Eelgrass, Part 2 – Status, Threats, and Restoration.


Map of the Salish Sea & Surrounding Basin, Western Washington University, 2009.
The southern part of the Salish Sea is Puget Sound while the northern part is The Strait of Georgia in British Columbia. There are no clear dividing lines except for political borders.

In Part 1, I made the case that eelgrass (Zostera marina) and other sea grasses are critical to local estuaries and near shore areas as well as to the health of the planet in terms of all of the myriad of ecological functions they serve. I also noted that they are among the world’s most threatened ecosystems. In part 2, I review the current status of eelgrasses, the numerous threats to their viability, and many conservation and restoration efforts currently underway both locally and worldwide. Most emphasis is on eelgrasses in Puget Sound and the Pacific northwest but most of what applies here is applicable elsewhere.

Seagrass coverage is being lost globally at a rate of 1.5 percent per year. That amounts to about 2 football fields of seagrass lost each hour. It’s estimated that 29 percent of seagrass meadows have died off in the past century.


Health of Puget Sound/Salish Sea Eelgrass

New eelgrass growing near a large meadow, Marine Park Beach, Bellingham, recently de-armored.


A recent study  by NOAA and the University of Washington published in the Journal of Ecology examined the change in the eelgrass distribution over large sections of Puget Sound shoreline and reported some startling results. These data were based on over 160,000 observations of eelgrass beds covering over 300 miles of shoreline and were collected over the past 41 years. The surprising result showed that as a whole, the eelgrass population was “stable and resilient” in spite of the fact that this region had doubled its human population during this time with its attendant pollutants. This finding was particularly surprising since world wide, eelgrass is in a significant decline.

However, these results were not uniformly positive as there were site specific trends that were diametrically opposite of the general trend. Some areas had absorbed significant losses of eelgrass, including some sites where it totally disappeared over this 41 year time period.

One such area of decline was Fidalgo Bay, adjacent to Anacortes WA. The loss of eelgrass in Fidalgo Bay which had been a major herring spawning area in Puget Sound, had contributed to the overall loss of both eelgrass and herring production over the past 41 years.  The time series data showed that while there was a slight increase in Fidalgo Bay eelgrass over the past decade, that gain did little to counter the longer term decline since the 1970s. Ongoing studies continue to monitor the grasses and the herring.

Interestingly this treasure trove of data was initially collected by the Department of Fish and Wildlife as a survey of herring spawning beds to better understand why the herring population was declining. I noted in Part 1 that herring spawn their eggs on eelgrass leaves.  And so inadvertently, while sampling herring spawning grounds, the department collected 41 years of data on eelgrass itself and it was only recently discovered by University of Washington Scientists.

A very similar profile is found in the Canadian portion of the Salish Sea. Canadian scientists are currently conducting eelgrass mapping studies that will be the foundation for subsequent conservation and restoration efforts along the British Columbia coast.

Threats to Eelgrasses

In spite of the relatively good news from the NOAA /UW study concerning Puget Sound eelgrass, it is clear that there are serious difficulties world-wide and locally in certain places. Although all of the causes of eelgrass loss are not yet clear,  there is considerable evidence that many of the usual suspects are involved.

Disease: In the Early 1930s, eelgrasses on the Atlantic coasts of both America and Europe were decimated by an “eelgrass wasting disease” thought to be caused by a slime mold Labyrinthula zosterae. However, similar to seastar wasting disease, this suspected pathogen is also found in healthy beds leading experts to suggest that that it preys on plants that are otherwise stressed making them more susceptible to the disease.


Close-up view of an eelgrass leaf lesion caused by Labyrinthula that prevents it from photosynthesizing.


Whatever the cause, 90% of the east coast eelgrass was lost as it was on the Atlantic coast of Europe. Much of it has returned both on its own and with restoration programs but the disease is still present and seems to prey on beds that are stressed by the more increased temperatures and various pollutants.

Also It is reported that 90 percent of California’s eelgrass has been lost since the 1850, probably due to many man-made causes as outlined below.

