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Published in Diver Magazine UK October 2020

THE LEOPARD'S LAIR
by Nigel Marsh

The Leopard Shark would have to be one of the most beautiful of all the sharks. They are big, docile and exquisitely decorated with a wonderful spotted skin pattern. But encounters with these sharks are quite rare, unless you visit - the Leopard’s Lair.

The Leopard Shark (Stegastoma fasciatum) or Zebra Shark as it is sometimes known, is the only member of the family Stegostomatidae and is easily identifiable by its leopard-like skin pattern and by the ridges that run along its body. These sharks also have an exceptionally long tail, which is almost as long as their body. Leopard Sharks reach a maximum length of 2.5m, although many shark books inaccurately state 3.5m.

Leopard Sharks are oviparous, laying large leathery egg cases, but very little is known about their reproductive behaviour. These sharks reach maturity at about six to seven years of age, but their reproduction strategy may be more bizarre than ever suspected as a female Leopard Shark in a Dubai aquarium was recently documented as cloning itself, laying eggs that hatched without any prior mating, with the young sharks having identical DNA to the mother. Young Leopard Sharks have a zebra-like skin pattern, hence the other common name, and reach adult size in approximately two years.

Leopard Sharks are most often seen resting on the bottom throughout the day and are thought to feed at night. They have rows of small teeth set in powerful jaws and feed on molluscs, shrimps, crabs and small fish. They are found in tropical to subtropical seas in the Indo-West Pacific region, from South Africa to Japan and the northern half of Australia to Samoa.

Most shark books label the Leopard Shark as rare or only locally common, and there are only a few places where you can guarantee a sighting. But one place you can see them is Australia. Now Leopard Sharks can occasionally be seen on Ningaloo Reef in Western Australia and also on the Great Barrier Reef, but the best place to see these sharks is around southern Queensland and northern New South Wales, a small stretch of coastline I call the Leopard’s Lair.

IMAGE BELOW - TWO LEOPARD SHARKS AT MANTA BOMMIE

I first become aware that Leopard Sharks were seen in the area when I moved to Brisbane in 1990. Local divers told me that they see them regularly, but after a year of diving a variety of local sites I hadn’t seen any. That was until April 1991 when I received an excited call from a friend Kev Russell, saying he had found a new dive site that day with resident manta rays.

The next day I was heading out to a spot that is now called Manta Bommie off North Stradbroke Island. Within seconds of hitting the water I saw a large Reef Manta Ray. I followed it for several minutes until I spotted four Leopard Sharks lazing on the bottom. The manta forgotten, I headed for the much rarer sharks.

Four Leopard Sharks lying side by side, I couldn’t believe my luck. In a dozen trips to the Great Barrier Reef I had seen only a handful of Leopard Sharks, and never more than one at a time. I took several photos of the closest shark before it lifted off the sand, also disturbing two of the other sharks. The fourth shark remained in place allowing me to capture many close photos. Over the next 45 minutes I was to photograph manta rays, shovelnose rays, eagle rays, turtles, stingrays, wobbegongs, and more importantly for me, a dozen Leopard Sharks in only 6 to 15m of water.

This dive site was something special, especially for someone that loves photographing sharks and rays, so every chance I got I dived Manta Bommie. For the next month there were Leopard Sharks everywhere, resting in the gutters and out on the sand. On one dive I counted over twenty sharks, they were all over the bottom, looking a bit like large speed bumps. However, by the beginning of May the Leopard Sharks had suddenly disappeared!

Over winter there were no Leopard Sharks to be seen, I didn’t know where they had gone, but suspected that they didn’t like the cooler winter water.

By November the waters off Brisbane had started to warm again and the Leopard Sharks were back again in force at Manta Bommie. Where they had gone for their winter holiday was a complete mystery; had they headed north to warmer water or had they gone into deep water?

That summer, after numerous dives at Manta Bommie, Kev mentioned to me that Leopard Sharks were sometimes seen at nearby Flat Rock. Flat Rock is a deeper dive site with coral gardens and steep walls in 10 to 36m of water. I had done several dives at Flat Rock and never seen a Leopard Shark so was curious to follow up on Kev’s comment. We moved the boat over to Flat Rock, jumped in on the western side and enjoyed a lovely dive, but no sharks.

At the end of the dive we headed into the shallows to do a safety stop. The water was very clear, 30m visibility, and staring into the distance I was surprised to see a Leopard Shark swimming around in shallows. Following it through a gutter I saw another leopard, then another and another. There were around a dozen Leopard Sharks swimming around in the shallows, no wonder I hadn’t seen them here before as I had never spent time in these shallow gutters.

Not having my camera with me, I stopped and studied what was happening. The sharks weren’t just swimming around they appeared to be following each other. It was then that I noticed that it was the males following the females, could this be a mating aggregation? All of the sharks were quite large, over 2m long, and there appeared to be an even ratio of males to females.

IMAGE BELOW - DIVER AND LEOPARD SHARK

In the summers of 1992/93 and 1993/94 I again dived with the Leopard Sharks as often as I could. They could always be found at Manta Bommie during the season, November to April, but not always at Flat Rock.

