Lovells Island, Observations of Tide pools and Lands Snails

1. Tide pool observations:
Upon arrival at Lovells Island we were guided to a secluded tide pool ideal for investigation during low tide. The low tide had caused piles of seaweed to accumulate just out of reach of the lapping waves. I attempted to identify four of the varieties of seaweed I saw in the seaweed carpet.

Referring to the small sketches I drew on site I have attempted to identify these seaweeds as rockweed (Fucus sp.), sea lettuce (Ulva lactuca), brown kelp (Laminaria agardhii) and Irish moss (Chondrus crispus). The rockweed is brownish green, very abundant and most easily recognisable by the air bladders located throughout the "body" of the algae. Sea lettuce is a striking almost neon green and was one of the less common seaweed varieties I observed. Sea lettuce is very thin and almost translucent. The leaves are broad and felt fragile out of water. I believe I observed brown kelp which is a dark brown color, long and leafy. I observed some pinhead-sized dots scattered on the leaf. These which grew more frequent towards the bottom of the brown kelp leaf. Lastly, I believe there was abundant Irish moss along the beach and in the water. Irish moss is very leafy. The sample I looked at had three branches growing out from the base, each of these branches branched off into three or four more and on and on...much like the the capillaries of the circulatory system. 
Periwinkles were abundant in the tide pool. I think that they were either common periwinkles (Littorina littorea) or rough periwinkles (Littorina saxatilis), both of which are common on the rocky shores of the Atlantic coast. They were often in clusters on the rocks and when I picked them up and out of the water for a closer look, they would fall off and splash back into the tide pool. Perhaps they fall so easily as a defense mechanism. According to the New York Times article, periwinkles eat almost entirely algae. I noticed that there was a lot of algae on rock, they were very slippery. The periwinkle's shells were a dark brown and spiralled to a point at the top. They smallest periwinkle I observed was about half an inch long and the largest was about 2 inches long (length of the shell, not the soft body).
Other notable creatures I observed in the tide pools were Asian shore crabs which were very abundant and found under rocks. Asian shore crabs are an non-native species to the rocky shore of the Northeast but they have apparently created a thriving community. I also observed a school of small gray fish about 2 inches long darting through the tide pool, but I cant identify them because they were so fast.

2. Land snail observations
Our afternoon on Lovells Island was spent searching for and observing land snails. We collected samples of empty shells and samples of living snails. We soon found out that the snails have an affinity for Sumac trees, as almost every living snail was found on a Sumac leaf. They were often found on the bottom of the leaves which I think might be a mechanism for protection, they are less visible to predatory birds on the underside of leaves. We were told that land snails generally move in two directions: down and up. The move down during or after recent rain, and up when it is dry. Accordingly, we found most of our snails up above head level as it was a dry day with no precipitation. We also noticed that as we lost elevation and the path began to slope down that we instantly we able to find more snails. The abundance of empty snail shells also grew as we moved down the hill. 

Once we finished collecting our living samples and our empty shells we gathered as one group and discussed the different ways to categorize the shells in attempt to decipher how many species might inhabit the island. We all had different ideas of how they should be grouped and the possibilities were endless. Our class came to no consensus as to how many species inhabit the island or as to the correct method to categorize our shells. We later were informed that we had been looking at two species of land snails, the brown-lipped snail (Cepaea nemoralis) which has a brown lip at the opening of the shell, and the white-lipped snail (Cepaea hortensis) which has a white lip at the opening of the shell. 

While I was wading through the tide pools early in the day I was struck by how many more living organisms I saw on the Barking Crab wharf compared to the healthy tide pools of Lovells island. This disparity might be due to the fact that we spend over an hour examining one hand-full of mussels and seaweed on the wharf and about 20 minutes peering into the tide pools, but I think that I am beginning to hypothesize that the wharf was more biodiverse that the Islands.

Overall it was a beautiful day out in the field and I left feeling very knowledgeable about snails. 

Lovell's Island Observations

We went to explore the tidal pool at low tide. The bottom of the pool was very rocky. I saw two different types of crabs while I was there.  The first crab that I saw was found underneath a rock. It was about 2" wide and was a dark brown-black color, very similar to the rock color. The crab appeared to lighter brown bands along its shell and legs. Its legs were a little longer than the crabs body and very thin. Its pinchers were short, about 1/3". Im not sure what type of a crab this is. I thought it was a Say's mud crab, but it was too large as they only grow to be less than an inch wide. 

The second crab was yellow with dark spotting that looked either red or purple. Its legs were short and thick, and its eyes protruded out to the sides. The crabs pincher claws were about 1/2 the length of its legs and it had a circular body about 2" wide.  I think that this crab is the Atlantic Rock Crab. Although they can grow to be almost 6" this may have been a young specimen. They are often found in rocky or sandy bottoms, ranging from intertidal zones to open water. 

There were plenty of periwinkle snails in the tidal pool. All of the snails were a brown color that was very similar to the rocks on the bottom of the pool. However, the snails all had different markings. Some appeared to be striped while others appeared to be mottled. Additionally, the striations on the snails' shells were very different. On some of the snails the striations followed the curvature of the shell and on other snails they went perpendicularly across the shell. 

 

When we gathered all of our samples together it became clear that there were many different types of periwinkles. I noticed that the snails could be grouped together in different categories based upon their color and size. I did a quick grouping of the snails we had and I found three different categories. In one group of sails, the point of their shells was a single solid color and the rest of the shell was another color. These snails were the smallest, and they were all very close in size to one another. The second group of snails I found were those with mottled shells. The third group of snails that I found were those that appeared to be a solid color. The last two groups were very close in size to one another. This lead me to believe that there were different species of periwinkle snails and definitely observable variations. 

I did find a piece of tunicate that looked very similar to some of the tunicate that we found on the dockside at the barking crab. I think that it is Orange Sheath Tunicate. However, there wasn't much of it found on the island. 

Searching for land snails was not as easy as I thought it was going to be! My group started a little further inland than the other groups. After a long period of time where we didn't find anything I found 2 baby snails. They were on the leaves of some sumac trees, about 4 feet off the ground. They were both about 2mm wide and had translucent shells with a brown stripe down the middle. Their bodies were both an opaque off-white. I was able to take a better look at land snails after regrouping with the class and seeing the examples they had brought back in.