Shoreline armoring:   In some ways, these tidelands and estuaries are being loved to death – everyone wants beachfront property. Those building close to the beach typically build bulkheads referred to as “Shoreline Armoring.” Shoreline residents build these bulkheads in front of their houses or cottages to keep sea water at bay, for storm protection and to prevent erosion.

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Bulkhead and cottage on Pleasant Cove, Chuckanut Bay, WA. This cove used to be a very productive crabbing site in its eelgrass beds 

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Bulkhead armoring plus boat dock, also in Pleasant Bay


Similarly, building docks into seagrass meadows, dredging bottoms, and pleasure boat anchoring in seagrass beds all contribute to the degradation of this vital ecosystem.

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Edmonds WA, Marina, breakwater, and fishing pier at the right. All are very popular recreational structures but there is a price to pay in terms of eelgrass loss.


Roche Harbor Marina, San Juan Island, WA. A popular boating destination — a lovely bay


Although much of this armoring is for private homes and vacation cabins, it also  includes cities’ waterfronts, parks, shoreline industries, marinas, sea ports, and railroad bedding that runs along the water.

Another recent study of the effects of Puget Sound armoring found that:

A lovely place for children to play on city park beach — rip-rap, Bellingham, WA. My granddaughter had fun anyway. But wait, this beach is significantly changed as part of its restoration that I illustrate below.


        “…armoring was consistently associated with reductions in beach width, riparian vegetation, numbers of accumulated logs, and amounts and types of beach wrack and associated invertebrates.”

Beach Wrack is the residue from sea grasses, here largely eelgrasss, that washes up on the beach from tides and storms. Essentially this study shows  that armoring reduces beaches as well as the amount of available seagrasses in adjacent waters that typically became beach wrack and which becomes home for many beach invertebrates.

Beach wrack, swept onshore by the tide from eelgrass meadows immediately off shore.


To illustrate the scope of the armoring issue problems in Puget Sound I was surprised to learn that there are currently about 700 miles of “armored sea walls,” (about 25% of the total Puget Sound shoreline) from these sources.

Armoring with garbage fill of concrete slabs and old bricks does not prevent erosion — Boulevard Park, Bellingham, WA. To be regraded and de-armored.


A significant portion of these armored seawalls are unlikely to change as they include industrial sites, shipping terminals dependent on sea water access, and large civic marinas mooring boats which support major recreational and economic activities in the sound as illustrated in the above photos.

These same sources of armoring are of course found globally and with the same effects on seagrasses. Our local issues are global issues.

Pollutants:  Polluting salt water and its attendant impacts on eelgrass beds is little different from what we all know as polluting fresh water streams, ponds, and lakes.  The majority of Puget Sound’s pollution comes from water runoff from impervious surfaces that contain petroleum products.  Similarly, industrial pollutants released directly or spilled into streams leading to sea water are contributors. Related are on-water polluting sources such as (illegal) marine fuel spillage and bilge flushing directly into near shore waters by both commercial and recreational boats.

The majority of our region’s Puget Sound pollution is caused by rainwater runoff from our streets, driveways, lawns and rooftops! In fact, 14 million pounds of toxins enter Puget Sound each year.

Commercial, agricultural, and residential runoff often comes in the form of fertilizers and/or manure that runs into rivers that in turn drain to the saltwater estuaries and hence affect eelgrass. Here fertilizer runoff from yards, lawns, dairy pastures and farmland that uses manure and other fertilizers stimulate growth of algae blooms in coastal waters. These blooms “muddy” the water and block sunlight from eelgrass beds inhibiting growth and reducing health of the eelgrass. It also supports the growth of other nuisance and competing sea vegetation.  Added to this fertilizer effect is warming waters that also facilitates algae growth as well as speeds up eelgrass respiration. This increased metabolism causes the grasses to use oxygen at a rate faster than it can photosynthesize. This in turn stresses the plant, leaving it more susceptible to disease.

Direct disruption of eelgrass beds: More direct harm comes from boaters and marinas dropping anchors in eelgrass beds where anchors and their heavy chains drag about the bottom and physically rip up eelgrass plants.

