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TIDE Scientists inducted into AAAS – Part II

From L to R: Jane Tucker, Anne Giblin, and Sam Kelsey

From L to R: Jane Tucker, Anne Giblin, and Sam Kelsey

Anne’s recent election into AAAS is well-deserved, and if there were a companion award for outstanding achievements in kindness, generosity, and commitment to others, she would rightfully be awarded that, too.   I have had the privilege of working closely with Anne for over 20 years, and I should know.

Anne Giblin “speaks “ biogeochemistry, thermodynamics, biology, physical chemistry… really all the “hard” sciences…as a first language.  They seem to be part of her innate intelligence.     But she is not a desk scientist.   She loves to be in the lab, or even better, out in the field conducting experiments or collecting samples.   Adverse field conditions are her forte!    She is not stopped by freezing temperatures or clouds of mosquitoes on the North Slope of Alaska, nor by tropical heat, “no-see-ums” or scorpion stings in Panama.   She does not let little things like utter darkness in the cold depths  of Adirondack  lakes  or a blanket of sewage sludge on the bottom of Boston Harbor dampen her enthusiasm for collecting more mud and adding dives to her SCUBA log.   She does not send her students or employees out to do this work for her….she jumps in first.   All of this to keep adding pieces to the puzzle of element cycling in sediments, particularly with respect to nitrogen, carbon, and her first love, sulfur.  

Hard work is often matched by good cheer. A long day with the PIE-LTER team in the marsh at Plum Island, in itself fun, is routinely followed by a good meal (often prepared by Anne),   a good local brew (often provided by Anne), and good stories (often told by Anne).   Over the years, these days and stories and Anne’s optimism have become encapsulated by some memorable lines, now used affectionately by the team.  Three of the classics are:  “Done by noon!” (as in, “It won’t take long, we’ll be ….”), “That’s not thunder, those are jets!” (at next occurrence, accompanied by a bright flash of light) , and “No herics!” (i.e. heroics… I mentioned Anne’s first language is science, not English, didn’t I? It’s really the only thing I can help her with!).  

Sure, Anne has the necessary stats on her CV that attest to her accomplishments as a scientist.  But the best testament of her success may be that, in an increasingly difficult funding climate, and at an all soft-money, independent research laboratory, Anne has kept herself and her team funded for over 25 years.  It is tribute to Anne as a mentor, colleague, and friend, that we have all wanted to stay.

Jane Tucker is a Research Assistant at the Marine Biological Laboratory.


TIDE Scientists inducted into AAAS

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This weekend, Dr. John Fleeger, a former TIDE Principal Investigator (PI), and Dr. Anne Giblin, a current TIDE PI are being inducted as a member of the American Association of the Advancement of Science (AAAS), known to us scientists as Triple-A S, because we’re too busy for real words.  AAAS is like the Hall of Fame for scientists and it’s a big deal.  We at the TIDE Project are incredibly proud of John and Anne’s accomplishment.  It is well-deserved.

In this post I will highlight John.  In the next, Anne.  

I could list many of John’s accolades including his 150 publications in the scientific literature including topics from the Gulf of Mexico oil spill to carbon sequestration in the deep ocean to community ecology of very small crustacean in the dirty, dirty mud to studying the Plum Island marshes here on the TIDE Project.  I could highlight his wonderful teaching career at Louisiana State University spanning over 30 years.  But what I’d rather do is talk about John as a mentor.  My mentor, who guided me to my Ph.D.  

John’s mentoring style can be summed up easily: his door was always literally open.  And no matter the crazy nattering that spewed from my lips, he looked at the floor while nodding and waiting for me to finish.  Then we would discuss.  He never said my ideas were stupid, though he gently said they needed more ‘development.’  

And he was patient.  I can’t tell you how many times I heard him say without annoyance “Again David…” meaning that he already told what he was about to say and he was gently reminding me.  

I appreciated how quickly he made comments on my scientific manuscripts.  Well, how quickly he massacred them.  My words were slain without mercy for their wrongness and their bodies littered the battlefield of my manuscript.  It frustrated me because I prided myself as an excellent writer.  But academic writing has its own style and language and John was teaching. Today I’m a better writer because of the time he took.    

One Saturday morning in Baton Rouge I was at the scope sorting samples.  John came in with a draft of my research proposal that he massacred.  He asked me, “David, what are you trying to say here?”  Then before I had a chance to answer, he looked at the draft and said with rare exasperation, “Do you even know what you’re trying to say?”  I started to say something, but said, “Well no.”  And then he took the time to help me start over. 

I still seek John’s advice today on my manuscripts.    

