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Are bulkheads bad for Puget Sound?

Enviros and waterfront owners have argued the question for years. UW biologist Megan Dethier is out to find the answer.
Jeff Cordell and Erin Morgan survey sea wrack on a Puget Sound beach.

Jeff Cordell and Erin Morgan survey sea wrack on a Puget Sound beach. Megan Dethier

Puget Sound has more armor than the Tower of London — 600-plus miles of concrete, rock and timbers enclosing about 26 percent of its total shoreline. And it’s still spreading: According to data collected by the Washington Department of Fish and Wildlife, a little over a mile of concrete and riprap gets laid along the Sound each year, 76 percent of it on residential property. This trend may accelerate as climate change proceeds and sea levels rise, spurring waterfront owners to seek more protection.

Bulkheads and beach berms disrupt shore currents and block natural beach replenishment, which starves intertidal zones of sand, gravel and sea wrack. These zones are essential incubators for forage fish such as sand lance and surf smelt, and feeding grounds for young salmon, and armoring is widely thought to be dreadful for them. “It’s really death by a thousand cuts,” says Randy Carman, who manages DFW’s near-shore section and monitors the spread of bulkheads.

Nevertheless, good, hard local data on armoring’s habitat effects have until now been lacking. In that absence, often contentious debates have flared for years between environmentalists and scientists eager to restore, or at least preserve, natural beaches, and affluent landowners who fear their waterfront villas will wash away.

Megan Dethier, a biologist at the University of Washington’s Friday Harbor Marine Labs, would like to change that. (Disclosure: Dethier gets funding from Washington Sea Grant, a marine research and education program that I work for.) She’s undertaken the elusive task of documenting the ecosystem effects of shoreline armoring on Puget Sound. Elusive, she explains, because “it’s trying to look at a process that takes decades. Funding organizations don’t tend to provide money for a study taking longer than two or three years.”

Those impacts have been studied and confirmed in Europe, New England and Hawaii, where studies conducted over many years, taken together, provide the long view needed. “As naysayers are quick to point out, conditions are very different here,” says Dethier. And there have been “surprisingly few” studies documenting impacts in this region.

Dethier decided to beat the clock and compress that process by comparing conditions at 31 pairs of neighboring beaches, 25 in West Seattle and elsewhere on Central Puget Sound and six on the South Sound. One beach each pair was armored, the other not; together they reveal effects accruing over decades.

For three years, Dethier and her colleagues have surveyed the beaches’ topography and overhanging vegetation, measured their sediment grains and deployed wave gauges. They’ve tallied washed-up logs and wrack, the insects, crustaceans and worms dwelling amid them, and the abundance and types of juvenile clams in the low shore. To unravel what this means for the food web, graduate student Sarah Heerhartz (at left) snorkeled the Central Sound sites counting juvenile salmon and recording their behavior. She’s also developed studies (still underway) to quantify beach use by land birds. Spoiler alert: Fewer birds appear to congregate on armored beaches, and they use them differently.

Dethier and Heerhartz have submitted two papers for publication, on the relative abundance of the organic debris called “wrack” on armored and natural beaches and on how young salmon behave along those beaches. They’re still working on a third paper, which will look at insects and other invertebrates there.

They haven’t found differences in grain size or clam abundance at mid-shore levels, though Dethier cautions that impacts may yet occur in the longer term. Further up, they found slightly steeper foreshores on armored beaches and coarser sediments — a concern for surf smelt and other forage fish that spawn there. The armored beaches also had less riparian vegetarian and substantially fewer logs (important as wave buffers and habitat), as well as less of the sea and terrestrial wrack — seaweed and leaves, respectively — that shelters the invertebrates on which fish and birds feed.


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Comments:

Posted Mon, Nov 4, 11:08 a.m. Inappropriate

If only we'd never privatized so many of our tidelands in the first place.

Posted Tue, Nov 5, 11:41 a.m. Inappropriate

Well, I'm far from "affluent" and my "waterfront villa" is a 900 square foot beach cabin built in the 1930s, but I can relate my experience in replacing the wood bulkhead my grandfather installed in the 1950s. The bulkhead was essentially gone. The wakes from boats and jet skiers had washed the beach down to hardpan and were undermining the trees which hung out over the beach. One tree was hanging 35 feet out from the undermined bank. The roots of those trees extended under the house, which has a post and pier "foundation."


In my case, it was either replace the bulkhead, or cut down the trees.


I chose to replace the bulkhead with one made of rock. This was expensive. About $40,000. But in the end it preserved both the beach and the yard. Stumps were hauled in and placed on the beach to provide fish habitat. "Fish mix" gravel and sand was spread on the beach. The height of the bulkhead is equivalent to the average mean-highest tide level (a 15' Winter tide with a south wind) so there's no protection from sea-level change there. The result is that the beach is recovering. There are more fish and more diving ducks. Even more crabs. The rough surface of the rocks breaks up waves from boats the reduces the scouring of the surface that those waves produce. It seems to be a winning situation for everyone. The marine creatures are happy, the trees are happy, and I've been able to absorb the cost of the structure, the permit fees it required, and the increase in my property tax.


But "affluent"? Gimme a break. Very decidedly middle class. Maybe in a few more years I'll even be able to get my threadbare furniture recovered...

dbreneman

Posted Wed, Nov 6, 9:26 a.m. Inappropriate

Just out of curosity - did you consult with anyone on a more "soft" design using keyed in logs with more resiitent hard materials and laying back the beach? This more fish-friendly design type has been used quite a bit on restoration projects I've worked on - just curious if you considered this, thought it was to expensive, or if you engineers just said it was not feasible? Thanks.

