The Hopkinton Middle High School's 7th graders recently went on a field trip to Odiorne Point. We travelled there on two busses, and when we arrived, our backpacks were dropped by some picnic tables and ventured out to the water. After slipping and sliding on many unreliable rocks and dangerous seaweed, we reached the water and tidepooled for a while, finding several interesting creatures. After doing that, some of us ate lunch or began to play some kind of sport, but a few of us went back to the water. Mr. Woolner showed us the drowned forest, which was fascinating to see, and the we tidepooled for a little while longer before heading back onto the bus. We stopped for ice cream, then returned to school.
Tides occur because of the Moon. Tidal force, which is a kind of gravitational pull, causes the water from both sides of the earth to to move towards it. Whichever side of the earth with the bulges of water that the Moon is facing at the time is where the water will go. This results in high tide. However, the time and longevity of high tide depends on the earth’s rotation. In fact, at the time when the Moon is fuller, high tide is higher. Low tide is caused whenever that body of water is not facing the Moon. Thus, tides occur because of the Moon’s gravitational pull called the tidal force.
The black zone is one of the four intertidal zones in the water. It is named this because the rocks in that area are covered in cyano-bacteria, which gives off the black color. One of the other names for the black zone is the splash zone, because it gets sprayed by water from the waves but is rarely completely soaked/submerged in water.
Below the black zone is the white zone. It is given this name because the rocks have a mostly white color, as barnacles live on the majority of the rocks.
Located under the white zone, the brown zone is called this because of the plants, called Knotted Wrack and Rockweed, that live usually between (it can also be on top or under) the rocks. These plants are brown colored, so therefore, that is why it is given that name.
Finally, the red zone is the last of the four intertidal zones, and, like the brown zone, its name is influenced by the plant(s) that live on the rocks. In this case, Irish Moss most commonly lives on them, and it is sort of a reddish-maroon color, giving off that pigmentation.
We saw many different types of creatures while tide pooling at Odiorne Point. For example, one of the things we saw was a northern sea star and a daisy brittlestar, and those were very cool as that was what we were all looking for. There were several crabs, especially green crabs and jonah crabs. There was also an abundant amount of baby lobsters, but they were hard to catch since they were so fast. A few of the other things we saw were irish moss, sea urchins, periwinkles, knotted wrack, and barnacles. Tuna crate was also on many of the rocks, and that was also quite interesting to look at.
I think the most variety of life was found in either the brown zone or the red zone. However, in the black zone, there was a lot of seaweed, a good amount of snails, and some barnacles. In the white zone, of course there were hundreds of barnacles on each and every rock, as well as a few crabs, many snails, and more seaweed. Despite this, the brown and red zones still seemed to have the most variety of life. This is because these were the two zones that were either submerged or partly submerged in the water, meaning a lot of creatures were swimming there. They would use the rocks to hide from us, and the plants that sheltered them. For example, the brown zone has a lot of Knotted Wrack and Rockweed growing of them, and the rocks there are usually partly submerged in the water. I saw a lot of crabs, tuna crate, snails, some barnacles, and obviously the plants I mentioned above. The red zone has a plant called Irish Moss growing on those rocks, which is also good for hiding. In that area, I found sea urchins, more crabs, some baby lobsters, and also a good amount of tuna crate on the rocks. In conclusion, I spent a lot of my time in the brown and red zones because that is where I saw the most variety of life were.
| In the picture below is a lobster. These were mostly found in the brown and red zones. | In the the picture below is a periwinkle. These were mostly found in the white and brown zone. |
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| In the picture below is a sea urchin. These were mostly found in the brown and red zones. | In the picture below is a knotted wrack. These were mostly found in the red zone. |
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