Fall Findings

After our paddle, we worked hard to make claims from our spring studies, and summarize our findings as we wrapped up last school year and analyzed our fall salinity data, as well as depth findings.  Here is our presentation that we passed along to the town Conservation Committee.  Of note is our ideas for the future, and our plans to build and deploy more technology to capture data to continue our studies.

Paddling the Marsh

The back-to-school autumn weather was perfect for a paddle on the marsh!  After reflections on our work last year (see below), we wanted to broaden our experience and our ability to access the rest of the water for some additional data collection. Last year, we monitored salinity and we had alewife fry in different salinities to see if they were able to survive.

Since then, our town is requesting the Department of Marine Resources to re-stocking the marsh with alewives.  We wanted to provide depth information to help officials evaluate a re-stocking effort and we wanted to pull the Marsh Monitor probe for recent salinity data.

Our paddle experience also had the goal of thinking about “indicators” of the health of our marsh and how we might approach using technology this year to enhance our studies of the marsh and why alewives are not returning.

Thanks to a generous grant from the Georges River Educational Foundation, we were able to work with Port Clyde Kayak and have a fun paddle throughout the marsh and collect some valuable data in the process.

Our “headline” take-aways were:

The marsh is very shallow throughout!!  (Less than a meter)

Salinity is persistent…we measured 5-8 parts per thousand (ppt) throughout the marsh.

It is apparent that our freshwater marsh habitat is experiencing brackish conditions; not necessarily good news for alewife breeding habitat. Now we turn toward formalizing our findings to pass along to the Conservation Commission to inform and hopefully bolster a plan going forward.

Our reflections of last year…

“My highlight from last year’s science class for me was studying the alewives.  I enjoyed going down to the marsh and being able to have some time to myself down there. I also liked that when we studied that, we were solving a real life problem “Why did the alewives leave?” and “How can we get them to come back?” I think it helps us how to solve real world problems and how we can help our environment.”

“I really enjoyed doing research on the marsh and alewives, like going to the marsh and taking samples and doing experiments with the alewives.”

“I liked going down to the marsh and studying alewives.  It was great besides cutting my toe. I enjoyed it because it was outside and I like being outside where I can be more hands-on.”

“The highlight of our year last year in my opinion was learning about the alewives in our marsh. This is my highlight because I enjoy hands-on work and learning about the alewives allowed us to go down to the marsh and go on field trips outside, and we got to set up the tanks and many other things.”

“I like the outside activities because I focus easier with physical settings.”

“My highlight from 7th grade was the alewife project and measuring the salinity.  It was fun putting out the salinity probe and finding out what the salinity was different days and even after king tides.”

“My most memorable moment in 7th grade was taking the ear bone out of the alewife.”

Our Celebration of Learning!

Our Celebration of Learning on June 13th, 2019 was a rewarding experience!  We had many guests visit our classroom, including representatives from the Natural Resources Council of Maine who supported our project with grant money. Students greeted, guided visitors to numerous stations around the room to see the different facets of our work investigating the salinity effects to alewife reproduction in the marsh.  On display were our aquariums with varying salinities and demonstrations of daily observations, data gathering and feeding methods.

A clever zooplankton viewer was rigged up by Jayden to make it very easy to see the natural food of alewife fry.

How we measure salinity with a refractometer and how we monitor our aquarium salinities with our digital hand-held probe was demonstrated; our data from May as well as graphs and data analysis and claims were on display…Bryson had his Maker Space probe to talk to people about, as well as a display of June’s temperature, salinity and tide height data.

We had a live demonstration of how we identify alewives and their gender as well as otolith removal.  Otoliths are the earbones of fish and can give researchers an amazingly detailed analysis of the age of the fish and the waters in which it has lived.  Scale sampling and aging techniques via our classroom microscope were also on hand.

Our life cycle informational graphic displays were there to see and rounding out our displays were our Nature Notes, soon to be published by the Gulf of Maine Natural Resources Institute and their Vital Signs program.

We’d like to thank our visitors and our community for supporting our learning efforts!

Note:  Here is a link to our published Nature Notes in the middle level science journal “Findings From the Field” (Vol. 2).

Analyzing May Salinity Data

One our big goals this spring was to collect salinity data during the spring tides of May and June.  We met that goal with the deployment of the Maker Space digital salinity probe.  The data card yielded the following analysis, which is promising for the alewives.  

