Talk NERRdy to Me: Kerstin Wasson

Talk NERRdy to Me: Kerstin Wasson

Talk NERRdy to Me is a monthly column about leaders and luminaries from across our 29—soon to be 30—Reserves. This month, NERRA’s correspondent-at-large Nik Charov interviewed Dr. Kerstin Wasson, research coordinator at the Elkhorn Slough Reserve. They talked about marsh making, work marriages, ungrateful and grateful children, Indigenous knowledge, and the non-monetary valuations of mud.

Nik: Welcome to Talk NERRdy, Dr. Kerstin Wasson! You recently told me Kenny Raposa was your work husband. How does your home husband feel about that?

Kerstin: Many days I interact more with Kenny than with my husband. We often send hundreds of messages back and forth within a week. We don’t really talk or see each other, but we interact through collaborative manuscripts. It’s been one of the high points of my last decade of work to interact with Kenny Raposa. It’s just what a collaboration should be when you’re challenging each other and debating things, but making it better as a result of that.

Nik: Are you referring to the National Synthesis?

Kerstin: In the last decade of NERR work, my main papers have been with Kenny. The assessing tidal marsh resilience to sea-level rise (MARS) project was the first in a series of collaborative projects. Then we looked at crabs across the NERRS, wrote another paper on that, then we coordinated a thin layer sediment restoration experiment across eight Reserves. We’ve been trying to camera trap across all the Reserves but haven’t found the funding yet.

Wasson with her “work husband” Kenny Raposa (right) and sediment science rockstar Neil Ganju in Rhode Island.

Nik: That all sounds exhausting. Also, didn’t Elkhorn Slough just build Hester Marsh? Is it fun to play God? 

Kerstin: Scary, but fun. We are super proud that we did this, with a huge team and a lot of funding, of course. We asked, “How high should we make it?” and the answer was “as high as possible without becoming a grassland.” The king tides need to get it wet so that you don’t show your funders, “Look at this weedy pasture that we made!’”

Nik: I’ve got a weedy pasture in my backyard. Agreed: not impressive.

Kerstin: And because it was going to sink, we wanted to overfill it, but how much do you overfill? And what about tidal creeks? If we fill the whole thing, it has no creeks. Where are we going to put them and what should they look like? We decided to use history as a guide and look at the 1931 aerial photo—our oldest—and make them that way.

Nik: What does it mean to “make” a tidal creek?

Kerstin: We thought about maybe filling them with straw or something and protecting them, but it was more effective to just dig them out at the end. On a smaller scale, we are now doing lots of experiments.

My hero, restoration scientist Joy Zedler, encouraged the NERRS to use large-scale restoration activities as a place to learn and do science, and we have really taken that to heart.

When the landscape was bare, people used to ask, “Is it a flag farm?” Because there were so many red flags for this experiment and green flags for another. We planted 17,000 plants! We are learning from this restoration and that part is a lot less scary than playing God at the large scale.

Nik: You generously bumped a graduate student off your schedule so that we could talk today. How are the kids coming up? Did they do all that planting without complaint? What faith do you have in the future?

Kerstin: They’re awesome. My academic daughters are so much more grateful for the advice I give them than my biological daughter. 

Nik: Because you’re not related to them. I have teenagers, too.

Kerstin: I love having graduate students and working with them. The gold standard of what we know about the estuary comes from graduate theses that really dive into something. We provide a lot of guidance and logistic support in return.

Nik: There will be $77 million over the next five years for NERRS habitat restoration. Are we all going to build enormous outdoor sandboxes? Or does 30 by 30 mean everybody will get another 100 acres of marsh? “You get a marsh, and YOU get a marsh, and YOU get a marsh!”

Kerstin: Sea level rise is threatening marshes in so many regions. If we can save an existing marsh, that’s better than anything we can create. Meters of peat represent thousands of years of carbon sequestration and plant and animal communities that take hundreds of years to form. But sea level rise is not going to leave us many choices. 

In Elkhorn Slough, modelling suggests we will lose all marshes to 50 centimeters of sea level rise. If we want there to be a marsh for our great-grandchildren, the one we built is going to be the only one there. However, we also made some migration space for it to move up. I think that a lot of us will be doing that across the System in the coming decade. 

