Howdy folks. My name is Marshall Strong, and I’m here at the TIDE Project on behalf of Dr. Sallie Sheldon, from Middlebury College. For several years, Sallie and her interns have been investigating the filamentous algae which grows on the creek walls to see if there’s any difference in growth between the fertilized and the unfertilized creeks. Our current technique involves using bridal veil as an artificial substrate for the algae to grow on. We use a terribly high-tech device (a typical kitchen cheese-slicer) to scrape the existing algae off of a section of the wall and use drywall screws to screw the bridal veil into the mud, then wait for the algae to colonize it. In past years, we’ve found no significant difference between the fertilized and unfertilized creeks, which has been a bit of a surprise, so this year we’ve added exclosures around our bridal veil to try to control for the possibility that something may be eating the algae. The bridal veil squares have been out for a few weeks now, so we’ll hopefully get some data when we collect them at the end of this week and we can start coming up with some answers.

In the meantime, while I wait for my algae to grow, I’ve been taking a look at the pannes surrounding the creeks. There seems to be some debate over what exactly a panne is – a low-lying area of the marsh with different vegetation, or an actual pond in the middle of the marsh. For my purposes, I’ve been just looking at the ponds. Unlike the rest of the marsh, the pannes aren’t affected by the tides on a day-to-day basis, making them a bit of an anomaly. They get flooded with the rest of the high marsh every spring tide, but the rest of the month they just sort of do their own thing. I was interested in how the water chemistry changes over the course of one of these tide cycles, so I identified six pannes at both Sweeny and West of various sizes, and went to work taking some measurements. I’ve been out multiple times a week with a YSI the past month, taking temperature, dissolved oxygen, nitrogen, pH, and salinity readings. It’s still very much a work in progress, but there seem to be some trends in at least the pH of the pannes. More results soon to follow!

In other news, the spring tide was this weekend, which means late-night flume night sessions for all of us here at Marshview (with the exception of yours truly, who managed to pass out on a couch before sampling occurred last night!). We did Clubhead and West Saturday night, and Jimmy did his very best to scare the pants off of us all as we emerged from the woods. Caitlin and I got a bit jumpy, but Nate was convinced a coyote was about to end him. We all went out to Sweeny and Nelson this morning to collect our fishy harvest, which will keep Nate and David busy for the rest of the week, as well as our high schoolers and anyone else with some free time on their hands.

In addition to spring tide, the end of the month has brought some welcome relief from the insect population. I don’t want to jinx it, but I didn’t have to swat a single greenhead on the marsh today! That’s not to say I got off scot-free – the greenheads who managed to colonize our boat are intrepid little biters, and seem to have survived the spring tide. In any case, the next few weeks should be gorgeous and insect free. The TSA is blooming, there are pretty little blue flowers all over the marsh (no clue what it’s called, I’m no botanist), the dripper is dripping, and the bugs are all dropping dead. I’ve got another three weeks here at marsh view before I jet off to Copenhagen for a semester abroad. Looking forward to some data analysis in the near future!

Marshall… Marshall… Marshall…

 

Hey everyone!  My name is Caitlin and I am mainly focusing on Tall Spartina Alterniflora (TSA) for the TIDE project.  More specifically, I am looking at its growth in both the fertilized and the unfertilized creeks by cutting and collecting plants from two small plots, known as clip plots, at each of three set point, known as transects, along creeks each month.  Each plot is taken from two set elevations at each transect, one lower and one higher, across all of the creeks in order to standardize the water coverage at each plot.  Unfortunately, some of the creeks did not want to cooperate and finding plots with the right depth of water coverage and a large enough plot of TSA proved to be harder than it sounded.  In order to determine depth of the water, we not only had to measure the distance from the high marsh to the mud in which the TSA was growing, but we also had to put out 108 tide sticks to measure the water level at high tide.  These sticks were homemade with Phragmites, an invasive reed we cut down in the backyard with a machete, and were pained with glue dyed with food coloring.