Here are two student claims about our data.

A graph displaying the changes in the height of the tides and the changes in salinity, May 14th – 23rd, 2019

Two small alewife fry, approximately 2 cm in length, swimming against the backdrop of our data sheet!

The Salinity Claims about our Marsh (Ella)

We were able to collect data from our Maker Space probe, here is what we got: 

During the May spring tides there was salt brought into our marsh. Our evidence is the data collected from salinity probe. We made a graph to show what the salinity was day to day from May 8th to May 23rd. On the day of the spring tide, May 18th the salinity shot up from 0.3 PPT to 1.6PPT. On this day the height of the tide was 11.3 feet. 

On our graph we saw that the height of the tide is the independent variable and the salinity is the dependent variable. That means that the salinity depends on the height of the tide. For an example, when the height of the tide is increasing then than the salinity would also be  increasing. For an example on May 17th we had an 11 ft tide and the salinity was 0.3 PPT. Then as the tide increased on May 19th to an 11.3 ft tide with a salinity of 1.3.     

The salinity of the marsh changed quickly, in small amounts. Our evidence is, in the days between May 17th – May 2oth. There was a range of  0.1 PPT over 3 different samples in a 40 minute period. This proves that our salinity probe can measure small amounts of salt at short period of time.  

 

Salinity Data (Brooke)

The May 2019 spring tides brought salt in to our marsh. We gathered all of our data in the marsh from the salinity probe built in the Maker Space by a classmate. The highest spring tide was 11.3 ft on the 18th with a salinity of 1.6 parts per thousand (ppt). 

There is a positive relationship between the height of the tide and the salinity in the marsh. When the height of the tide gets bigger, the salinity increases. When the height of the tide is decreasing, the salinity decreases. For example, on May 19th the tide was 10.6 ft and the salinity was 1.2 ppt. The next day on the 20th, the height of the tide was 10.4 ft and the salinity was 0.8 ppt.     

The salinity changed by small amounts in short amounts of time. From May 17th-20th, for the first forty minutes of each day the salinity changed by 0.1 ppt.

If we had eggs in our marsh they should be able to survive the 1.6 ppt salinity that was measured in May, based on two professional science studies that found eggs can survive in salinities under 2.0 ppt. We read about these studies before setting up our tanks in our classroom.

 

Setting Up Our Aquariums for Alewife Eggs!

We are now in LAB mode!  The alewives are spawning in North Pond, where we have a collection permit, and we have some eggs in a bucket (with the cool spring, the eggs have not concentrated in the waters making collection challenging). Now we need to set up our aquariums with the different amounts of salt we have decided for each tank.  Our question is:  Will a salinity greater than 2.0 ppt affect the survival of alewife eggs or fry?  Most classmates think that salinities greater than 2.0 ppt will decrease the survival of eggs and fry.(Substitute student hypothesis here?)  The question and our hypothesis was framed and informed by published results of the few previous salinity studies (a peer review process!) that we found.

 

We have to figure out how to create salinities of 2 ppt, 4 ppt, 6 ppt, and 8 ppt for the aquariums we’ll compare to our control aquarium.  Salinity is the one variable we are testing.  Our constants will be to use the same size tank, the same water level in the aquariums, the same temperature, and the same number of eggs.  To figure out our salinities, we used our math skills.

Massing a specific gram measurement of “Instant Ocean” salts to add to distilled water to make 6 PPT salinity

We started by putting a gallon of distilled water into a clean (large) aquarium.  We added 1/8 of a teaspoon of “Instant Ocean” salts, which we massed and determined was 1.14 grams, to the gallon of distilled water.  Interestingly, the gallon container was marked 3.78 L (3,780 ml), but we measured its contents and found the gallon to contain 3,880 ml of distilled water.  We mixed the solution thoroughly, then let it sit for about 5 minutes, then measured its salinity.  The salinity was 0.26 PPT.  Both our classes did these steps, and we both measured a salinity of 0.26 PPT.  From here, the rest was math to get a basic salinity “recipe” to make whatever we needed.  We had to use math to solve for how many grams of Instant Ocean would make 1 PPT.  Once we knew this, we could double our amount of Instant Ocean to make 2 PPT, for example.

 

The tanks are now all set up and ready for eggs!!