I saw a great variety of snails. All of their shells were very similarly shaped, however they were different in their colors and markings. There were snails with yellow shells and snails with brown shells. For each color there were snails that had a single brown stripe or multiple brown stripes ranging from 3-5. Initially I thought that the darkly colored snails had darker bodies and the lighter colored snails had lighter bodies, but then we saw a light colored snail with a very dark body. I think that all the land snails are the same species with different traits. If the lighter snails had light bodies and the darker snails had dark bodies only I might have thought that there were multiple species that we were seeing. However, after seeing a light shell with a dark body, I believe that they are all the same species.... Although now that I'm typing it out, I remember someone suggesting that two species could have interbred.  To be honest, Im not sure how many different species of land snails we saw. It was very frustrating because there were so many different ways that the snails could have been sorted into groups. Overall they all looked very similar to one another, and in the end Im guessing that there is only 1 species. 

 

Periwinkles and Land Snails

Erald Pelari

Date: August 4, 2008

Location: Lovells Island

Weather: Hot and Sunny

Temperature: High 70’s and low 80’s

Species: Periwinkles and Land Snails

Intro:
Today we took a trip to Lovells Island near Boston Harbor and we observed and took data on Periwinkles and Land Snails. After we got off the taxi boat we walked across to the North East corner of the Island where there is a large tide pool. While walking around the islands shore line we stopped and decided to flip some rocks and see if there were any crabs lying underneath them. I myself had to turn three rocks until I found one where there were two crabs lying underneath. They had green color, were about 2 inches wide and 3 in long. They had very small claws probably around 1.5 inches and their legs were of similar length as well. I believe that these were Green Rock Crabs. We arrived at the island around 10 AM and started our data gathering and observation at around 10:30 AM. Luckily for us the water had receded enough due to a low tide and we could walk into the water about 20-30 ft off the shore and gather periwinkles. After the periwinkles we were separated into groups and looked for live land snails and shells of dead snails. We were supposed to collect at least 10 shells per group.

Method:
Observed Periwinkles at the tidal pool, took measurements of height, measured the opening of the shell where the mouth is. I also observed the color of the periwinkles and the shape of their shells. We were also looking to see how they moved around when placed on a rock outside the water. Then we moved into gathering land snails. Here we were looking for shell color and the body color of the snail, texture, and other things.

Tools:
For this trip I decided to bring with me more tools that would help me investigate the species a lot better then what I brought with me the first day of observations.
Digital Camera- used to take pictures of the periwinkles and land snails as well as film the movement of periwinkles
Ruler- used to measure the length, height and width of the various periwinkles
Magnifying Glass- to take a closer look at the shells and opening/mouth of the periwinkles and at the complete texture of the land snail’s body
Notebook- to keep notes and records of the data and observations
Pen- used primarily for writing but also for poking the periwinkles and the snails and observing their reaction.
Guide Book- used to help in identifying any species that I saw and did not know the name of for example: The Green Rock Crab.

Observation and Data:

Smooth Periwinkle
What is a periwinkle?
According to Peterson’s Field Guide book the periwinkles come form the shelled Gastropods Family. It has a spire, a body whorl and a suture and an operculum. It is the most common northern rock and wharf piling winkle. There are common, smooth, rough and Gulf periwinkles.

Data and Observation:
The first periwinkle that I pulled out of the water was small and had a blackish color. It had a height of 2.5 cm and an opening of 1.2 cm in diameter. The shell had a few cracks on top indicating that the periwinkle must be mature. The opening of the mouth is of brown color and if poked with a pen will retract into the shell to seek protection. All the periwinkles that I saw and captured were sort of glued to smooth rocks. I also grabbed some periwinkles that were smaller in size. Their height was about 1.5 cm and the opening of the shell was about .7mm long. Looking at them closely one could see even with the magnifying glass that their shells had no cracks, meaning that they must be young periwinkles.

I believe that these are smooth periwinkles because they look similar to the ones shown on Plate 20 in the Guide book. Also if you look at the picture posted above you will see that at after their shell dried it does resemble a smooth surface seeing by the human eye. I also came to this conclusion after I read the article by the young naturalist Emily who dictated that Common Periwinkles are found in the coast of Maine and if you look at the pictures you will see that they have a smooth shell and it resembles the shape of a small moon shell. One thing that I can not prove is weather or not they had an umbilicus because I did not look for it. But if a periwinkle is smooth then it can not have an umbilicus.

Land Snails

Land snails come in two verities Brown-lipped snails and White-lipped snails. One can distinguish what sort of a snail it is by looking at the opening of the shell where the snail comes out also called the “lip” and see whether that part of the shell has brown a brown ribbon circling it or a white strip. The first snail that I saw and grabbed for more observations was stuck behind a leaf. I guess snails love to stay on the back of the leaves to avoid being seen by predators but also the fact that the back of a leaf might be a little softer then the top part (my opinion), making it easier for the snail to bite. This snail had brown color with a white ribbon around it. The snail’s superior and inferior tentacles were both out of the shell and extended as well as its back end “the tail”. This was a white-lipped snail.

We ended up gathering a few live snails and a lot of shells from dead snails. The live ones were primarily white lipped, but we did have some brown lipped snails as well. They were very active and would move around the container and eat the leaves. The shells form dead snails came in various colors. Some yellow, some brown, some dark brown, and some had different colored ribbons and various numbers of ribbons. Out of all these shells that we had gathered only one shell was plain white. This would lead me to believe that a yellow shell is not the best color for protection where you are surrounded by green leaves and brown tree branches. But that must also be that the area that we were looking at did not have many yellow shelled snails. We also designated one tem member to collaborate with other team members to try and sort the shells. One system was to divide them by color and the number of ribbons. Others decided to separate them depending on background color. One thing we did not do and should have done was to try and sort the shells based on white and brown lipped.

Periwinkles vs. Land Snails

Periwinkles have strong shells whereas Land Snails have softer shells. Land Snails have a superior and inferior tentacles whereas periwinkles do not have tentacles. When periwinkle moves they do not show their head and the tail end as does a land snail (Please see the video posted by Kris Pandeli on his blog). Periwinkles have a pointy shell and land snails have a more round one.

