Federal Government silent on dodgy science for Queensland fish stock assessments

Fisheries Queensland has been under immense pressure from fishers who have had their livelihoods destroyed. Despite declaring the stocks of Spanish Mackerel “sustainable” as recently as 2018, a change in assumptions and modelling hugely cut the quotas that fishers were allowed to take.

These changes to the model have been labelled unscientific by industry groups and scientific reviews. I thought the Australian Fisheries Management Authority had at least reviewed the changes to see if they were scientifically sound, but unfortunately this wasn’t the case.

One Nation will continue to fight for fishers to ensure that fair quotas are issued based on proper science.

Transcript

Senator Roberts: Thank you for being here today. Can you please discuss some of the background on the Spanish mackerel fisheries management, especially in Queensland? I understand that in recent times there have been significant changes in the management and the quotas are being reduced. Do you have more information on exactly what has happened?

Mr Norris: I’m afraid I don’t. The Queensland Spanish mackerel fishery is managed by the Queensland government. The only things I know about it are what I read in the media and from talking with colleagues. I don’t have a lot of insight to offer, I’m afraid.

Senator Roberts: Maybe I can share a couple of points and you can chime in. I understand that in 2018 the stocks of Spanish mackerel were considered sustainable, but a change in modelling has turned that on its head.  There is a lot of scientific disagreement about whether the new modelling is sound. Have you seen that?

Mr Norris: I have seen that play out in the media, yes.

Senator Roberts: On the new changes and a previous mackerel stock assessment, one reviewer named Klaer in 2021 said, and I quote: I am unable to support the conclusions regarding future harvest levels for the east coast Spanish mackerel stock until reservations regarding the most appropriate central value for steepness for the base-case are resolved.  Does AFMA have a view on whether robust science has been applied by Queensland fisheries setting the Spanish mackerel quotas?

Mr Norris: Perhaps I can make some very general comments. All fishery stock assessments are very sensitive to the assumptions built into the model. This concept of steepness is a particularly heavy driver. Certainly we have encountered disagreements about what steepness values should be in some of our assessments of Commonwealth fisheries. In terms of whether or not I am confident with the science done by Queensland, as I say, I haven’t reviewed the science because it is not a fishery we are involved in or manage. I would say as a general observation that I have a very high respect for the fishery scientists who work for the Department of Agriculture and Fisheries in Queensland. As I say, I haven’t been through the technicalities of this.

Senator Roberts: Could you tell us about steepness?

Mr Norris: Steepness is a value that comes from part of a stock assessment model called the stock recruitment relationship. What the stock recruitment relationship tries to explain is how many adults you need in the water to produce a certain number of babies for future cohorts. Traditionally, you might think it is probably linear; the more adults you have, the more babies you get. While that is true, it is very rarely a nice straight line. It’s a curve, and it is very difficult to estimate. Steepness is the gradient of that line.

Senator Roberts: I must say that you hit the nail on the head. A lot of people are disagreeing with the model used. The models have cut the quotas as a result of the modelling and the underlying assumptions; that is my understanding. We also had a really disastrous, I would say almost fraudulent, basis for the reef regulations that are decimating the east coast in Queensland. We questioned the scientists themselves at an inquiry that the Senate held in Brisbane. We showed just how false the science is; there is no basis for them. That is why a lot of fishermen are also now upset about the modelling and assumptions for their fishery quotas. So, what you are saying makes perfect sense. Thank you very much. Thank you for your clarity.