Plans to protect common rock lobster artificial habitats

As the forestry industry celebrates a record-breaking month for regional wood export, Eastland Port general manager Andrew Gaddum is disappointed that a consent to rebuild aging port infrastructure is being challenged.

The decision to issue consent was made on behalf of Gisborne District Council by three highly regarded and experienced independent commissioners. It grants Eastland Port consent to rebuild 60-year-old wharves 6 and 7 and reshape the derelict 1920s-era slipway.

As outlined in the consent decision the main reasons consent was granted are the social and economic benefits for the Gisborne community.

“We’ve been granted consent to fix wharf 6 and 7 so the port remains functional for the region’s industries – industries that are putting food on the table for thousands of local families,” says Mr Gaddum.

“I’m surprised that a collective group whose submission was heard by the commissioners, should subsequently seek an appeal as the commissioners’ process and decision demonstrates that industry, local government and communities can work together to face any challenges.”

“The region should be reassured by the decision as it helps ensure that forestry, and in time coastal shipping and international container trade, will be economic for the region now and in decades to come. Fixing port infrastructure also offers regional resilience should we suffer a serious earthquake or weather event.”

Mr Gaddum says the consultation and consenting process was thorough. “We were pleased to take part in such a robust process and now we have a workable decision with concessions that take into account submitters’ concerns.”

The port company and the appealing submitter were both concerned about the effect of the wharf rebuild on the artificial habitats frequented by the common rock lobster (Jasus edwardsii).

“Over the years the port has been, and continues to be, supportive when it comes to maintaining the habitat.”

“After about 18 months offshore these creatures, that are commonly found in New Zealand, Australia and the Chatham Islands, drift into many places along the East Coast including the harbour. They stay a few months and then must seek natural adult habitats beyond the shore.

“Some of those that drift into the harbour choose to live for this short period in holes in the papa bedrock under the wharf.  Others settle into artificial habitats called crevice collectors that have been hung in and around the port for the past 30 years by researchers.”

“Crevice collectors are manmade homes for young lobsters using stacks of small squares of marine plywood with gaps between them to form artificial crevices. The collectors make retrieval of the small lobster easier if they’re required for research or numbers are being monitored.”

“We’re mindful that Eastland Port is one of the most accessible places to monitor the rock lobster and that’s why we’re making sure our development plans include more, and better designed artificial habitats and crevice collectors. It’s expected the new homes will appeal to the same numbers, if not more, rock lobster,” says Mr Gaddum.

Mr Gaddum says the consent conditions include the chance to create a Kaitiaki Partnership Group for engagement and collaboration with all tangata whenua so that cultural values can be included in projects and operations.

“The partnership group gives us all a way to formalise the way we work together and we’re looking forward to establishing the role, purpose and functions of the group with the iwi and Council representatives that will be part of it.”

The consent came through just days after Eastland Port broke its monthly wood export record. In August 2018, 316,000 tonnes of wood was swung across the wharves.

“Shifting over 300,000 tonnes of wood in one month represents thousands of hours of work by a massive range of people be it harvest crews, hydraulic mechanics, transport operators, diesel technicians, road workers marshallers and accountants.”

“Everyone involved in the industry can be very proud of their achievement and should be encouraged that with this consent we can now fix our aging infrastructure in readiness for the future.”

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The wharves and slipway

Originally built for fishing boats, wharf 6 will be used to berth Eastland Port tug boats, and in the future, help tie up 200m long log vessels off wharf 7. Meanwhile, wharf 7 will be rebuilt stronger to meet the demands of increasing vessel lengths and depths.

While appearing reasonably robust to the eye, underneath, wharves 6 and 7 are nearing the end of their serviceable life. Cracked pilings, rusting reinforced concrete and obsolete old oil pipes abound under the wharves. In the report the commissioners’ noted: ‘We think it essential that they are replaced so the safety of people and vehicles using the wharves is not eventually put in jeopardy.’

Eastland Port has also been granted consent to reshape the slipway. The slipway needs to be made smaller so Eastland Port can safely manoeuvre two 200m long vessels in port at once. It is currently so degraded that material is being washed off the slipway into the harbour basin on a regular basis.  If not reconstructed or demolished it will start falling to bits. Demolishing the slipway will avoid future adverse effects and it can be replaced by a structure that is more attractive and robust, and one that has no effect on salinity.

Image credit: Brennan Thomas, Strike Photography

Image cCaption: Artificial marine real estate! Eastland Port has always acknowledged the presence of the common rock lobster underneath wharf 6 and 7, and the ease with which researchers can monitor them. To mitigate any disruption to their current artificial habitat Eastland Port is creating custom housing or artificial marine real estate as part of the new wharf structure. In this photo Eastland Port manager Andrew Gaddum holds some very early design ideas by University of Canterbury engineering students. New design ideas prepared by New Zealand crayfish expert Dr Andrew Jeffs involve honeycomb-like homes made from PVC pipe.