16 Apr 2007 - By Jen Riches*
- Population fragmentation. It doesn’t exactly
pack the same punch as “extinction”. But
for New Zealand’s South Island Hector’s
dolphin and North Island Maui’s dolphin
— one of the rarest marine dolphin species
in the world — it could be catastrophic.
“Numbers of Hector’s and Maui’s dolphins
are now so low that populations are starting
to fragment,” explains marine biologist
Dr Steve Dawson, associate professor at
New Zealand’s Otago University.
“As populations shrink you get small groups
of dolphins which are isolated from each
other and they literally become fewer and
further between. Lose one of those surviving
groups and you lose a vital link to the
next.”
Dubbed the “kiwis of the sea”, Hector’s
dolphin numbers (both North Island and South
Island populations) have plummeted from
over 26,000 in the 1970s to just over 7,000
today. Maui’s dolphins, a subspecies of
the Hector's, are faring even worse and
are now critically endangered with a population
of just 110 individuals. Without immediate
protection, Maui’s may become extinct within
a generation.
Fragmentation is the path to extinction,
according to marine scientists, and for
the Maui’s in particular, this is a very
real possibility.
“These animals don’t range very far, so
as the distance between groups grows, the
chances of those groups interacting, breeding
and surviving becomes more remote,” says
Dr Dawson. “The reality is their future
survival is dependent on our actions today.”
Close to shore
Maui’s dolphins live off the west coast
of New Zealand’s North Island, and are usually
found in isolated pockets within 10km of
the shore. During summer they are even closer,
moving to within 1.85km (1 nautical mile)
of the coast in search of food.
Although found so close to shore, tracking
Maui’s dolphins by sight remains problematic.
Aerial surveys and sound recordings are
more reliable methods and are currently
being used to find out more about this critically
endangered dolphin.
Recent sound recordings of the Maui’s dolphin
conducted by Dr Dawson and other scientists
from the University of Otago are providing
new information about the Maui’s presence
in harbours.
“We now have scientific evidence to support
the argument that Maui’s really are at risk
of drowning in nets being used by fishers
in harbours along the North Island’s west
coast,” said WWF-New Zealand marine campaigner
Rebecca Bird.
The results will contribute to learning
more about the dolphin’s’ distribution and
abundance and use of harbours, and will
be used in WWF’s advocacy work, which seeks
greater protection for the species.
Public sightings
WWF, with help from researchers and Toyota
New Zealand, has also developed a WWF Sightings
Network in order to learn more about the
dolphins’ movements from season to season.
Data generated for the network by the public
provide vital information that can be used
to determine future research and management
priorities, and returns responsibility for
Maui’s back to the community.
“We believe people have an important role
to play in saving Hector’s and Maui’s dolphins,”
Bird explains.
“The information we get from the public
tells us where the dolphins are from season
to season. At the end of the day, the responsibility
for saving these iconic animals lies with
all of us.”
Returning from the brink
Fishing in coastal areas is seen as the
biggest threat to the dolphins, where they
become entangled and drown in commercial
and recreational set nets, or caught as
accidental bycatch in fishing trawlers.
Add to this boat strikes, disturbances from
tourism and increasingly polluted waters,
and survival for the world’s rarest dolphins
is a losing battle.
To reverse the trend, WWF has been working
to reduce the threats so that the species
can return from the brink of extinction.
“Our conservation challenge to the New
Zealand government calls for an action plan
for the recovery of the species, to address
the causes of the dolphins’ decline,” says
WWF-New Zealand Executive Director Chris
Howe.
“We envision a future where Hector’s and
Maui’s dolphin numbers increase, where they
recover to their natural historic range
and where population fragmentation is reduced.
That means ending fishing-related bycatch,
protecting their habitats and reducing marine
pollution.”
By law, the New Zealand government is required
to protect its native flora and fauna. Although
the government has introduced interim protection
measures and set net bans are in place in
some areas, it has yet to develop a comprehensive
action plan for the dolphins’ recovery.
“If we are serious about saving the species,
we can’t deal in half measures,” stresses
Howe. “We need a total ban on set netting
and trawling where the dolphins range.
“We still have a chance to save these unique
creatures,” he adds, “but we have to act
now to make sure New Zealand doesn’t become
the first nation to drive a marine dolphin
species to extinction.”
* Jenny Riches is a Press Officer at WWF-New
Zealand.
+ More
Banning ship waste in the Baltic
19 Apr 2007 - Helsinki, Finland – With
the summer holiday season rapidly approaching,
WWF is calling on shipping companies operating
in the Baltic to protect the marine environment
by halting the practice of dumping polluted
waste water into the sea.
According to the global conservation organization,
cruise ships and ferry boats operating in
the Baltic Sea carry up to 80 million passengers
annually. Overall shipping activity is expected
to increase significantly in the coming
years.
Polluting the waters
Waste water released from shipping vessels
currently discharge up to 460 tons of nitrogen
and 150 tons of phosphorus into the Baltic
each year, contributing to large-scale toxic
algal blooms and a reduction of water quality.
Waste from ships also carries bacteria,
viruses and other pathogens, as well as
detergents and heavy metals.
“The discharge of waste water from ships
poses a serious threat to the Baltic Sea’s
marine environment and coastal areas,” says
Sampsa Vilhunen, head of WWF-Finland’s Marine
Programme.
“Knowing how sensitive the Baltic is, there
is simply no excuse for allowing the continued
untreated discharge of waste water directly
into the sea. Since many countries already
forbid small pleasure boats to discharge
their waste, it hard to believe that we
do not hold these enormous cruise and ferries
to the same standard.”
Discharge ban needed
WWF is urging the shipping industry operating
in the Baltic Sea to voluntarily commit
to a ban on all waste water dumping at sea,
including international waters where it
is currently legal — and to certify that
waste is either properly treated on board
or disposed at onshore facilities.
“By making a pledge to stop discharging
waste into the sea, shipping companies can
show just how serious they are about protecting
the Baltic’s unique marine environment,”
says Lasse Gustavsson, Director of WWF’s
Baltic Ecoregion Programme.
In June 2007, WWF will publish a list of
companies that have agreed to the voluntary
ban, setting an example for others to follow.
END NOTES:
• Eutrophication is a process where bodies
of water, such as lakes, estuaries, or slow-moving
streams, receive excess nutrients that stimulate
excessive plant growth. This enhanced plant
growth, or algal bloom, reduces the water’s
oxygen supply. This can lead to the death
of marine life, including fish species.
• WWF’s Baltic Programme works to decrease
the amount of nutrients entering the Baltic
by promoting best practices for sustainable
agriculture, the reduction of harmful EU
subsidies and the restoration of wetlands.
Lasse Gustavsson, Director
WWF Baltic Programme
Dr Sampsa Vilhunen, Head of Marine Programme
WWF-Finland
