Credit: Tim Marshall

Posted on 31 August 2021

New research helps weigh up risk and uncertainty in the ocean

A recent study by our Communicating risk and uncertainty project reviewed existing marine risk assessment frameworks to determine if these approaches are applicable to EBM in Aotearoa New Zealand.

Managing the declining health of the marine environment is one of the most wicked problems we humans face today. A major obstacle is that we don’t know enough about how the incredibly complex and interlinked marine ecosystems are responding to increasing human activities and cumulative effects. Add climate change into the picture and it’s even harder to understand.

For the collective well-being of the moana and the people who depend on it, Aotearoa New Zealand is shifting towards ecosystem-based management (EBM), a more holistic and inclusive way to manage the marine environment.

An important part of doing EBM is making decisions that account for risk and uncertainty. It can be difficult to assess risk when our understanding is incomplete, or uncertainty is high. Making decisions in the face of uncertainty is challenging because the actual outcome may be very different from what we predicted. This may lead to management failures or decision paralysis.

Decision-makers use risk assessment frameworks to understand uncertainty and prioritise management actions and trade-offs. As we progress towards EBM, marine risk assessments must move beyond only looking at the direct impacts of a single stressor on a species or habitat.

“We did this review to understand how useful existing risk assessment frameworks are in the New Zealand marine environment context,” says Dana Clark, report author and marine ecologist at Cawthron Institute.

“To support EBM, a framework can’t just be driven by purely biophysical data, it must also be able to incorporate qualitative information. Specifically, we were looking at what frameworks, if any, can uphold Treaty principles and incorporate mātauranga [Māori].”

This type of review is a New Zealand-first. Six frameworks and methods were identified by co-development partners from across different sectors and industries operating in the marine space.

The project team looked at the pros and cons of each framework and assessed them against 12 criteria designed to align with the 7 principles of EBM and meet the needs and aspirations of Māori.

The researchers found that most risk assessment frameworks and methods currently used in Aotearoa New Zealand are not fit-for-purpose for aligning with EBM principles.

“It’s a bit of a Goldilocks situation. Many of the risk assessment models are either too simple (and can’t deal with complex ecological issues), or they are too complicated, expensive, or difficult to understand and communicate,” says Rebecca Gladstone-Gallagher, report author and researcher at University of Auckland.

However, the researchers did find that Bayesian Networks (BNs) meet most of the EBM suitability criteria.

“BNs ranked highly because they can incorporate ecological complexity, and draw on information from various sources, including mātauranga Māori,” says Rebecca.

“BNs are already well-known to decision-makers in the context of environmental management. Now through our review and engagement with co-development partners, we also know that they can be used to assess risk and uncertainty to inform EBM.”

In addition, a generic BN model can be created and tweaked to the relevant location. The ability to tailor management decisions to a particular location is aligned with the ‘Tailored’ EBM principle.

Co-development partners involved in the review also ranked BNs highest.

“One of the key strengths of Bayesian Networks, I think, is the actual process of building these models which can be done with multiple groups, values and knowledge sets,” says Megan Carbines, Principal Environmental Scientist at Auckland Council and contributing co-development partner.

“Using Bayesian Networks can bring people along on the journey, widen the assessment of risk to capture diverse values and perspectives, and lead to better community understanding and acceptance”.

But while BNs show promise, they’re not perfect, or ‘just right’.

“We also looked at what methods are being used internationally, to see if they can inform future development of the current frameworks here,” says Dana.

“But we found that people overseas are also grappling with this problem, with no standard methods completely suited for assessing risk in an EBM context right now”.

The researchers recommend developing an inclusive, hierarchical framework that takes a mixed approach using BNs and two emerging methods used overseas: coupled and non-coupled social and biophysical risk assessment models. The Communicating risk and uncertainty project will test this in future research.

Read/download the report

These findings are widely applicable to anyone undertaking or managing activities in the marine environment eg, aquaculture, fisheries, resource management, oil and gas, biosecurity, or transport/shipping/cruise ships.

Further expected outputs from this research include practical guidance for scientists, policymakers and/or practitioners to appropriately design risk assessments and support the implementation of EBM.

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