Nik: Why “Hester” Marsh, by the way?

Kerstin: Andrea Woolfolk, our stewardship coordinator, has done a lot of historical ecology research in the region to really inform our restoration work. She discovered that one of the first European landowners in the area was a woman named Hester Miller. She had a dozen or so kids and that seemed like a good omen for our marsh, to have a female name and a fertile landscape.

Nik: It rolls off the tongue. Hester sounds like a heroine in an Austen novel.

Kerstin: You’re thinking Scarlet Letter

Nik: Hester Prynne! Right, but that’s New England. Speaking of which, let’s get back there, because I’m too jealous of California’s beauty.

My chat with Kenny was a little depressing—he’s  spent his entire career in Rhode Island and he expects that, within his lifetime, everything that he’s worked on may disappear. I guess I understand why you’re on a first name basis with your marsh—it’s something that will outlive you and won’t drown. It’s gotta be pretty gratifying to bring that into the world. And scary as well. Like parenting.

Kerstin: Climate change is going to alter our estuaries but that scares me less than the outright loss we’ve seen in the past century. Half of the Elkhorn Slough estuary is behind dikes and water control structures, which is a much bigger change than a marsh converting to a mud flat.

When marshes drown in sea level rise, migratory shorebirds will feed on the mudflats they become, and fish nurseries will expand in the eelgrass, which is actually thriving in the estuary. Sea level rise may allow us to regain disconnected wetlands, and conservation organizations may restore some of those lands. It may actually look better in 50 years, so I’m optimistic.

Sorry… my [home] husband’s coffee timer keeps beeping. He doesn’t want the french press to brew too long or too short.

Nik: We use an eight-minute brew in my house. How do you do it? 

Kerstin: I’m a tea drinker.

Nik: I don’t trust tea drinkers. First, you’re lauding colonialism with your Hester Prynne Marsh, now you’re talking about tea. Why couldn’t you have named it after the Native Americans?

Kerstin: I wish we had more of an understanding of who was living around our estuary and what they were doing. But we are partnering with the Amah Mutsun Tribal Band, who are trying to reconnect with their ancestral lands.

Most of them can’t afford to live in coastal California but they come back and do activities along the coast with partner organizations. On December 1st, they’ll be doing oyster restoration with me. We’ll learn from each other; our Reserve staff will learn about cultural perspectives and spirituality that they bring to interactions with nature and coastal stewardship. Their tribal members have never seen, touched, or eaten a native oyster even though their ancestors ate them for millennia.

Nik: More and more it seems that there are connections with local tribes in the NERRS, working together and sharing traditional ecological knowledge, but your approach sounds different.

Kerstin: I think there are prospects of learning from Native American communities further north on the coast that still have experience passed down directly from generation to generation. There are reservations near the Padilla Bay Reserve on coastal lands and oyster restoration efforts. Not every culture had the same practices but there are probably commonalities that could be exchanged up and down the coast. We’d love to work on that in the coming years. 

Celebrating finishing planting at Hester Marsh at the end of a muddy day, Karate Kid style.

Nik: What else is going on at Elkhorn Slough? We’ve gotten 20 minutes into this and you haven’t said the word “otter” once, which makes me happy.

Kerstin: What do you have against otters, and how long has this issue been troubling you? 

Nik: I went to school in California and I dated a girl who really liked otters and that was the beginning of the end of our relationship. And I can’t stand that some Reserves have such charismatic megafauna that they could live on the proceeds of otter stuffed animals for the rest of their existence.

Kerstin: I decided to be a biologist when I was five because I wanted to study marine mammals. I wanted to learn dolphin language. But when I took invertebrate zoology, I realized that invertebrates are so much cooler than marine mammals. I ended up doing my PhD on modular organisms that have many bodies per genetic individual. It’s like having thousands of twins.

Nik: Is that a colonial organism?

Kerstin: Yeah, and that’s a lot weirder than dolphins.

Nik: It sounds pretty slimy. So you’re a zoologist by training?

Kerstin: I am.

Nik: So what are you doing, plugging plants into a marsh? That’s botany!

Kerstin: They’re modular! The pickleweed I work with reproduces clonally, so there are some commonalities there. The invertebrates I was working on, Phylum Kamptozoa, don’t look that different from a pickleweed plant.