Lovells Island - From Periwinkles to Snails

On the morning of August 4, Monday, we traveled by boat to Lovells Island, (http://www.nps.gov/archive/boha/parkmaps/lovells.pdf), an island located in Quincy Bay. Along the walking path going from south to north, the group encountered land snails along the way around 10:40am.

These snails were found mostly on or under leaves and out of the sun. They appeared to be found in groups in certain areas of the island and had much more varied coloring than the perwinkles discovered later in the day. The trees the snails were found in were predominantly sumac trees ranging from approximately 6' to 15' feet tall.

The class traveled to the north end of the island at low tide at approximately 11am, August 5th, 2008. We passed through what was an old marsh that had predominantly old mussel shells, there were periwinkle shells, though rare. The shells were only a couple inches deep.

One of the first animals encoutered was a wharf crab. The crabs were not found on shore and commonly appeared when the bottom of rocks were lifted.

The low tide allowed easy access to groups of common periwinkles. The perwinkles sampled were found on hard rock surfaces in water approximately two to three feet deep and 20-40 feet into the water.

Two periwinkles were selected for a experiments. Both were healthy and alive. The first was to examine how a perwinkle would gain a footing if was left on it's back. The perwinkle extended itself slowly using the weight of it's body to cause the shell to roll over at which point the perwinkle was able to regain adhesion to a solid surface in a few seconds.

Another experiment was done to test for survivability in fresh water. One was placed back into the original sea water while an other was put into a fresh water aquarium. The fresh water caused the periwinkle to become unresponsive almost immediately.

Saturday, August 2, 2008

Objective: Determine weather the Inner Harbor biodiversity is greater then the biodiversity Boston Harbor Islands State Park. 

1st Location: Left side of the Marriott 

Time: 9am EST

Tide: Low (about 9ft.)

Weather: Overcast about 70

Observation: Water is clear for about 3 ft, little fish, rocks with green seaweed, brown growth, and shells

2nd Location: Harbor Rock, right side of Marriott

Time: 9:15am EST

Tide: Low (about 9ft)

Weather: Overcast about 70

Observation: Bird flow by with stick, 4 ducks, green seaweed growing on the rocks and docks in a large amount, blast marks on the rocks, and broken shells from what I believe is from birds. 

3rd Location - Harbor Rock, right side of the Marriott, out further on the dock

Time: 9:25am EST

Weather: Overcast about 70

Observation: Green & brown seaweed growing in mass amount and appears to be always immerged  in water. The docks move with the tide. Therefore the seaweed is always wet. I believe this is why it is growing in larger amount. Then on the first observation location. 

4th Location: Left side of the Harbor Towers

Time:9:40am EST

Tide: Low (about 9ft)

Weather: Overcast about 70

Observation: Docks with shells, muscles, and seaweed

5th Location: Front of the Harbor Towers

Time: 9:50am EST

Tide: Low (about 8 1/2 ft)

Weather: Overcast about 70

Observation: Waves crashing about 1/2 foot on the rock wall, green moss on the rock wall, more sunlight then the other 4 locations, and black rocks.

6th Location: Left side of the Northern Ave Bridge

Time: 11am EST

Tide: Low (about 8 1/2 ft)

Weather: Overcast about 70

Observation: Green seaweed thin like paper, delicate, smooth, and looks to have air pockets or bubbles. Shells that were white and yellow, which I believe are barnacles. Worms with lots on legs brown and live in groups. Which I believe are Burrowing Scale Worms, Bright orange smooth sponges growing within the seaweed and on wood, but I think it is two different kinds of sponges. 

Day 2. Observations: Perwinkles & Land Snails (Kris Pandeli)

Monday: August 4^th, 2008.

Weather: sunny

Location: Lovells Island

Method:

Observed the periwinkles at the tidal pool at Lovells Island, took picture, took measurements, recorded colors, shapes, stripes, texture and other examinations of the samples we collected. Then we moved to the inland snails of the island to collect yet another diverse sample of snails and take the same approach as stated above. Many approaches were taken by students to group these snails and snail shells by their visible traits; mostly their color stripes and shape. Below there will be a better description by steps and procedures along with photos to make the descriptions more clear.

Tools:

This time I was better prepared as I brought with me a variety of tools to examine the species. The tools include: pen, pencil, paper, ruler, digital camera, magnifying glass, binoculars, and the guide book.

Observations and Data:

COMMON PERIWINKLES

First I will describe the periwinkles sampled form the tidal pool behind Lovells Island. About 30 to 40 ft. into the tidal pool me and fellow students pooled out a few different sizes of periwinkles ranging from .5 cm to 3cm wide in diameter. The first one I examined was 1.5 cm in diameter. On the tip or the cone it was a light brown color (area of 3-4 mm), with the major part of the shell being a dark brown/black color taking up (area 1 cm). The opening or the mouth of the periwinkle is a very bright brown about 1-2 mm all around.( See the sketch/See photo).

The second periwinkle was about 2.5 cm in diameter. Light brown all around only with 2 mm of white tip-top. The shell appears damaged and repaired/healed as you can see small cracked stripes. The texture of the surface is harder not as smooth as the younger/ smaller periwinkles. The coloration and the texture of the shell can be due to the fact that this could be somewhat older and more beat up against rocks and salt.

Another third sample was a few old periwinkle shells by the shoreline. They were 3.5 cm in diameter 1. lighter color probably due to deterioration and bleaching 2. Cracked shells and stripes 3. Light brown/yellow color close to the opening of the shell or the mouth.

LAND SNAILS/Comparison to Periwinkles

My first find happened to be of the two most common land snails found at the island. The Yellow snail with a black ribbon and the dark brown snail with the yellow/light brown ribbon. The brown snail also has the brown lip and you can also see the yellow snail with the white lip, and they both are eating at the green leave (Refer to the pic). They were mostly found stuck below the leaves of small trees. They were stuck underneath of the leaves because that’s the way they consume the leaves or maybe because they are less visible to predators, like the predatory birds. Fist of all the main difference that stuck out at me was that the land snails were rounder and not with at pointy tip like the periwinkles. Their shells were also smoother and they were more diverse in colorations. The color combinations included, yellow, brown, light brown, white, and pinkish. To my conclusion, I decided that these were still the same species (1 species). The second difference from the periwinkles was that the land snails when they moved you could see the whole lip, ears and head sticking out. The land snails moved faster than periwinkles as they also seemed to produce more of the slimy/slippery saliva. The periwinkles moved a lot slower and one almost could never see the lip.

