The image above shows the dominant brown seaweed groups on the shore. The greener seaweeds growth beneath these and near the high water mark, the seaweed that we are focusing on is called bladderwrack, this is show on the image above, and is positioned about middle shore, this means that is covered by water a large percentage of the time, but then sometimes is left exposed from the salty water.
Bladderwrack (Fucus vesiculosus) has pairs of air bladders which float its fronds towards the light. Like most algae many variants develop in response to changes in environmental factors, on wave exposed shores a bladderless form occurs. It grows rapidly after establishment though individuals at the edge of the range may remain small.
As shown above the bladderwrack seaweed we have the different components that make the array of the bladderwrack, we have the fronds, these are basically a leaf structure of the seaweed. Then we have the air bladders, these vesicles are found in pairs of a central midrib running along the centre of the strap-like frond. Then the hold fast, located at the base of the seaweed, is like the anchor of the alga, it holds the seaweed fast to a rock or such alike, this maintains a strong hold useful in harsh conditions, the hold fast is not like a rooting system on plants, the hold fast does not absorb and nutrients or water. The absorption of water and nutrients as needed is done by osmosis within the fronds; this is the lower pressure of water potential acting on the salt and nutrient intake.
Competition of the bladderwrack occurs mainly under more sheltered conditions because the main competitor is knotted Wrack (Ascophyllum nodosum), this is unable to survive in wave action, both the knotted Wrack and the bladderwrack habitat on the middle shore. Because bladderwrack only lives for about three years the knotted Wrack then takes over when the bladderwrack dies, and the knotted Wrack can live for about twenty years. The knotted Wrack is very familiar to the bladder wrack, despite some visual differences, such as the fronds on the knotted Wrack are much longer, but thinner, the gas filled vesicles on the knotted Wrack are not particularly in pairs they are at regular intervals and the knotted Wrack grows much slower than bladder wrack. The knotted wrack is found mostly on sheltered sites on shores in the mid-littoral where it can become dominant species in the littoral
Hypothesis
There will be more bladders on the seaweed that is more exposed because the seaweed will need to sustain positioning and staying afloat more, if in these conditions, because the seaweed needs to photosynthesise.
Equipment List
Quadrat
Tape measure
Metre rule
30cm rule
Anemometer
pH scale and litmus paper
Compass
Field identification cards
Soil thermometer
Air thermometer
Recording sheets
Method
- I will find the appropriate area on the exposed side of the island, I will have to choose an area that least looks humanly interfered as human interference factors could cause disturbances within my results.
- I will measure the air temperature and wind speed (using the anemometer) for the exposed area, then record this, this is to gather the dependent variable, that I cannot change, so doing this I can still include it in my analysis and explain the effects of it.
- I will test the pH of the sea water and the sand, by using litmus paper, and identifying the pH using the pH scale, I will then record this, this is again to use later on, to show the effects of the pH, if there is any and I cannot control this variable
- I will then throw the quadrat down onto a random area within the exposed area that I am in. I am doing this randomly to ensure that fair testing is accustomed for, rather than throwing the quadrat onto an area with large amounts of seaweed.
- I will record the percentage of bladderwrack seaweed; I will then measure each one and record this along with the amount of bladders on the piece of seaweed. I will then record the percentage of other species and the percentage of exposed rock or sand. I will also record the percentage of organism found within the quadrat, I will also count the amount of periwinkles on the seaweed.
- I will repeat steps 4 and 5 until I have obtained all 30 samples.
- I will then repeat this in a less exposed area of the island. I will repeat steps 1-6 in the less exposed area.
Fair Testing
Because I cannot control some of the variables, I will have to analyse the effects of them, and discuss this within my analysis, some such as the amount of times I throw the quadrat I can control, this being 30 times on the exposed side and 30 times on the less exposed side. I am doing this as it is plentiful to prevent problems that could arise when using a smaller number of samples; also this would come in extremely useful when I am doing the statistical work, as the statistical system I am using would be easier with this high number of samples.
In my method I am accounting such things as the pH, periwinkles and the air and soil temperature because these could have direct effects on the growth and survival of the bladderwrack seaweed, this also means that I can analyse the results further using the measurements from this and draw more acute conclusions and perhaps solve some problematic results.
Bibliography
