Experts dump on dung beetle

Grant Guilford

Dr Grant Guilford said there had not been enough duty of care around protecting New Zealand’s biosecurity in assessing the beetle’s introduction.

Leading scientists and health experts believe there are major risks if dung beetles are released in New Zealand.

The beetles are in caged field trials in Northland after approval was granted by the Environmental Risk Management Authority (ERMA) for 11 species to be imported.

ERMA has since been disbanded and the Environmental Protection Authority (EPA) has taken over its role.

Championed by Landcare, the beetles are intended to assist rapid breakdown of animal waste, help reduce fly infestations resulting from dung presence, and possibly reduce the need for drench use.

However, Dr Grant Guilford, dean of science at Auckland University, has voiced concerns over how significant the benefits of the beetle are and the robustness of ERMA’s risk assessment.

Guilford’s ability to speak openly about the beetle’s release was constrained earlier by his position on the Landcare board, the science organisation sponsoring the beetle’s release.

He resigned from the board last year, in part because of significant misgivings he had over the assessment process.

He said the last straw was Landcare’s decision to disregard a letter from the Auckland Medical Officer of Health advising of a need for better assessment of public health risks in beetle release.

The caged trials on the beetle do not include close analysis of human health risks.

Guilford’s concerns rose initially when his research staff, veterinary and medical colleagues sounded warnings on the beetles’ potential to act as carriers for a variety of diseases affecting animals and humans.

Submissions to ERMA against the beetles’ release in NZ included concerns from two of his staff.

But issues were also raised by the Auckland Council, the Auckland Regional Public Health Service, and Fonterra.

Guilford then compiled a report for EPA and Landcare highlighting the beetles’ potential as disease carriers.

The peer reviewed report contained extensive overseas research challenging ERMA’s (now EPA) view the exotic beetle’s release would not cause adverse effects on human health or safety. 

The paper highlighted beetles’ ability to carry gastrointestinal diseases of humans, livestock, dogs and wildlife. They include cryptosporidium, giardia, E.coli, campylobacter and salmonella.

“The overarching comment from those assessing the paper was ‘there is a real level of risk here and we need to do more research to quantify the risk’,” Guilford said.

Other risks included the ability of the beetle to fly long distances, giving it the potential to spread exotic or local diseases across regions, and to spread diseases by contaminating rural water supplies.

Guilford described the information ERMA had based its beetle assessment on as poor quality and too reliant on the Australian experience with the beetle.

“The application was not what we would call a good, quality piece of work. It wasn’t thorough or balanced and lacked assessment by animal or human health experts.”

He said it was wrong for Landcare staff to answer “no” to the application question asking if the beetle could cause disease, be parasitic, or be a carrier of human, animal or plant diseases.

However, Landcare chief executive Dr Richard Gordon said while many organisms, including flies and earthworms, were capable of also carrying diseases, Landcare did not believe dung beetles could transmit those diseases to people. 

He said Landcare’s beetles also had a clear preference for cattle dung, with research suggesting they would be attracted to other animals’ dung only when that was not present. A constant supply of cattle dung made that unlikely.

“Dr Guilford’s report was assessed thoroughly by EPA and was not found to substantiate concerns about the dung beetles subject to approval.”

But having spent more than 20 years at Massey’s veterinary school, Guilford said his “veterinary bones” told him there had not been enough duty of care around protecting New Zealand’s biosecurity in assessing the beetle’s introduction.

A year ago he felt concerns were being heeded, when a technical advisory group (TAG) was created to examine the concerns closer and establish beetle trials.

“It was a good, well-qualified group and they decided they needed to do cage trials on the beetles. It was late, but at least good oversight.”

Auckland Council biosecurity manager Jack Craw also confirmed misgivings his scientists had over the beetles’ release, despite providing some initial funding for the project.

“We were keen on the concept but are concerned there has not been an appropriate level of environmental audit on this.”

As a member of the advisory group, he has had no response from his queries to Landcare since trials started in early October last year.

“I think a lack of funding is a big part of it. The trials should have been done even earlier, before a hearing was carried out, given how important they (the beetles) are.”

However, Gordon said that trial’s results would be presented to the group as soon as they were available.

Gordon emphasised while no longer in containment, the beetles were contained in cages during the field trials. He said should the beetles be found to be unsuitable for field release they could be destroyed