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.)

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 other Nature Notes (links)

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

 

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.

 

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

 

  

In addition to monitoring the salinity of the marsh water this spring during big tides, a significant part of our inquiry around the changing salinities in the marsh this spring will be to raise alewife eggs in our classroom.  We’ll have different fish tanks set up with different salinities.  We want to see what effect different levels of salt will have on the eggs and the fry, since we have spring tides and storm tides that bring ocean water right into the marsh.  We have to have a reliable way to set up the tanks with specific salinities and keep the salinities at those levels.  Thanks to he Natural Resources Council of Maine, we were able to purchase a high quality hand-held digital salinity probe that will help us do just that.

This week we learned how to use it, and then test the salinity of a sample of ocean water (collected on a recent rainy Monday afternoon).

.

Here’s what Dylan Lord found out:

“The salinity of our test was 10.00 parts per thousand (ppt).  Out of eleven data points all of the tests read that the salinity was 10.00 ppt.  We took this sample from right outside the marsh on the other side of the culvert (the ocean side).  We took this sample as the tide was coming in and it was the reason the salinity was so low was because it has been raining all week and kind of diluted the salt water.  On that side it probably never really gets up to 30 ppt because there is always fresh water flowing through there and then mixes with the salt water creating brackish water, which dilutes the water making it have a lower salinity.

This is a reliable test because all eleven people got the same answer and the more data points you have the more reliable the test is likely to be.  It was calibrated so that distilled water read 0.00 ppt and that shows that it is accurate because if it had said 1.00 ppt that would mean the probe reads one ppt higher than the actual reading.”

We also needed to compare our hand-held probe results with Bryson’s Maker Space probe to see that they both read the sample at the same salinity value.