Sunday, July 24, 2011

View from the Docks

Kathy Geoghegan-Barek


  1. To sharpen observation skills
  2. Recognize different habitats (inter-tidal and sub-tidal zones, salt water, fresh water and brackish water)
  3. Attempt to identify the life forms observed with the use of a field guide

Specimen Collection

Date = 7/23/11, Time = approximately 10:00 am – 11:00am

Tide = Going out, Low tide due at approximately 11:30 am, therefore close to low tide

Weather = Warm, had a brief thunderstorm earlier that morning. Prior to that weather had been hot and dry for several days.

Water clarity = 7 on a scale of 1 to 10 where 1 is clear and 10 is turbid

Collection Location = Mouth of the Fort Point Channel, river water meets seawater here. Samples taken from the side of the float.

Habitat = brackish water, sub-tidal.

Observations and Specimen Description

One observation I made occurred by the courthouse. As I walked down the ramp I could see on the wooden post under the dock 3 specimens. Each of the 3 specimens occupied a distinct area of the post and presumably this means 3 different habitats. On the bottom, submerged in the water and floating was long strands of a brown seaweed-like plant. Above that, on an area of the post that was wet but currently not in the water (the inter-tidal zone) were white specks, which I suspect may have been barnacles but the post was at a distance so I wasn’t able to get a good look. The top of the post has a green fuzzy substance that I believe was algae. When I looked at the Seaside Educators Guide posted on blackboard I saw a drawing of a post that looked like mine. They called the top area of the pole the spray or black zone.

Then my team, The Mighty Star Fish, began collecting samples from the docks at the Barking Crab. We collect 3 plant samples and numerous animal samples and 1 sample of “orange stuff” that was on the shell of a Blue Mussel.

I also identified Frilled Anemones on the side of the float, but every time I tried to pull it up I got something else instead.

I personally only looked at 2 of the plant samples. A green one which we identified as Sea Lettuce and a brown one which I think is brown kelp.

One thing that really impressed me was that each time we tried to pull up a sample, we got multiple samples. There seems to be some sort of inter-dependence on the various life forms we examined We pulled up several Blue Mussels that had living things on them. One of the things on the mussels we identified as being a skeleton shrimp. We had also pulled up an open empty mussel shell which had 6 dark round things with orange strips going through them 2 of them appeared to have white centers. I wasn’t able to identify these but we considered the possibility that these could be anemones that had closed up.

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