Cumulative effects assessment: from individual to population level effects

A major limitation of the current knowledge base for Cumulative Effects Assessments (CEA) is that there is no accepted methodology to translate the effects of a specific human activity reported at the level of an individual to an effect at the level of the population as required for such assessments.

Within the upcoming research topic of CEA, methodologies for effect assessment at a population level are under development, but there are still essential knowledge gaps and needs to address. The Wageningen Marine Research (WMR) approach for iCEA (integrated CEA) includes the CUMULEO-RAM model that provides a methodology for effect assessment at a population level of marine species. However, the methodology is only described in grey literature and an important inconsistency has been identified that limits peer-reviewed publication.

To improve the current version of the population model, we will develop a simple stage-structured matrix population model based on an international accepted approach for population models. This model should be applicable for different species(groups), depending on different population dynamics. As a secondary support for model acceptance, a literature review on existing methodologies for translating individual level effects to population level effects within CEA will be conducted. Specific attention will be put on the applicability of methodologies developed for a specific cause and effect chain (e.g. effects of underwater noise on harbour porpoise) to other chains, i.e. the potential for an integrative approach. Within this project we thus aim to: develop a matrix model for translating individual effects to population effects for different species(groups); implement this methodology in the WMR approach/framework for iCEA (integrated CEA); and enable peer-reviewed publication of this methodology.