Nik: I’m getting more into the colonial and slimy. I learned about Bowiebranchia in an interview a couple months ago and that was one of the highlights of my year.

Kerstin: I’m drawn to slimy things. But I’ve come around to the fact that it’s hard to get our community to fall in love with mudflats and marshes. Otters are such a great flagship for why they should care. 

Nik: They’re wonderful and adorable, and I don’t want to hear any more about them. Let’s move to ecosystem services and their valuation: Why do we have to put a dollar figure on everything? 

Kerstin: I understand having that as a tool in our conservation toolbox when we’re working with partners, private landowners, and businesses who don’t necessarily care about protecting our wetlands. 

I recognize the value of the tool, but if we already own the land and we have communities who can afford to love music or art for its own sake, those same people can afford to love nature for its own sake. I think we can, with no embarrassment, love our marshes and our oysters for their own sake, not for what they do for us. And isn’t the whole framework of, “what can nature do for humans”, what got us into trouble in the first place?

Nik: If you could put a dollar figure on otters, where would it land? 

Kerstin: I have no idea. You’re making a face. Did you actually want me to say something more about otters? 

Nik: No! Stay outta the otters! ….How did you get into all this? Where did you go to school? Where did you grow up?

Kerstin: I grew up in LA, but my parents both grew up in villages—in Arkansas and Northern Germany. My happiest times were wading the creek in Arkansas and walking in the woods in Germany, so I decided I wanted to live and work with nature.

I would see the park rangers and be like, “Oh you get paid to live on a nature reserve in beautiful places? That’s what I want to do.” But I was also this nerdy intellectual that liked books and writing. Conservation scientist melds those two for me. 

Nik: And you never deviated from that course?

Kerstin: It was completely indirect, but it’s a long story. I was a professor at Humboldt State University, and I met my husband when he was a new professor here. I don’t know if you know California geography but that’s like 400 miles apart. Not so good for a marriage. 

Nik: “Here” being UC Santa Cruz

Kerstin: Yes, that’s where I’m zooming from, I live on the UCSC campus. So there I was, 22 years ago, in the market for a Monterey Bay area job and didn’t know a darn thing about estuaries. 

Nik: We’ll strike that from the interview.

Eating a native Olympia oyster—there aren’t many grown commercially on the West Coast, so most people have never tried one—with former collaborative lead of NSC-funded Native Olympia Oyster Collaborative and current graduate student leading conservation aquaculture efforts.

Slogging through the mud excited to go use calipers to measure aquaculture-raised Olympia oysters.

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Healthy Lands Feed Students in Need

Healthy Lands Feed Students in Need

Sandra Sanchez from Pajaro Middle School distributes fresh organic produce to local families. Original story courtesy the Elkhorn Slough Foundation, friends group to California’s Elkhorn Slough Reserve.

The Elkhorn Slough Foundation’s “Healthy Lands, Helping Hands” program connects organic farmers who cultivate Foundation-protected lands with the Hall District Elementary School to distribute fresh, organic produce to local families in need.

Since mid-April, the program has distributed more than Four tons of produce. It began as shelter-in-place orders threatened food security for local families, many with students who visit the Foundation’s Carneros Creek Outdoor Classroom for docent-led field trips in ecology and environmental science.

“In April, we were approached by an anonymous donor who challenged us to find ways to help local families in need,” says Foundation Executive Director Mark Silberstein. “We thought about the kids from Hall School, no longer able to gather under the spreading oaks of the Outdoor Classroom, and their families, impacted by the sudden loss of jobs and income. We also thought about the organic farmers who cultivate Foundation-protected lands and were impacted by the reduction in demand and income. We reached out for a way to link our local farms and families.”

Pajaro Valley High School students volunteer to distribute food to their peers at Pajaro Valley Middle School.

That link was forged at Hall School in Las Lomas. Through generous contributions from individual donors, family foundations, the Community Foundation of Monterey County, and the Community Foundation of Santa Cruz County, the Elkhorn Slough Foundation raised $45,000 to purchase organic produce farmed on conservation lands just across the road from the school. With this support, Pajaro Valley Unified School District coordinators and the school’s food service distribute more than 500 meals a day and serve an estimated 150 families a week. Funding will allow the program to continue through the summer.

