Day 4 Survey of the Merrimack River Estuary

Day 4 Reflection


Top of Olde Town Hill looking toward Plum Island

Today was the final day of the four. I will say to all that read this blog that if you like the outdoors, prefer instruction that is a bit less facts centered, and sponsors and inspires creativity, Boat Camp for graduate credit is the place to go. Twice now I've had exposure to some incredible places that have clearly helped me develop real usable lessons for my class and had some fun too.

Weather condition were cool and very windy so we again began at the boat house for discussion on the impact of fishing with nets on the marine environment. We were asked to design a net specific too a type of fish with basic materials from simple netting, string and play doe. From my perspective it was a great springboard into discussing the effects of commercial fishing practices have on the marine environment, particularly how net types can cause collateral damage to species that are not of commercial interest. The discussion wasn't anti fishing but was about intelligent designs of nets (or lack of) can be a major benefit or problem. The Gill net, for example is very destructive because it is suspended in the water at at varying depths potentially several miles long and many feet deep. All sorts of marine creature (mostly fish but may include dolphins) get hung-up in the net and are unable to escape even though again they have no commercial interest. Since they can't swim many can not get oxygen and suffocate to death. Also most are made of microfibers (plastics) and takes 600 years to decompose, if a net breaks free it can continually snag and harm fish for years, called a ghost net. However in contrast there are practices and net designs that minimize many issues. I've personally used seine nets, useful in estuaries, ponds and lakes, and have found them to be useful for study. Rob mentioned using them for capturing bait species such as sand lance. Historically I did find it interesting that the Native Americans may have designed and built the first Weir net, fashioned from tree stems, which is effective in capturing channel fish where tides rise and fall.

Top of Olde Town Hill/Fallen Trees

Gary and Rob designed a field exercise that gave us access to the marsh but importantly was sheltered from the high winds. I have used Olde Town Hill in the past for geology lessons on drumlins and barrier beach formation. The downed trees at the top covered a huge area was awesome from the perspective of the impact of winds coming off the water, specifically from the northest. It was stated the February storm brought wind over 80 mph. This is a great site for visually seeing the barrier beach, the Merrimach River and the Great Marshes. It puts in perspective the entire estuarine system. On the south side there was a trail that I was unaware of that lead out in to the salt marsh to the the Little River, which flows through the marsh and empties into the Parker River. Since I already use Old Town Hill for a field trip I am likely to use the marsh for discussion of the formation of peat, indigenous species and adaptations. If I can figure out a way to have students investigate the fact that the peat in the marsh has nearly no smell, in contrast to the mudflats that had a strong sulfur odor I'll bring samples back to the lab as an addition to the field excursion. The aerobic and anaerobic thing I get and believe the kid will also but to have the student figure out the basic biology of why one smells but not the other is the sticking point for this moment. I'm also going to steal Gary's question "why put a field in the middle of the forest?" for the purpose of discussion of the historical use and related changes over time.

Day 4 Log

The mouth of the Merrimack River is a lagoon, a surprise to me, which is the mouth of a river that is protected by a barrier island with a narrow opening. The Estuary includes the lagoon,marshes and associated creeks. It is the barrier beach that creates the lagoon. The Great Marsh (mentioned above) is the largest in all of New England and extends from Hampton,NH to Gloucester incorporating approximately 22,000 acres. The Low marsh is closest to the ocean and has the highest levels of salt and the high marshes ,further up river have the lowest levels of salt. All fauna and flora, including plankton must be adapted or tolerance to changing salt conditions. During storms and spring tides salt water can reach even the high marsh.

Little River and Marsh

Marsh are formed from mudflats were species of Spartina are able to take hold. Spartina patens (salt marsh hay) is less salt tolerant and found farthermost away from the river water were as Spartina alterinifora (cord grass) is closest to the water and can be frequently completely covered by the brackish water. It is mostly these plants, especially their roots, that decompose in the mud becoming peat. Peat is pasty, not particularly smelly and can be compressed by as mush as 50 %, you could feel it move when walking or jumping. Marshes are the most productive ecosystems on the planet, specifically in regard to biomass, potentially accumulating up to 2 to 3 feet per year.

Coffee Bean Snail

We did find lots Coffee Bean snails, a shrimp species on the peat, along with oyster shells with barnacles on them. A number of cedar trees on the margins of the marsh had numerous Cedar Apple Gall (a rusty-red fungus). Charlie netted, in his own trap, a half dozen mummichogs which are small fish of about 2 inches that can be used as bait. Also observed was one Redwing Black Bird. Birds were not generally observable because of the high winds. The only invasive species observed was Fragmites brought here from England during colonial time. The problem is that they out complete native species such as cat-and-nine tails dominating an area and are not digestible by most native species, not allowing the transfer of energy up the food chain. Greenheads, nasty biting flies locally, turns out that its only the female that bites. She bites a hole in the skin and laps the blood for the rich protein, however the normally large number of birds eat lots of these greenheads, an important food source for them. Yea for the birds!