 

 

Student writing to be published in “Findings from the Field” Middle Level Science Journal!

The Gulf of Maine Research Institute’s Vital Signs program began a state-wide science journal for middle level science students last year.  The journal’s name is “Findings from the Field“.  The journal models the peer review process of scientists and invites student submissions, which are then peer reviewed by other schools as the initial step toward published findings.  The feedback of peers in other schools helps to create a science community among learners to give authors specific feedback to consider in order to revise and re-submit to a final board of journal editors.

Students worked through multiple revisions to produce their very best writing. They clarified their understandings of alewife restoration efforts in town and changing salinity levels in the marsh because of periodic tidal flooding.  The observation of tidal flooding is the basis of our inquiry project to investigate the impact of varying salinities on the eggs of alewives, which we have just begun setting up in our classroom.  In the process, they realized they are scientists, seeking information that can only come from a science study, and that they can make an important contribution to their community.

We are pleased to announce that a number of our students’ “Nature Notes” have been recommended for publication in the June volume.  (A Nature Note is an interesting observation of significance that prompts an inquiry question or initiates an investigation, using 500 words or less.)

Review Nature Notes from another middle school

Links to all the students’ Nature Note submissions are below this submission from Natalie, which has been recommended for publication!

Salinity in the Marsh

Natalie Vanorse

The marsh is located down the hill from St. George School next to the Jackson Memorial
Library the marsh flows into Ripley Creek. The marsh is home to eagles, gulls, kingfishers,
frogs, snakes and more. Our class goes down to the marsh about once every week. It is a quiet
and beautiful place to be.

Our class went down to the marsh at 1:03 PM on Thursday, April 25th to collect a sample
of water to see what the salinity levels were. The salinity level we got was 0.27 ppt. The place
we took the sample was in marsh. The type of weather on April 25th was sunny and a little bit
windy.

The significant thing is that there is salt coming into the marsh each month with the
highest tides, which could change the spawning habitat for the alewives. In the mid 1980’s the
alewives stopped coming into the marsh. The state started to restock the alewives in 2009-2013,
but we have only seen a few alewives in the past four years. We are not sure why the alewives
have not come back since the restocking. We are worried about the saltwater that is coming into
the marsh because we are thinking that it may affect the alewives eggs after spawning. Alewives
normally lay their eggs in freshwater.

These observations make us wonder how much saltwater is coming into the marsh with
the tides. Is that why the alewives have not come back? Because we have warming climate it is
making the tides high enough for saltwater to come into the marsh.
We are going to try and hatch alewife eggs in different amounts of salt to see how much
of an effect the salt will have on the eggs. When we figure out how the salt is affecting the
alewives we would like to share our information with the town of St. George and maybe the
town would consider restocking again.

The Marsh in Tenants Harbor

 

The other Nature Notes (links)

Leah, Jayden, Hayzel, Evie, Ella, Colby, Brooke

Pulling the Data Card and OUR FIRST DATA!

 

OUR FIRST DATA!!

Bryson programmed the probe to collect data every 20 minutes (calculated via milliseconds!) and our first analysis is for the first date and time stamp of each new day.  For that first data collection that day, we also used the US Harbors, Tenants Harbor tide chart and added the time of the “nearest” time of high tide to the table of Maker Space Probe data.  What we mean by the “time of nearest high tide” is the time of the high tide that was closest to that first data point occurring just after midnight.  Sometimes, it is the previous high tide, if that high tide occurred after 6 pm the day before.  We also recorded the date of that high tide, and the height of that tide.  We can continue to display it in different ways; for example, we could graphically represent the varying height of the tide in comparison to the varying salinity.  Then we are going to see what kind of claims this evidence can support as we look for patterns.

