Two years ago I held my breath as I sent an email to an address I didn’t know, but was listed as a contact for a project called TIDE. I closed my eyes, pressed “send,” and seconds later heard a ding–which turned out to be an automated message letting me know that the email address was no longer in use.

Several messages and a few meetings later, I found myself stumbling down a forest path and spit suddenly into what I would come to think of as one of my favorite places in the world. Spartina patens spread out before me and wind turbines in the distance, I, now dubbed a TIDE Project Intern, followed my mentors into the marsh to learn as much as I could during my twice-monthly field visits.

That summer took a lot, but it gave a lot, too. I remember showing up at Marshview afraid that I wouldn’t be good enough for the position, half-believing that I wasn’t fit to be a scientist. I beat myself up over the smallest mistakes and expected myself to be perfect at every turn. I set such high standards for myself that I managed to make it harder to take in all that was going on around me–creating the only real roadblock in my learning process.

I managed, however, to learn a whole lot despite accidentally holding myself back. When I looked back after what I thought would be the end of my time with TIDE, I remembered learning how to program finnickey automatic water samplers, running benthic algal samples using UV Spectrophotometry, and sampling for plant biomass during the Annual Harvest. These were processes that I couldn’t define when I began, let alone master–and, in the end, I felt confident that I could take these skills and apply them to wherever I went next.

It’s a good thing I didn’t go too far!

Now, two and a half field seasons later, the person I was when I began working with TIDE is almost easy to forget. I’ve been lucky enough to train a handful of other TIDE interns over the last summer and a half, and am constantly in awe of how they each adapt to their new, slightly more salty, environment. Already they filter with swift precision and jump into creeks as if they’ve been doing so for years, yet sometimes I see an inkling of my former self in them. I love teaching them and hope to help them understand, if not only the science itself, that they are beyond capable of being what we call a “scientist”–no matter what they (or society) may believe.

And I am grateful that my TIDE journey gets to continue.

– Katie Armstrong (Summer Research Assistant, Woods Hole Research Center)

 

Check out the most recent coverage the TIDE project has received!

Researchers start study of Great Marsh recovery

Plum Island study to examine salt marsh recovery from pollution

 

I am the type of person that attributes songs to the work that I do. And after my first day sampling for benthic algae last summer, I already had the chorus of the Beatles’ Twist and Shout running through my head.

That may seem an odd choice of song, but I assure you that there is no better musical masterpiece to describe the complete process of benthic algae sampling and running. In the field, with our four-centimeter diameter corers, we cut back the cordgrass Spartina patens in the high marsh to reveal the sediment beneath. The dense Spartina patens roots woven through the soil, however, force us to twist the corer to break up those roots, eventually releasing our sediment core sample. There we have the lyrics “Twist and shout,” shouting in joy (or frustration) optional.

The next week, I travel with my samples back to the lab at the Woods Hole Research Center, where I extract the cores in acetone before running them on a UV Spectrophotometer, to measure chlorophyll a absorbance at different wavelengths of UV light (which, in turn, tells us benthic algae abundance). With running the samples, though, comes a lot of tube shaking, after adding acetone and again before being spun down in the centrifuge to run on the Spectrophotometer. Hence, “Shake it up, baby, now.” Shake those samples!

If you couldn’t already tell, I’m quite passionate about benthic algae, the topic of my independent research. However, it took a little while for this interest to grow on me.

The first time I heard the words benthic and algae together was last summer, when it was proposed by the Lead Principal Investigator Linda Deegan that I be in charge of field sampling, organizing the past fifteen years of data, and eventually finding the story behind the microalgae response to nitrogen fertilization. I did my best to act knowledgeable about the topic, but in my two years of undergraduate study, I had only come across macroalgae, and never algae described as benthic. Cue the background research!