The schools, farmers, and families appreciate this circle of health—healthy land and water, healthy farms, healthy food, healthy families!” says Silberstein. “We are discussing expanding the program to additional schools including a school adopted by the Reserve.”

Farmers Javier Zamora and Jesus Calvillo, who deliver fresh-picked produce, are proud to help the school and families in their community—they are also grateful for the support of their farming operations during economically uncertain times.

“Jesus and Javier are great—good farmers and good people,” says Connie Norris, the school’s  food distribution supervisor. She says the families truly appreciate the quality of the fresh produce. “They love the vegetables and are making soups and trading recipes. They tell us they’re making cauliflower ceviche and stuff like that. It’s great.”

Pajaro Valley High School students volunteer to distribute food to their peers at Pajaro Valley Middle School.

“The Elkhorn Slough Foundation is grateful for the opportunity to highlight the link between the health of our lands and the health of the people in our community,” says Silberstein. “Conservation is all about the connections between land and people, and programs like this and our Outdoor Classroom offer hope for the future.”

The Carneros Creek Outdoor Classroom is an open-air learning space on Foundation-conserved land, a short walk from Hall School. For five years, fourth-grade students from Hall District Elementary have gathered there to learn about natural history and conservation science from their teachers and Foundation staff and volunteers. This year, the program was expanded to additional local Title I schools—just before shelter-in-place measures went into effect.

The Foundation has worked hand in hand with the National Estuarine Research Reserve for nearly 40 years. The non-profit assists with administering grant funds coming into the Reserve and is proud of the strong partnership between the Reserve, the California Department of Fish and Wildlife, and NOAA.  

The Elkhorn Slough Foundation is the only nonprofit land trust dedicated to permanently conserving and restoring the Elkhorn Slough and its surrounding lands. For more than 35 years, the Foundation has promoted community involvement in the slough through award-winning education, volunteer, and research programs. 

Elkhorn Slough, located at the heart of California’s iconic Monterey Bay coast, features the largest tract of tidal salt marsh south of San Francisco Bay. The area’s mix of oak woodlands, maritime chaparral, sand dunes, coastal prairie, freshwater and tidal wetlands support rich biodiversity. The slough’s distinctive ecological communities are among the most rare and threatened habitats in California. In 2018, the Elkhorn Slough was designated a Wetland of International Importance by the Ramsar Convention on Wetlands.


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Still Snail Crazy After All These Years

Still Snail Crazy After All These Years

From left: Kerstin Wasson, Jeb Byers, and Rachel Fabian investigate Batillaria snails at California’s Elkhorn Slough Reserve. Photo and story courtesy of Kerstin Wasson, research coordinator at the  Reserve.

The invasive mudsnail Batillaria attramentaria has intrigued me for decades. My first investigation at Elkhorn Slough was a survey for invasive invertebrates conducted in 1998 as a little side project while I was a postdoctoral fellow focusing on the evolutionary ecology of tiny colonial animals. Carrying out the study had value for me personally—I’m guessing it is what got me my job as research coordinator at the Slough, because it was my only experience with estuarine ecology, and had introduced me to Reserve staff. Now, more than twenty years later, I’m revisiting the topic of Batillaria, and finding it has been a recurring theme for the Reserve and for my career.

In the paper describing the 1998 surveys, we estimated that there were at least a billion mudsnails living in the Slough. In a map in the paper, I labeled a particular mudflat as “Batillaria Heaven,” because the invasive snail was so abundant there—it was like a gravel beach, except instead of gravel, a covering of snails. This mecca for snails was the site of field experiments by a NERR graduate research fellow, Jeb Byers, who I met in the field there.

Then, in 2015, I was doing some other work at “Batillaria Heaven” and was astonished to discover the snails had completely disappeared from this site where they used to occur in the thousands per square meter. That launched a three year investigation of potential causes. We pulled together a dream team that included Jeb Byers, now a professor in Georgia, as well as other past NERR graduate fellows and current NERR interns.

We explored a whole variety of hypotheses for the Batillaria decline, including agricultural molluscicide, parasite loads, and acidification, and none of them fit. So what did cause the decline? We think one major culprit was predation by shore crabs—when our interns tethered snails with dental floss, many were eaten rapidly by snails at the sites with the strong declines.