Habitat: When we pulled the periwinkles out of the water they seemed to get dry and not moving slower than anything I have ever seen. They seemed like they did not like the heat of the sun. They felt more comfortable in the water. But the land snails even though they too were found in some wet/ humid areas they seemed more relaxed than the periwinkles out in the sun, and they moved a lot faster as they where slipping away from our hands. With our class discussions and listening to professor Berman the theory was that these two species could have evolved from one another.

The end of our collections we collected many shells of dead land snails. These shells differed in colorations and texture. Many students were chosen to try and group them by color and texture and many selections led the four main groups as seen in the photos below.

Today the weather was great and the trip was amazing. A little too long of a field trip but we all made it through. We all went home with more data and samples to write about. Today’s observations were a lot clearer and fascinating.

Enjoy the short video clips below.

~Kris Pandeli

SnailCam is now up, Fishcam is down.

I doubt that any of you will be as enthusiastic about this as I am, but snailcam is now up and running, with live images of the Lovells snails refreshed once or twice an hour.

You can find it here:
http://www.bostonharbor.com/webcam.html

(Don't be surpised if they seem to move slowly. They are snails.

Lovells Island observations - Ann

Field observations Monday Aug 4

Low tide: 7:55am
High tide: 2:13pm
(http://www.boatma.com/tides/augblt08.html)
Sunny and hot (80degreesF), low breeze, minimal wave action

Tide pool

We arrived at the tide pool at approximately 10:45am, and at the time the water in the tide pool got no deeper than approximately 2 feet. Sean and I waded further out than the rest of the people in the group did because we were curious to see what we would find in the more exposed areas of the pool. We went out beyond the left edge of the curve of the pool, and turned back when the water got too deep to see to the bottom.

The substrate throughout the area was rocky, with a mix of large (6-12”) and small (pebbles to a few inches across) stones. There was very little vegetation- we observed only small patches of seaweed that looked similar to the rockweed we saw in the Inner Harbor. However, we noticed that it didn’t look exactly the same, so we weren’t sure of the ID. Later consultation of my field guide confirmed that it is a type of rockweed, likely Fucus vesiculosus, the same type we saw in the Inner Harbor. This is the most common type of rockweed, and the only type with air bladders. The morphology can vary depending on the level of wave disturbance.

View into tide pool

One or more small dark snails (later identified as periwinkle snails) were evident on all but the smallest of stones, making these animals the most abundant living creature (at least that was visible to the naked eye). There were very few mussels, even along the rocky intertidal zone. There were also grey crabs approximately 2-3” wide hiding under the larger stones. We could see them when we turned over the stones, but they moved too fast to catch and inspect closely.

We noticed a number of seaweeds that we had not seen in the Inner Harbor. These seaweeds were floating free in the water, so likely washed in from deeper water. Because of this and their general appearance, I believe these are two species of kelp. Although it is difficult to make an accurate identification without the stems of the plants, I believe the flat one is a Hollow-stemmed kelp (Laminaria longicruris) and the helical one is the Common Southern Kelp (L. agardhii), both of which are found in this region of the world.

We walked out to the farthest left edge of the curve of the tidepool, which was the most exposed part of the area. Here we found two examples of the “orange stuff” that was so plentiful in the Inner Harbor (actually a tunicate, but I am still unsure of what type). Both samples we found were free-floating pieces of rockweed-like seaweed, which was engulfed by the “orange stuff.” One of these samples had a 1.5cm translucent body attached to it, which squirted water in a stream when gently squeezed. By holding this structure up to the light, we could see what looked like organs inside. I tentatively concluded that this was an animal of some sort, possibly a juvenile sea squirt (based on the fact that it squirted water). This was later confirmed by Mr. Berman.

Baby sea squirt (top center of sample)

I was very curious to see what kinds of amphipods, the bug-like creatures that were so plentiful on the docks, live on the islands. Unfortunately, given the collecting conditions (no place to put down specimens for close inspection) and lack of time, I did not get to look closely at our specimens for these animals. Next time I will bring a bucket!

Snail Trails

In the afternoon, we split up into groups to search for land snails. Having been told by the rangers that most of the snails they see are in the sumac trees, almost everybody scattered across the island to search for tree-dwelling gastropods. Shashana and I decided to stay and investigate the ancient Mayan ruins (actually remnants from the old military installation on the island) we were standing near. We did this because the area seemed like prime snail habitat – damp and cool. At first we saw lots of slugs, but only a few tiny black snails scattered amongst the leaf litter on the bottom of the concrete depression. We almost gave up, but decided to check the other depression, just in case. Jackpot! Although the ground within this depression looked just like the other one, when we looked into a deep crack that ran around the entire circumference about a foot from the top (see first picture below) we saw numerous large snails. These were gorgeously colored – either a dark purple/brown or a deep goldenrod yellow.

Interestingly, looking back on my pictures of these snails before we collected them, it appears that they all have a single dark stripe, which is in contrast to the variation in stripe patterns the class identified later. An interesting future project would be to explore whether live snails found in this type of habitat have a greater preponderance of individuals with a single stripe than those live snails found in the trees.

When we reconvened with the group, we discussed periwinkle variation, then closely examined the pool of land snail shells that had been collected by the group. The first task was to sort the shells into distinct groups, which turned out to be more difficult than it first appeared. A number of groups of students attempted to sort the shells, first by color variation and variation in stripes, then by number of stripes and background color, and then by the shape of the aperture. The latter approach did not work out when the group discovered that all of the apertures were identical. The other two approaches were stymied when it became apparent that there was no easy way to categorize the colors or the stripe patterns on these shells. There was a gradient of yellow into tan into brown into purple, and variation in stripe number from zero to many (in addition, on some individuals it was difficult to tell which part was the stripe and which part was the background color).

