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Kahawai - Letter to Marine Conservation Unit
option4
7
July 2004
After meeting with Felicity
Wong, manager of DoC's Marine Conservation Unit, in Whangarei at
the NZRFC conference we decided to compile a letter expressing our
concern that the Department of Conservation had done very little
to protect the interests of seabirds and kahawai in the inshore
ecosystem by not submitting to the process to introduce kahawai
into the QMS.
A copy of the option4/NZBGFC/NZACA submission
was sent with this letter in an effort to give DoC some understanding
of our concerns regarding the interaction between seabirds and kahawai.
Felicity Wong
Manager
Marine Conservation Unit
PO Box 10 420
Wellington
July 7, 2004
Kahawai and seabird
interaction
Dear Felicity
It was good to meet you at
the NZRFC annual conference in Whangarei last weekend.
At the conference you stated
that seabirds and marine mammals are the core business of the DOC
Marine Conservation Unit. We believe DOC has missed a critical opportunity
to provide information and advocate for the importance of kahawai
in the complex inshore ecosystem.
We also believe there is
an urgent need for the Department to brief the Minister of Conservation
on the critical role of kahawai in the inshore ecosystem and to
encourage a precautionary approach to the management of this species
by the Minister of Fisheries. It was heartening to hear your views
on the close relationship between the current Ministers of Conservation
and Fisheries.
It is our position, since
the Minister of Fisheries has already determined that kahawai will
be managed as a QMS species, the TACC for kahawai should be set
at a bycatch level. This would effectively discourage the targeting
of kahawai schools by purse seine vessels. More detail of this aspect
is contained in our submission to
MFish (attached).
We believe the viability
of flocks of seabirds have been jeopardised in the pursuit of kahawai
by the purse seiners. We estimate up to 4000 schools of kahawai
have been targeted and removed from our waters. And still the Ministry
of Fisheries is suggesting the stock could be reduced by another
60%. This is unsustainable in our opinion, both for kahawai stocks
and the birds that depend on their schooling activity to provide
them with a source of sustenance.
Kahawai are also a source
of food for bottlenose dolphin and orca, animals that the Department
has a keen interest in.
Seabird interaction
with kahawai
Kahawai are one of the few inshore fish that push krill and small
fish to the surface where seabirds can reach them. The absence of
kahawai schools is most often noticed by the lack of flocks of white-fronted
terns (also called kahawai birds), whose darting and diving feeding
flight can be seen at a distance. The white fronted tern is an endemic
species that breed only in New Zealand, though they may spend time
in Australia. It is described as especially common around the northern
coasts of the North and South Islands. Shearwaters and red-billed
gulls also interact with kahawai schools.
Birds that have a strong
symbiotic relationship with kahawai around East Cape are Fluttering
and Bullers shearwaters ( Puffinus gravia, P bulleri ).
Sadly they are rarely seen with gannets when a kahawai school emerges
now. It seems seabirds are a much less common sight in northern
New Zealand as well, both in the air and at the once packed rocky
roosts.
The ability of kahawai to force baitfish to the surface is important
for birds which breed during winter. These birds include the grey-faced
petrel (Pterodroma macroptera), which breed on the offshore islands
around the upper North Island and the rare Westland petrel (P westlandica)
whose population is estimated at only 2000-5000 pairs. The Fairy
prion (Pachyptila turtur) return to nest sites in the Poor Knights,
Cook Strait and Foveaux Strait areas in May and June and the Little
shearwater (Puffinus assimilis) inhabit the upper North Island.
Less kahawai schools has to have an impact on the potential of these
birds to feed their offspring.
We are not aware of any study that has been conducted to examine
the relationship between food availability and nesting success of
seabirds but it's obvious that the more difficult it is for the
parents to obtain food the less chance there is of the chicks fledging.
There are other rare inshore seabirds that rely on kahawai such
as the rare native Caspian tern (Sterna caspia) and the critically
endangered Fairy tern (S neresis). A strong kahawai stock will increase
the chances of breeding success and survival of all these bird species.
A school of surface feeding
kahawai will attract a flock of birds that may "work" an area of
baitfish or krill for hours. It also can attract the aerial spotter
planes used by purse seine boats to locate school fish. Removing
an entire school of kahawai with a single purse seine shot destroys
the bird/fish interaction instantaneously and the dependent species
are displaced from the area. Under the current Ministry policy,
fishing stocks down to 20% of the virgin biomass is encouraged,
as this is the stock size that will support the Maximum Sustainable
Yield. If 80% of kahawai schools are gone then dependent species
like seabirds will have to expend at least five times as much energy
searching for food sources made available by kahawai. Kahawai tend
to move to core areas of preferred habitat. In a depleted population
kahawai may seldom be found in areas where they were once common.
Seabirds in many areas may not be able to reach their food supply
at all from nesting sites distant from the core areas.
Kahawai in the food
chain
Larger kahawai form an important link in the inshore food
chain, feeding on plankton and small fish such as anchovy and pilchard,
and in turn become prey to larger fish. Dolphins, including the
endangered Maui dolphin feed on kahawai. Considerable effort has
gone into protecting this species including a set net ban on the
west coast of the North Island. It would be appropriate for the
Minister of Fisheries to ban purse seining from the same area.
Submissions
We have completed our initial analysis of the submissions
made in respect of the introduction of kahawai into the QMS. Of
the submissions made by four commercial interests no reference was
made regarding the impact of fishing for kahawai on seabirds. The
majority of the 2000 individual submissions made online via the
option4 website, that included comments, mentioned the impact of
bulk methods on their fishing experience including the declining
numbers of seabirds.
It was notable the only
reference made to the seabird interaction was from non-commercial
interests and the two conservation boards who made the effort to
submit, Northland and Bay of Plenty.
Summary
These are just some of our
concerns regarding the seabird/kahawai connection but there are
more. Despite our best efforts to work with and gather information
on this subject from other groups with an interest in the environment
we failed to get any data from DoC, Forest and Bird, Auckland Regional
Council, Ornithological Society of NZ, Ecoquest or ECO. Although
disappointed with the lack of response, the opportunity to work
with these groups in the future remains.
The impending allocation
decision for kahawai will have a significant impact on the sustainability
of kahawai.
We look forward to maintaining
contact and are particularly interested in meeting with you and
your new colleague familiar with fisheries management in the near
future.
Yours sincerely
Trish Rea and Scott Macindoe
On behalf of the team at
option4
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