As I tried to take a photo of the eight foot long tawny nurse in the cramped confines of the cave, the shark become aware of my presence and started to turn around, using its pectoral fins like hands. It was a tight fit, but the tawny quickly maneuvered its long body and tail, stirring up the sand as it did. With the head of this large shark now pointing towards me, I quickly started backing out of the cave when suddenly the shark shot out of the darkness toward me. I managed to fire off one photo and then had to jump out of the way, almost getting bowled over by this bulky shark before it disappeared from view.
That fleeting encounter with a tawny nurse shark was the highlight of the dive trip for me, and I couldn’t wait to get my slides developed when I got home. After getting my slides back I searched through every image, but no tawny nurse shark. It must have been a great photo because someone at the lab decided to keep it! Fortunately, I have since seen many more tawny nurse sharks and enjoyed some really close encounters with these shy sharks.
The tawny nurse shark (Nebrius ferrugineus) is one of three nurse shark species found in tropical waters, the others being the more common Atlantic nurse shark (Ginglymostoma cirratum) and the rarely seen West African nurse shark (Ginglymostoma brevicaudatum).
The tawny nurse shark reaches a length of eleven feet and is found in tropical waters in the Indo-Pacific region. This species of shark is very easy to identify, being large in size, uniform light brown to grayish brown in color, with tiny eyes, nasal barbels and a rather long tail.
This long tail is the first part of a tawny nurse shark that most divers will encounter, as during the day they spend most of their time resting in caves. They appear to work on the old ostrich ‘head in the sand’ theory, and at times will only have their head covered with the rest of their body exposed. Tawny nurse appear to have
a
home range, and regularly return to the same caves for shelter, either
singularly or in small groups.Taking photos of tawny nurse sharks can be challenging at times, especially when all you can see is a tail. I have encountered dozens of these sharks over the years and have quite a lot of tail photos! They can also be very stubborn, refusing to move from a good hiding position. My old dive buddy Vicky Oakhill once tried to extract one from a small cave by pulling on its tail, but the shark refused to budge. Vicky, always fearless, decided to squeeze into the cave next to the ten foot long shark to try and get it out. But no matter what she did the shark won’t move, just wedging itself deeper and deeper into the cave.
Being nocturnal feeders, tawny nurse sharks are rarely active during the day. However, I had another memorable tawny encounter when snorkelling the Great Barrier Reef off Gladstone. I was snorkelling around a series of gutters which where packed with cardinalfish. Millions of these small fish covered the bottom, and parting them down the center were two tawny nurse sharks. One of the sharks was huge, ten foot long, while the other was only half its size. For several minutes I watched them swim up and down the gutter. This allowed me to position myself at the end of the gutter to take photos of the sharks, before they finally disappeared over the reef edge. It’s possible that the presence of so much food had drawn these sharks from their daytime slumber to enjoy a feast.
Although regular visitors to shark feeds, the only time they are not shy, tawny nurse sharks usually only feed at ni
ght
on fish, octopus, squid, crabs, molluscs, crayfish and even the odd sea snake.
They have one of the most unique feeding methods of any shark as they suck their
prey into their mouth using a vacuum action. This suction is so great it is said
to be able to suck fish out of ledges and even clams out of their shells. They
are also very determined feeders, known to lift heavy coral heads in order to
obtain prey.Tawny nurse sharks mate in shallow water and give birth to live young that develop inside individual egg cases held in the womb. Litters average eight in number, the young being around 16” long at birth and covered with a pattern of sparse spots. Young tawny nurse are rarely seen, hiding in shallow water, deep under ledges.
I have most commonly encountered tawny nurse sharks on Australia’s Great Barrier Reef, but divers also regularly see them off Thailand, Indonesia and Papua New Guinea. As they have a home range they can generally be found at the same dive site on a regular basis.
While tawny nurse sharks only have very small teeth, a number of divers have been bitten by these sharks, either provoked or unprovoked. They also have a tendency to hold on when they bite, so I wouldn’t recommend tangling with a tawny nurse shark.