Despite a lot of rain, I was able to collect my first set of clip plots with help from all of the TIDE researchers here at Marshview during the last few days of June.  Once I brought the samples back to the lab, I washed the mud off of each plant and out of the crevices of the leaves and then froze them.  While this wash process is tedious, it ensures that the mud will not get into any of the lab equipment while I take measurements.  In the coming weeks, while I wait for the plants on the marsh to grow taller and for my next clip plot date in late July, I will be processing the plants here.  In addition to looking at stem density, leaf counts and plant height, I will be taking leaf area measurements to gain further insight on the growth of the plants in each of the creeks.

When I am not working with the TSA, I am working on other portions of the TIDE project that have been introduced in previous posts.  Some days I help Nate and David count and measure fish, others I go out with Marshall to work with salt pans.  Yesterday I went out with Belle to take routine nutrient samples and to try to obtain larvae in Plankton nets.  Today we collected mud cores to test for benthic chlorophyll levels for the month of July, then I helped Nate and David look at the gut contents of mummichogs.  As for the rest of the summer, only the tide will tell.

Just in case anyone was wondering… TIDE: Trophic Cascades and Interacting Control Possess within a Detritus Based Ecosystem.

Hello, my name is Nathan Andrews, and I am a TIDE REU (and proud of it!).  I am a Marine Biology major at the University of Rhode Island. I am a rising Junior and play rugby for the Rhody Men’s Rugby Club and for the Semiprofessional Rhode Island Rebellion League. I have a very vast interest in the Marine Bio World. My interest range from diatom genetics, to population dynamics of horseshoe crabs, to marine ecology and fish. During the school year, I work in the Rynearson Lab at the URI Graduate School of Oceanography as a lab intern researching diatom genetics and in the past I have worked as a marine educator for Save the Bay, Narragansett Bay, RI. You can only imagine the excitement that fell upon me as I read the job description for this REU position and applied to work as an undergraduate researcher for MBL, and get paid for it! It was a no-brainer.

I intend on using this fellowship to build upon my academic background, as well as gain experience in the Marine Ecology field. I am very interested in Oceanography and intend on going to graduate school to get masters in it. I love science, and my love for science is only matched by my love for the ocean and all of her wondrous functions, niches, and organisms. Science has so much to offer the world and so much ability to heal it, protect it, and renew it. Biology offers me five things: a rewarding career, fieldwork where I get my hands full of science, lab work where I test the truths of nature, and deriving scientific results, which when results are produced it yields new knowledge of the world around us. This excites me!

Life here at Marsh View Farm is awesome. Here, I live with other undergraduate researchers, Marshal, Caitlin, Wesley, and David, and our wonderfully scientifically inclined, helpful and most talented RA, Belle; all of whom are just as excited about marine science as I am! We are lead by Dr. James Nelson (aka Jimmy), who is extremely knowledgeable about everything that is remotely scientific and has been a phenomenal mentor thus far. In this TIDE program, we are more than just members of a scientific community; we are like a family here. We all work together on each other’s projects and we all pitch in when one of us needs help. Being a scientist, under these conditions and within this program is a great lifestyle, and it is something that I would gladly commit my life to.

Here at the marsh, as they say, the “tides wait for no one.” This could not be truer. Our lives are run by the tide. 3 days a week we lug a ton (literally a ton) of fertilizer out to the marsh on the TIDE John Boat, the Apeltes, and do a fill. We all pitch in to help the six projects going on here during the times when we are not catering to the tides to do the fill, once a month we take sediment core samples, once a month we pull about a 48hr shift and do flume nets, and once a month we do a week of sane net collecting 1000 chogs and about 2000 grass shrimp per creek and spend a couple weeks analyzing the collections. Lots and lots of Science!!! And each of these activities and the times that we get up to do them in the morning, afternoon and night, are dictated by the tides.