The following is from the Acknowledgements of my dissertation:  “In 2003, the brave or foolhardy Dr. John Fleeger, with his nodding head and seemingly infinite patience that I tested more than once took in my independent and sometimes irascible spirit and navigated it down a tortuous, yet productive path.  I thank him for reading (and re-reading and re-reading) every word I’ve written as a graduate student, for swatting and cursing mosquitoes with me in the marsh, and for always having his door and mind open.”  

Five years later, those words, unmassacred by John’s pen, still ring true. 

Congratulations John.  Your induction into AAAS is well-deserved on many levels.  


 David Samuel Johnson is a Principal Investigator on the TIDE Project.  A version of this blog post first appeared on David’s blog, New Leaf.

A student of the marsh

There are so many stories of science from the Plum Island marshes and it’s wonderful when they are written down.  The one below is from Harriet Booth, a recent graduate of Brown University, who was also anTIDE Project intern working with me on the idea of a trophic bottleneck (that snails could gobble up a lot of energy and store it and choke off energy flow to fish).   And bless her heart, not only did she survive a summer in the boot-sucking mud and pain-in-the arm, face, and leg flies, but she went on to write an honors thesis.  Recently, she wrote a wonderful blog post about her experience, some of which is excerpted below.  I particularly like “…a small snail, muddy-colored and roughly the size of a peanut, emerged from the edge of the plastic, making a bid for freedom across the mudflat.”  I encourage you to read the entire essay here.   

Harriet is currently a Research Fellow at the Atlantic Ecology Division of the EPA in Narragansett, RI.  She is looking at the effect of ocean acidification on bivalves.  Way to go, Harriet!   

“The square, plastic quadrat slapped down where I tossed it, splattering me with little droplets of mud.  As I bent down to examine the sampling area, I noticed one side of the small quadrat seemed to be moving slightly, lifted by some tiny but determined force.  I looked closer and watched as a small snail, muddy-colored and roughly the size of a peanut, emerged from the edge of the plastic, making a bid for freedom across the mudflat.  I watched this little guy trundle resolutely away from me, making slow but steady progress across what must have seemed to him, a vast expanse of mud.  His tiny antenna occasionally appeared from beneath the front of his shell, wiggling about and seeming to wave at me as I crouched in the creekbed.  Eventually, I picked the snail up and placed him back inside the quadrat, counting the rest of the remaining snails at the same time.  However enjoyable it was to watch these little creatures bumble around, I had many more quadrats to toss before making my own escape out of the sucking mud of the salt marsh.”

David Samuel Johnson is a TIDE Project principle investigator from the Marine Biological Laboratory.  He writes about marshes at his New Leaf blog.

Acid plus middle school equals outreach

Dr. Johnson is fixin' to learn you some chemistry!

Dr. Johnson is fixin’ to learn you some chemistry!

Twenty-four pairs of eyes are upon me.  These eyes, these critical eyes, belong to 12-year-olds.  Twelve-year-olds who expect this real-life scientist standing in front of them to teach them about ocean acidification (OA).  They’ve had no chemistry and I’ve never taught middle-schoolers.  Do they know about pH?  What makes an acid?  Calcium carbonate?  No?  I’ve got 50 minutes?  Deep-breath.  Okay.  Go! 

Over two days last week I taught OA to 200 7th graders at the Rupert Nock Middle School in Newburyport, Massachusetts.  We tested household solutions (e.g., milk, lemon, spit) with pH strips.  We learned how added CO2 lowers pH.  We learned about chemistry through role playing as elements and compounds.  We learned how the loneliness of H+ ions (lonely ions like to bond) make them highly reactive and how that loneliness can steal the bricks (carbonate) needed to build the shells of marine organisms (Thanks to science teacher John Reynolds for a wonderful Home Depot metaphor that I will blatantly steal).  We developed hypotheses about the consequences for marine life and conducted a multi-day experiment on the effects of an acid (dilute vinegar) on mass loss of bivalve shells. 

While OA is not a current focus of the TIDE Project, it is a major concern for marine ecosystems.  Outreach is a supporting pillar of the TIDE Project’s scientific philosophy (as well as the larger group of Plum Island-LTER scientists) and one goal is to strengthen coastal education by working with young scientists and K-12 students. 

My classroom demonstrations also emphasize the important presence the TIDE Project has in the communities local to the marshes we study.  The OA module germinated from a conversation I had when John Reynolds brought a dozen of his students to the marsh as part of his outdoor curriculum.     

