War of words erupts over health of seagrass in harbour
A ROW over the health of seagrass in Gladstone Harbour has erupted again, with an environmental expert attacking the interpretation of data on seagrass by Gladstone Ports Corporation.
GPC fired back on Thursday, saying it had the data and scientific evidence to back its claim that seagrass was recovering and had not been impacted by dredging.
Meanwhile, the Western Basin Dredging and Disposal Project team said a survey this week revealed an unexpected increase in seagrass cover over the past month.
That comes despite a report released in October, which gave a mixed scorecard for seagrass levels across the harbour.
Former Greens candidate Andrew Jeremijencko said 99% of inner harbour seagrass was dead in the toxic turbid inner Gladstone Harbour.
Dr Jeremijencko has accused GPC of misrepresenting the data collected by scientists.
He said the authority's own report shows seagrass levels at dire levels, particularly at Fishermans Landing.
But dredging project manager Peter O'Sullivan said surveying at Fisherman's Landing this week showed a strong recovery.
"The comments coming back from the latest six-monthly study say that across the inner harbour, even though there are variations and some areas are still at a low-percent cover, that we are seeing a generally good increase in the amount of seagrass," he said.
Mr O'Sullivan said it was a mistake to think of 100% as the target for seagrass levels since that was not a 'normal' level.
"In 2011 as a result of the floods, there was a significant decline in the seagrass," he said.
"What we're starting to see is some areas are back to pre-flood levels and other areas we're also starting to see significant growth in the seagrass population and obviously that's very pleasing."
Dr Jeremijencko said GPC's own data showed seagrass levels in the harbour were in a poor state and that was due largely to dredging activities.
"The ports are killing the grass. They dredged over the limit to 'fix' the leaking bund wall and have continued to dredge over the limit every month since then," he said.
He said high turbidity had contributed to the seagrass's inability to recover despite it being the growth season.
"The State Government has ruled because the light monitors on top of the dead seagrass say the light is okay the ports can keep dredging," he said.
"We don't care what the light monitors say. If the seagrass is 99% dead in the inner harbour and not regrowing while Moreton Bay seagrass is regrowing there is something wrong."
Mr O'Sullivan said it was simply not correct to say 99% of seagrass in the harbour was dead.
He said the figure '100%' did not mean 100% of normal seagrass levels. Instead, it was a measurement of the density of seagrass cover in a given area.
"In our view, what some people like to do is make a bad news story about Gladstone and what we're saying is, look at the data and look at the reports out there.
"All the reports have been very positive about the state of the health of the harbour."
GPC said on Thursday monitors for Department of Agriculture Forestry and Fisheries had been surveying seagrass in the harbour this week and had been coming back with encouraging reports.
A monitor has reportedly said seagrass was growing in areas she had not previously seen it in. That data will be published in December.
If it turns out to be as good as expected, it will be a large improvement on the October data collected by DAFF.
In that report, DAFF stated: "Percent cover has remained extremely low (<1%) with seagrass extremely patchy along transects.
"Seagrass cover has not reached the levels observed at the same time last year (Oct 2011).
"Observers noted the continued presence of a layer of sediment over the transects, with a sand bar appearing to have shifted and possibly raised. This site is closest to the dredge operations (within 75m)."
The report gave the Gladstone's most important seagrass meadow, Pelican Bank, a much better result.
"Seagrass percent cover has increased significantly (to 24%) since Sept 2012.
"Percent cover has continued to increase at the site since July 2012, exhibiting typical increases expected in the growing season (Aug to Jan).
"Cover was not as high as October 2011 but very similar to Sept 2011."