What we refer to as benthic algae is microalgae, such as cyanobacteria and diatoms, found in the first few centimeters of marsh sediment. Benthic algae is important for the uptake of nitrogen and carbon, and serves as a source of energy for grazers, among a myriad other things. This algae is also resilient to many environmental factors like extended darkness and hypoxic or anoxic environments, which means that it could play a role in salt marsh recovery from nitrogen loading; but should benthic algae be negatively affected by that nitrogen addition, there could be potential consequences for the salt marsh ecosystem.

Through research, I began to see benthic algae as a link between marsh invertebrate ecology, a topic I was familiar with and loved, and biogeochemistry, an area new to me when I began with TIDE. Armed with my corers in the field, a UV Spectrophotometer in the lab, and fifteen years of historic data in the office, I hope to unlock the full, fifteen-year story of how benthic microalgae responds to nutrient loading and marsh recovery this upcoming year.

– Kate Armstrong

Imagine for a moment that you are a crab larva. Floating in the middle of an urban estuary (say, the Port of Rotterdam in the Netherlands), you just hatched, and are one of millions of little baby crabs hoping to survive long enough to make it to adulthood. Then suddenly, inexplicably, you are sucked up into a strong current that you don’t understand. The sun disappears, and you are surrounded by thousands of your brothers and sisters, but also many other larvae that you don’t recognize. Time seems to stand still, and you do what you can to make the best of a bad situation. Then suddenly, the same current again pulls you, but now in the opposite direction, back the way you came. Hooray, you are free! But wait, this new water feels different; this is not at all what you remembered of your home. By this time, you are a little older, a little larger, and a little bit more aware of your surroundings. You recognize you must be in a different place entirely, but you again make the best of a bad situation, and settle along the marshy shores of your new locale (not knowing you just entered Boston Harbor). You grow into an adult, and you discover to your relief that your home is not so bad after all. Predators don’t recognize you as prey, and parasites don’t infect you. So you yourself then reproduce, your offspring survive in massive numbers, and your species excels in this new home; a truly crabby paradise.

Congratulations! You just experienced what it was like to be an invasive (i.e. non-native, non-indigenous, etc.) species transported from Europe to the Eastern United States by ballast water from a commercial vessel. In order to maintain buoyancy and pitch while at sea, ships take on various kinds of ballast including rocks and water. Rock ballast was more commonly used in early shipping in New England in the 17th, 18th, and 19th centuries. In fact, the first arrival of the European green crab Carcinus maenas to New England was through British and American merchants unloading rocks (which also contained crabs) at ports along the Gulf of Maine. A second wave of green crabs was introduced to the eastern seaboard more recently in the 1980s through water ballast (much like your own crab experience). Although seemingly beneficial for the crab, bioinvasions rapidly became a problem by the mid to late 1980s not only for native organisms, but also for people. In 1988, the zebra mussel was introduced accidentally to the Great Lakes in North America from Bulgaria in Europe. A fouling species of mussel that grows on practically any surface it touches, intake pipes from Lake Michigan to Chicago were clogged for weeks until utility companies were able to replace the critical infrastructure. The result: zebra mussels cost taxpayers millions to remediate the problem. Therefore, it is incredibly important to continue to understand global effects of bioinvasions on a variety of ecosystems including the Plum Island Estuary, and how to prevent their spread; no matter how much those crabs need a change of scenery!

– Michael Roy

 

By Sophie Drew

Adapted from Lewis Carroll’s “Jabberwocky”

‘Twas brilliant, when the golden sun
Did show its face upon the marsh
All set were we to work as one
The heat arising, greenheads harsh

Behold the power of plants, my friend!
CO2 in, oxygen out!
I’ll tell you before poem’s end
What my research is about

We have a chamber, logger, tubing,
Across the marsh these things we heave
We set it up, we get it grooving
And watch, in real time, marsh grass breathe

Full sun, then shade, then darkness too
That’s three light levels for ya
To see how our dear friend responds,
Spartina alterniflora

And why do this? What can we learn?
Seems an odd summer vacation
It’s to find out if these plants just might
Recover from eutrophication

