THE END

And with that, my group of grand geeks (not really), I would like to put a close to this blog. We have brainstormed ideas, researched, gone into the field, harvested specimens, tested them, observed, drawn conclusions, and shared reflections. I doubt we could've done a more thorough job on this project.

It was been a pleasure working with you.

Hi everyone!

To add to what Erik has already posted (looks great!), the amount of time that it took for the bull kelp bulb to burn in relation to the other kelps demonstrates its resistance to heat, far beyond temperatures it would encounter in its natural environment. (It would be interesting to find the rate at which the blades burn . . .) This could indicate that its cells have very strong, yet flexible walls, compared to the other species of seaweed examined.

Of the three types of pigment that were discussed, bull kelp contains fucoxanthin, which typically absorbs light at wavelengths of 450-540 nm, toward the high-energy end of the visible spectrum. (http://www.sea-thin.com/assets/documents/Japanese%20Fucoxanthin%20Clinical%20Study.pdf) This pigment also gives the kelp its brown tinge. The fact that the pigment is able to absorb light optimally at higher energy wavelengths suggests that it might be able to thrive at deeper levels than red seaweed species, since they can absorb the wavelengths that would be more likely to penetrate to deeper levels of the ocean. This would enable it to survive and grow during the earlier phases of its life, before reaching heights of up to 35m. (http://www.racerocks.com/racerock/eco/taxalab/bio2002/nereocystisl.htm) The high elasticity (anouther indication of the strength of the cell walls) would enable it to survive in regions with strong tidal currents, such as in the waters around this area.

This pigment/protein is also being researched for its fat-burning properties (meaning that there is lots of hype about it, and also that it is hard to find actual research on it on Google), though it has yet to be tested on humans, meaning that its effects are not yet actually known (http://www.sea-thin.com/assets/documents/Japanese%20Fucoxanthin%20Clinical%20Study.pdf).

So that's more from the biochem perspective!

Alex

Hello my friends!

So, I do believe that the experiment we did this last Saturday was a resounding success. The trip to the beach to gather our specimens and the actual experiment itself all went quite well!

First, I'd like to thank all three of you for making this project one of the best I could have hoped for. Although it may seem melodramatic, I would have to say that I couldn't have asked for more competant scientists.

I'd like to start off by apologizing -- I seem to have misplaced my transfer cord for my camera, and therefore I will be unable to upload any of the pictures I took of our project on Saturday. If I find it before tomorrow, I will be sure to post the pictures.

Now, in terms of the experiment itself, I feel as though I am obligated, as a chemist and biologist, to explain why the bullkelp and seaweed turned green after it burned (Mr. Marine has already touched on it), and why the bullkelp and seaweeds have such fastly different elasticities (in terms of the chemistry, as opposed to the physics, like Horacio spoke about).

So let me first discuss the burning experiment. As has been previously outlined, we burned the kelp and, whenever an observation about a change could be made, the observation and the time (counted up from when the heating began) were recorded. The most noticible change was a change from the original color of the seaweed and bullkelp to a green color. To explain this change, Mr. Marine has already identified the different pigements present in this aquatic life -- that is, cholorphyll, fucoxanthin (absorbs in the blue-green to yellow-green spectrum), phycocyanin (absorbs in the orange-red spectrum), and phycoerythrin (absorbs in the blue-green/yellow spectrum). This is why each specimen was a different color. Now, I would conclude, from a scientific point of view, that the reason why the color green was found after burning was because chlorophyll was the only pigment left. However, this is where the chemistry comes in -- why would this be so? The answer lies in the nature of the pigments -- fucoxanthin, phycocyanin, and phycoerythrin are all accessory pigments. What this means is that they are found in smaller quantities in these organisms, but still change the color of it (hence red algae, brown algae, etc). Because they are not as important, nor found in as great a quantity, as chlorophyll in these animals, it makes sense that when heated, these pigments are burned away the quickest. It is because they are accessory pigments that aid chlorophyll that chlorophyll was the only pigment left after burning. Of course, the chlorophyll eventually burns too, which is why a black substance (i.e. carbon) formed on the area most exposed to the bunsen burner.