Charlee's Trap

Humans have use the salt marsh extensively for the salt hay as animal feed, even cutting canal into the marsh for irrigation to increase productively. In Ireland peat is dried into bricks to burn as a fuel. Today the salt marsh are a Protected Bird Area however in colonial days bird hunting was common.

Day 3 Survey of the Merricmack River Estuary

Day 3 Reflection





Today was full of activity from beginning to end. We started in the boat house classroom with discussions of varied resources that included a number of incredibly useful websites. The NOAA site and the National Estuarine Research Reference System site was full of basic, yet very useful information, that provides broad presentations and content that can easily be used by the teacher and student. The tides presentation made use of a BBC video clip and a number of other clips that really helped with conceptualizing the cause of tides and human connections. Some of the media linked through YouTube, if only my school would allow access, however I will be trying Rob's recommendation of making use of TeacherTube as a possible way of getting around this problem.


Fishing no matter what!


An open review and discussion of Moodle, which I will have access as of July 1st, has me sold in using with both my curriculum and students. It's flexibility, depth of use and security are big selling points that open up a number of Departmental options for sharing resources, planning and coordinating lessons within same courses taught by different teachers.







Plentiful Urchins along the docks of the mudflats

Using activities to foster creativity is a powerful tool for learning and such an important skill to have. Rob's discussion of creating "interconnections" and "drawing student backs" to find the "point" are things I know I've used, but perhaps didn't emphasize it enough or give it its place as a key to effective learning and motivation. I believe this method does sponsors creativity and helping with building effective constructs.



The next time we have better weather I"m definitely trying the "create something outside with natural materials" which then leads students to categorizing biotic and abiotic items. For my field trip this week with my class, I will be adding the mapping activity immediately upon return to school and have them write a reflective piece for homework.

Sample from the Mud Flats

I definitely want a Secchi Disk, I'm thinking I might be able to do an integration project going with our Machine shop. It's a simple devise that is a simple disk, painted half black and half white. with a line hook in the center. I know NST student could easily machine aluminium for this purpose. What you need to know is this usually leads to an open discussion of what it is , how it works and what it does. Last week I mention I was going to have carpentry make Rob's "Beach Profile Sticks" which I did. What happen next was interesting integration with students of the shop class asking about all aspects of the device to the point that they not only finished the project for me but went outside with me demonstrating how it works and what it does and so on. A perfect integration between academics and shop programs_received by the students with enthusiasm.

Sample Specimen for Otter Trawl

As a final statement of my day is that we did a Otter trawl, valuable for surveying marine life. The conditions were rainy, damp, foggy, and some numerous small waves. Again I did get a bit unsettled, still don't have my sea legs, but it was a short time and being able to interact with the task helped a lot. Pulling the trawl and sorting through the haul was really interesting. Believe it or not I would still go back for more. I do need to read Rachael Carson's book "silent Spring as a post script.

Day 3 Log

Tides are created by wind called fetch or generated by gravity called a tidal wave, not related to a tsunami. The longer the distance that winds travel over water the greater the fetch or waves created and likewise for shorter distances. In general there are "spring tides"(high highs), unrelated to the seasons, and "neap tide" (low highs). These represent tidal ranges during the diurnal periods of high and low tides. Tides are created by the tidal bulge caused by the influence of the gravitation pull of the sun and moon, higher high tides occur when they are aligned directly with the earth and lower high tides occur when the sun and moon are aligned at right angles to the earth. The bulge does occur at opposite end about the earth, rotation of the earth causes one budge to effect a high tide followed by the flattened side of the bulge, to effect a low tide and then a again the high and low.

Estuaries are shallow (1-2 meter) have significant tidal influence and are highly changeable. Life must be well adapted to these conditions. Salinity, for example can vary at different depths, as well as with the move of tides or even rain and so on. Estuarine life must be able to deal with changeable osmotic conditions. Most marine creatures live a relatively stable saline environment for which they are adapted. If conditions change substantial as they may in the estuary, the cell would swell or shrink depending of the direction of the gradient, causing harm or death. Its often the gill and kidney cells that are most effected osmotic regulation.

Comarants keeping an eye on....

