Download Marine mammals of the Hauraki Gulf

Marine mammals
of the Hauraki Gulf
Auckland
Whales and dolphins
Whales and dolphins abound in the waters of the
Hauraki Gulf, and are all protected under the Marine
Mammals Protection Act, which is administered by the
Department of Conservation (DOC).
Common dolphin
T. Greene
Auckland Conservancy
Published by
Department of Conservation
Christchurch
2006
RS0009
More than 22 species of whales and dolphins have
been recorded in the gulf. Common and bottlenose
dolphins, Bryde’s whales and pilot whales are the
most often sighted, with sei and minke whales also
seen. Humpback whales pass through on their way to
the Antarctic in summer and on their return in winter to
their tropical breeding grounds in the South Pacific.
Bryde’s whales are the most commonly seen whale
in the gulf. They are often found feeding on ‘boilups’ of fish with schools of common dolphins and
seabirds. Research is being carried out to increase
our knowledge of this species, which live around the
northern coast of New Zealand for most of the year.
Orca (killer whales) visit the Gulf in small pods of
5–15 animals, and sometimes venture into the
Waitemata Harbour. These distinctive black and white
toothed mammals, which are the largest member
of the dolphin family, are often recognised by their
long narrow dorsal fin that can measure up to 1.8
metres high. They can be seen close to shore hunting
stingrays and eagle rays in the shallows. Long-finned
pilot whales, common in the outer gulf, are also
occasionally seen closer to shore.
Behaviour you may see
Bow-riding is when dolphins ride the pressure wave
formed by the bow or stern of a boat.
Whales are often spotted from boats when they blow
a spray of water as they exhale at the surface, also
called a spout.
Fluking is when a whale raises its tail before a dive,
which may be proceeded by a distinct raising of its
back near its dorsal fin.
Whales also use body language to communicate with
tail slaps and swipes often used for intimidation. In a tail
slap, the flukes are slapped against the surface of the
sea, while in a swipe the whale flings the tail and flukes
sideways out of the water.
A pec slap is when the whale is lying on its side or back
and hitting the surface of the water with one or both
pectoral fins.
was at Whangaparapara on Great Barrier Island. This
was closed in 1962 after the nationwide moratorium on
whaling ended more than 200 years of whaling in New
Zealand waters.
In 1946 New Zealand was one of the founding
members of the International Whaling Commission
(IWC), established to manage the world’s whale
resources. In 1982 the IWC voted for a moratorium
on commercial whaling and in 1994 established the
Southern Ocean Whale Sanctuary. Combined with the
Indian Ocean Sanctuary established by the IWC in
1979, almost a third of the world’s oceans are now a
whale sanctuary.
All marine mammals within New Zealand’s Exclusive
Economic Zone are protected under the 1978
Marine Mammals Protection Act, and New Zealand
is recognised as a world leader in marine mammal
protection.
Threats to whales
in the Hauraki Gulf
Breaching is when a whale leaps out of the sea into the
air, rotating and landing on its back or side, or forward
in a chin-slap.
A spy-hop is when a whale raises its head above the
surface to expose the eyes, usually for taking a look
around.
Logging is when whales lie at the surface resting
between dives.
Feeding behaviours often seen include skimming and
lunging movements above and below the surface.
Mating behaviours can include all of the above, and
time of year and context usually determine whether
surface behaviour is for mating or feeding.
From whaling to protection
Whalers and sealers were among the first Europeans
to arrive in New Zealand, with the first shore-based
whaling stations established in the late 1820s. In 1839,
the peak year for New Zealand whaling, 200 whaling
ships were working the coastal waters, but whaling
quickly declined due to over-exploitation.
The last operating whaling station in the Hauraki Gulf
Any boat can be a threat to the well being of whales
and dolphins. A number of whales have been struck
by ships and killed in the Gulf. Whales have also
arrived in the Waitemata wrapped around the bows of
container ships, including the 20-metre pygmy blue
whale whose skeleton hangs in Te Papa, the Museum
of New Zealand, in Wellington.
If out on the water, please keep to the following
guidelines to help protect our whales and dolphins:
Responsible whale watching
•
Do not disrupt the normal movement or behaviour
of whales and dolphins, or assume they will move
out of the way.
•
It is illegal to approach closer than 50 metres to
a whale. This increases to 300 metres if there are
already three boats close.
•
Any approaches to whales and dolphins should be
made parallel to, and slightly to the rear.
•
Do not throw food or rubbish near whales and
dolphins.
•
•
Do not swim with juvenile animals.
Any whales or dolphins accidentally struck or any
dead carcass should be reported immediately to
the Coastguard on VHF Channel 16. Ask them to
notify the Department of Conservation. Please also
report any whale or dolphin strandings.
Further information
More detailed information on marine mamamals in
the Hauraki Gulf is available from DOC offices in
Auckland, Warkworth and Great Barrier, and the DOC
Visitor Centre in the Ferry Building on Quay Street,
downtown Auckland. Also check the DOC website –
www.doc.govt.nz
Orca
DOC