Next, moving on to the elasticity, the chemistry behind it is actually rather simple. The bullkelp because brittle when it is dried, but is strong and flexible when wet. This is clearly demonstrated in our experiment, and in the results that Horacio has talked about. The reason for this is that when the bullkelp is hydrated, it aids in the fluidity of the cells in the bullkelp; the cells become strong and healthy once more (unless the bullkelp dies; then the cells decompose and the entire thing will not return to its former state), and are then able to withstand more force. However, when they are dry and brittle the cells shrivel and are weak, and are therefore unable to withstand as much force. It is quite similar to human behavior -- when humans are dehydrated, they cannot withstand as much force as they normally could.

So, my fellow scientists, I once again apologize for being unable to submit the pictures (albeit I did talk to Mr. Marine about it, and he suggested I use my SD card instead -- however, when I opened up my camera, I realized I had an xD card instead...well, I'm no technological whiz kid or anything, but I knew that a) they had different names and b) the latter card did not fit into my computer), and again I'd like to thank you for a great Group 4 project.

I will end with a quote by our own Logan Richard: TO INFINITY AND BEYOND! (as our research shall take us!)

Elasticity

Hello dear scientists,

I am posting the results that we got for the second experiment that we carried out, calculating the elasticity constant of different kelps and seeing how much force was required to break it. I have the raw data and I have processed it but I cannot upload a word document. I have sent you an e-mail with it. Here I am writing the results. First I am going to explain how I processed the data: we hanged the bull kelps (three of them with different diameters) and we hanged weights. The force applied was calculated with Newton's second law: by multiplying the mass by g=10 m/s^2 (rounded Earth's gravitational field strength). We measured the distance that the bull kelps were stretched. From there I drew the graph force against displacement and I calculated the elastic constant (by Hooke's Law: F=k·x). Then knowing the elastic constant and the displacement at which the bull kelps were broken I calculated the force that was applied (in order to break it we stretched the bull kelps with our hands, this is an important point to taki into consideration as an evaluation of the experiment, since there is likely to be an error in the displacement that we measured). Here are the results:

For the first bull kelp (diameter at the base: 4 mm; diameter of the bulb: 19 mm):
The elastic constant was 27.8 N/m and it broke when a force of 9 N was applied.

For the second bulb kelp (diameter at the base: 7 mm; diameter of the bulb: 47 mm):
The elastic constant was 42.6 N/m and it broke when a force of 13.2 N was applied.

For the third bull kelp (diameter at the base: 17 mm; diamter of the bulb: 55 mm):
The elastic constant was 921 N/m and it broke when a force of 197 N was applied.

I think that we should look at the diameter of the base to realize that the greater the diameter the greater the force that was required to break it. I do not think though that we could draw a relation between the diameter and the elastic constant with only three trials.
With the information that was given by Alex (the rate of growth of the Nereocystis is very rapid-sometimes as fast as 17 cm per day- being able to grow up to 36 m long) we can conclude that if the bull kelps grow so quickly and therefore the diameter increases and the strength also increases, the force that is needed to break it is very large (we have seen that for a bull kelp with diameter 17 mm at the base it was needed a force of 197 N; we have to consider that the bull kelp was about 50 cm long, so when it grows more, the force will be much greater). I have also found that the storms and waves can drag them (which means pull them out the soil but not break them, althought we could think that it is needed a great force to do it since the elastic constant of the bull kelps, as we have also seen, can be quite large).

Well, this is the physics of the bull kelps dear fellow scientists,

Horacio

Bull kelp

Sea lettuce

Rockweed

Turkish towel

Microcladia borealis

Pictures

Hello fellow scientists,

As Mr. Marine said, the project that we did on Saturday was carried out very well, we had to bike, we got wet in the beach, but we got the bull kelps and did our experiments (thank you to Mr. Marine for the summary of the day).

I think what we found with the first experiment whose results were posted by Mr. Marine very revealing. First of all, I think we have found a lot about the pigments of the seaweeds. Moreover the bull kelp took more time to burn so I think we could hypothesize that that is an example of the strength of the bull kelp.

The image above contains the different seaweeds that we were examining, the three above are brown seaweeds and the two underneath are red seaweeds (turkish towel and microcladia borealis). I will put more detailed pictures in other entries.

Horacio