David and I are both being mentored by Jimmy. We are researching nekton of the marsh creeks, looking at mummichogs and striped bass population and energetics. I am particularly looking at growth, diet, and energetics. To determine the growth of the ‘chogs, we do a length frequency analysis. Once a month we do a week of sane net collecting 1000 chogs and about 2000 grass shrimp per creek and spend a couple weeks analyzing the collections. Each fish and shrimp is counted and measured. Chogs and shrimp are major food sources for the striped bass. ‘Chogs hatch on full moons and each month that they are born there is a certain survivorship. This can be determined through their size and number for that particular size range. Fish hatched during the same time are known as cohorts. These cohorts and there alteration in size can be monitored throughout the summer. This data can be used to assemble a graph that plots biomass over time and growth rate over time. The point immediately after the intersection of this two lines gives us a projection of where the max yield and max reproductive potential of the fish can be achieved to form a sustainable fishery. This is important to know because of the extreme interconnectedness of the ocean and her food web, we can monitor changes in other populations due to the change in the ‘chog population. The same analysis can be done for the shrimp.

I have not really gotten into the energetics and diet portions of this project so I will leave that and discussing flume netting for next time! I hope this gives you a good understanding of what is going on here in TIDE.  This is an amazing program and a fantastic opportunity for me. I am getting paid to do what I love! I get to go out almost every day and play in the mud and catch fish, every kid’s dream. I get to soak in the sun and enjoy the sites and sounds of the marsh. Sure we all may have to eat a few midges and swat away a few green-eyed flies, but I get to stay active and learn at the same time. This is my dream job, and I am living the dream.

Hello and welcome back to the marsh, everyone! This year is a very special year, as it is the 10^th anniversary of pumping fertilizer into the field. According to marriage.about.com, clearly the foremost authority on all things anniversary, the 10^th anniversary can be celebrated with gifts including a “tin paperweight” or “diamond jewelry.” The “tin paperweight anniversary” doesn’t bear the same gravitas as “Marshview: Diamond Edition,” so here we are.

I’m excited to be out in the creeks, as this is my very first year! My name is Jessica, but everyone calls me Belle. I’m the RA this year, filling some very big shoes with big thanks to those who came before me.  My interests include invertebrate physiology and food web ecology. I just graduated from Tufts University in the spring.  It’s been a fast-paced month as I’ve gotten caught up on the rhythms of the marsh, and now I have been joined by 4 wonderful undergrads to help.  Marshall Strong (Middlebury), Caitlin Bauer (Bryn Mawr), David Behringer (Washington and Jefferson), and Nate Andrews (URI) are all undertaking projects of their own, which they’ll write about later this summer! We’re all being mentored by Post-doc Jimmy Nelson, mummichogologist and a veritable jack-of-all-trades. I’ve been told he is called neither Dr. Jimmy nor Jimmy the Magnificent. This might need to be remedied.

Right now I’m working on teasing out the mechanisms of mud snail (Ilyanassa obsoleta) delivery to the marsh.  There are many more snails in fertilized creek than unfertilized creek, so I’m trying to explain how that might come about. I. obsoleta are absolutely everywhere on the mud flats, and understanding their population dynamics can help us work out the flow of energy through food webs in the marsh.

Mud snails lay eggs which hatch into swimming larvae called veligers. Those veligers swim around for a while until they find a spot they like to metamorphose into juveniles, no longer swimming little snails, and will develop into adults. I’ve laid out mesh netting which the snails will hopefully lay eggs upon, in an attempt to get a sense of how many eggs are getting laid at the various creeks.  Next, I will deploy scouring pads into the water column and will sort the critters that get trapped in there, to determine how many larvae are swimming around in the creeks. After that, we will try to find the juveniles by scraping through the creek mud and get some counts of adult survivorship.  Hopefully, through these investigations, we’ll get a better idea of why the snails are overrunning our creeks. (Though if you ask me: the more the merrier!)

With much thanks to Dr. Deegan and the other scientists who joined us this week to officially kick off our summer season, we go boldly into the marsh for this exciting tenth year of TIDE!

As a highly productive ecosystem, salt marshes are known for their diverse range of primary producers that can support a whole host of organisms, from microscopic invertebrates to large fish.  Fertilization of the tidal creeks results in a large increase in benthic microalgae, which is a main food source for primary consumers (benthic invertebrates).  The predominant secondary consumer in this system is the mummichog (Fundulus heteroclitus), which feeds on both the benthic microalgae and the primary consumer invertebrates.