 

Damariscotta Fish Ladder and Warren Fish Trap Visit

Today, May 22nd, we enjoyed a spectacular spring day to see two of the largest alewife runs in the state; Damariscotta River alewife and the St. George River alewife runs.  Together they represent 86% of the state’s harvest of alewives.  Our local lobstermen frequent the fish trap in Warren for fresh alewife bait, and the fish ladder in Damariscotta Mills is an amazing sight to walk along when filled with fish.  Here are some student reflections…

“I think of the fish as characters in an adventure story…very, very determined to swim to their spawning grounds.  The fish were dark gray and were very packed in the water.  If one was spooked, they all would move with the fish.  There were more fish there than I suspected there would be.  The river was black with them.  I have been wondering how the fish have the unending strength to swim all that way.  I think that we might need a fish ladder to help bring the run back (in Tenants Harbor).  The most interesting thing about the fish today is how many there were and how many dangers there were.  I learned and was more of how difficult the alewive’s journey is.”  Evie

“When I saw the fish it reminded me of the summer, when my friends and I would go fishing and lobstering.  It was so cool watching all the fish and feeling like I could reach my hand out and an alewife would just swim right into it.  I noticed that all of the fish were facing the same way.  There were lots more fish than I expected to see.  I wonder if the fish will always be there?  Is the water there getting saltier?  When I’m 32 will alewives still be in these places or will they be in our marsh by then?  The most interesting thing was walking along the bridge and watching the alewives.  Another interesting thing is how many birds eat alewives that are around where we went today.  What I understand more now, are the rules about alewives that we have now than what we used to.”  Ella

“I thought that it was really cool to see both of the runs from Damariscotta and Warren because personally, I have never seen any alewives in our marsh, so to see thousands all at once was very cool.  I noticed that the fish have to go against the current in Damariscotta to go upstream. There were way more fish than I expected, because I didn’t realize how dense they could get together.  I wonder what the salinity and temperature is in the streams from both Damariscotta and Warren.  I understand the alewife life cycle and can visualize it better now by going to see them today.  I learned that it takes three days to smoke alewives.  I learned what a fish ladder and trap look like.”  Brooke

“I thought it was really cool to see the alewives because we are studying them.  I noticed that the alewives were all going in one direction.  I also noticed that the alewives were moving very slow and going one by one up each ladder.  I thought that the interesting part was the way that the fish stay in a big group.  One thing I learned about alewives is they do not like the light and that they use the current to tell where to go.  I wish that we had restoration that Damariscotta has in St. George.”  Colby

“I noticed that there was a rock, not in the way, but the fish were going around the rock, and there were three to four fish with a chunk taken out of them.  There were more fish than I expected.  I think we should restore our run because I think it would be fun.”  Isla

“It was the best experience ever.” Jayden

“The fish were cool and I noticed that the fish were swimming two different directions. I thought that there were going to be less fish than what I saw.  The most interesting thing about the fish was that there were so so many of them and I have never seen that many fish in one spot before.  What I understand now that I have had this experience is how you smoke the alewives and that alewives like shady spots. What I learned about the fish that I didn’t know was that it takes three days to smoke alewives.  Step one: salt, step two: smoke, step three: smoke again.  I also learned that alewives have a difficult journey.”  Natalie

“I thought that is was amazing to see all of the alewives.  The big ball of alewives under the bridge looked like seaweed because of how they swayed and wiggled.  I found looking at the mechanisms and contraptions of the alewives were really cool.  I really like to look at things like that.  I also thought that the smokehouse was really interesting and I like the fact that they used actual wood to produce the smoke. I am really glad I went on the field trip and I would like to than everyone who made this trip possible.”  Dylan

“The fish were like a swarm of bees trying to go through the current.  The fish had the colors of green, silver, and dark blue.  Another detail is the fish were waiting until the current changed so they could leave the entrance of the stream. There were more than I expected.  What would happen if the alewives became an extinct species?  I learned we were hunting alewives ever since the 1600’s.  The most interesting part of this was learning that there were 3,000+ alewives in the smokehouse.”  Jacob

“I thought that it was really cool to see all the fish schooling up.  It made my day seeing the huge brown trout with all the alewives. I want to try a smoked alewife.  The warden was very informative.  It was a great day.” Nathan

“It was so cool to see all the fish in the water.  They were like the water itself. It was so beautiful to see them in the water.  I noticed a lot more fish than I expected, I thought there were going to be maybe, 500 fish, but it was more like 5,000 fish.  I noticed that all the fish stuck together, even if something disturbed them in the water.  I wonder why our alewives haven’t come back.  I learned that people have been fishing in the waters for 9,000 years.  I thought that all the birds near all those alewives were interesting, because they didn’t even try to get one to eat. The experience was really amazing.  I got to see all those fish, and it is super cool because all those fish have made it back to their natal rivers and they have survived.”  Leilani