect to see wobbegongs in their habitat.

Diving with Abyss Scuba Diving allows you to see these amazing creatures up close while following safety guidelines and precautions. Following the operator’s recommendations, divers can safely experience the thrill of seeing wobbegongs in their natural environment.

Wobbegong Shark Bites and Lockjaw

Wobbegong shark bites can be painful and may cause lockjaw, but are not usually life-threatening. None of the 32 recorded attacks were fatal. Lockjaw is a phenomenon where the jaw muscles become rigid, and you can’t open or close your mouth. It can be caused by tetanus infection, injury or temporomandibular joint disorders.

Wobbegong shark bites don’t always cause lockjaw, but it’s good to be aware of the risks and take precautions to avoid provoking these amazing creatures.

Precautions to take when diving with Wobbegongs

When diving with wobbegongs, divers should remain calm, move slowly and steadily beneath the surface and don’t chase, touch or agitate them. Divers should remember that wobbegongs can bite their own tails, and touching a shark is risky. Divers should also know their surroundings and not accidentally disturb a wobbegong.

Also, follow the operator’s guidelines or briefing, and always be aware of your surroundings so you don’t surprise these amazing creatures. By following these safety precautions, divers can enjoy the thrill of seeing wobbegongs while minimising the risks.

Wobbegong Behaviour around Divers

Wobbegongs are not aggressive towards divers, they are curious and sometimes indifferent to our presence. But remember they have sharp teeth and should not be touched or provoked as this may make them aggressive and attack.

See wobbegongs from a safe distance and let them come to you. This will be a safe and enjoyable experience for both divers and sharks.

Wobbegong Population Decline and Conservation

The wobbegong population has been declining in recent years, with overfishing being the main reason. Accurate identification is crucial, as the Spotted Wobbegong is often confused with similar species like the common catshark. In response to this decline, the government introduced stricter regulations for commercial and recreational fishing in 2008, and the wobbegong population has been rising since then.

Conserving these amazing sharks is important to maintain the balance of the marine ecosystem and to keep the whale as a top predator.

I’ve been diving in Sydney for 30 years, and I used to see a wobbegong on every dive; now I’m lucky to see one in a month of diving.

Reasons for the Sharp Decline and Impact on the Marine Ecosystem

Overfishing is the main reason for the sharp decline of wobbegongs, as predators keep the fish populations in balance in the marine ecosystem. Their decline can have a domino effect throughout the ocean floor food web and lead to an overabundance of prey species, which can then negatively impact other marine life.

Knowing the reasons for the decline is key to implementing effective conservation and ensuring the future of these amazing creatures.

Conservation

Although the wobbegong population is declining, they are not listed as endangered. Recreational fishers have been completely closed out since 2008, and commercial fishers are limited to 6 per day and have a minimum size of 130 cm.

These measures, protected areas and sustainable fishing practices are part of the ongoing conservation efforts to protect these amazing sharks and ensure their future in the marine ecosystem.

Wobbegongs in Sydney

If the current rate of wobbegong loss in NSW continues, they could be a threatened species in 10-20 years. The wobbegong population in Sydney is not protected, but Project Wobbegong and a NSW Government-funded study are underway to learn more about their behaviour and life. Anecdotal evidence suggests that fishing south of Sydney has contributed to the decline of the local population.

With more research and conservation, we may see the wobbegong population in Sydney recover and thrive, ensuring the future of these amazing creatures and their role in the marine ecosystem.

In summary, the world of wobbegongs is an interesting and complex one, with unique adaptations, many species and weird behaviour. As we have seen through this wobbegong journey from their hunting techniques to their interaction with other sharks and humans, these amazing creatures are key to the balance of the marine ecosystem. The ongoing research and conservation of wobbegongs is essential for their future in Sydney and beyond. By learning and loving these fantastic creatures, we can work together to protect and conserve them for future generations.

Are wobbegongs harmless?

Overall, wobbegongs are harmless to humans as they are not aggressive and don’t attack unprovoked.

But still be careful around these predators as their teeth can cause injury if touched or provoked.

Are wobbegongs native to Australia?

Yes, wobbegongs are native to Australia and are found along the southern coast from southern Queensland to southwestern Western Australia.

Are wobbegongs protected in NSW?

After a 50% decline in catch in 10 years, fishing regulations were introduced in 2008. Commercial catch was limited, and recreational fishing was closed for all wobbegong species.

Are wobbegongs poisonous?

No, but their bites can be painful due to their teeth. Don’t touch or provoke them as they may attack if threatened.