In recent years, however, decreases in mummichog densities have been observed in the fertilized tidal creeks—an unexpected occurrence in the face of such an apparent abundance of food.  Classic bottom-up theory of food web control predicts that increased primary production stimulates productivity at all higher trophic levels.  In this case, however, it seems that bottom-up control may be attenuated if nutrients stimulate inedible or inaccessible herbivores, which can end up dominating the primary consumer community.  This phenomenon is the idea of a trophic bottleneck.  If the majority of primary production is consumed by inedible herbivores (snails with large, tough shells) or inaccessible herbivores (high marsh invertebrates), secondary consumers can’t access that energy and are at a disadvantage.

As an REU intern for the TIDE project this summer, I am studying the effects of nutrient enrichment on the benthic invertebrates in the salt marsh, including those species that may be responsible for a trophic bottleneck in the Plum Island Estuary.  I investigated invertebrates in the three main salt marsh habitats: the mud flats, the tall Spartina alterniflora along the creek banks, and the high marsh.  The dominant invertebrate in the mud flats is the mudsnail, Nassarius obsoletus, (which is inedible because of its large, tough shell) and the edible infauna, which consist mainly of subsurface-feeding annelids.  Both the mud flats and the tall S. alterniflora are main feeding refuges for the mummichogs because they are flooded well over 50 percent of the time.  In the tall S. alterniflora, the main invertebrates are various species of edible infauna, which are also present in the high marsh.  In addition to these subsurface invertebrates, the high marsh supports amphipods, isopods, and Melampus bidentatus (small snails), which are all edible to mummichogs, but only accessible to these predators when the high marsh is flooded (roughly 4 percent of the time).  Both the inedible energy in the mudsnails and the inaccessible energy in the high marsh invertebrates can contribute to the trophic bottleneck problem.

In order to examine the surface invertebrates, I used to a 0.0625 square meter quadrat to randomly sample at points both in the mud flats and in the high marsh.  In the mud flats, I ran a 200 meter transect along the creek bottom and sampled at 20 random points along that line.  In the high marsh, I sampled at 10 points along the creek banks, where I clipped all the grass away within the quadrat to count and collect the invertebrates.  In the lab, I counted all the invertebrates and measured the shell heights of all the high marsh and mudflat snails.  Using the counts and measurements, I calculated the densities and biomass of the mudsnails, high marsh snails, amphipods, and isopods.

I sampled for infauna by taking small cores (6.6 cm diameter) from all three habitats.  I took 2 replicates in each habitat and did this 3 times for each of the two branches of all the creeks.  In the lab, I rinsed and sieved these cores before storing them in formalin to process throughout the fall.  I’ll be comparing my 2012 infauna results to infauna data from 2009, which I also processed this summer, using a microscope to count and identify the different annelid species.  In addition, I will examine my early season and late season data to measure growth throughout the summer.  By comparing the primary consumer communities between fertilized and reference creeks, I hope to determine whether nutrient enrichment is causing a trophic bottleneck in this salt marsh food web.

Welcome to the first (and probably only) issue of the Chog Blog! This week on the Chog Blog I have some great information to share with you about the lovable Mummichog! Known by scientists as Fundulus heteroclitus, it is a crucial secondary producer and primary predator in the salt marsh food web! But before we get too excited, I must share some background information about what we do here at TIDE and just how it ties into the daily life of a Mummichog.

The TIDE Project’s objective for the past 9 years has been to add nutrients to salt marsh creeks of the Plum Island Sound in order to determine the effects of eutrophication on the ecosystem. My role this year as an REU has been to continue the research previously done and determine how eutrophication is affecting Mummichog productivity. In order to do so I had to collect data to determine the density/m² and biomass/m² as well as a seasonal growth rate.

