The founder of the Pink Lake Recovery Project has called on the community to protect the area after a new case of illegal dumping.
Scrap metal and other trash was found on the north eastern corner of the lake towards Keenan Road.
Chris Pope said it was vital to protect the fragile area from "lazy" dumpers.
"People aren't really aware that there is actually an accumulation of stromatolites in the area and the dumping was near that area," he said.
"People are disrespecting the area and could've damaged the population of stromatolites which takes hundreds of years to create and could be destroyed within seconds."
Mr Pope said he hoped illegal dumpers would be fined for their actions.
"A lot of it is metal, and the scrap metal pile at the tip is free, you don't need to pay to dump stuff there," he said.
"I've investigated dumping before and these last instances I've found not one of them had been because of financial hardship, it has just been purely disrespect and laziness."
Last year, the group called on the state government to extend the nature reserve to surround the lake and close off vehicle access to the tracks being used to dump waste.
Despite cases of illegal dumping continuing, Mr Pope thanked the state government, Shire of Esperance and Environment Minister Stephen Dawson for their support to protect and rehabilitate the area.
A Department of Planning, Lands and Heritage spokesperson said they shared the responsibility of the land surrounding the lake with the Department of Biodiversity Conservation and Attractions and the Shire of Esperance.
They said the land where the trash was found fell under the control of the shire for 'recreation purposes'.
Shire of Esperance chief executive officer Matthew Scott said the shire was aware of the dumping and regularly monitored the area.
"Shire staff and members of the community regularly monitor the area and are involved in the environmental protection and rehabilitation of Pink Lake," he said.
Mr Scott said the Shire and community groups had led clean-ups, planted vegetation and recently installed fencing to prevent access to the lake's sensitive shoreline areas.
"The Esperance Tjaltjraak Native Title Aboriginal Corporation Rangers, Shire staff and the Shire 'work for the dole' team installed the recent fencing with funding from South Coast NRM and the Shire," he sad.
"It is a shame that people still choose to do the wrong thing, damage fencing and continue to illegally dump rubbish and damage the environment.
"The material will be removed and surveillance of the area will be increased."
Mr Scott said the Shire was aware of suggestions that illegal dumping may be a result of the cost of disposal or limited access to the landfill site, however, the responsibility remained with the perpetrators.
"Some Local Governments provide residents with free use of their landfill and some operate with extended access hours," he said.
"However, these measures have not been shown to solve the problem as it seems there are some people who simply will not take a responsible attitude to disposal of their rubbish."
The maximum penalty for illegal dumping is $62,500 for individuals and $125,000 for corporations.
Anyone can report illegal dumping to the Department of Water and Environmental Regulation's Pollution Watch hotline on 1300 784 782.