From middle-school students peering through refractometers while standing on the marsh to undergraduates publishing papers, the TIDE Project has engaged at over 1000 middle-school, high-school, undergraduate, and graduate students combined through its outreach activities.  Whether standing at a white board or knee-deep in marsh mud, we hope to engage thousands more.

David Samuel Johnson is a principal investigator on the TIDE Project.  He is particularly fond of invertebrates.  All photos courtesy of Lisa Furlong.

Here a snail but not there a snail?

by forest, a research assistant

Though unnoticed on my first visit to the Rowley marshes, I soon became well acquainted with Melampus bidentatus, or the coffee bean snail, during subsequent stem counting, transplant planting, and genetic sampling ventures. While working in close proximity with the coffee bean snails, I began to notice trends in their distribution across the high marsh. Coffee bean snails appear more abundant but smaller in Spartina patens dominated high marsh, less abundant but larger in short form S. alterniflora dominated high marsh, and conspicuously absent from the tall form S. alterniflora where the high marsh boarders the creek bank. The question is: what factors are determining the distribution of coffee bean snails on the high marsh at Plumb Island? I needed to know more about the snails.

Coffee beans snails are pulmonate (air-breathing) as adults but are tied to the sea by a planktonic larval stage. Snail spats settle into the high marsh at the size of 690 um and do not reach their adult size of ~12 mm until over a year of growth (Apley, 1970). Coffee bean snails feed mainly on decaying plant mater and algae (Graca et al., 2000). A number of marsh predators prey on coffee bean snails such as the ubiquitous mummichog, many different marsh birds (Hausman, 1932), and green crabs (David Johnson, pers. comm.).

Could predation be the key to snail distribution? A 1976 study by Vince et al. supports the predation hypothesis. This study shows that the high stem density of S. patens acts as a natural ‘fence,’ excluding predators from eating palatable snails. Thus, small snails, which make up the majority of the population, are confined to S. patens by predation pressure, while larger snails inhabit the low stem density, ‘un-fenced,’ S. alterniflora habitat because their size protects them from most predation. Vince et al. (1975) hypothesizes that larger snails are drawn into the higher risk habitat because the lower snail density in S. alterniflora may lead to greater resources per snail. This study may explain the difference in snail sizes and abundance I observed between S. Paten habitat and short form S. alterniflora habitat on the high marsh. But what about the complete absence of snails in the tall form S. alterniflora on the creek bank edges at the Rowley Marshes?


Dr. David Johnson (aka Mr. Marsh to the Marshview House faithful) posited an alternate hypothesis. He suggests that physiological limitations are the primary driver of coffee bean snail distributions. Because coffee bean snails are air breathing, they do not thrive in areas with a high frequency of tidal inundation. S. patens occurs at higher elevations on the marsh platform (wet only during spring tides). Conversely, the tall form S. alterniflora dominated habitats on creek bank edges are likely the lowest areas of the high marsh (wet at almost every high tide). Differences in the frequency of tidal inundation across habitats could influence the abundance of coffee bean snails on the high marsh. Just as too much water can drown snails at high tide, too much sunlight can cause desiccation at low tide. As a result, coffee bean snails avoid direct sunlight (Hausman, 1932). Larger snails may be more resistant to desiccation than their smaller counterparts. High marsh short form S. alterniflora seems to provide less percent cover than S. patens and this difference in shading could influence the abundance and size of coffee bean snails in these habitats.

I cannot test these competing snail hypotheses at the moment due to the frozen creeks and snowy peat of the winter marsh. Indeed the short days and cold weather has put an end to most marsh fieldwork and I have been effectively exiled to the lab until spring. For now, I am stuck with many questions, some guesses, and no answers. However, the New England winter gives me time to hone my knowledge and plan my approach so that when I get the chance, I can pursue informative questions in an efficient manner. In a way, by taking a step out of the marsh, I am gaining a better understanding what I want to do on the marsh and how I want to do it.

Forest Schenck is a Research Technician at Northeastern University Marine Science Center in Nahant, Mass.  He works with TIDE collaborators Drs. David Kimbro and Randall Hughes of Northeastern.

Rise of the Chog

Talia Hughes holds a large mummichog

Talia Hughes holds a monster mummichog.  Seriously, that’s a monster ‘chog.

We all know that fertilizer grows plants, but can it grow fish?  The answer turns out to be yes in salt marshes according to a new TIDE paper published in Marine Ecology Progress Series by Konner Lockfield and John Fleeger of Louisiana State University and Linda Deegan of the Marine Biological Laboratory.  After six years of nutrient enrichment at the landscape scale (350-500m of tidal creek length, a total area of 60,000 m2), the abundance and biomass of the dominant marsh fish, the mummichog Fundulus heteroclitus, increased by up to 60%. 