To go about collecting the necessary data, there are a few different methods involved. The first bit of information that we want is what the densities of the fish are in fertilized and non-fertilized creeks. We employed 30m² flume nets and trenched them into the marsh. The area that they enclose includes both types of habitat used by the Mummichog: high marsh and tall Spartina alterniflora (TSA). There are four of these nets on each branch of each creek which is a total of 24 flume nets. The fish and various other nekton were caught in these nets on the shoulder of the spring tides during June and July and have yet to be done again in August. The catch was then brought back to the lab where each individual organism was counted, weighed and measured to get the averages for each creek.

We have also conducted a length frequency analysis of Mummichogs to determine a relative growth rate for the season. For this, we used seine nets to catch approximately 1000 Mummichogs from each of the six creek banks. The fish were measured and the data entered into a histogram to visualize size classes and how they progressed from June to July. I must thank all the great REH’s that we had this summer: Nora, Molly, Patrick and Chris as well as budding marine biologist Jack who volunteered his time, for helping me tremendously with processing the oppressively large amount of Mummichogs that we caught!

The final project that I worked on was analyzing gut contents of Mummichogs from five different size classes from each creek. The size classes were 30, 40, 50, 60, and 70mm. As close to twenty fish as possible from each size class were obtained from each creek and then cut open to examine their guts. The percentage of animal to vegetable matter in their guts was recorded and also any solid organisms that were identifiable. An interesting observation I made was that Mummichogs in the 60 and 70mm size class in the right branch of West were consuming Melampus coffea. One individual even had as many as nine snails in its gut! Wow!

Now I know you all saw this coming but I hate to say that this issue of the Chog Blog is coming to a close. I am currently in the final stages of data analysis and assembling some beautiful figures to sum up my findings. I’d like to thank everyone who helped me along with my field work and got my feet off the ground! I’d also like to thank you, loyal reader, for taking the time to learn about what I’ve done here with TIDE as an REU this summer!

A salt marsh is comprised of fine sediments brought in from the sea, held together by the roots of plants. Without the roots of Spartina alterniflora in the low marsh and Spartina patens in the high marsh, the sediments have nothing to hold them together. They will break down and are washed back out to sea with the falling tide. In 2006 after 4 years of fertilization in Sweeney Creek, TIDE scientists began noticing a decrease in the structural stability of the creek banks and an increase in cracks and peat islands. The bed of tall Spartina alterniflora that lines the creek banks appeared to be breaking off into the creek, leaving a cliff bank lined with Spartina patens. They began studying two additional creeks, Clubhead and Nelson, in 2009 in order to measure these observations from the beginning.

This summer I am an REU for the TIDE project, and I am concentrating on quantifying the changes in geomorphology that have been observed. My goal was to count and measure the high marsh cracks in every creek, measure the width of the Spartina alterniflora band along the creeks, and to count and measure the peat islands. This data is to be used to compare the fertilized and reference creeks to determine if there is a significant difference and if this decrease in structural stability is being caused by the excess nutrients.

So far this summer I have finished the majority of my field work. With the help of Chris Haight, the other REU’s Harriet and Tim, as well as two REH’s Nora and Chris, I have been able to measure all the cracks and peat islands, as well as the band of Spartina alterniflora at every creek. To measure the cracks, we walked along the creek bank on both sides to feel for cracks with our feet. I recorded the measurements, as well as the location along the creek. When we measured islands, Chris H. walked in the creek and measured the islands, as well as counting the number of low marsh and high marsh crumbles.

Measuring the Spartina alterniflora band was a bit more complicated, as it took a few tries to get a system that worked. In the end, our method was to lay out a tape measure parallel to the creek on one side, and have two people on either side holding another tape measure that was perpendicular to the creek. A third person was in the middle of the creek. I held the end of the tape measure where the Spartina alterniflora stopped and it turned into high marsh, and I moved along the side of the creek and stopped at every meter. Chris would be in the middle reading where the Spartina alterniflora stopped on my side to where it began on the other, and Nora was on the other side of the creek to read where the Spartina alterniflora stopped and the Spartina patens began. This gave us the width of the Spartina alterniflora on both sides, as well as the width of the creek habitat that did not have vegetation.

