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| 50 Owen St, Huskisson NSW 2540, Australia. Ph: 02 4441 6311 Fax 02 4441 5885 |
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| Macquarie University has been conducting
research on dolphins in Jervis Bay since the early 1990's, including
investigations into distribution, abundance, social organisation,
genetic relationships & acoustic behaviour. Current research
on their distribution is being undertaken in conjunction with
Jervis Bay Marine Park & Dolphin Watch Cruises. |
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Where are bottlenose dolphins
found?
Bottlenose dolphins are only one of the 35species of marine
mammals that live in Australian waters. There are a total
of 70 species of dolphins & whales worldwide. They
are found from cooler temperate to tropical waters &
while they are often seen frolicking in bays & lagoons
just like Jervis Bay, they are also sighted quite a distance
offshore. |
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What are their feeding habits?
Bottlenose dolphins are skilled hunters that eat a variety
of foods, including fish, squid,
octopus & eels. They may consume about 8 kg of food
a day. Dolphins do not chew their prey, they generally
eat it head first & whole. |
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What is their breeding cycle?
Female dolphins generally begin to breed when they are
between 8 & 14 years of age, In males, sexual maturity
is reached by the age of 10 years-. Gestation takes about
12 months, & a single calf is born, usually in the
warmer months. |
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Mammals or fish?
Dolphins & whales (scientific name: cetacea) are all
warm blooded, air breathing, give birth to live young,
suckle their young with milk & have hair follicles!
Yes, believe it or not, when dolphins are born they have
hair follicles on either side of their rostrums (or beak).
It is thought that the hair assists the calves with feeding. |
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How do we recognise the dolphins
in Jervis Bay?
Dolphins can be individually recognised by unique features
on their dorsal fins such as nicks &
scars. These scars may arise through fighting & at
times, sharks & close encounters with boats! Researchers
are able to recognise individual dolphins by photographing
their dorsal fins, which is similar to our fingerprint. |
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What is the size, shape & family
history of the Jervis Bay dolphins?
Just like people, dolphins vary in size, shape & colour
between individuals & geographic location. At birth,
dolphins are usually less than 1 m in length & weigh
only about 10kg. Adult male dolphins can grow to about
2.5 metres & up to 200 kg, while the females are slightly
smaller in both length & weight.
Dr. Luciana Moller from the Macquarie University Marine
Mammal Research Group has used molecular methods to show
that the dolphins in Jervis Bay belong to the inshore
species of bottlenose dolphins (Tursiops aduncus). Tursiops
aduncus is generally smaller in size than the offshore
bottlenose dolphin of television fame Flipper, which is
the closely related Tursiops truncatus. |
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How many dolphins live in Jervis
Bay?
Based on photo-identification research by Dr. Luciana
Moller, it has been determined that around 80 dolphins
regularly reside in Jervis Bay, with occasional visits
from dolphin groups from outside Jervis Bay. |
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Do dolphins sleep?
Dolphins don't actually sleep as we do, but have ‘cat
naps' where they rest one half of their brain
at a time. |
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| How can I be careful when watching
dolphins by boat?
Watching dolphins in their natural environment is exciting
& enjoyable. However, without due care watching dolphins
may disturb or harm dolphins by introducing underwater noise,
pollution or even causing physical injury. Undue stress to
the dolphins can result in disruptions to their behavioural
patterns. Dolphin watching in Jervis Bay follows Guidelines
developed by the Australian & New Zealand Environment
Conservation Council. These guidelines describe a cautious
way to watch dolphins without disturbing them.
When on the water, please observe the following:
- Only approach dolphins from the side.
- Stay at least 50m away.
- Don't approach if there are any small calves.
- If the dolphins are showing any sign of disturbance, then
move away slowly.
- Minimise changing gears & reversing.
- & finally... enjoy & learn!
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Where do they live in Jervis Bay?
Resident Jervis Bay dolphins generally inhabit areas where the
water depths are less than 20 metres & primarily close to
shore. They are found in a variety of habitats that include
sea grass meadows, soft sediments & around rocky outcrops. |
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Where can I find out more about dolphins
& current research in Australia?
Marine
Mammal Research Group
Uni
of Sydney's Veterinary Education Information Network Marine
Mammals Links
Facts
about Dugongs
Behavioural
Ecology of the Bottlenose Dolphin in SE Queensland
Leatherwood, S. & Reeves, R. (1989). The Bottlenose Dolphin
. Academic Press, San Diego.
Harrison, Sir R. & Bryden, M. (1988). Whales, Dolphins &
Porpoises. Golden Press, Sydney.
Mandelc, F.G. & Fairweather, P.G. (1995). Jervis Bay:A Place
of Cultural, Scientific & Educational Value. Australian
Conservation Agency, Canberra. |
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By Michelle Lemon & Luciana Molle,
Marine Mammal Research Group
Macquarie University Sydney Australia |
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| "Free return cruise if no dolphins are sighted
on a dolphin cruise" |
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| 50 Owen St, Huskisson
NSW 2540, Australia. Ph: 02 4441 6311 Fax 02 4441 5885 |
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