When nitrate’s added in excess
To a system so fine-tuned
The carbon cycle becomes a mess
If we’re not careful, it’s all doomed

‘Twas brilliant, when the golden sun
Did set across the shining creeks
Carbon fluxes, July, done!
Until again, in four short weeks

New England’s salt marshes were some of the first ecosystems I was immersed in (literally) as I began my jaunt into marine science. For many people, the draw is their tranquility, as looking out onto a cordgrass meadow gently rippling in the breeze can be quite relaxing. Something that fascinated me then, and still does now, is how these peaceful feelings can be evoked by such a harsh environment. Large, strong tides, cold, salty water, and hot, unrelenting sun all represent real hazards for animals residing in these coastal margins. Yet salt marsh critters don’t run from these dangers: in fact, food webs in these areas are designed to meet stressors head on, taking life-threatening risks in order to reap the energetic rewards that pushing these boundaries can provide.

I am here studying Plum Island’s food webs. One of the major cogs in the always-churning ecosystem machine is the mummichog, a small minnow that easily dominates the other marsh critters in terms of sheer numbers of individuals residing in the creeks. You can catch these baitfish by the hundreds in all sorts of traps and nets, and though they can eat a plant-based diet, in order for them to truly grow big and strong, they need some protein! Big fish can eat the shrimp and invertebrates found in the creeks, but how can a mummichog get to that size in the first place? The answer is by risking life and fin and riding the tide up to the dangerous high marsh, to snack on unsuspecting insects and spiders. Seems crazy, but the risk of getting stranded up there, or eaten by a bird or other predator, is definitely worth it for the potential energetic boost they can get. In this way, mummichog function as an incredibly important link between these two (high marsh and creek) distinct habitats, gathering energy in the form of food produced in the high marsh (insects and spiders) and making it available to the consumers we all love, like striped bass and flounder in the creek. Not bad for such a little guy!

One of the most interesting effects of increased nutrient load on these coastal systems is the sloughing and disintegration of the low marsh area of the creeks, which normally act as a ramp for these mighty minnows to make their daring climb. How does the loss of that ramp affect the mummichog’s ability to bridge the two ecosystems, and what does a change in the strength of that link mean for the creek’s other residents? How does the ecosystem respond to this decoupling of the creek and high marsh? These are the questions I’m hoping to answer this summer. As we head out to West Creek with our trusty seine net to collect fish, shrimp, and other marine critters for our analyses, we come across a dead American eel on the path, stranded as the tide receded and desiccated by the strong summer sun. Clearly, the high marsh bounty is worth risking everything for, and I hope to understand how that link, and its loss, drives the function and long-term stability of these “peaceful” ecosystems.

– Justin Lesser

 

The day begins early, tide dependent of course. My team assembles. We are a small group consisting of PhD candidate Michael Roy, Jarrett Byrnes’ undergraduate lab assistant Richard Wong, and I, Byrnes lab undergraduate field tech. We gather our gear; our scientific instruments, our boots and buckets. We set out for a glorious day of experimental set up in the salt marsh. I am so excited to be here as this is my first time working in the field. This is the reason I went to college for Biology, to have a career in which I am spending copious amounts of time in nature.

So far I have gotten to be very close to nature, sometimes waist deep in it when catching the fiddler crabs for our particular experiment. I feel beyond honored to have been selected to be a field tech this summer. Michael reminds me that I earned my place helping him at the field station with my hard work and enthusiasm in my marine ecology this past school year. Michaels’ experiment is on comparing the affects the marsh fiddler crab at various densities have on the marsh sediment in there native region South of Cape Cod verses the Gulf of Maine were they have recently expanded their range to include because of the changing climate. It just so happens to be a question I find myself very interested in as well.

We are headed to the marsh today to catch the crabs that will be occupying the cages we built for them in the marsh. We have taken our initial measurements of the sediment strength, buried a log of peat in mesh to examine root growth, and buried small mesh bags of grass to assess how decomposition may increase as the crabs burrow into the sediment.

