We have been tracking, and trying to understand dramatic and novel mortality of sword ferns in our old-growth forest’s understory. Only sword ferns (Polystichum munitum) are affected.
Two Univeristy of Washington students spent the summer surveying throughout the Puget Lowlands of Washington state, establishing that the sword fern blight is intermittently present throughout that region. This project is reported here.
At Seward Park, we have observed the “split site” (see map tab) informally for two years. This summer (2025) we approached it systematically, by
have no obvious canopy differences (though month-by-month insolation data have not been collected)
are separated only by a fallen Douglas-fir log which, in the site, has a ground clearance averaging three inches (need to verify this!) allowing easy passage air, insects, small mammals and rainwater.
Nonetheless, and for several years, sword mortality is dramatically different between the two halves. The remnant dead fern crowns (dark grey markers on the map) indicate that mortality struck here three-to-five years ago. This summer (I write in September 2025) a few of the “healthy side” ferns show their first signs of blight.
On the affected half-site, the survival of 3 of 21 ferns (14%) fits our informal sense that even in heavily affected pure stands, and perhaps due to genetic variability, 10% of the stand survives the blight.
A simple chi-square calculation shows that the significance (p-value) of the separation is 4.887e-07. In lay terms: there is 1 chance in two million that this contrast happened by chance.
Thus this site, judiciously studied, and with many conditions and features identical, and dramatically different outcome, may help us to understand the nature of the sword fern blight.
Results of Soil Tests Conducted Separately on the Two SubSites
Four soil samples were collected on each subsite, to a depth of three inches. These were pooled to create two aggregate samples, one for each side, and sent to EarthFort of Corvallis Oregon for analysis.
There are many healthy sword ferns in the forest – esspecially right by the trails. Those which have died (or are now dying) are easy to overlook.
But the die-off continues – this video shows. We estimate that more than 100 of these normally long-lived plants die each year. For the full history of the research, look here.
One thought on “Sword Fern Mortality Continues”
Hi. Do the Seward park rangers advise folks at pavilions and parking lots to lower the volume of their music? A loud base has been heard around the park and beyond on Saturday morning 8/16 for hours. It’s quite annoying for the sound to invade the space of others. Thank you
New forest steward Jenny Dooley kicked off this restoration project on May 17th. This half acre in the middle of the forest has 605 dead ferns, some surviving ferns, and a smattering of other understory plants.
Garfield High School Senior Nate Butcher and UW’s Dr. Tim Billo worked through the summer of 2024 collecting the first comprehensive baseline vegetation data for future monitoring of Seward Park forest. Wonderful insights into the structure of the forest emerged. See slide show here.
One thought on “Forest Survey & Inventory – 2024”
alluring! Major Hotel Chain Goes Carbon Neutral 2025 sophisticated
We mapped 56 dead sword ferns. Having learned that natural regeneration takes decades, we spread mulch thickly over the site – with a few cubic yards of mulch still to go. We will plant high-survival native species next winter.
Attending: Lizbeth Coller, Paul Talbert, Al Smith, Ted Weinberg, Chris Hollinger, Paul Shannon, Nate Butcher, Liz Van Volkenburgh.
Paul Talbert called the meeting to order at 9:35 am.
Announcements. Paul Talbert moved that renew our business license. Moved, Voted, Passed (MVP) Paul also announced that FoSP must file a Beneficial Ownership form, related to its 501c3 status. This will be taken care of by Paul or Lizbeth.
Audubon Update. There was no Audubon Update as Joey was not present.
Monthly Reports. Lizbeth gave the Treasurer’s report: FoSP has $62,974 in its budget. A check for $960 has been written for Dylan Mendenhall for his contracted work on the sword fern sequencing project. Two donations have been received with no restrictions ($250, $5000). The Secretary’s report written by Patty Borman was emailed to the Board members on November 18. With no objection, those minutes stand approved.
Luminaria. The Luminaria organized for November 30 by a neighbor, Meghan Austin, and supported by several volunteers from the Board was a success. People coming to see the Christmas Ships were pleased and offered many thanks. Paul Talbert will send a thank you note to Meghan.