We discussed how many species of snails we thought there were, and most members of the class thought there was one species with a large amount of morphological variation within the species. While it is impossible to ascertain the answer to that question with the limited data we had access to, I am inclined to agree with that assessment given the obvious gradient of colormorphs that we observed. This morphological variation should give the snail a diverse set of options for niches in which it could succeed.

I was surprised that such a large (relative to a snail) island with so many different ecological niches would (apparently) have just one species of land snail. However, regardless of how many species are there, there is clearly quite extensive variation in the morphotypes that are exploiting all of those niches. If I were to explore the question further, I would investigate whether the color morphs vary with the habitat in which they are found. As I described above, if I were to design a new study, I would hypothesize that the animals with more stripes would be more common in trees, and animals with fewer stripes would be found in more uniform environments, such as on the concrete structures that dot the island.

Thoughts on jellyfish

My post about yesterday's field work will be coming soon, but I thought you guys might be interested in this article from Sunday's NYTimes:

Stinging Tentacles Offer Hint of Oceans’ Decline
http://www.nytimes.com/2008/08/03/science/earth/03jellyfish.html

"But while jellyfish invasions are a nuisance to tourists and a hardship to fishermen, for scientists they are a source of more profound alarm, a signal of the declining health of the world’s oceans.

“These jellyfish near shore are a message the sea is sending us saying, ‘Look how badly you are treating me,’ ” said Dr. Josep-María Gili, a leading jellyfish expert, who has studied them at the Institute of Marine Sciences of the Spanish National Research Council in Barcelona for more than 20 years.

The explosion of jellyfish populations, scientists say, reflects a combination of severe overfishing of natural predators, like tuna, sharks and swordfish; rising sea temperatures caused in part by global warming; and pollution that has depleted oxygen levels in coastal shallows."

Physics...

Following up on our discussion on Lovells Island yesterday.

For a brief explanation of what causes tides, visit this site at Woods Hole Oceanographic Institute

For a more complete look at tides, check out the National Oceanic and and Atmospheric Administration's site as well.

For those of you who are still believe that the sinks drain differently in the Southern Hemisphere than in the Northern Hemisphere, please visit this site maintained by the Library of Congress

You can also find a pretty good discussion of the Coriolis effect at Wikipedia as well.

By my count, three of you owe me a total of $1.00 and two free lunches.

B-

The Snails

Hello, everyone!

Today on this lovely warm day, we boated out to Lovell's Island in the Boston Harbor Islands National Park.Our first stop took us to the Northeastern side of the island to a large tidal pool. The pool was physically connected to the broader ocean, and was exposed to small waves of 2-6". Brave bare-footed or flipflop clad students traversed the slippery rocks a dozen or more yards into the tidal pool in search of the Periwinkle Snail. Fortunately for us, they were not terribly difficult to find.

The snails were all relatively small, I'm fairly certain that every specimen found was less than an inch in diameter and an inch high. I would estimate that the smallest periwinkle I found was 1/8th inch across. Their shells were dark brown when damp, sometimes mottled with a lighter brown color. It is important to note, however, that dry shells become a lighter sandy color, and very worn out aged dry shells could turn light gray. Shells had closable trapdoors that are used to close in water for the snail to breathe when it is stranded by the tide above water (useful for an intertidal zone creature).

Periwinkles could be found on or around the rocks that litered the floor of the tidal pool. Many were on rocks alone, however I would say that most appeared to share rocks with others in groups of 2+. On one rock, I saw around 8. Although they stuck a bit to the rocks, removing them only required a light tug, they barely put up a noticable resistance. Once extracted, however, getting them to emerge above water was rather challenging! I had little luck simply leaving them in the palm of my hand. After setting one on a moist rock resting upon one hand, and shading it with another (in an attempt to imitate their 'natural' habitat), I found them more likely to emerge. I do not know how valuable this method was, because I also overheard conversation that would imply that singing, humming, or poetry had also been found to be effective (perhaps my snail merely overheard someone elses story!). In spite of the difficulty of balancing snails on rocks, it got the job done for me whether it is silly personal supersticion or has some scientific merit.

After 3-4 minutes of sitting on the rock, the first 3 snails I tried this with emerged (it had to happen more than once because they kept falling off their rock!) and slowly crawled across the rock. I would estimate that it took them aproximately 10 secons to cross a 2.5" rock, though admittedly they were not travelling perfectly straight and may have been distracted and not moving their fastest.

The Periwinkles only emerged slightly at any point. The snail's flesh was dark brown to black and appeared slick and moist.When coming out of their shells, first extending two small feeler-like tentacles to probe the air and rock and wiggle slowly. If disturbed by physically poking or rock-shaking at this point, the snail withdrew rather quickly. If the snail is permitted peace long enough, its head will also emerge. I am not sure if it is possible for their heads to come out further, but in my examples, and those of classmates that I saw, the head only comes out maybe a 1-2mm, aproximately a semicircle to the shell. I did not see it come out further than this under water or above ground, and it appears that at this point it is able to move around. Once the head is out, shifting of the rock did not seem to disrupt the periwinkle as much and cause it to withdraw, however, poking of the shell did cause it to hide.

Back by popular demand, an MS-Perwinkle:
We found evidence of other types of Periwinkles as well, though we did not see them. Further out in the water, hermit crabs were found living inside darker, smoother, larger periwinkle shells. These shells might have at one point housed a variety of periwinkle that lives completely under water beyond the intertidal zone. Bruce additionally hinted at a third type of Periwinkle that lives in the spray zone, but we did not see these or anything to indicate they might be around.

We spent the next portion of the day looking at the Periwinkle's distant cousin, a variety of Landsnail also making Lovell's Island home. On the way to the tidal pool, we had already seen evidence of these critters in the form of numerous broken snail shells littering the pathside. Challenged with finding both living snails and these old snail shells, my group began at a higher altitude closer to the middle of the island. Here, we found numerous very small snails ( perhaps as small as a centimeter across), though we were more successful finding these down sloping side paths that ran off the hill. These tiny snails almost exclusively were found clinging to the underside of the leaves of Sumac Trees. Upon descending the path, we were more successful at finding both snail shells, and larger live snails. Larger snails might be found on the bark of Summac trees or the leaves. Some were found in blackberry bushes as well. Shells were most easily found almong the side of the paved path, by the edge or shaded by overhanging plants.