Another factor that plays a role are tidal restriction gates. The artificial conditions upstream of dikes seem to allow the invader to thrive. We saw a major change at one site on the Reserve, Whistlestop Lagoon, following restoration of natural tidal exchange there in 2014. The crabs had become much more abundant, and today there are hardly any live mudsnails left there. Restoring natural tidal exchange is not only good for water quality, but also for getting rid of this invader!

These snail investigations exemplify what I love about working at a NERR—joyful collaborations, long-term perspective, place-based research, and solving mysteries that help us take better care of our estuary.


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Talk NERRdy to Me: Mark Silberstein

Talk NERRdy to Me: Mark Silberstein

Talk NERRdy to Me is a column about leaders and luminaries from across our 29 Reserves. To jump into this leap year, NERRA’s correspondent-at-large Nik Charov, president of Maine’s Laudholm Trust, chatted with Mark Silberstein, executive director of California’s Elkhorn Slough Foundation, the capital “F” friends group for the eponymous Reserve. A humble paterfamilias to the NERRS community, Mark is a conservation veteran in one of the toughest land markets in the U.S: Central California. Guess it helps when your marshes are “stupendous! brilliant!” and actually getting bigger, thanks to partnerships between the Reserve, the Foundation, and others.

Nik: My notes say you’re new to the Monterey / Santa Cruz area and this Elkhorn Slough thing just started recently. 

Mark: It sure seems like a blink. Elkhorn Slough Reserve was established 40 years ago—in 1979–1980. We’re celebrating the 40th anniversary, and I’m happy to be here.

Nik: And you’ve been involved for how much of that time?

Mark: I was hired as the Reserve’s first Research and Education Coordinator, which is what it was called at the time, in 1983.

Nik: RCs and ECs were the same thing back then?

Mark: They didn’t have enough money to do anything else!

Nik: Where’d you come from?

Mark: I’d just finished my graduate studies at Moss Landing Marine Lab, and I’d been hired by The Nature Conservancy to start a volunteer program at Elkhorn Slough. When I was hired to work on Reserve programs, I brought the volunteer program over to the Reserve and began working with teachers on education programs. So it was like a gumbo of programs.

Nik: You’re a marine zoologist, though—aren’t teachers just too strange an animal to work with?

Mark: We had some great volunteer teachers who were passionate about this place and getting kids out here. So it was actually a good fit. But you’re right. I first came to Elkhorn Slough on an invertebrate zoology field trip from San Jose State in 1968 and was digging around in the mudflats. All that mud and all those strange creatures— it was intoxicating! 

Nik: Did you grow up in the Bay area?

Mark: I grew up in Cupertino. Back then it was just transitioning from thousands of acres of fruit orchards to the technology hub it is today.. It was called ‘The Valley of Heart’s Delight.’ Now it’s Silicon Valley.

Nik: The valley of Teslas and nannies.

Mark: The valley of expensive stucco homes. We used to go hang out in the local creeks and steal fruit from the orchards. When you see a place change like that it’s a real motivation to take care of places like Elkhorn Slough. I serve on the board of the California Council of Land Trusts. On top of the great work that public agencies have done, the land trust community has protected hundreds of thousands of acres of coastal California and millions around the state. Around here, it’s a neat contrast: right next to 4 million people you can walk into those mountains and see mountain lions, bobcats, foxes, all of that. We’re pretty lucky.

Nik: Your Elkhorn Slough Foundation is an accredited land trust. Why should I trust my land to you? 

Mark: As an accredited land trust, the Elkhorn Slough Foundation adheres to a set of standards that ensure these lands are protected and that we’re working in an ethical and legal way. We’ve got a track record. The promise that land trusts make is ‘we’re going to take care of this land in perpetuity.’ 

Nik: Who’s been around long enough to see if they are forever?

Mark: To be quite honest, these are all experiments. But I think of experiments with unregulated development, and we’ve got pretty good data showing that doesn’t work very well for the long term. Elkhorn Slough’s a place to answer the question—how do you do conservation in a working landscape? Based on the archeological records, people have made their living here for more than 10,000 years. We’re going to continue doing that. We need to find a way to make it both economically and ecologically sustainable.