Scars and bottom disruption in the sea bed from anchor and mooring gear in Outer Manchester Harbor, MA  The small white dots are mooring buoys, the fuzzy disruption ahead of the boat is caused by swinging around with the tide and dragging its chain.


Harbor dredging to rid it of accumulating silt is another sources of direct disruption of eelgrasses. Over-water walkways built along the shores are quite popular and provide excellent recreational opportunities for citizens to enjoy the salt water environment. Often however, they are built in or around eelgrass beds which typically are close to shore. If they are over eelgrass beds and not constructed properly, they can restrict sunlight to the eelgrass affecting its growth and viability.

Over the water walkway on the edge of eelgrass beds

Conservation and Restoration efforts: 

As I wrote this section on conservation efforts I was worried that by the time this comes out there wouldn’t even be an EPA and a NOAA to support the current programs. My fears were well founded. The EPA plan is out and proposes to cut 2 billion dollars from the budget and 3,000 jobs.

The proposal specifically targets many of the EPA programs described here. Cuts proposed as follows: Puget Sound, 93%, San Francisco Bay, 100%, Great Lakes, 97%, Chesapeake Bay, 93%, and beach water quality, 100%. If these cuts come to fruition, the local effects will be devastating. This is nothing less than an all-out assault on the environment and those who value it. Calling it a step backwards is a massive understatement.

Although much of the conservation work what we are aware of comes from these agencies, and they are currently doing a lot, there is much more going on than just in the US. Significant efforts are underway worldwide focused on maintaining current levels of seagrasses and restoring those areas where significant loss has already occurred. Coordinating much of the international effort is the Blue Carbon Initiative:

The Blue Carbon Initiative is a global program working to mitigate climate change through the restoration and sustainable use of coastal and marine ecosystems. The Initiative currently focuses on mangroves, tidal marshes and seagrasses. The Blue Carbon Initiative brings together governments, research institutions, non-governmental organizations and communities from around the world. The Initiative is coordinated by Conservation International (CI), the International Union for Conservation of Nature (IUCN), and the Intergovernmental Oceanographic Commission of the United Nations Educational, Scientific, and Cultural Organization (IOC-UNESCO).

Restoration activities in Puget sound are joint ventures subsumed under the Puget Sound Partnership organization that is (was) supported financially by the EPA, the State of Washington, and NOAA. Similar groups are organized around the country that partner with NOAA to direct regional restoration efforts such as …Chesapeake Bay, San Francisco Bay, Martha’s Vineyard, Tampa Bay and many more.

Changing anchoring Behavior. At a very basic level, to the extent that we can change individual’s boating behavior, we can have large effects. Two such programs have done just that on opposite sides of the country.

Port Townsend harbor is a popular boating destination on the Olympic Peninsula in Washington state. Boaters love to visit, eat and browse the quaint shops. But there was a problem. The boaters anchored close to town which was convenient for them to row to shore. But their favorite anchoring spots were where the eelgrass beds were. What to do?



Working with Washington State University extension services, they developed an information and outreach program that informed boaters of the problem and asked them to anchor out a bit further just beyond the eelgrass beds that they marked with buoys. Over 10 years of monitoring boat anchorages, they report a 98%  voluntary compliance rate. The area protected has since been expanded and now covers 52 acres of eelgrass beds along the Port Townsend waterfront.

Tisbury Massachusetts had a similar problem with boaters anchorages. There boaters tied up to buoys that were set up for them but that were anchored to the bottom with large concrete blocks in the eelgrass beds causing problems. Tisbury partnered with NOAA and other conservation groups to install a new buoyed mooring system that does not use concrete blocks and chains that drag over the eelgrass beds.

These pocks in the seabed can be healed with the conservative anchoring techniques as in Tisbury.


This new system screwed into the sea floor and had floating anchor lines instead of chains and thus reduced footprint on the sea bottom allowing clearer water and more sunlight reaching the eelgrass.

Restoration of Damaged Eelgrass Meadows

Working with NOAA and the Nature conservancy, the College of William and Mary’s Virginia Institute of Marine Science (VIMS) has determined that an effective procedure for restoring eelgrass beds is replanting seedlings.