Sequencing update. Paul Talbert had sent out an update prior to this meeting and reviewed that for the Board. Paul Shannon objected to approving Dylan Mendenhall’s progress as “OK” stating that Dylan is 4 months behind schedule. After considerable discussion it was agreed that Paul Talbert would reach out to Dylan by phone to let him know there is a check in the mail for him ($960) and to share the Board’s frustration with Dylan’s slow progress. It was further agreed that by January 15 Dylan must show evidence (e.g. a photograph of bands on a gel) of successful bacterial, fungal and/or oomycetes amplification from his samples of fern fronds. In the event that no microbial DNA is amplified, the question of whether to proceed will come to the Board for a decision. The issue is whether the Board will want to risk funding DNA sequencing on samples that Dylan was unable to amplify microbial sequences from. In conversation with Dylan, Paul Talbert would also offer him an off-ramp to exit the project. Paul Shannon discussed options for pursuing the project with other labs and was encouraged to seek a bid from Dr. Marianne Elliot at WSU. Another option would be to approach Dr. Ryan Kelly at the UW eDNA Collaborative via Tim Billo.
Richard reported the discussion about speed bumps from the WDOT meeting with Seattle Parks. The meeting was organized with group work and reporting out but was quite contentious.
Forest Report. Paul Shannon reported that work parties have been happening every month following a gardeners’ strategy to mulch one foot deep, wait a year, then plant. So far, this strategy has been successful for revegetating parts of the park. Nate Butcher provided a brief update on his research project supervised by Tim Billo making a baseline vegetation survey utilizing 18 randomly positioned plots. Nate will provide a formal report in January. He is also seeking assistance with analyzing the data with appropriate statistics.
Other business. Paul Shannon asked for time to brainstorm creation of a 500 year plan as an update to the Vegetation Management Plan made in 2006 by FoSP with support of Seattle Parks. This idea was discussed and clarified – the intent is not to specify what will be planted when or what the park will look like in 500 years, but rather is to specify how to figure out what steps to take to keep the vegetation healthy. These ongoing management processes could include surveys, research studies, implementation of plans known to be successful in similar situations, etc.
We have wanted to do this for ten years, and finally the day has arrived. Our documentary film helped us to gather $15k, so on September 17th, Dylan Mendenhall of Haven Ecology collected sword fern tissue samples. We hope to identify contrasting microbiomes by comparing diseased tissue (from an active die-off site at Seward) and healthy controls (from Seattle’s Interlaken Park). Our informal studies suggest that the ferns are being killed by a water-borne pathogen, or by the loss of a protective microbe. DNA sequencing may identify the species.
Dylan is now extracting DNA for submission to Dalhousie University, where PCR amplification of fungal, bacterial and oomycetes primers prepare for sequencing. Dylan will analyze the data, with results ready by the end of the year.
The sword fern die-off is now broadly recognized as a regional problem, common across the Puget lowlands. Nonetheless, this loss of a foundational PNW forest understory speices has failed to garner interest and funding from government and academic researchers.
That may change. Washington’s Department of Natural Resources and UW researchers tell us they will be interested in following up if we obtain significant results.
Three students, UW’s Dr. Tim Billo, forest steward Paul Shannon, 500 hours of field work, 724 trees. We determined that hemlock mortality is concentrated in one six-acre site, with thriving hemlocks elsewhere, of all ages. This establishes that neither climate nor old-age is the cause. And it presents an opportunity for further study. Something is killing hemlocks, but it is not weather patterns, soil, geology or old age. The final report, with interactive map, data table, and statistics is here. DNA sequencing of failing hemlocks and sword ferns scheduled for this summer.
We held our first this past weekend, April 6th – to repeat every first Saturday of the month, year round. Email us if you wish to be on the notification email list.
Here are some of the volunteer crew, relaxing after moving a ton of mulch into the Fairy Tree play area. We have two goals: to keep this spot safe, open and for kids, and to protect the forest from enthusiastic overuse.