Nik: What’s the favorite part of your many jobs that you’ve had? Mud lover that you are, the Hester Marsh rehabilitation project must have been such a gas for you.

Mark: That project is stupendous! Brilliant! It’s awesome to watch it evolve before our eyesit’s being colonized by pickleweed and other marsh plants. You see the extraordinary richness of this place. January 1st, we participated in the annual Audubon Count, the so-called Christmas count. For 40 of the past 45 years, Elkhorn Slough has been one of the top 10 counts in the country for number of species sighted in that single day. Last week, 196 species were sighted in one day. Over 45 years, we’ve recorded  340 species of birds identified in that 15-mile diameter circle.

Nik: Is [reserve manager] Dave Feliz the most peculiar animal found in Elkhorn Slough?

Mark: Dave’s a great naturalist, a stupendous birder, and a dyed-in-the-wool herpetologist. And so he brings us all sorts of interesting things and has made some ground-breaking observations. There are three endangered species of amphibians here: California red-legged frog, California tiger salamander, and the Santa Cruz long-toed salamander. He’s found them all! It’s a pleasure working together for the good of the Slough.

Nik: It’s nice to hear someone talk about the reptiles and amphibians of Elkhorn Slough and not your damn otters.

Mark: One of our board members is an algologist; she gets furious when we wave the otter flag. So everyone knows, we’re on record as loving the whole system. But otters are awfully cute.

Nik: Yeah, yeah. And everything flows down into a marine sanctuary?

Mark: Elkhorn Slough is, I think, the only site in the country where a NERR and a marine sanctuary are adjoined. The tidal waters of Elkhorn Slough fall under the jurisdiction of NOAA’s Monterey Bay National Marine Sanctuary. And the 1,700 acre Reserve adjoins that, and the Foundation has preserved another 4,000 acres around that. We’re embedded in a rich agricultural area. I think something like 70-80% of all the strawberries that are consumed in the United States come out of these areas. Ironically, I think that has helped buffer this place from development.

We’ve really worked hard to build relationships with the farm community. An acre of prime farmland never goes on the market here, but the few times it does it goes for 60, 70, or $80,000 an acre. About ten percent of ESF’s land is in some kind of farming or ranching operation. We lease land out, we’ve converted 150 acres into certified organic production. We also lease out a cattle ranch. We’re trying to balance all these interests. Our uppermost goal is protecting these natural resources, water quality, and the extraordinary biology. 

Nik: Hey, I’ve always meant to ask—most of the rest of us NERRs have bays, rivers. What the eff is a slough?

Mark: It’s actually an Old English word. Look it up in the geological dictionary: it’s a meandering waterway through marshy or muddy ground. And for some reason, the use of that term is spottily distributed geographically. Here in the West there are sloughsfreshwater, saltwater, tidal, mud sloughs. But how that term leapt over the East Coast and landed here is one of those etymological mysteries. Maybe we need a Graduate Research Fellow on that.

Nik: Lighting round: salty or fresh?

Mark: Hard to choose. Which one of your kids do you like best?

Nik: The older one.

Mark: Well, I say both.

Mark Silberstein (left) visits the tide flats at the mouth of Elkhorn Slough with Dr. John Pearse (center), Professor Emeritus from the University of California Santa Cruz, and Jane King Silberstein from the Monterey Bay Aquarium (right).

Estuaries key to sea otter recovery

Estuaries key to sea otter recovery

Sea otter on a salt marsh. Photo courtesy Ron Eby, ESNERR volunteer.

San Francisco has one of the hottest housing markets in the U.S.—and new research out of the Elkhorn Slough Reserve indicates that’s as true for endangered sea otters as for people. These furry critters are the perfect potential residents for the San Francisco Bay Estuary, and making a home there could triple their existing numbers.

The global sea otter population hovers at 3,000; less than 2% of their historic numbers, due to overhunting in the 18th and 19th centuries. The study, published in PeerJ: the Journal of Life and Environmental Sciences, suggests that using estuaries as a prime habitat in sea otter recovery could be key to their  survival. 

“Elkhorn Slough’s protected habitats provide a special haven for sea otters, as well as remarkable opportunities for studying them,” said Kerstin Wasson, research coordinator for the Elkhorn Slough Reserve and study co-author.