Students from VIMS (William & Mary) scatter eelgrass seeds in Chesapeake Bay


However, they more recently found that harvesting seeds and then spreading the seeds directly into the water is a more efficient method to grow new beds. They have restored thousands of acres of eelgrass beds in Chesapeake bay this way.

Rain Gardens to cleanse the Puget Sound:

A low tech but highly effective means of cleansing pollutant runoff waters is building rain gardens. Rain gardens are strategically placed gardens designed to work like a forest floor or riparian strips along a stream that absorb and filters rain water before it runs into creeks and rivers.

Rain garden in action taking on water from the street and filtering it before in enters the drain system


A cooperative group partnering with Washington State University extension service is sponsoring a campaign to have 12,000 rain gardens built in the Puget Sound watershed.  Although they haven’t met their goal of 12,000 yet, they are making good headway. There are well over 200 rain gardens in Bellingham on the edge of the Salish Sea. Some gardens are in private yards and many are adjacent to public streets where the gas and oil runoff are the worst. As the city redoes streets and sidewalks, they install rain gardens along the way to handle the street runoff. Nearby residents must agree to maintain the garden.

De-armoring the Shoreline:

As illustrated above, armoring the shoreline, even with good intentions, has negative effects on beaches and shores. De-armoring has been shown to have positive effects on the adjacent beaches but this is no small issue to confront. The task is daunting, and in many cases such as industrial related bulkheads, will not happen. Shipping keeps the Puget Sound economy going and we can’t deny that.

Many properties can be de-armored but it is neither easy nor cheap. Historically beaches became dumps for old concrete and bricks, rationalized in part as a protection against erosion. Now we know that it contributes to beach erosion as shown previously.

A couple of  prime examples comes from my favorite waterfront park that was armored with concrete and bricks back in the ‘60s and ‘70s. And an over-the-water walkway was built over an eelgrass bed. Today these misguided activities are being rectified by reclaiming beaches and converting them into a sustainable and extremely popular recreational beaches.

This is the beach (de-armored) shown above where granddaughter was playing on rip rap. Note the changed slope of the beach with groins poking into the water to reduce current flows and erosion. Most of our beaches in this part of the country are rock or pebble based.


The pebble beach shown at the right is the same beach that I showed above with my granddaughter sitting amid concrete slabs by the water. The basic procedures in the reforming of beaches is to provide a gradual slope rather than a wall, and to put in groins (groynes), which are rigid structures, often large rocks or logs, running perpendicular to the beach that restricts water flow along a beach. Breaking up the beach water flow, keeps sand or small pebbles and creates beaches while inhibiting erosion.

Another example from my park that facilitates eelgrass bed growth involves the very popular over-the-water walkways. Since there is eelgrass below the walkway, they retrofitted it with hard grating materials that allowed for sunlight to shine onto the eelgrass below. Now everyone is happy – people get to walk over the water and the eelgrass can to do its photosynthesis while sequestering carbon to store in the seabed.

Perforated materials to allow sunlight and drainage through to the eelgrass below the over the water trail.  


As I delved into this topic of environmental preservation and restoration, the more really exciting projects I ran into. There is so much going on locally and world wide to combat climate change and environmental protection at every level. In spite of what the Rs say, government is working at all levels — from the UN, numerous countries,  right along with most of our states, NGOs, local governments, and individuals. Scientists, citizen-scientists, interested lay persons, kids in schools, are highly involved, all with the same goal of saving our precious environment that we have collectively trashed.

If it were not for our current administration that is attempting to gut the EPA of all “non-essential services,” and NOAA, I would be very optimistic about our environmental future. I believe that we can conserve and restore our environment if allowed to do so. We all need get out and fight for what is left of it. And we’d better get out there and enjoy it while we can. While you out there, help with the clean up.




  1. So, here is part 2. As you will see, there are some pretty cool projects underway to maintain and restore our eelgrass beds and the good that they do. Unfortunately, this too has become political and politics is trying to kill it. We can’t let them.

  2. There are so many projects that need to be saved. I am hoping that the destroyers end up so busy bickering among themselves that none of their plans are implemented.

    Thanks for this series, RonK.

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