I can’t help but think that our cages look beautiful when they are up and running, with their steel flashing affixed around the tops which ensures no crabs crawl out or in. I am really enjoying my job as I am standing in the cool creek on a beautiful sunny summer day, poking crabs out of their holes in the mud. We will leave them over the rest of the summer and measure how they have changed the marsh in their cage after some time has passed. I truly can’t wait to evaluate the results and find out!

Written by Linnea Sturdy 

A study recently published in Ecological Applications from the TIDE Project reveals that plants don’t respond to eutrophication the way you might expect. Below is a press release originally posted by the Virginia Institute of Marine Scientists.

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Add fertilizer to your garden and your plants will probably grow bigger and taller. Add fertilizer to a salt marsh and the plants may not get any bigger. That’s according to a new study led by Dr. David Samuel Johnson of William & Mary’s Virginia Institute of Marine Science.

Salt marshes are intertidal grasslands that grow at the interface between land and sea. These ecosystems can receive excess concentrations of nutrients such as nitrogen from wastewater and runoff of agricultural fertilizer. This “eutrophication” affects coastal waters and estuaries worldwide and can lead to fish kills, harmful algal blooms, and areas of low oxygen. Johnson and his team wanted to know how eutrophication impacted salt marshes.

To do so, the team conducted an unprecedented experiment and flooded football-fields worth of salt marsh in northeastern Massachusetts with fertilizer-rich water for almost a decade. Scott Warren, a professor at Connecticut College and study co-author who has studied salt marshes for four decades, says “When we were able to mimic a eutrophied estuary at an ecosystem scale—quite a challenge I must add—we found that salt marshes did not respond as you might have predicted from fertilization experiments done over the past half a century or so.”

Despite the abundant supply of nitrogen, a key plant nutrient, plants in the fertilized marshes didn’t grow much bigger than those in unfertilized marshes. “We were surprised at the mild responses, even after almost a decade of fertilization,” says Johnson. Earlier salt marsh studies reported plants growing larger in response to adding fertilizer. Previous studies also found that fertilizer changed species composition, causing some species to outcompete others. “The species composition didn’t budge during the entire experiment,” Johnson says.

One reason the team’s results differed from previous studies may be their choice of fertilizer. “We used nitrate fertilizer, which is the most common form of nitrogen in eutrophied estuaries,” says Johnson. “Much of the previous work used ammonium fertilizer. Those studies had different questions than ours; they weren’t specifically looking to understand eutrophication.” Wetland plants prefer ammonium to nitrate because it takes less energy to process, so bigger plants with application of ammonium would not be unexpected.

Another reason the plants may not have responded strongly was the way the fertilizer was delivered—with flooding tidal water, which meant that less fertilizer reached the plants compared to previous studies that had added fertilizer directly to the marsh surface.

The mild response of plants doesn’t mean that salt marshes are safe from eutrophication, however. Johnson notes that when it comes to understanding eutrophication’s impact on salt marshes, the answer may lie beneath the surface. In an earlier paper from the same field study, published in Nature, the research team found that fertilizer treatments caused the marsh edges to collapse and erode away. Again, this is opposite of what they had predicted. “We hypothesized that the grass would grow taller, which would trap more sediment and help the marsh grow,” says Johnson. Instead, they found that plants in fertilized marshes had fewer roots and rhizomes than those in non-fertilized ones, which may have contributed to the collapse.

The team’s research results have important implications for the management and care of salt marshes. These critically important coastal resources are thought to be “nutrient sponges” that soak up excess nitrogen to help prevent dead zones and fish kills. One way they can do so is by putting the nitrogen into bigger plants. Since the plants in the current study didn’t grow bigger, it limited the marsh’s ability to absorb excess nitrogen.

Johnson adds, “Our work underscores that we can’t simply rely on salt marshes to clean up nutrient pollution. We need to do a better job at keeping nutrients out of the water in the first place.”

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