Saturday, July 31, 2010

Harbor class Barking Crab Ted Williamson


Our second day in the field began with instructioon to concentrate on obsetrvation and hypothisis forming once we got to our destination. We were asked to observe the habitat, consider scale, color, texture and any other facts we could gather to help us stay objective.
We met at 9:45 at the Marriott in Boston Harbor. It was a clear, sunny day, approximatly 80 to 85 degrees, and it was low tide. We got into teams and walked over to the harbor and abserved the shore in front of the hotel.

We observed the following:
- Water was pretty clear
- 2 types of plant life (green. mossy and blackish seaweed-like vegetation.
- Barnicles
- Empty shells from some kind of shellfish
We also saw evidence of human interaction:

- Pipes that drain rainwater
- Trash in water and on shore
- Film on water surface, looks like gasoline or oil

I also saw birds: (gulls and this bird), not a Finch as first thought, but it was a Sparrow

(identified from Golden Guide Families of Birds)

We then took a walk over to the Barking Crab.
On the way we ran into a man who works at a NOAH (an agency that gathers data on tides)

He is measuring tides to ensure accuracy of the tide charts.

Once at the Barking Crab, we went down to the docks, divided into groups and explored the life and habitats located under the docks. It was a smelly area - like old dumpster (it may have been). The water was pretty clear and the water temprature varied from 70 degrees at the sea floor (18' down) to 74 degrees at the surface.

Team #2 was prepared with all the tools needed to dig in! We used our net to grab our first sample of stuff that we pulled from under the dock.

We discovered lots of interesting creatures and plant life.

- Lots of mussle shells and mussels in what seemed like different stages of development.

I determined the large empty shells were Blue Mussels. Not sure, but seems like the smaller ones were baby Mussels. The small bugs in the water were plankton and other small animals the mussels eat.

- We also found a seaworm (Clam Worm) and a Longhorn skeleton shrimp

A Female crab (Mudd Crab - probably not fully matured)

We also caught a small fish under the dock that was swimming with approximatly 20 others and seemed to be using the plants for protection. I reserached this animal based on the characteristics and habitat. I determined that my best guess is that this was a baby Atlantic Mackerel.
My drawing as I could not get a clear picture

Pink Shrimp Two types of plants
The one on the left is a sea lettuce called Umbraulva Olivascens (researched at Michael Guiry’s Seaweed Site)

My drawing of the plant on right which is Fucus Spiralis Linnaeus, also researched at Michael Guiry's Seaweed Site)

The mysterious orange Daisy and the other orange tubelike things are Tunicates.
Here is the Tunicate definition from Wikepedia:
Tunicates, also known as urochordates, are members of the subphylum Tunicata or Urochordata, a group of underwater saclike filter feeders with incurrent and excurrent siphons that is classified within the phylum Chordata. While most tunicates live on the ocean floor and are commonly known as sea squirts and sea pork,[1] others – such as salps, doliolids and pyrosomes – live above in the pelagic zone as adults.
Most tunicates feed by filtering sea water through pharyngeal slits, but some are sub-marine predators such as the Megalodicopia hians. Like other chordates, tunicates have a notochord during their early development, but lack myomeric segmentation throughout the body and tail as adults. Tunicates lack the kidney-like metanephridial organs, and the original coelom body-cavity develops into a pericardial cavity and gonads. Except for the pharynx, heart and gonads, the organs are enclosed in a membrane called an epicardium, which is surrounded by the jelly-like mesenchyme. Tunicates begin life in a mobile larval stage that resembles a tadpole, later developing into a barrel-like and usually sedentary adult form.
Tunicates apparently evolved in the early Cambrian period, beginning c 540 million years ago. Despite their simple appearance, tunicates are closely related to vertebrates, which include fish and all land animals with bones.
The Tunicate in the picture above is a Botryllid Tunicate
The other was a Orange Sheath Tunicate

This was a good day - time to go to bed.

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