Core Element 5: Cumulative Impacts

Ecological effects of human activities can be additive, and the cumulative impacts can cause a decline in nature’s services. This is the case even when some of the activities seem harmless, the activities happen at different times or places, or the activities occur in different sectors of the economy. EBM practitioners develop and implement policies, management plans, regulations, and enforcement procedures that account for these cumulative impacts.

Focus Questions

  • How do human activities, some of which may seem relatively harmless on their own, combine to impair nature’s services in the geographic focus area?
  • How can policy and management be changed to account for cumulative impacts?

Learn More

Listed below are selected resources for learning about and implementing this Core Element of EBM. The list is far from comprehensive and highlights only a few especially useful examples.


A Global Map of Human Impact on Marine Ecosystems
Halpern, BS et al. 2008. Science 319:948-952

Halpern, BS et al. 2007. Ocean and Coastal Management 51:203-211

Chapter 5: Cumulative Impacts in Ocean and Coastal Ecosystem-Based Management: Implementation Handbook
By Kathryn Mengerink, Adam Schempp, and Jay Austin

Marine Spatial Planning Toolkit and Marine Spatial Planning: A Step-by-Step Approach for Marine Spatial Planning toward Ecosystem-based Management
Marine spatial planning (MSP) is one approach for addressing cumulative impacts.


A Global Map of Human Impacts to Marine Ecosystems
The website allows users to view maps of cumulative human impacts and each of the individual component datasets that were used to calculate cumulative impact.

NatureServe Vista
This tool supports cumulative impacts assessment, creation of multiple-use spatial plans, and evaluation of imported or created spatial use plans against stated objectives.

Marine Geospatial Ecology Tools
Marine Geospatial Ecology Tools (MGET) is an open-source geoprocessing toolbox designed for coastal and marine researchers and GIS analysts who work with spatially-explicit ecological and oceanographic data in scientific or management workflows.

Ecopath with Ecosim and Ecospace (EwE)
This free suite of ecosystem modeling tools is one of the most user-friendly and least data-intensive whole-ecosystem models, although it does requires data that may be difficult to obtain in some places.

MIMES (Multiscale Integrated Model of the Earth System’s Ecological Services) is a modeling framework that is useful for understanding cumulative impacts.

Connection with other Core Elements (CEs) of EBM

CE1:Nature's Services
Cumulative impacts may impair nature's services.

CE2:Scientific Evidence
Scientific evidence is needed to understand cumulative impacts.

CE3:Geographic Scales
The geographic scale of an EBM focus area affects the role and importance of different cumulative impacts.

CE5:Ecological Linkages
Ecological linkages can magnify or reduce the cumulative impacts of human activities.

CE6:Tradeoffs Among Human Activities
Cumulative impacts are one factor that leads to tradeoffs among human activities.

CE7:Adaptive Management
Cumulative impacts can lead to unanticipated outcomes of management actions, making adaptive management essential.

CE8:Network of People and Information
People engaged in EBM need to know about cumulative impacts.


Read about Core Element 6: Tradeoffs Among Human Activities