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.
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