Puget Sound Eelgrass (Zostera marina) Recovery Strategy

A 2014 report from the Washington State Department of Natural Resources outlines a recovery strategy for native eelgrass in Puget Sound. The strategy is designed to address a target set forth by the Puget Sound Partnership to increase eelgrass by 20 percent in Puget Sound by 2020. 

Executive Summary

The Puget Sound Partnership established eelgrass as an indicator –or “vital sign”–of the health of Puget Sound in recognition of the regional ecosystem services it provides and its sensitivity to changes in environmental conditions. Regional population growth and land use development have contributed to historical losses of eelgrass habitats. Although sound-wide estimates of eelgrass remain relatively stable in recent years, monitoring continues to document localized declines.A combination of stressors can adversely impact eelgrass beds, including algal blooms, overwater structures, sediment loading, and shoreline armoring, vessel moorage and anchoring. The relative magnitude of specific stressors varies spatially and temporally across sites within Puget Sound.

In 2011, the Puget Sound Partnership (PSP) adopted a 2020 target to increase eelgrass extent by 20 percent. The 2012/2013 Puget Sound Action Agenda tasked DNR, in collaboration with the Puget Sound Partnership, to develop a comprehensive recovery strategy to advance eelgrass recovery. DNR and PSP invited partners in local, state, and federal government, tribes, non-governmental organizations, and business groups to participate in a collaborative process to develop the recovery strategy. The interdisciplinary workgroup reviewed the scientific understanding of eelgrass stressors in Puget Sound, defined overarching goals and objectives,and prioritized implementation measures to address critical stressors and support conservation and recovery. Although the plan defines what implementation measures are necessary to advance recovery efforts, many of the priority actions are not feasible without additional funding.

The recovery strategy is organized by five overarching goals and nine strategic objectives:

1. Conserve existing eelgrass habitats;

  • Ensure existing policies, regulations, and non-regulatory programs avoid impacts to existing eelgrass beds and enforce a “no net loss” standard.

2. Reduce environmental stressors to support natural expansion;

  • Design new/retrofit existing in-water and over-water construction projects to avoid impacts to existing and historical eelgrass habitats.
  • Expand eelgrass compatible boater infrastructure to reduce damages to eelgrass beds as a result of recreational and commercial vessel mooring in high-use areas with extensive eelgrass habitats.
  • Reduce anthropogenic nitrogen and sediment loading to improve marine water quality and minimize the frequency and magnitude of algal blooms and eelgrass epiphyte growth.
  • Reduce adverse impacts of shoreline armoring and conserve unarmored feeder bluffs to enhance nearshore sediment delivery and reduce beach erosion.

3. Restore and enhance degraded or declining eelgrass beds;

  • Utilize strategic eelgrass transplants to accelerate recolonization and expansion at sites shown to possess suitable ecological conditions.
  • Restore tidal wetlands associated with river deltas, coastal inlets, and barrier embayments to restore ecosystem processes and recapture lost linear nearshore habitat that supports eelgrass growth and expansion.

4. Identify eelgrass research priorities; and

  • Implement targeted research initiatives to understand the short-and long-term factors driving localized changes in eelgrass beds and inform an adaptive approach to recovery efforts.

5. Expand outreach and education.

  • Target public outreach and education to foster community stewardship, individual responsibility, and collective action to benefit eelgrass conservation and recovery.

The recovery strategy recognizes the reality of resource constraints and highlights geographic focus areas to help managers prioritize stressor reduction efforts. Focus areas were identified based on: (1) strength of evidence of eelgrass decline or loss; (2) evidence of decline in nearshore habitat conditions; (3) recently completed and/or planned stressor abatement projects; (4) feasibility of recovery; and (5) level of site protection. Focus areas include Quartermaster Harbor, Lower Hood Canal, Purdy Spit/Henderson Bay, Fisherman Bay, and several large river deltas. These areas provide an opportunity to test the effectiveness of various strategic actions, understand the reversibility of specific stressors, and if successful, help build momentum for implementing actions at a larger scale.

Download the full report (external link)