Sunday, July 24, 2011

Day 2: The Under-Dock Experience at the Barking Crab

Field Experience Observations

Location: The Barking Crab docks, right off the 4-Point Channel
Mini Habitat: The Lower Intertidal Zone
Time of Day: ~10AM - 11:30AM
Tide: going out, low tide at 11:30AM
Water Clarity (1-10): 8, Where water closer to 10 is more turbid
Temperature: 75+ C degrees toward the latter half of the morning

This is one of the most common specimen we discovered on our tour around the peers and tidal zones of Boston Harbor and the Barking Crab more specifically. Barnacles. North Atlantic Barnacles to be more specific. The difference is really just in the surrounding attachment, these barnacles have more of a flared attachment rather than a more distinct circle. You can see the lines on the side which help show that distinction.

Another specimen we found a lot of was algae. We discovered two types, red and green. Also, to be more specific, they were very leafy and coincidentally we identified them as Green Sea Lettuce and Red Sea Lettuce which I found to also be called Halymenia. The two algae have a very slimy texture and are swarmed with creatures in this location!

The picture to my right I believe to be baby sea anemones. I say this because they are very squishy to the touch and when you do touch them, they retrieve into a smaller ball (look at the anemone on the left for that example) which larger anemones also do. I also believed they were anemones because the one on the right shows a bunch of white squigglies in the center. None of which come out, but that may be because they have yet to fully develop? Who knows. Either way, I looked them up and found they match a description of "Striped Anemones" especially considering their orange stripes on the black body.
In the picture to my right are two sea anemones and some Bushy Bryozoan. The two sea anemones while similar are quite different in color. The top anemone is a more pale apricot, while the bottom anemone has more of an organish-tint to it... interesting yes? Well I thought so, so I tried to see if they were any different in the guide book and came up with the following conclusion. They are the same. Haha, the speces just comes in different shades. They are both Frilled Anemones.
These creatures were easily seen by the hundreds along the dock. They were literally crawling and squiggling over and on everything. While when there are that many of them they can be hard to distinguish between, but I believe we either found more than one type of arthropod, or there is a major distinction between the female and male sex of these creatures... it's one of the two assuming they aren't asexual.

Look closely to my right and notice that the long stick creature on the lower left portion of the picture is more of a dark red color and seems to be tougher than that on the upper right above it. This creature on the upper right seems a bit more transparent as seen by the end of it's leg/tail that we see. If they are different creatures, the bottom specimen may be the Long-horn Skeleton Shrimp. Unfortunately though, the guide is also makes it a little difficult to distinguish between these creatures so lets hope that until I adapt to using this tool my gut instinct is leading me in the right path.

This picture on my left also suggests further that these specimen are not the same. Notice how the creatures you see in this picture are more transparent and have more defined claws than the darker red creature depicted above. For these reasons, I think this specimen on the left could be the Smooth Skeleton Shrimp. It is fairly long although not 2'' like the guide suggest, however it was the closest picture match I could find. However, as we discussed in class the pictures aren't the most important information to go off of, so though it could be the Smooth Skeleton Shrimp, I think it is more probable to be the Linear Skeleton Shrimp, since it's location includes Boston Harbor.

If you look closely at the orange matter on the mussel displayed at my right you will notice it is a very bright orange and has little clustered holes. This organism is Orange Sheath Tunicate.

Here is a close up of the weird piece of metal/plastic that at one point served as a bumper for the dock. It has a different specimen of orange biomass. This I believe to be Club Tunicate, more commonly found on docks and tends to be a rougher, stalked organism.

Bait Fish Comparison

Fish #1
Chub Mackerel
Fish #2


Janelle B. said...

Hi everyone this is Janelle, I meant to fix this the other day but did not realize I woudn't be able to fix it laterm so hopefully Professor will read this comment and count it, but I wanted to correct the following:

Fort Point Channel---not "Four Point Channel"

You could see about 3-4 feet into the water as far as water clarity/turbidity goes.


Janelle B. said...

Also, the second fish was a Herring.