Hundreds of eels found dead in Marlborough creek
Hundreds of dead eels have been found floating on the surface of a creek in Marlborough.
A vineyard worker noticed the smell of rotting flesh before finding the shortfin eels in a roadside creek near Rarangi, north of Blenheim, on Wednesday morning.
Marlborough District Council freshwater ecologist Pete Hamill said he counted more than 200 eels in the two-kilometre creek, and estimated there could have been hundreds more below the surface and out of sight.
"It's killing the plants along the bank as well. Whatever it is, it's toxic to both," Hamill said.
The eels would be left to decompose in the creek.
"The creek has steep edges, and it might be quite dangerous for workers. We don't really know what's in there," Hamill said.
People were known to catch eels in the creek for consumption but Hamill said it was not safe while the water was contaminated.
Other fish in the creek would be affected including whitebait and bullies, he said.
"It's a bit tough on the poor old eels ... they do play an important part in the habitat."
Hamill said the cause was not yet clear but he suspected a chemical had leached through the soil nearby and entered the creek.
"It could be anything from cement to herbicide to paint to hydrocarbon."
Standard herbicide used on grape vines would not leach into creeks because it was a targeted practice that used small amounts, Hamill said.
It was possible somebody had dumped hundreds of litres of chemicals into the ground, not realising the harmful effect it could have, or even thinking it was the correct method of disposal, he said.
"It just shows that everything is interconnected ... What you dump into the ground here can flow through the gravel and affect the water there."
He urged Marlburians to dispose of biohazardous waste appropriately, which generally meant taking it to the council refuse transfer station.
It was more likely an act of ignorance than of malicious intent, Hamill said.
A culprit could only be charged with illegal discharge if the act was proven to be negligent, which was rare, Hamill said.
If a possible source was identified, a water sample would be tested to try to match a pollutant with the source.
The creek was fairly shallow and stagnant which prevented dissolution of pollutants, Hamill said.
- The Marlborough Express