There’s a dive site at Rottnest Island known as The Nurses Quarters. It’s believed to be a congregation or breeding site for Grey Nurse Sharks. I’ve dived it a few times over the years and always love it. We ventured back there again on the weekend to find at least eight sharks swimming back and forth through the cave. Being in the water with these beauties is truly amazing!
There are two population groups of Grey Nurse Sharks in Australia, the critically endangered east coast population and the vulnerable west coat population. Grey Nurses look fierce with row upon row of ragged teeth but they are considered harmless and placid. Due to their fierce appearance, they earned an underserved reputation as a maneater and were hunted extensively in the 50’s and 60’s. Today, Grey Nurses are protected and a recovery plan is in place to grow their numbers.
Like many sharks, Grey Nurses are slow to mature and reproduce, with male sharks reaching sexual maturity at 4 – 6 years of age, and females at 6 – 8 years. Both males and females mature at about 2.2 m and reach a total length of about 3.6m. The breeding of Grey Nurse Sharks is quite unusual. Mating occurs mainly in autumn and is followed by a 9 – 12 month gestation period and the young are born in winter. Towards the end of the gestation period, the more fully developed embryos eat the less developed embryos and unfertilised eggs within the female shark’s uterus. As a result, only two pups are produced per litter – one in each uterus. Grey Nurse Sharks tend to breed only once every two years. This is the lowest reproductive rate of any shark and makes it more susceptible to external pressures that increase mortality. Read more here.
Part of what I love about diving and underwater photography is identifying the animals and learning more about their habitat, distribution and behaviour. Diving with the Grey Nurse Sharks is such a pleasure and I hope they are around for many more years to come.