In February 1994, rumours of leopards saw me heading 100km south to northern New South Wales to dive Cook Island off Tweed Heads. Going no deeper than 15m I had a great dive and found a dozen Leopard Sharks resting on the sand. After the dive I was informed by local divers that Leopard Sharks were always seen in the area over summer, and not only at Cook Island, but also at nearby Nine Mile Reef and Fido Reef.

With further research I also discovered that over the summer months they are also found in good numbers another 80km further south at Julian Rocks off Byron Bay. While north of Brisbane the next main sites they were found at was Wolf Rock and Round Bommie off Rainbow Beach, 200km north.

It was then that I realize that southern Queensland and northern New South Wales was a hot spot for Leopard Sharks, a 400km stretch of coastline - the Leopard’s Lair. Nowhere else in the world was there such a concentration of these wonderful creatures and no one seemed to realised it at the time.

In December 1994 I received a phone call from Scott Michael, an American marine biologist, shark expert and author of the great book ‘Reef Sharks and Rays of the World’. Scott was in Western Australia photographing wobbegongs and was chasing me for some shark photos. I mentioned the local Leopard Sharks to him and the possibility of a mating aggregation in the region. He promptly cancelled a trip to the Great Barrier Reef and came to Brisbane the following week.

Scott arrived very eager to see a Leopard Shark, he actually had a drawing of a Leopard Shark on his business card, but had never seen one in the wild in all his travels around the world in search of sharks. With rough conditions at Manta Bommie we headed to Flat Rock, but after 20 minutes we had found only one shy shark. I then saw two Leopard Sharks swimming off in the distance. We followed and once over a ridge found ourselves at the rarely dived northern end of the island, and with dozens of sharks swimming around us. We promptly returned to the boat and relocated to the northern end of the island.

Changing tanks, we quickly descended to be surrounded by Leopard Sharks. Some were swimming along the bottom, others in mid-water, and even a few were close to the surface. With 20m visibility I did a quick head count as I turned around and counted over 30 sharks in view, so estimated that there was at least 50. This was the greatest concentration of Leopard Sharks I had yet seen.

After a few minutes observing the sharks it soon become apparent that this was a mating aggregation. The ratio of females to males was even, but watching the sharks I soon saw the following behaviour again. Whether in pairs or groups it was always a female followed by one or more males. All the males looked sexually mature, with long battered claspers.

I watched one pair winding up the reef, the male very close to the female, almost like a pair of synchronized swimmers. The female then gave a shudder and stopped in mid-water, which allowed the male to put his nose close to her cloaca. This lasted only a second before she continued up the reef with the male in hot pursuit.

For the entire dive I was completely absorbed watching these beautiful sharks. I had hoped to observe some mating, but after an hour we exited the water without seeing any contact between sharks. After the dive Scott and I were both ecstatic, and in agreement that this was a mating aggregation. But when were they mating? At night or in deep water? I still don’t know.

IMAGE BELOW - LEOPARD SHARKS ARE VERY DOCILE

I wrote several articles after that amazing experience with the Leopard Sharks at Flat Rock, which finally let the cat-out-of-the-bag and attracted the interest of research scientists. In 1999 a tagging program was started but never completed. I saw a few of these tagged sharks, but as most of the tags were quickly fouled by algae growth, they became useless to science as they were completely unreadable.

In 2003 Dr Christine (Chris) Dudgeon, from the University of Queensland, began a more comprehensive study on the Leopard Sharks of Manta Bommie to better understand the migratory movements and genetic effective population size. Using photo-identification, as each shark has a unique spot pattern, Chris was able to identify 388 sharks at Manta Bommie, with some of the sharks recorded multiple times over a twelve-year period. Recreational divers had a big hand in this research providing images to a Spot the Leopard Shark project. Modelling done by Chris estimated a local population of approximately 460 Leopard Sharks using the Manta Bommie site.

Chris and her team tagged a number of sharks, to confirm that the spot patterns didn’t change over time. They also fitted 18 sharks with acoustic tags, and receivers placed at sites along the east coast of Australia told them that the sharks headed north to warmer water over the winter months as suspected, off Hervey Bay, Bundaberg and Gladstone, but one shark was even recorded travelling 1300km to Townsville. Most of these sharks returned to Manta Bommie the following summer, but some ventured even further south to the Solitary Islands off Coffs Harbour, approximately 400km south of Brisbane.

Chris and her team also found that the sharks preferred a water temperature above 22°C, quickly disappearing if the water cooled, and they also don’t like rough conditions, moving on if seas are greater than 1.5m. Why they aggregate at Manta Bommie is still not clear, it is obviously a day time resting spot, but they may also gather here to mate and feed.

While the research has unlocked a little of the secret world of Leopard Sharks, there is still much that remains a mystery about these lovely sharks. I now eagerly await each summer for the sharks to arrive in local waters and spend much of my time searching for Leopard Shark eggs and juveniles, but am yet to find any of these locally and suspect that both are in warmer northern waters.

I have travelled the world to photograph sharks, but feel very fortunate to have the very unique Leopard’s Lair right on my doorstep.

IMAGE BELOW - LEOPARD SHARKS HAVE UNIQUE SPOT PATTERNS