Government Science Failures on Fish Stock Claims

There is a smell of something worse than failure: The Queensland government is claiming that the mackerel fish stocks on the reef are at alarming low levels, and it wants to drastically curtail or close the fishery. They base this on two things:​​​​​​​

(a) Calculations of fish stock going back to 1912, from data on fish catch and how many boats were operating; and

(b) a computer model that calculates how many mackerel are in the reef now.

I could make the accuracy of the input data of the model the focus of this post. The fish catch and effort numbers in 1912, or at any time prior to the last few decades, is little more than an educated guess.

But my concern is that Queensland Fisheries has claimed that this work has been “peer reviewed” and is very solid, failing to point out that their peer reviewer states very explicitly that he has considerable DISAGREEMENT with the main conclusion of the original report. He states in the last sentence of his summary:  “I am unable to support the conclusions regarding future harvest levels for the east coast Spanish mackerel stock…”

The disagreement, damning as it is, is not what worries me. The fact that they have not been open about their own reviewer disagreeing with the report smells of deception, even if it was not deliberate. For example, in the media report in the link below, Queensland Fisheries apparently stated that the work was peer reviewed but presumably did not mention to the journalist that the reviewer disagreed with a major conclusion of the work. They implied a greater level of confidence in the report than was warranted.

The peer reviewer took issue with a parameter in the fish model called the “steepness.” I will not go into detail, but it affects the calculation of how many fish are out on the Reef. Using the value suggested by the peer reviewer, there could easily be three times as many Mackerel as the Queensland Fisheries are stating, meaning the fishery is actually not in any trouble. This is not a minor issue.

But the scientific debate on the value of the “steepness” parameter is not the main worry, it is that we have been deceived (and I would naturally never say deliberately) about the result of the peer review process – and you would have to wonder why that happened.

This is just another example of a broken quality assurance process for reef science. This time fishermen are in the firing line rather than farmers.

The report and review (Stock assessment of Australian east coast Spanish mackerel) can be downloaded here.

[See also the ABC reports, Fishers spitting chips over Spanish mackerel fishery ‘crisis’, here, and Spanish mackerel stock report ‘imminent’ as stakeholders fear for fishery’s future, here.]

This is slightly edited version of a post that first appeared on Peter Ridd’s Facebook page, here