Pelican rescuer claims vindication in EPA letter
Pelican rescuer Ms Wendy Gillespie said her five-year campaign to get to the bottom of bird deaths at Blackwall had been vindicated by a letter from the NSW Environmental Protection Authority (EPA).
"The EPA would like to thank you for your assistance in this investigation," said the EPA's head of the Hunter Regional Operations Unit, Mr Peter Jamieson, in a letter dated September 20.
"The EPA considers that, based on the evidence available and the advice from relevant experts in this field, there is a strong likelihood that the ongoing water bird mortalities at the site may be linked to algal growth and associated toxins in stormwater, particularly at the stormwater canal directly north of Alpha Rd.
"Based on this new information, the EPA has written to Central Coast Council recommending that Council should investigate and implement actions at the site in order to mitigate the potential for growth of potentially toxic algae.
"The EPA has recommended that Council liaise with relevant experts as to possible solutions so that unexpected negative results do not eventuate from Council's proposed management actions," the letter said.
According to Mr Jamieson's letter, since 2014, the EPA has received reports from Ms Gillespie and other concerned community members of ongoing water bird mortalities (mostly pelicans and ducks) in the Blackwall and Woy Woy area.
The deaths have occurred near a stormwater canal north of Alpha Rd which discharged into Brisbane Water.
"The EPA understands this issue has been ongoing for some time and the cause of deaths has remained unclear despite investigations by relevant agencies into potential causes," the letter said.
Ms Gillespie made reports to the EPA in 2014, after which the authority worked with and consulted with the Office of Environmental Heritage, Taronga Conservation Society of Australia, the University of Tasmania, the Department of Primary Industries, National Parks and Wildlife Service and the former Gosford Council.
The EPA set about collecting and interpreting relevant data in an attempt to establish a potential cause for the mortalities.
Mr Jamieson said veterinary pathologists at Taronga's Australian Registry of Wildlife Health had undertaken numerous necropsies on deceased birds from the area since 2011.
"Most recently the EPA, with assistance from the former Gosford Council, has undertaken targeted water sampling at the site and has coordinated further necropsies at Taronga of a number of deceased ducks found in the area that displayed symptoms consistent with previous mortality events."
As reported previously in Peninsula News, water sampling investigations in 2015 found no evidence of elevated levels of pesticides or heavy metals.
"Nutrients were at concentrations expected for this type of environment.
"Symptoms were not consistent for other potential causes such as viral, parasitic and bacterial infection or avian botulism.
"Water sampling did, however, find evidence of potentially toxic blue-green algae present in the stormwater canal.
"Necropsies conducted on deceased ducks found algae in the stomach content on the deceased ducks.
"The stomach contents were tested for a range of algal toxins and all tested positive for high levels of cyanobacterial toxin, Microcystin-LR, associated with blue-green algae.
"Pathology reports ... showed symptoms consistent with exposure to Microcystin-LR toxins."
Mr Jamieson said pathology slides containing stomach contents and toxicity testing results were sent to Dr Gustaaf Hallegraeff, an internationally-recognised expert in harmful algal blooms at the University of Tasmania.
Dr Hallegraeff concluded that the Micricystin-LR found in the stomach contents of the ducks was a probable cause of mortality and noted that this hepatoxin could readily be ingested when dissolved in water when the ducks came into contact with toxic blue-green algae surface scums.
Email, 12 Oct 2016
Wendy Gillespie, Pelican Rescue