How does fertilizer make fish? 

“Of course fish don’t directly eat the fertilizer,” John said in an email.  “Fertilizer helps plants and algae grow and even improves the nutritional value of these primary producers.  In salt marshes, snails and a legion of small crustaceans (including grass shrimp, amphipods, isopods, and copepods) increase in abundance because their food supply is enhanced.  [Mummichogs] forage for these small invertebrates.  The increased amount and value of food below mummichogs on the trophic ladder leads to a “bottom-up” stimulation of mummichogs that was started by the addition of fertilizer.” 

This paper is the first to experimentally demonstrate bottom-up control on the secondary production of salt-marsh fish.  

It is the first study of it’s kind because fish are highly mobile and cover a lot of ground, er, water.  Mummichogs have a home range of 300-500 m, which is the length of tidal creek fertilized by the TIDE Project.    

Because of the size of the experiment, the study required tremendous effort.  Konner, the lead author, cooridnated a swarm (a dozen) of undergraduates, high school, graduate students, and post-docs to collect and tag 7828 mummichogs with coded-wire tags for this large-scale mark and recapture study.  Konner was understated when he said, “It was a lot of work.”

A surprising finding from the study is that in the fertilized creeks fish had more algae in their guts.  “Mummichogs are omnivores meaning they consume plant matter, algae, and animals,” John said.  Previous TIDE work has shown that mummichogs can exert strong top-down control on algae in certain scenarios. 

John asserts, however, “We aren’t sure why mummichogs eat more algae in fertilized creeks.  Animal prey is richer in protein than algae and should promote faster growth.  Theoretically then, mummichogs should prefer animal prey and should increase animal consumption when the food web is stimulated.”

Konner suggests another hypothesis, “One possibility is that they’re eating it incidentally as they consume more benthic prey.”  Konner agrees with John’s assessment that, “More research is needed to examine the behavioral and dietary preferences in mummichogs and the nutritional content of the various food sources when grown under fertilization.”

The fertilization conducted by the TIDE Project mimic run-off of nutrients (nitrogen and phosphorus) from agriculture and sewage sources.  The current study suggests positive effects of this run-off on fish production in the short-term.  We remain uncertain, however, about long-term effects, which may be detrimental.  For instance, we have found that chronic enrichment fragments the vegetated low marsh.  Loss of this habitat may ultimately affect fish production in the long run.  We continue to study this question to understand the fate of our marshes in ever changing conditions.

This work was funded by the National Science Foundation under Grant Nos. 0816963, 0923689 and 0423565.

 Fundulus fun facts – the term ‘mummichog’ is an Indian term meaning ‘going in crowds’.  They are also called ‘killifish’ (as are a host of other minnows).  ‘Kill’ comes from the Dutch word for river or stream.  Thus, killifish are river/stream fish! 

This publication is part of Konner Lockfield’s Master’s thesis from the TIDE Project.  He is currently employed the Audubon Aquarium of the Americas (lucky!) in New Orleans, Louisiana. 

Dr. John Fleeger is emeritus at Louisiana State University and though he technically retired, he stays active as an adjunct professor at the University of Missouri at Kansas City where he teaches Ecosystem Science and Ecotoxicology and is able to spend more time with his grandkids.

Dr. Linda Deegan is a Senior Scientist at the Marine Biological Laboratory but decided that wasn’t enough work so she is currently on leave as a Program Director at the National Science Foundation in Washington, DC.

Lockfield, K., J.W. Fleeger, and L.A. Deegan. 2013.  Mummichog Fundulus heteroclitus responses to long-term, whole-ecosystem nutrient enrichment.  Marine Ecology Progress Series, 492:211-222.

written by david

The marsh: a living laboratory

by david

Gulp!  Phragmites can swallow all.

Gulp! Phragmites can swallow all.  Mr. Reynolds and students.  All made it out alive.

11 October 2013
Rowley, Massachusetts

I’m standing in the sandy soil of Stackyard Road adjacent to the marsh of Clubhead Creek.  The day is overcast and the light wind makes it cool, but it’s still a nice day on the marsh in October with an air temperature of 18 C (60 F).  A white van arrives, bouncing in the tire-swallowing holes.  Mr. John Reynolds, a teacher at Ruppert Nock Middle School in Newburyport, emerges.  He’s thin and a young-looking 50.  His dark complexion signals that he spends a lot of time outside.  In fact his teaching curriculum is centered on taking his students into the wilds of Essex County to explore the local ecosystems.  The students have been kayaking on rivers, biking to parks, and sitting in nature to listen, to watch, and to smell.  Today they are here to experience the living laboratory of the salt marsh.  