Elkhorn Slough is the only estuary in California that supports a self-sustaining population of southern sea otters, making it virtually the only place in the world to study how otters and estuaries support each other. This also makes it a model site for what repopulation efforts could look elsewhere, including the San Francisco Bay Estuary.

“Moving sea otters into the estuary would essentially end up lifting the species out of its endangered status,” said Brent Hughes, assistant professor of biology at Sonoma State and lead author of the study. Hughes was formerly an Elkhorn Slough Reserve staff member and NERR graduate research fellow. “For the conservation of the sea otter, this would be huge.”

ESNERR volunteers monitoring otters—visible here as black dots in the water just left of center—in tidal creeks. Photo courtesy Kersitn Wasson.

“The focus on otters in estuaries began with two Reserve volunteers who noticed how differently otters interact with estuaries than kelp forests,” added Wasson. “One of them sleuthed historical evidence and found that otters formerly were abundant in San Francisco Bay. That really sparked the subsequent investigations, and our Reserve served as a nexus for collaboration among  students and researchers with questions about otters and estuaries.”

Traditionally, sea otter conservation and restoration efforts have focused on kelp beds as target habitat, perhaps as an artifact of where surviving populations have persisted.

“The only southern sea otters off of Big Sur were in that habitat,” said Wasson. “But if you go back in history, you’d be as likely to think of otters as salt marsh and seagrass animals.” 

One reason sea otters have not been able to reestablish themselves in San Francisco Bay is the presence of great white sharks near the Golden Gate. The sharks prey on otters and prevent them from moving into the estuary. However, if otter populations were established inside San Francisco Bay and out of the range of great whites, they would likely thrive.

For now, the only place to observe sea otters foraging in eelgrass beds or napping on salt marshes is Elkhorn Slough. The estuary will continue to attract researchers and otter fans alike for this reason.

New Study Explores the Secrets of Marsh Happiness

New Study Explores the Secrets of Marsh Happiness

Field data from National Estuarine Research Reserves and the U.S. Geological Survey combined to tell us surprising new things about marsh resilience. Photos courtesy of the Elkhorn Slough Reserve.

What do tidal marshes and families have in common? According to a new study published in Environmental Research Letters, they both follow theAnna Karenina Principle.”

“We found that happy marshes are all alike, but every unhappy marsh is unhappy in its own way, just like the families in Tolstoy’s story,” says Dr. Kerstin Wasson, Research Coordinator at California’s Elkhorn Slough Reserve and lead author of the study. “We compared one marsh that was falling apart and one that was stable in eight regions to identify the features that these habitats have in common.”

The multi-partner analysis ground-truthed previous marsh resilience findings from the National Estuarine Research Reserve System (NERRS) and the U.S. Geological Survey (USGS).  It confirmed that “happy,” or persistent, marshes exhibit common traits, just as happy families often have characteristics like love, health, and financial well-being in common. Vegetation in healthy marshes tends to grow in high areas relative to current water levels; they import (rather than export) sediment; and they exhibit a low ratio of unvegetated to vegetated areas. 

By contrast, the new study found that “unhappy” tidal marshes deteriorate in diverse, complex ways. One finding contradicted a previous assumption: namely, that gains in marsh elevation and sediment indicate greater resilience. Marshes with these characteristics performed inconsistently, sometimes deteriorating into the muddy mess that signifies a marsh is falling apart.

“Unhappy” marshes in Rhode Island (left) and California (right) have distinctly different ways of degrading.

Studies like these support coastal communities by helping them make more informed conservation decisions based on which tidal marshes are likely to persist in place and which are likely to degrade. 

“This was a great opportunity for USGS and the NERRS to integrate our newest methods of marsh monitoring,” says Neil Ganju, research oceanographer at the U.S. Geological Survey’s Woods Hole Coastal and Marine Science Center and an author on the study. “As a result we discovered that our previous approaches are stronger when combined.”

Other partners in the study included Rhode Island’s Narragansett Bay Reserve, Louisiana State University’s Department of Oceanography and Coastal Sciences, University of Michigan Water Center, Woods Hole Coastal and Marine Science Center, the Patuxent Wildlife Research Center (now the Eastern Ecological Science Center), and the Western Ecological Research Center.

ReservesElkhorn Slough, California