I am now in the data analysis phase of my project, where I will be using the data the compare the fertilized and reference creeks. In addition to regular tank fills, we just finished the second round of flume netting, Chlorophyll-A samples, and routine water samples. Chris and I have begun taking sediment cores, and next week the N₂/Argon sampling begins.

I turn onto the sun-dappled dirt road.  The shagbark hickories and red oaks that line the road nod with familiarity.  Welcome back friend, they say.  I park and my nose can see faster than my eyes and finds more familiarity.  A rich, organic smell tinged with sulfur floods my mind with memories.  I walk the brief path through the trees and emerge into a sweeping openness of green and home.  I stand at the edge and take in marsh.  I have returned.

This is my tenth season on this marsh.  As I struggle to find an academic position, a friend joked that this may be the only way I get tenure (“ten-year”).  I will accept that promotion proudly, a young scientist educated in the open and salty halls of the marsh.  I step onto the marsh again for another lesson.

A tossed quadrat.  Clipped grass.  I am face-to-face with 100 coffee-bean snails that glide over the sediment surface.  This is Melampus bidentatus (the snail climbing the grass in the blog header is Melampus).  Just as the marsh is an ecosystem that shares qualities with its aquatic and terrestrial cousins, Melampus’s place in the family tree appears transitional.  Melampus is a pulmonate snail and just like you and me, breathes air.  It has highly vascularized tissues behind its head that act as a primitive lung.  Land snails and slugs in your garden breathe the same way, while true marine snails often have gills.  And while Melampus lives in a part of the marsh that’s not flooded 96% of the time, it still practices the rituals of its marine ancestors.  A week or two before the spring tides flood the high marsh in June, there is a scramble by Melampus, which are not known to scramble, to get eggs laid on the stems of Spartina patens and S. alterniflora.  When the water pours over the marsh during a full moon, veliger larvae, which look like tiny coiled snails with Dumbo-like ears, emerge and enter the water column.  This air-breathing snail has aquatic larvae.  After a few weeks, the larvae settle, the Dumbo-like flaps shrink and the snail becomes a tiny version of the adult.  This is Melampus’s marsh.

I start collecting snails.  There’s a piercing bite on my hand.  A greenhead (a horsefly with big green eyes) has found what little skin I have exposed.  With greenheads, as with mosquitoes, it is the female that seeks a blood meal to provide protein for her egg-laying.  Males are relegated to nectar and plant juices.  So she cuts into my hand with a handsaw-like mandibles and sucks up my blood.  She will lay eggs in the high marsh and from those eggs will emerge fat, tough wriggles of larvae that are voracious predators of the high marsh.  Isopods and amphipods take note.  This is the greenhead’s marsh.

I swat at her and miss.  I hope that the dragonflies that dart about the marsh will have better luck in catching her.  The dragonflies are early this year, as are the greenheads.  Insects aren’t typically thought of as marine invertebrates, but the aquatic naiad larvae in the salty ponds that dot the marsh suggests insects are important in this ecosystem of salt.  This is the dragonflies’ marsh.  Unless of course, the dragonfly finds itself in the beak of a swooping tree swallow that carries it to its nest.  Then this is the marsh of the swallow.  And it’s my blood that feeds the swallow.  This is my marsh.

In step with swallows, the dragonflies, and the snails, humans bring new and young recruits to the marsh each year.  This year we have another crop of bright and eager undergraduate and high-school students that have recruited to the marsh to sink in the mud, fall in the water, and participate in exciting science.  Throughout the summer you will hear about the many projects and brilliant science being conducted.  Chris Haight has returned for his fourth year and has emerged as a brilliant coordinator of the project and a fearless hauler of fertilizer.  We will miss him when he goes to graduate school at Columbia next year.  Jimmy Nelson returns for his second year as a post-doc and continues to chase the small, but tenacious, mummichog.

I have returned because ultimately, we all came from the sea.  And each year for the past ten, I have been compelled to return home.  I have returned because this is my marsh.

Below are some young scientists in action.  This is their marsh.

– David