Ten seventh-grade scientists of varied sizes emerge from the van and are joined by the Assistant Principal Ms. Lisa Furlong.  We get right to work.  These scientists are eager and excited to be outside.  Instead of smartphones, these students have field notebooks and pencils in their hands.  Instead of distractions, the students have questions.

We start with the first step of the scientific method:  observation.  They observe that the invasive reed Phragmites is found only near the upland edge or near the road and that most of the marsh is dominated by Spartina spp.  We move to the next step:  Hypothesis generation.  They hypothesize that soil salinity is driving these plant patterns, specifically, that Phragmites is limited by high soil salinities and that Phragmites soils will have lower salinities than the Spartina soils.  After a quick lesson on how to use a refractometer, we move on to the next step:  Hypothesis testing.  Two teams sample the marsh soils for salinity in the two plant zones.  The Phrag team is swallowed by the reeds and a member of the Spart team discovers that straight lines in the marsh mean leg-swallowing ditches.  They create data tables and convene to share their data.  The results?  Phragmites soil: ~32 parts per thousand (ppt), Spartina soils: ~45 ppt.  Hypothesis supported!  In fact, in general, Phragmites is limited in growth and expansion by higher soil salinities.  A more detailed study in the Parker River marshes by Mass Audubon can be found here.

Red blazes of sea-pickle streak the marsh.  It is a succulent, like a cactus, and after some rigorous coaxing (squeezing the heck out of it) we get some sea-pickle juice on the refractometer.  It has an internal salinity of 90 ppt (marine salt water is 32-35 ppt)!  That’s almost 10% salt!  You can learn more about why sea-pickle (also called pickleweed) is so salty here.

The eager young scientists are let loose on the marsh to find what life lies beneath the now brown, but still thick grass.  They combine their treasures in a box and we discuss what they had found in a scientific show and tell.  I kneel down next to the box on the ground and am surrounded by a forest of middle school students.  Mr. Reynolds and Ms. Furlong are pushed to the side, like the losers of a game of Duck-Duck Goose (does anyone play that anymore)?  The young scientists point to their individual treasures.  There’s the coffee bean snail, Melampus bidentatus, which is a pulmonate (air-breathing) and mostly terrestrial snail that is still connected to the sea by planktonic larvae.  Scribble of pencils on notebooks.  There are small wolf spiders.  The molt of the invasive green crab, Carcinus maenasMore scribbling.  A field cricket (the males of which use their wings, NOT their legs, to make cricket calls to woo their ladies).  A ribbed mussel, Geukensia demissa which are not good to eat, unlike their cousins the blue mussel.  Scribble. And now zombie amphipods.  Amphipods (also called marsh hoppers) are normally brown, but orange amphipods are parasitized with a trematode that changes their behavior and makes them exhibit risky behavior so they can be eaten by birds (the bird is the final host of the parasite life cycle).   

I open the trunk of my Honda Civic for larger and possibly more charismatic critters of the marsh.  I pull out several horseshoe crab molts, including a large female the size of a hubcab and reported to have been at least 25 years old.  The scribbling is abandoned for tactile experiences.  I pass around the molts and let the students touch the lacquered, large female.  The students learn how to tell the difference between males (the ‘boxing glove’) and females and that sexually maturity occurs when they are at least 9-11 years old.  And why the male has ‘boxing glove’ claws (to hold on to the female for mating).  I tell them about the blue blood of these crabs and how it’s important to our own health (more on this later).    

For the final act I pull two unhappy, but alive lobsters from a brown paper sack.  I teach them how to tell the male from females (I teach the students, not the lobsters – I think the lobsters already know) and the function of their different claws (one is a cutter and one is a crusher).  More tactile experiences as the lobsters are passed around.  Now when they play with their food they will do it with knowledge!  And the phones finally come out.  Pictures taken, posted and tweeted to the field notebook of the world.

I am excited by the enthusiasm of these young investigators.  I mean, isn’t that why I do science, because it’s cool?

Dr. David Johnson, TIDE PI, showing students coffee bean snails.  Note the notebooks and the genuine curiosity!

Dr. David Johnson, TIDE PI, showing coffee-bean snails. Note the notebooks and the genuine curiosity!  Photo credit:  John Reynolds

The tide has risen to edge of the road, another cycle completing.  The students give their thanks and climb into the white van.  Handshakes and thanks are exchanged between me and the Ruppert Nock Middle School teachers.  And then we drive and bounce down the pocked road of Stackyard and reflect on what we all had just learned.