With this final result:
We also built a brambly barrier to protect this year’s new planting near the Hollow Tree, another favorite kid play spot, on the Woodpecker Trail.
Seattle Parks Trail Maintenance chief, Amir Williams, and crew, did an elegant & minimal pruning of the seqebeqsed trail in the last week of August. Thank you, Seattle Parks!
12 September 2023: Leaves with distorted shape and size dominate parts of many of the forest’s Oregon Ash trees. Total foliage in some is sparse. I think the initiation of further distortion ended with the summer dry period. The trees otherwise seem healthy. And if protracted spring/early summer rain recurs only infrequently, in future years, I predict no lasting harm to this species. I will continue to watch.
Andrews Bay separates Bailey Peninsula from the rest of southeast Seattle. It is home to breeding peamouths, juvenile and spawning salmon, and other fish and invertebrates. Bald eagles, ospreys, double-crested cormorants, great blue herons, kingfishers, mergansers, and Caspian terns regularly fish the bay. Buffleheads, goldeneyes, scaups, ring-necked ducks, widgeons, gadwalls, mallards, Canada geese, coots, gulls, and occasional eared grebes and loons find food and shelter in the protected waters. Pied-billed grebes make their floating nests among the cattails and bur-reeds. Turtles sun themselves on rocks and fallen trees. Beavers, otters, and muskrats make their homes in the bay or visit to find food. Red-winged blackbirds sing from the shorelines, while dragonflies, swallows, and bats catch flying insects over the bay.
The native people living on the shores of Lake Washington most likely hunted ducks in the bay from their canoes, and gathered wapato for food and cattails for mats. With the arrival of Euro-American settlers, the bay was named for Lyman B. Andrews, early pioneer of Issaquah and Seattle, who was a chainman on the crew of the cadastral survey of 1861 that first used the names Andrews Bay and Andrews Peninsula. Though the name of the peninsula changed with different landowners, Andrews’ name is still attached to the bay.
Boats in the bay
In their 1912 Preliminary Plan for Seward Park, the Olmsted Brothers firm envisioned Andrews Bay as being for small pleasure boats, not for steamers and commercial boats, the motorized boats of the day. As early as 1905, before Bailey Peninsula had been acquired for a city park, the Seattle Boat Club held boat races in the bay. A public swimming beach was created at the head of the bay in 1918, and has been popular ever since. By the Great Depression, neighborhood groups strongly opposed a proposal to make a permanent race course in the bay because of the roar of motorized boats. Nevertheless rowing or crew races were very popular in the bay in the 1940s. The route of the races is still used for training by the Mount Baker Rowing and Sailing Center. Today the bay is used by swimmers, rowers, canoeists, kayakers, and paddleboarders, but the most visible use in the summer is for anchorage of motorized boats.
Ordinances
In 1909, the state granted jurisdiction of waters and tidelands fronting or adjacent to a city or town to the city or town to the middle of the bay, river, sound, lake, or other waters (RCW 35.21.160). When the city acquired Bailey Peninsula in 1910 and owned both sides of Andrews Bay, it acquired jurisdiction over the entire bay.
In 1996, a temporary ordinance (Ordinance 118114) that was soon made permanent (Ordinance 118570 in 1997) established the eastern portion of Andrews Bay as a location for overnight anchorage of boats (up to 72 hours).
Seward Park Anchorage Zone
The capacity for the bay suggested by Seattle Parks and Recreation (SPR) is 80 boats, though on a summer weekend it is more common to find 150-300 boats. Despite a persistent myth that Andrews Bay is the only place to anchor on Lake Washington, overnight anchorage of up to 72 hours is also available at Kenmore and Juanita Bay. That said, the distribution of anchorage sites is highly inequitable, with most lake communities banning anchorage outright. Union Bay Natural Area, reclaimed from a landfill, is protected as a natural area and prohibits motorized boats. In contrast, Andrews Bay, a natural bay flanked by old-growth forest with some of the best available salmon habitat left on the lake, receives a high concentration of motorized boats and no active protection.
