Adaptive management is a structured, flexible approach that allows project teams to respond to uncertainties and changing conditions by continuously learning from the outcomes of decisions and adjusting management actions accordingly. With adaptive management, practices evolve based on real-world observations, data collection, and feedback loops. This approach is important in sustainable dredging projects, as a number of factors relating to all elements of sustainability (environmental, social and economic) tend to be unpredictable. 

The starting point for an adaptive management-led project is the determination of a strategic objective. In the case of responsible marine solutions, based on the Dredging for Sustainable Infrastructure philosophy, the strategic objective will be heavily influenced by the outcome of an Environmental Impact Social Assessment (EISA). This may result in strict thresholds, to assure environmental performance with levels deemed to be acceptable, based on the findings of impact assessments. In other cases, less clear environmental limits are specified. This can be due to the level of uncertainty about the effects on, and responses by, nature caused by the inability to fully appreciate and judge environmental conditions (sensitivity of receptors) and potential project effects (vulnerability to changes); or for other reasons such as sharing responsibilities and risks.

Ideally, the EISA will allow for the flexibility to enable finalisation of the management measures through discussion with the dredge contractor and other stakeholders. This can be achieved through the EIA recommending a set of performance objectives for the project to achieve through management of the dredge. An example of this would be managing potential impacts to ensure a maximum given percentage of loss of a resource within the potential zones of impact, or achieving a minimum area of habitat to be rehabilitated.

An example of a strategic objective in a sustainable dredging project could be to ensure the sustainable preservation of local habitats in the presence of marine infrastructure development activities. Once the strategic objective is in place, a set of operational objective should be set, which all feed into the strategic objective. An example of an operational objective that supports this strategic objective could be to prevent significant impact on corals due to the presence of a suspended sediment plume affecting water quality.

It is on the operational objective side of things where the adaptive management approach comes into play. Operational objectives, and the actions needed to achieve them, should develop over the course of the project  (from inception to realisation) through decision-making that incorporates monitoring, feedback, and adjustment, based on the evolving understanding of environmental and operational dynamics. This can be understood through a four-step process: 

With these objectives in mind, the six basic steps should then be followed:

1. Plan – Defining the desired goals and objectives, evaluating alternative actions and selecting a preferred strategy with recognition of sources of uncertainty;

2. Design – Identifying or designing a flexible management action to address the challenge;

3. Implement – Implementing the selected action according to its design;

4. Monitor – Monitoring the results or outcomes of the management action;

5. Evaluate – Evaluating the system response in relation to specified goals and objectives; and

6. Adapt – Adapting (adjusting upward or downward) the action if necessary to achieve the stated goals and objectives

Adaptive management in dredging projects: challenges

While the benefits of an adaptive management approach are clear, putting it into practice is not without challenges.

For example, the availability and quality of data can produce obstacles, as effective adaptive management relies on robust data collection and monitoring systems, which can be resource-intensive and expensive to implement. This challenge is exacerbated by uncertainty surrounding ecosystem responses, due to the inherently complex nature of ecosystems.

Another risk in the approach in terms of dredging projects is that the monitoring and management required can change regularly throughout the project causing difficulties for overall project budgeting. As the approach is not yet a standard industry practice, it may cause unexpected difficulties during implementation as standard ‘off-the-shelf’ solutions are still lacking. 

Still, developing adaptive management as part of a project execution strategy will potentially facilitate implementation of a more optimal (less conservative) project, with inherent cost savings. Therefore, when incorporating adaptive management into a project, it is very important to have early involvement and open dialogue with all stakeholders, taking into consideration all viewpoints, throughout all phases of the project.

With all that in mind, adaptive management is a powerful tool for ensuring the sustainability of dredging projects. While challenges exist, the benefits of adaptive management in promoting sustainable dredging practices are clear, making it a valuable strategy for managing the complex and dynamic nature of dredging projects.