Oxygenation of the ocean water are typically caused by rain, wind, wave action and phytoplankton. Dissolved oxygen, influenced by temperature, along with salinity are critical measures. They can be lowered by high rates of decomposition and algal blooms (may create monoxic zones) for example. Since estuaries are the "nurseries" for enormous numbers of marine creatures, supporting life with dissolved oxygen is critical. Mudflats are good example, the dense packing of particles of the mud is low in oxygen limiting the mud to anaerobic life, when digging has a distinct hydrogen sulfide smell. At the mud flats the mud was found just a few inches below the the sand nearest the water at mid to low tide. As you dig upward toward the high tide line the sand gets significantly deeper. Sand is on the top because it doesn't pack well and is moved about by wave and wind action. The quieter areas of the water allow for the finer silts to settle and pack forming the mud. Digging holes at a few feet from the low to high tide line revealed changing substrate profile with a changing life profile and their adaptation at each location and conditions. If time allows I will try this with my class.

Biotic Observations:

Dead dogfish, small herring, arctic tern, harbor seal (migratory-leaving soon), lots of sand dollars, asian shore crab-invasive, blue mussels and barnacles clustered on the docks with starfish and good size urchins.

Specimen Collected from Docks

Gary mentioned that horseshoe crabs as a ancient creature that mates briefly on the beaches (30days-ish) and migrate 20 to 30 mile offshore the rest of the time. Also that barnacles standing on their heads all the time-weird.

Field measures include surface and bottom measures temperature and salinity, and the use of the secchi disk for turbidity measures. We sampled up river at the Gillis Bride, down river at the ice break and at the mouth of the Merrimack River. The river measures were within one degree (average of 61.5) top and bottom for the Gillis measure and Ice Break with no salinity. However at the mouth the temperature fell to about 49 degrees with salinity at average of 26.5, 1 ppt difference top to bottom. The expected ppt for the open ocean in our region is 33 to 38 ppt. The higher temperature and lower salinity would be expected because of the convergence of river water with the ocean, along with the heavy rains of the day. One would expect a high degree of variation for this environment.

Day 1 and Day 2 Survey of the Merrimack River Estuary May 2010

Here I am again using Boat Camp a second time around in spite of rough weather and sea sickness on the first tour, seriously you really can't blame Captain Rob for everything_maybe. I do believe I will be able to enhance my knowledge and instructional strategies with a primary goal of adding and improving field based activities to my environmental biology class. With the Captain's permission, I will be able to" borrow" strategies and practices, with a bit of creativity, I will be able make my students experiences more meaningful and fulfilling. Yes my lessons will be consistent with the Massachusetts Science Frameworks addressing "content", however I hope that it will inspire students to embrace the larger issues that all citizens have responsibilities, both locally and globally, such as: sustainable fishing, values of protecting estuaries, including the full genre of pollution issues and so on.


As for the new reader to my blog I am high school biology teacher of 33 years at North Shore Tech in Middleton. I do have a wide variety of graduate training in my field, including some marine biology. However with this graduate class on the Erica Lee (a most worthy vessel) we have had access and exposure to an incredible variety of marine ecosystems that would not be possible other wise. This provides for a greater depth and breath to the class. The instructional and marine experience of the instructional team are professional and always willing to share their wealth of knowledge.


Reflection for day one at the boat house.

This session was a simple forum where class members could get acquainted and Rob could introduce the course. It was interesting and intriguing when three "mates", who had completed a different marine biology class the prior week with Boat Camp, shared and presented their lessons. It was amazing how varied the projects were and how creative they had to be to convey the content and concepts. All three had very different back grounds, subject and grade levels to teach. All three developed lessons for lower grade levels, however it did give me perspective on how the younger minds needed a difference conceptual strategy, since they often are lacking in knowledge and experiences. Keep in mind during my entire professional life I have been dealing with a much older high school student, which I believe may have narrowed my instructional view. For example Megan used nesting tubes for an elementary school class in order for students to conceptualize the food chain. This was an incredible simple method yet a powerful means that immediately created a mental construct that could be used for any age. I should include Charlies demonstration of the Coriolis Effect, this I may steal for my marine unit that's still under development. I hope I can get it from his wiki page.





Plum Island Wave Action

Further, Rob's historic perspective of the river was informative and useful since I have found that students do frequently find historic information, preferably brief, interesting or at least curious if present well. I am looking forward to our "quantitative" methods of collecting information from and on the estuarine ecosystem. The Chart Hunt Survey activity was impressive for developing an understanding of chart reading and familiarity of a both general and specific details of the area. Marine chart reading at this time is not useful for my current instructional assignments but can be applied directly to terrestrial map reading that we do use in the field. This will be used this fall for our White Mountain trip. When I teach trophic levels I will be using Rob's demonstration of transferring the expected 10% energy transfer by having students transfer 10% of water given from student to student, starting with a liter, for visual energy availability.


Content Log for Day one lesson.


