The Land and Environment Court convicted Forestry Corporation of NSW for "breaching its approval and carrying out unlawful forestry activities in an exclusion zone" due to mapping errors.

A spokesperson from the Environmental Protection Agency, who prosecuted the case, said Forestry "failed to mark the boundary of an environmentally sensitive area during logging activities in 2019".

"(The area was) a potential bat roost for the Eastern Horseshoe Bat," they said.

"(Forestry) was convicted of three offences and fined a total of $230,000 for the breaches."

The court ordered FCNSW to pay $45,000 of the penalty to the Australasian Bat Society for research into the impacts of wildfire on a key roost in the area.

EPA Acting Executive Director Regulatory Operations Regional, Greg Sheehy, said the EPA would continue to hold FCNSW to account.

"FCNSW must have the correct procedures in place to ensure all exclusion zones remain untouched," he said.

"Potential subterranean bat roosts in the Dampier State Forest may be critical habitat for various types of subterranean bat living in the forest. While the Eastern Horseshoe Bat is not threatened, the population is thought to have declined over the past few decades in parts of NSW. It's important they have roosts and areas to forage.

"These activities by FCNSW had the potential to cause harm to any Eastern Horseshoe Bats roosting in the area and the EPA will continue to enforce the law when breaches are found."

The court also ordered FCNSW to undertake an audit of its field mapping and marking activities including understanding the level of experience and competency required to comply with the law. Any recommendations arising from the audit around training must be followed.

FCNSW was also ordered to pay $8000 for the EPA's investigation costs.

Forestry Corporation did not respond to the Bay Post's request for comment.