Categorizing snails and shells by specific features to identify either morphs of one species or to seperate species all together proved challening for our class as a whole. Some difficulty included identifying what "yellow" is, or the exact number of stripes on snail shells. In general, I would say the most common colors found of the dead snails of a 'random' sampling of 113 (narrowed to 100) were yellow, light brown, and darker brown, most having darker brown-black stripes and a few stiped with a lighter brown color. Shells either appeared to have one central stripe down the middle of the shell or several rings of stripes. Counting these stripes was another challenge because many of the shells were broken, so I really could not say how many stripes they had total. Color was also challenging to identify because brown shells, for example, appeared to turn a pinkish color with age. At first we thought this might be its own category alltogether. The one shell that really stood out was a solid yellow shell.

One group looked at the entrance to the shells and determined that all of the openings looked to be aproximately the same shape regardless of the shell color.

The live snails were also difficult to differentiate and brought a new factor to the equation: skin color. Snails appeared to either have brown or yellowy-white flesh. Skin color seemed to have little to do with shell color, as we found an example of a dark-shelled snail with light skin as well as yellow-skinned snails in yellow shells and brown skinned snails in brown shells. They looked a bit sticky/slimy/shiny visibly.

Here is a Landsnail:

To compare them to their seadwelling cousins, they did appear to emerge further from their shells than their Periwinkle cousins, as I attempted to demonstrate in my doodle. They had an additional set of visible tentacles mounted higher up on their head. Landsnails came in a far greater variety of colors and patterns, at least at first glance. Perhaps Periwinkle mottling patterns or shell shapes vary more greatly, but it was hard to tell at a quick glance. The periwinkles we looked at also had harder shells than their landsnail brethren as well as trap doors to contail water.


I am very tired after today's snailing and am going to go to sleep now, but I may come back and add more if I think of anything I forgot. Enjoy the break, everyone!

Presentation Photo

You can find a high-resolution version of this photo at our course info site by clicking here.

Barking Crab Dock Observations

Caitlin Klinger
Observations for Saturday, August 2, 2008
Location: Docks behind the Barking Crab restaurant
Weather: high 70s and mostly sunny at time of observation

Method: This was not originally a deliberate plan, but I began observation with the naked eye by lying on one of the smallest docks and looking into the water directly off the dock (see photo 1). This area is likely to receive very little light, as it was directly shaded by the bridge at the time of observation. I would later move to an area that was exposed to light at the time of observation to see if there were different specimens in the different locations. Although I began by simply taking pictures of the area I was observing, I would later extract small sections by hand for further observation.

Tools: pen, notebook, digital camera, gloved hand, magnifying glass, "National Audubon Society Field Guide to North American Sea Shore Creatures". Most of the time I focused on recording each specimen's appearance in the most accurate way possible, and then followed with determining its tactile properties (is it firm? soft? gelatinous? etc). Afterward, I would attempt to locate it in the field guide if I had time before moving on to the next specimen.

Photo 1: This is what I saw when I first leaned over the shaded dock at the Barking Crab. As others have concluded, I believe the shot is dominated by a number of Frilled Anemones. Although I came to this conclusion rapidly, I began to have doubts when I noticed the given size range in my guidebook for the Frilled Anemone is 18" high by 9" wide. However, in the end I concluded that these specimens, although smaller (perhaps because they are younger and close to the surface) are indeed the same anemone. There are also at least six Blue Mussels and a bit of the infamous "Orange Stuff", which I will discuss later.

Photo 2: This is a sample of Rock Weed taken from that same shady dock.

Photo 3: Another sample of Rock Weed, but this time from the dock with more sun exposure. If you click on the picture it gets really enlarged and you can clearly see that the "Orange Stuff" is actually clear with many smaller orange circles inside. According to the "Hitchhikers Guide", this appears to be Orange Sheath Tunicate. However, there are so many color variations occurring on this one sample (yellow, varying oranges, reddish) that I wonder if there might be some Red Sheath Tunicate here as well. Once this piece of Rock Weed had been exposed to the air for more than a second or two, a number of "bug like creatures", as others have been describing them, began to send the Rock Weed into a flurry of activity. These creatures were varying in size, but no bigger than approximately four mm. They were striped, and almost shrimp-like in silhouette, but I have yet to determinate what they were, as all of the amphipods were much larger than these and did not have the correct striping pattern.

Photo 4: This is another sample of Orange Sheath Tunicate, which we further investigated by hand. It turned out that although appearing gelatinous, it is quite resilient and will withstand a lot of poking without breaking. Although this picture is turned, the other specimen is the "orange coral" to which Helen was referring. I still cannot figure out what it is, as the only orange coral in this area looks nothing like it. If you enlarge the picture, you might be able to see what looks like a tiny curly stick coming off of the coral. This was, I believe, a Skeleton Shrimp (according to the Complete Seaside Guide). When it was still alive, it resembled a moving stick.

Entry 8/2/2008

Name: Helen Chang
Date: 8/2/2008
Location: Fort Point Landing, 88 Sleeper St, Boston, MA. Docks behind Barking Crab.
Weather: Near 70s-80s, Cloudy with thunderstorms later in the day.

Tools: Eyes, poking instruments(pencil), notebook and guidebook.