Anchored boats on Andrews Bay
Four similarly sized bays that ban anchorage
The growing noise from increasingly sophisticated sound systems on boats motivated local neighborhood activists around the lake to lobby for noise ordinances. In 2012 a noise ordinance was passed for Juanita Bay and in 2013 one was passed by the Seattle city council at the behest of park users and Andrews Bay neighbors. However, while Juanita Bay enforced their ordinance, the Seattle Harbor Patrol, headquartered an hour away in Lake Union, did not enforce the noise ordinance on Andrews Bay, and the noise instead worsened when noisy boaters from Juanita Bay relocated to Andrews Bay.
Seattle Ordinance 124225: “It is unlawful for any person to negligently cause, make or allow to be made from audio equipment under such person’s control or ownership sound from a watercraft that can be clearly heard by a person of normal hearing at a distance of three hundred (300) feet or more from the watercraft itself.”
In 2018, ostensibly to clarify jurisdiction, the State Department of Natural Resources (DNR) granted a 30 year lease of Andrews Bay including the use of the anchorage area “for no other purpose” to Seattle Parks and Recreation without any apparent public input or notification (Aquatic Lands Lease No. 22-096863). It is unclear why this was necessary, given that the 1909 law already gave the city jurisdiction. This “clarification” and a claim that “Harbor Patrol can better control unruly behavior if area is under SPR management” did not result in any enforcement of the noise or anchorage ordinances from either the Harbor Patrol or Seattle Parks and Recreation, despite the fact that the lease allows “Andrews Bay to operate as a public park.”
DNR lease area
Worsening impacts
The situation became less tolerable to neighbors during the 2020 pandemic, when summer weekend noise, derelict boats, and overcrowded drunken floating parties without personal flotation devices for the participants were accompanied by two drownings. The Save Andrews Bay neighborhood group formed to lobby city officials and park employees to enforce the ordinances. Save Andrews Bay is concerned not only about noise, but the safety of swimmers and boaters, fuel and sewage spillage into the bay, anchorage outside the designated area that reduces space and safe passageway for non-motorized users of the bay, and the impact on both surface wildlife and the benthic flora and fauna when 200-300 boats are anchored in the bay.
In direct contradiction to the desire of the Olmsteds to prohibit commercial use of the bay, commercial cruises advertise “waking up on quiet Andrews Bay” by booking an overnight bed-and-breakfast cruise. It is unclear whether these cruises are permitted by Seattle Parks and Recreation.
Enforcement
In 2022, after no visible action by the city, Save Andrews Bay teamed with the Friends of Seward Park to raise $17,000 to hire the Harbor Patrol to patrol Andrews Bay on summer weekends. This was significantly successful, with noise levels reduced because the Harbor Patrol had a presence, even though no tickets were issued. There were no drownings. Unfortunately, raising private funds to patrol a public park is both inequitable and unsustainable, and our hope is that having been shown that enforcement can make a difference, the city will budget for future enforcement. To date no such funding has been budgeted, but $50,000 has been budgeted for buoys with better signs marking the anchorage area.
A permitting system for anchorage has the potential to control overcrowding and noise and pay for itself, but thus far the city has shown no interest.
Help us monitor sword fern die-off with time-lapse photography
With advice and approval from Seattle Parks, yesterday I installed the first of two photo monitoring stations in the Magnificent Forest. The time-lapse (still at an early stage) can be viewed here. This photo, from the chronolog.io website, shows how it works: take a photo with your smart phone, and email it to the address on the sign. This photography post is at the intersection of the sqebeqsed and Windfall trails.
Reading six poems 1993 (including “Settling”) – click to see video
Denise Levertov lived the last eight years of her life a block from Seward Park. A plaque installed in 2016 marks her home nearby. She was an anti-war activist, a feminist, an environmentalist – “a fiery pilgrim who never wanted to be known as any of those things” (Rich Smith in The Stranger, 2015). If rankings and company matter, then she comes off well, grouped with Wallace Stevens and Elizabeth Bishop, a young correspondent with T.S.Eliot, mentored by William Carlos William, associated with the Black Mountain School. With her friend Robert Duncan she was viewed as among the most important post-war American poets.
