Biodiversity offsets in the marine environment

On land, biodiversity offsets are an established instrument for reconciling economic development with biodiversity conservation. In the marine environment, however, the potential is still being explored.

This research examined issues associated with the design and implementation of marine biodiversity offsets. First, the performance of offset strategies (comprising a management approach and offset objective) when cumulative impacts are present, and second, community preferences for aspects of offset design (such as location/distance from the impacted site and direct or indirect offsets). The effect of offsetting on developers’ social licence to operate was also explored. These issues are pertinent to agencies responsible for conserving marine biodiversity and regulating activity, particularly given the complexity of the marine environment, uncertainty around impacts, and increasing pressures and demands for use. Such issues have the potential to generate community concern about resource allocation.

Diagram of marine system offset model.

ABOVE: The marine system offset model links biological and human systems. The arrows denote positive effects, and the lines ending in dots denote negative ones. The habitat element supports a biological resource exploited by society in a predator-prey relationship. Habitat is damaged by development, but may be remediated by offsets. The relative strength of this remediation is determined by management, which in turn is influenced by a social process that allows a threshold level of ecosystem service loss before offsets are required (dashed blue lines).


IMAGE: Choice modelling elicted community preferences for offsetting in relation to seagrass habitat in WA waters. Image: Curtin University.


Different approaches and methods were used to address each issue. A simple socio-ecological model was used to simulate the effect of annual development projects occurring over five consecutive years on habitat and resource recovery, human utility and offset costs under four different offsetting strategies. Choice modelling was used to elicit community preferences for biodiversity offsets for migratory shorebirds (Queensland and Western Australia) and seagrass (Western Australia), and a four-dimensional framework was used to evaluate the effect of offsetting on the Western Australian oil and gas industry social licence to operate. Data were collected through online public surveys.

Key findings

Socio-ecological modelling highlighted the importance of adopting an offsetting approach that either took a strategic assessment approach to development approvals, or explicitly accounted for cumulative impacts in project-by-project assessments. The link between alternative offsetting approaches and the distribution of offset costs across developers was also shown. A novel aspect of the research was that it accounted for the possibility that societies may allow a threshold level of damage to occur before requiring offsets, (depending on their perception of habitat status).

Respondents had strong preferences for offsets close to the original project, and a strong aversion to shifting the offset overseas, even if the costs of implementing the offset were much lower there. Distant offsets were only acceptable if the pay-off (additional shorebirds protected) was sufficiently high. Also, respondents were willing to accept protection of a smaller number of endangered shorebirds as compensation for losing numbers of common species. Indirect offsets (such as research and education) were considered acceptable if more birds were protected as a result.

Offsetting does not have a negative effect on a developer’s social licence to operate, (conditional upon the offsets achieving the stated ecological outcomes).

Outputs and outcomes

This research has begun building the knowledge required for the effective design and implementation of offsets in the marine environment. The socio-ecological marine system offset model is being enhanced to address additional questions, such as the uncertainty assumptions under which offsets portfolios are designed. Research on public attitudes to offsetting, including its effects on social licence to operate, and on preferences for offset attributes, can help policy makers, managers and developers identify socially acceptable approaches. It can also contribute to communication and education strategies that align public preferences for offsets with environmental effectiveness.


Sarah Jennings
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