Key Findings:
Blue Mussel Colony
Seaweed
Tiny shrimps
Stick like Worms
Orange Glob
Orange coral like items

Observations: Mussels were found scattered along the docks, possible seagull remains and also they were found along the side of the docks that we were looking at. Their were signs of a colony growing by the area which indicated a good source of nutrients growing and a healthy environment for these mussels. One these mussels we could observe various items attached to the shell. Some were orange, white and green. The ones that were pulled up were already dead and had opened already.
Seaweed was the most commonly found items near the dock. There were different kinds and shapes f the seaweed. Some were small leaf like, clover like, big leaf like, and some just grew with bean sprout like structures. When pulling up the seaweed to take a closer look items such as white tiny shells, orange palette like globs and brownish spots could be found on these seaweed.
The orange jelly-like item were also found on various times and could also be seen lying face down on the docks. We tried poking the orange glob and we found micro-organisms coming out of the glob. At first we thought it was a egg of some sort however different organisms were found to be living in the glob. Taking a closer look one could observe tiny little holes in the globs which made it possible for living organisms to be living inside this jelly like container.
We saw various tiny shrimps the size of half a staple also moving about this orange coral like item. Poking this structure with a pencil one could tell the texture was rather strong and hard to break. Also attached to the orange coral was these string thin like animals that were about a quarter of an inch long. They were attached to the orange coral and when touched would wiggle and move around.

Saturday- Long Wharf and Barking Crab Dock

Name: Erald Pelari

Saturday August 2, 2008

Location: Marriot Long Wharf and the Dock next to the Barking Crab

Weather: Sunny, Hot, and Muggy

We started our class and scientific journey at the Marriot Long Wharf. First thing I noticed was the low tide. Average tide around the Boston Harbor is 9 ft, but today according to professor Berman the tide could reach around 11 ft. which is below average. According to the “Boston Harbor Seaside Educator Side” a full and new moon offer the lowest tides. So I presume that the night before we had a full moon. The low tide allowed us to see a lot better the inter-tidal zone and notice the limited life on the rocks exposed to both air and water. The rocks had some green algae on them but there was hardly any other visual living organism on them. Most of the fully grown seaweed, some green and some brown were emerged under sea, but still visible with the human eye. Over here we also saw little fishes swim around the area looking and eating food. There were around 20 fishes swimming in a circle close to one another.

Since this area is also a busy dock with ferries and water taxis moving constantly one can not help but notice the trash on the water. This does have an affect on the species that can live and survive in that area. Polluted waters increase the risk of deadly bacteria growing on the seaweeds and the algae, and or other species where they then are forced to abandon this area or die and become extinct from a particular area.

We continued walking along the harbor and it was evident that areas not exposed to air had thriving aquatic lives, with larger and longer seaweed, mussels, and other things. One thing that I thought was sort of odd were the ducks in the water. From previous experience and what have read and heard is that ducks like and prefer sweet water so I am not sure as to what ducks were doing swimming in salty water? I am looking forward for some feedback on this puzzling issue.

Later we went to the dock next to the Barking Crab Restaurant. Here we did extensive observation and research. Here we analyzed the different species more carefully and tried to name the various living things that we saw using the Peterson field Guide on the Atlantic Seashore, as well as the opinions of our fellow peers.

Method:

All of us separated into groups and observed different locations on the dock. Here some of did visual observation, some drew pictures, other took pictures with their digital cameras, and some touched the different living species in the water as well as outside the water. Some conclusions on what the hell kind of species they are were based on our own previous knowledge.

Tools:

Being the first day on this one week long scientific expedition I did not have the proper tools and or the knowledge on how to record scientific data and what are some tools that will help me do a good job. Today I only had my pen, a notebook, and a pair of latex gloves and Peterson’s Field Guidebook. I’ll be frank with you the guidebook could have been a lot more helpful if I knew how to use it correctly. I used mostly my hand and my pen to try and move things around to have a close visual observation.

Observation and Data

First Specimen: Green Algae

My first observation was a green leaf about 7 in long 4 in wide with white little branches running along it just like veins in human body. While in the water this big leaf or algae was attached to the dock but because it was long you could see it move in wave motion due to movement in the water. This algae was dark green in the water, but as soon as we pulled it out of the water after a while it started to lose some of its color and got lighter. I can not find a specific name for it but I am pretty sure it is an algae.

Second Specimen: Shrimp Like creature

Obviously this is defiantly not the name of these creatures but they did resemble a shrimp 100 times smaller then a regular size. These little living things were found in between the algae and mussels. They had various legs, I can not give a number because their legs were so small and it was hard to count. They also had small like antennas on the top of their forehead and from my observation it looked like they had a shell around them similar to that of a shrimp. Some were white with little black dots on their backs.

Third Specimen: Blue Mussels

On the docks at the barking crab there were a lot of areas, where you could see various mussels. Some were fully grown and some were very small all combined together and tangled in between green seaweed. The mussels were dark in color one could say they were dark blue and if carefully cleaned and observed one could see that this is a blue mussel. According to Peterson’s field guides this could be a blue mussel judging from the color and the fact that it grows around this area of waters. One interesting aspect about these particular mussels at the dock near Barking crab was that the shell was still there but there were no mussels inside the shell. I believe that the level of pollution has something to do with the nonexistence of a mussel in the shell but after close observation one could see that almost all the big shells were covered with these orange looking bacteria if you will.

Fourth Specimen: Orange Sponge

The Orange Sponge is a name I gave to the orange area surrounding the mussels. They are squirting and encrusting the mussels shell. Closely looking at them they looked like a flower with a dark orange middle and flower like petals surrounding it. I would believe that this is some sort of a parasite that takes over the mussels shell after the mussel inside has died. These orange sponge looking bacteria are there to maybe help with the decomposing of the shell left behind after the mussel dies.