See here for example of bulkhead removal (yes houses there): http://www.coastalgeo.com/projects/restoration.php

Treker

Posted Wed, Nov 6, 12:30 p.m. Inappropriate

I assume this question is addressed to me. Unfortunately, I have an approximately 10" vertical bank to the beach. My house is 30' away from that edge. If by "laying back" the beach you mean sloping it gently up to the level of the yard, that would have required me to move my house. All of the houses on either side of me have vertical concrete bulkheads put in in the 50s and 60s. The original bulkhead on my property was wood. The former neighbor to my south has a bulkhead over 12 feet high, because he didn't want to have a slope to his yard. (A county worker with a lot of connections, he was able to put it in without a permit in the late 50s - I doubt it met regulations even then.)


My bulkhead is six feet high, and it's set back to be in line with the stringers of the bulkheads to either side of it (in other words,it's built on a plane with the original bank), since according to current law, a bulkhead cannot "create new land". It's made of native gray rock quarried from Olympia, so it blends in much better than the two other rock bulkheads fairly near me, which are brown in color. It's far from a perfect solution, but it was the least worst one. Again, one of my goals was to keep the trees which overhang the beach. Not only do they provide privacy, they provide needed shade for fish, crabs and other marine life at high tide. The trunk of one of these trees dips down to within two feet of the beach - and extends 35 feet from the bank. Most people would cut trees like this down for the sake of a view, but I sought to protect them. A bulkhead was the only route to go. And believe me - I'd rather have spent the 40+ grand on a new car!

dbreneman

Posted Wed, Nov 6, 12:32 p.m. Inappropriate

Oh, and yes, the engineer thought that this was the only practical route. So did the Fisheries agent and his supervisor, who made a couple trips to the site.

dbreneman

Posted Thu, Nov 7, 2:53 p.m. Inappropriate

Thanks - yea, sounds like a very constrained site.

Treker

Posted Wed, Nov 6, 9:51 a.m. Inappropriate

Love the smarmy tone of the article--affluent beach owners. Perhaps you should come out to the shoreline and talk to people sometime instead of sitting inside the echo chamber of the enviro-industrial complex.

This theory is accepted as gospel and Dethier and her co-grant recipients set out to prove it, come hell or high water. (No pun intended.)

Dethier decided to beat the clock and compress that process? That should be interesting. And just what IS a natural process? The poster above mentions boat wakes ripping up his natural beach. So what now? Surrender and go inland is the implicit assumption. Don't protect the home; we must protect the fish, even if we can't establish that there's a valid scientific relationship.

avocats

Posted Wed, Nov 6, 10:06 a.m. Inappropriate

I think you are misundersanding the attempt by the author to explain the statistical design of the project - by looking at unarmored beaches vs. those where armoring is in place, and over different shoreline geomorhological scales - you can get data on "control" and "experimental" sites - or as best you can in the natural environment, and then make your assessment based on statistical analysis of the data. It is a solid study design. And it will provide valid results rather than trying to monitor a new bulkhead for 30 years.

And your confusing policy analysis and implementation with science. Thre are already amble shoreline regulations in place for new bulkheads - and generally, replacement of existing bulkheads are allowed under the local Shoreline Managagement Programs.

Megan Deither is a well-respected scientist with a long list of peer-reviewed journal publications. Trying to paint her as an activist is neither fair nor valid.

How we, as a society, manage our shorelines based on science is another matter. One thing is for sure - globally we've decided to not do much about climate change and it is going to have significant effects to shoreline infrastructure. There is no way (even if I could afford it!) that I would own shoreline property - let's just say the long-term cost curve is steep.

Treker

Posted Sat, Nov 9, 9:42 p.m. Inappropriate

Given the near-universal findings, in very different shoreline environments, that bulkheads have a negative effect on aquatic vegetation and species diversity it would be pretty amazing to discover that NW beaches operate by different rules.

Avocats takes the position that there is some sinister enviro-industrial complex, presumably out to take away our property and freedom. Attacking researchers has become a standard tactic, usually with some implication that they are in it for the money. If anyone is motivated by personal financial interest it's you. Talk to people on the shoreline? Do these unnamed people have some wisdom beyond science?

The Puget Sound environment has visibly degraded in my lifetime. Historic declines in fish and species diversity are staggering and beyond dispute. I understand the concern of property owners. I have a small house on Hood Canal myself and have heard all the attempts to shift blame for environmental decline as small, rarely used cabins have been replaced with huge, lot-filling houses. Bad practices of the past don't excuse present bad practices. What might have been acceptable in the past doesn't work at current population and use levels. Sorry, that's reality.

Posted Sun, Nov 10, 1:06 p.m. Inappropriate

Grants that use any combination of funds that include taxpayer dollars should require that subjective descriptions such as "affluent beach owners" be denied grant funding, and if used once funding has been granted, be cause for immediate termination of grant funds.

Neutrality is critically important when utilizing taxpayer dollars.

Author Eric Scigliano has done nothing to further credible research by labeling waterfront property owners as 'affluent', nor by stating that 'good, hard local data on armoring's habitat effects are lacking' stated as a factual statement. There are many studies on bulkheads and armoring, and many experts making their living building same, researching same, and/or applying code guidelines to same.

My recommendation is to delete this offensive paragraph completely since it is incorrect from start to finish.

"Nevertheless, good, hard local data on armoring’s habitat effects have until now been lacking. In that absence, often contentious debates have flared for years between environmentalists and scientists eager to restore, or at least preserve, natural beaches, and affluent landowners who fear their waterfront villas will wash away."

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