Estuary's are partly enclosed coastal bay with one or more rivers flowing into it with a free connection to the ocean. This creates a transitional zone; that has a significant marine influence, that include changes in salinity, tide effect, and waves action, where as the river impact is from warmer freshwater that distributes nutrients and sediment. The inflow of both forces provides high levels of nutrients, warm gentle wave actions and continuous purging effects. What is created are incredible valuable nursery and habitats for an enormous number of marine species, including birds of coarse.

Glacial scouring of the ocean floor created contours that are similar to that found on land. The marine significance of this is that with temperature induced currents, typical of cold water regions creates upwelling. When ocean currents flow along the the ocean floor, rising and falling as it travels over low and high points, the current hits a land rise that sends the current upward toward the surface that also brings nutrients upward with it. The ocean floor is nutrient rich because decomposition of dead marine organisms and their like and their "poo". The importance of this is that the nutrients now are available to support the marine food chain. Marine food chain appear inverted as compared to land food chains because the producers (phytoplankton) are near the surface (closest to the sunlight) with zooplankton as the first order consumer and so on, downward to much larger consumers. Larger consumers do suffer with population reduction because the available energy is only 10% transferring form one level to the next. This reduction of energy from level to level translates to very significant amounts, meaning very limited energy availability for higher order consumers, thus limiting population size.



Reflection for Day 2 at Plum Island Point

This day was spent mostly at Plum Island Point which is the northern most region along side the Merrimack River. This was my first time exposure to the part of the reservation so I have little to compare too or draw upon from the past. The missing dunes and unnatural litter definitely made an impact. Certainly the eroded dune as described ran 50 to 100 yard deep and several hundred yard long. This is obviously a natural occurrence but does raise questions of the influence of global warming in perspective of the fact that dunes have been shifting for millions of years. It clearly demonstrates the force of the ocean and the dynamics of barrier beaches, light of the fact that human efforts to control this force has likely caused more harm than good or nature rolling over right over peoples efforts to protect fixed objects of interest. The exposed "cut" into the dunes can be used instructionally because it does reveal the layers during dune building and the adaptation of the dune grasses, also very useful for me.

Personally the most disturbing aspect is human created debris, such a syringes and countless amounts of plastic items on the dunes. Instructionally,, students need to see this first hand and be given an opportunity to experience and discuss the the causes, effects and possible long term impact on the environment and their personal lives by this unnatural occurrence. I have a planned field trip to Cranes Beach in two weeks which will allow me and my students to discuss these issues. We can also discuss the impact of other human activities, such as dams, for example, that have devastated the sturgeon population locally. Dams have prevented the sturgeon from breeding upriver.

At the point, Megan and I did a beach profile using a relatively simple tool (crafted by Captain Rob), that allowed us to create what appeared to a fairly accurate profile of the beach from the dunes to the river. This Monday I am going have our carpentry department to help us with four sets to use at Cranes Beach. This in an impressively simple yet accurate tool for a very small amount of money. Fortunately Rob didn"t seem to mind our modification to his original design. This task, especially over time, can reveal unique patterns of erosion, adaptions of life, actions of wind and water and so on. It furthermore integrates mathematics in the slope values calculation and graphing, technology with computer plotting and with the biology. Currently integration and use of technology are priority initiatives for my school.



Captain Rob discussing Erosion and Anchoring by Beach Grass

Content Log for Day 2

Acidification of the oceans is a currently small but increasingly occurring event. One likely cause may the the increases absorption of carbon dioxide as we know is measurable increasing and perhaps other acid pollutant that may include acid rain and waste water effluent. The marine concern here is that acidity dissolves sea shell (calcium carbonate) which will weaken and disrupt life cycles of many mollusk and coelenterates such as corals.

Glaciation was instrumental for the formation of Barrier Beaches which are directly responsible for the formation of the estuary and provides protection to the mainland from the ocean. Rocky till from the glaciers forms the point of contact for the accumulation of sand from wind and water action that creates the dunes. The loose sand is held in place primarily by the roots of the beach grasses and plants. The sands of the area are made mostly of quarts,mica and sea shells, however there are great variations in the composition of ocean sands. The sand grain size can be influenced by tide action. Ocean waves hits the Plum Island Barrier Beach the net wave effect current is north to south. This mean the the current generally flows North to south carrying the smaller grain southward. The North beaches have a larger heavier sand grain with the southern point having the smaller lighter grains.


Asian Shore Crab a new Invasive Species

Biologically we identified two invasive species, the Asian shore crab and the green crab witch are out competing native species. We also observed harbor seals, one gray seal, number of cormorants, a few American Black Ducks, and one mostly white with some black on the head yet still unidentified gull-like bird. I did observe that the rocky area exposed to regular and frequent wave action had very little marine life. In fact the only thing I could find were sparsely attached barnacle. This make sense since the rough surf would make conditions tuff to adapt too.