Levertov knew and loved Seward Park. She walked the trails of what she described as this “almost island, almost wilderness”. She captured some of its strength and depth in her late poems.
In a 1991 essay “Some Affinities of Content” she wrote “People say that every poet of the Pacific Northwest has to write a heron poem now and then.” And she soon obliged. Here is her second heron poem, from the 1992 collection Evening Train.
Heron II
Elegantly gray, the blue heron
rises from perfect stillness on wide wings,
flies a few beats
sideways,
trails his feet in the lake,
and rises again to circle
from marker to marker (the posts
that show where the bottom shelves downward)
choosing:
and lands on the floating dock where the gulls cluster —
a tall prince come down from the castle to walk,
proud and awkward, in the market square,
while squat villagers
break off their deals
and look askance.
And from the same collection (Levertov reads this live, the first poem in the video above):
Settling
I was welcomed here—clear gold of late summer, of opening autumn, the dawn eagle sunning himself on the highest tree, the mountain revealing herself unclouded, her snow tinted apricot as she looked west, tolerant, in her steadfastness, of the restless sun forever rising and setting. Now I am given a taste of the grey foretold by all and sundry, a grey both heavy and chill. I’ve boasted I would not care, I’m London-born. And I won’t. I’ll dig in, into my days, having come here to live, not to visit. Grey is the price of neighboring with eagles, of knowing a mountain’s vast presence, seen or unseen.
In 1961, witnessing the decline of her mentor William Carlos Williams, and the mental illness of Ezra Pound, she wrote these words – words which we may now apply fairly to her as well.
This is the year the old ones, the old great ones leave us alone on the road. The road leads to the sea. We have the words in our pockets, obscure directions.
And not always obscure: it is not easy to miss heron’s feet trailing in the water. And we all – knowingly, and maybe sometimes willingly – pay the price of grey to neighbor with eagles. This beautiful peninsula, almost island, almost wilderness, and with – almost – an official poet laureate.
Photo courtesy of Craig Rochester, Seward Park, July 2020 (with permission)Recording courtesy of Michelle McElhaney
The Forest’s coyote pack has become more vocal over the past weeks, a good sign that their breeding season has begun. Bonded coyote pairs announce their breeding territory with a multitude of vocalizations. Other pack members will often chime in. The result is a chorus of warbling yips, howls, barks, and more.
“Group yip-howls are produced by a mated and territorial pair of “alpha” coyotes, with the male howling while the female intersperses her yips, barks, and short howls. “Beta” coyotes (the children of the alpha pair from previous years) and current year pups may join in if they are nearby, or respond with howls of their own.
…the group yip-howl is thought to have the dual purpose of promoting bonding within the family group while also serving as a territorial display. In other words, the coyotes are saying “we’re a happy family, and we own this turf so you better keep out.” In a sense, the group howls create an auditory fence around a territory, supplementing the physical scent marks left by the group.”
It could be that the Forest pack is letting the word out to adventuring coyotes who might be looking for a home in the Forest, or they’re just letting the humans who walk in the Forest know of their presence. However, Seward Park is an urban park and the Forest’s coyotes also respond to urban sounds. Stop for a moment over the next couple of months and listen for their replies if you happen to hear sirens from fire trucks on the Blvd or the rumble of a seaplane flying low overhead.
Coyotes are an important part of the Forest ecosystem. They’ve been here for years and are doing a great job of controlling the rats and feral rabbits that live in the Forest. Coyotes are usually shy around humans, but it is important to discourage them from getting too familiar with us. Get big and loud if you come close to one. They’ll leave. And please keep your dogs on leash, for their safety.
Hi. Do the Seward park rangers advise folks at pavilions and parking lots to lower the volume of their music? A loud base has been heard around the park and beyond on Saturday morning 8/16 for hours. It’s quite annoying for the sound to invade the space of others. Thank you