Faecal bacteria turn up in harbour

A109 Light Utility Helicopter flight with mayor Gisborne City from the air in November 2023.

A TEST of the smelly discharge into Gisborne’s harbour two weeks ago shows a high count of faecal bacteria. The day after the event, Gisborne District Council said the discharge, accompanied by a foul stench that disturbed many at the Gisborne Tatapouri Sports Fishing Club Christmas celebration, was traced to stormwater from the log yard in Crawford Road.

However, independent test results from samples collected by environmental monitoring and laboratory testing company Hydro-Technologies Ltd (HTL) at the site of the discharge into Gisborne’s inner harbour have become available to the public.

HTL used to do all council testing and monitoring until earlier this year when the council decided to contract a laboratory in Auckland for all its testing.

HTL managing director Bob Back said a preliminary analysis of the results by a respected water quality scientist indicated that the dark, foul-smelling discharge was not caused solely by stormwater from the Crawford Road log yard.

“Faecal indicator bacteria results were extremely high and the tannins result was less than half the background result tested previously.”

For example, the health risk value in marine waters associated with faecal contamination is normally 160 enterococci per 100 millilitres.

“The actual enterococci result was 55,000 enterococci per 100 millilitres. That is hundreds of times above the threshold level for illness transmission reported in epidemiological studies.

“Recreational users of the inner harbour should be concerned,” he said.

The council’s results from the incident will not be available until the new year.

Mr Back said the testing HTL did showed the tannin level recorded was only 2.2 milligrams per cubic metre.

“This suggests any log yard runoff discharge into the harbour was diluted and unlikely to have caused the problem.”

HTL sent people to test the water on the night of the incident and microbiology test results were completed by 11am on Friday December 18.

Chemical test results came back at 3.30pm on Wednesday December 23.

The discharge and smell two weeks ago sparked activity on social media, with club members describing it as “disgusting, repulsive and gross”.

The council was alerted to the problem and sent its pollution control team, environmental health officers and contractors.

Discharge into the harbour during heavy rain events through a drain under the fishing club is not a new thing. It happens two or three times a year but it is not usually accompanied by such a bad smell.

Concerns have been raised about the natural rock lobster nursery which still exists under the harbour at the other end of the port.

People involved with looking after this area have said numbers have declined since the log storage expanded over the past 10 to 15 years.