The Department of Conservation has begun work on setting up a monitoring programme at the Poor Knights Islands Marine
Reserve, following a recent oil spill that reached its internationally recognised waters.
Auckland University marine researcher Russ Babcock visited the marine reserve twice during the week following the spill,
and said at this stage a number of organisms appear to have been affected.
The Northland Regional Council funded his initial work following the spill, although DoC is planning to follow this up
with a general monitoring programme that will also look at impacts of anchoring and diving at the marine reserve.
Dr Babcock visited the Poor Knights on the Monday 6th December three days after the spill, and investigated sites in
Rikoriko Cave and in Jan’s Tunnel, both popular dive sites located on the western side of Aorangi Island.
He observed that barnacles and coralline algae were the main organisms found living on the affected section of walls in
Rikoriko Cave, with barnacles in particular, fouled with oil during his first visit. Many of the barnacles were heavily
fouled but remained closed and it would be difficult to determine the degree to which they were affected by the oil, Dr
Babcock said.
Dr Babcock accompanied DoC staff for a return visit to the marine reserve last Friday and said it appeared that the
clean-up in Rikoriko Cave in particular had been very successful. The main organisms that remained visibly affected in
this area were the bryozoans, on which globules of oil could be seen on their fine branches.
Dr Babcock said the prognosis for this cave were good although he recommended a repeat visit be made to check the sites
he had photographed as part of his initial monitoring. He said he expected the encrusting communities to recolonise the
fouled areas over the coming months after the affected organisms died and fell off the walls.
It was uncertain how long this recovery process would take as there is not much information on the growth rates and
dynamics of these marine communities.
A wide band of oil remained at the back of Jan’s Tunnel, although a decision was made that the cleaning process was
likely to do more harm than good in dislodging the organisms living there as well as any oil sticking to them.
DoC senior conservation officer Keith Hawkins said Dr Babcock’s work was likely to become part of a more extensive
monitoring programme that would include looking at impacts of diving and anchoring.
Dr Babcock is also currently working on a monitoring project to determine whether full protection of marine life in the
reserve is leading to changes in reef fish composition and abundance.
An initial survey was carried out in September 1998 prior to the reserve being closed to fishing.
Mr Hawkins said DoC would be spending time on and under the water during the coming summer season to monitor activities
at the Poor Knights and asks that any unusual activity be reported.
“Naturally we can not be out there all the time although we would encourage the public to report anything out of the
ordinary to us as soon as possible,” Mr Hawkins said.
DoC has also produced an information sheet on the region’s protected marine areas and islands for distribution to
boaties during the summer season. These will be distributed from a number of points around the region including customs
offices, boating and dive shops and visitor centres.
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