Saturday @ the Long Warf

Today we observed the diverse sea life that exists on the docks of Boston harbor. Our first observations were on the Long Warf Marriot Hotel dock wall. We looked at the green “moss” that covered the wall above the intertidal zone and the seaweed that was growing on the rocks in the intertidal zone. The seaweed had bladders that help it float on top of the water. Later I found out that that was Rock weed and that its presence is actually a good thing. Since rock weed does not do too well with too much human waste (phosphorous, nutrients etc) its presence is an indicator of a healthy environment. Looking in the water I saw many little fishes swimming back and forth really quickly, they appeared to be feeding. We also saw a lot of evidence of human use. All of the observations were made from approximately 20 feet.
We proceeded to ponder on the question of where is there more biodiversity in the natural environment or on man made structures with lots of human interference. We split into two groups based on our opinion. I joined the group that thought that there would be more sea life presence where there’s more human presence thinking that all human use = more nutrients, bacteria and all that other stuff for the life to prosper. However, now I am beginning to wonder if all those nutrients and foreign bacteria (i.e. human waste) would kill some organisms and prevent only but a few of them to survive … I will need to do some more observing before I can answer that one.
We proceeded along the long ward waterfront and observed another wall that was covered in seaweed. However this time the seaweed was different (in color and appearance). I noticed that the water was much more turbulent here and was not as quiet in the protected area as at the first location (Marriott hotel). Lack of sunlight, constantly being underwater and turbulent water gave way to a different kind of seaweed (green leafy as oppose to red and floating around).
When we got to the barking crab docks I got down on the dock and took a look at what is going on below it. At first I just observed the mussels (blue mussels), seaweed and all of the other masses some that appeared to be porous, some looked more jellylike. I drew a picture and then reached down for my first sample. I first pulled up a single mussel and proceeded to visually inspect it. It was dark in color and was covered in some sort of grey stuff (that was hard). What amazed me the most was the abundance of living organisms that I saw running away in all different directions. There were tons of little creatures crawling everywhere. I saw at least 4 different kinds of “bug-like” creatures. There were little ones with thousand little legs (clam worm?) crawling away from me in a hurry as I was intruding on their lives. There were bigger brown creatures that looked like snails out of their shells that were trying to blend in with the mussel. Tons of cumaceans. There were also “tentacle-like” creatures that were attached to the mussel that were constantly in motion sort of reaching for something (After looking into the field guide there on the docks my first hypothesis was that it was polydora mud worm but now I think it is skeleton shrimp).
The second sample was much bigger and contained a lot more stuff. There were mussels (big ones, smaller ones attached to it, dead ones, live ones – sign of a healthy mussel colony) different kind of seaweed (brighter green and transparent, more brownish and covered with stuff), this orange spongy stuff (Orange Sheath Tunicate?)
Method was: individual visual observations, magnifying glass, binoculars, occasional pocking with sharp pencil.
(I cannot scan my drawing so I will bring it in to class tomorrow … today actually)

Vadim

P.S. I’m ready to see some whales now

Day 1. Boston Harbor Observations. UPDATED (Kris Pandeli)

Kris Pandeli

Saturday: August 2^nd 2008.

Weather: sunny and muggy

Location: Marriot Long Wharf

This morning it was a low tide at 9 am with an expected high tide at 1 pm. The tides change every 6 hours. A (+) tide is considered that above the average and a negative vice versa. On the stone wall of the harbor you can see green algae in different spots, about 6 ft. down you can see the seaweed. This intermediate zone as can be seen by the coloration of the wall which is called the inter tidal zone. Close to the wall you can see the fishes seemed to be feeding. Walking along the harbor we ended up by the Barking Crab doc. Here we observed, collected and drew analysis of many specimens trying to determine what they were as we shared thoughts with other students and by using Peterson Field Guide of the Atlantic Seashore.

Method:

All the students observed different locations of the harbor walls and the Barking Crab doc. Observations, drawings, and touching of specimens were made. Suggested conclusions were drawn based on the notes that were recorded. Later on the day more research is needed and the use Peterson’s Filed Guide will help us determine what these creatures and plants are; what their scientific name is.

Tools:

Being the very first day of class I must say I wasn’t very prepared for it, so there was a shortage of tools. That aside, I mostly used my hands and eyes for observation. Other tools included my pen, notebook, and my fellow students’ guide book.

Observation and data:

1.Hollow Green Weed

My first specimen was the green seaweed, 7 inches long and wide, which looked bright green but with many inside foldings almost looking like the surface of the human brain. It looked harmless until I found out that in those folding gap of the weed many little bug look-alike were crawling allover the place. So I moved my hand away from it. It seemed that this sea weed was providing a living/breeding place for these tiny creatures.

According to Peterson’s Filed Guide: This Seaweed I think is called Hollow Green Weeds (pg 27)

2. Skeletal shrimp:

Second specimen I observed with the seaweed was those tiny shrimp like creatures. They were moving like ants but when you looked closer they had these small arms/legs sticking out and the tail that crawled inward like that of the shrimp. And that’s’ when I drew my first conclusion that these were tiny baby shrimps. They were two mm wide and four mm long. They were white with a little reddish to yellow color.

3. Blue Mussels:

But then I put my hand in the water and pulled out what I call bigger seaweed attached to many roots and muddy material. Attached there were these three mussels and around were about thirty other baby mussels. This definitely seemed like the breeding place for mussels. The mussels were dark in color almost black to a dark blue color and the baby ones were lighter in color. I think these are the blue mussels.

4. Orange Sheath Tunicate:

The orange mushy stuff that seemed to be invading the surface of the mussels was like patches of some sort of parasite or some type of algae. In some mussel shells there was just a spot of this orange material but in some they had almost covered the whole mussel.
I thought this is some sort of orange sponge. But after I read my peers blog I realized that they had called the orange sheath tunicate. Further with my y research I came across the Marine Invasive Species and found out that this is called indeed the Orange Sheath Tunicate more accurately (Botrylloides Violaceus). And there it was described similarly to what I saw on the Barking Crab: “ Can grow over other organisms, leading to their possible death”. This is great stuff!!! I was happy to find it and be confident in identifying to what it was.

5. Sea Caterpillar?

My last observed creature included what I initially name the water caterpillar. It moved really fast trying to get away. It was hiding inside the shell of a mussel. I tipped it over and I could see the numerous almost netlike legs which obviously was the reason for this creature to move so fast. It was about 2.5 cm long and .5 cm wide. It had a dark brown color on top but a light one on the bottom. Maybe the coloration has to do something to do with this creature trying to disguise itself. I looked at Hitchhikers I think this is a Asian isopod because it looks somewhat similar but will a closer look it is quite different. The main difference is the legs. In the Asian isopod you can clearly see the legs but in water caterpillar the numerous legs almost form a net around this creature. I still cant figure out the scientific name but I did find a picture of it under the name of “Sea caterpillar”. If anyone will be able to identify it from the picture, please post a comment and let me know.

For the rest of the day we took the boat along the Boston Harbor from the Long Wharf to Quincy. On the way we listened to professor Berman discuss on ways of improving and maintaining the harbor clean. Overall it was a long day but exciting.

~Kris Pandeli