4. Accounting for Key Species | EcoPrinciples Connect

Principle: 4. Accounting for Key Species

Key species are individual species or a group of species that have a disproportionately strong impact on ecosystem structure and function, and may include foundation species, keystone species, top predators, or basal prey. Healthy populations of key species allow for stable, resilient ecosystems by creating habitat for other species, influencing community dynamics, and driving food web structure.

Related Actions

4.1 Identify the impacts to foundation species, basal prey, top predators and keystone species

Identify the impacts to: • Foundation Species (e.g., kelp, seagrass); • Basal Prey (e.g., sardines, anchovies, mullet); • Top Predators (e.g., sharks, tuna, sea lions, elephant seals); • Keystone Species (e.g., sea otters, sea stars)
4.2 Identify the impacted species' contributions to ecosystem functioning

Identify the impacted species’ contributions to ecosystem functioning (e.g., weigh significance of the impacts)
Different types of key species provide different contributions to the ecosystem. If possible, identify how impacts to the species would alter ecosystem functioning.
4.3 Evaluate whether the impacts will cause a trophic cascade in the system

Negative impacts to basal prey and top predators, in particular, can cause a domino effect that reverberates through the food web. For instance, the loss of basal prey species reduces the amount of available food, causing population declines throughout the foodweb.

Applying ecological principles

Ecological principles represent the core attributes of natural systems that must be maintained or restored in order to support healthy marine and coastal ecosystems, and include maintaining, restoring, or accounting for:

These principles are explained in a reference guide for agencies in California, called the Ecological Principles Guide . This guide also includes a series of case studies and checklists that demonstrate how the principles can be applied to day-to-day decision making.

State GeoPortal

The EcoPrinciples Connect tool links to data from the California Geoportal, which offers an easy and convenient way to search, discover and use authoritative geospatial data resources. This one-stop geospatial shop is helping to improve access to California’s geographic data portfolio and expand the use of those data resources in decision making processes.