Rocky Shore Investigation

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Rocky Shore Investigation

Null Hypothesis:

There is no pattern to the distribution of organisms over a rocky

shore.

Variables:

Factors that affect the distribution of organisms over an area of

shoreline are:

· The depth of water which may cover an organism at high tide.

· How resistant an organism in the littoral zone is to dessication.

· How efficiently an organism can conserve water.

· The proximity and availability of nutrition.

Stations

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I think that stations 1 – 4 are in the sub-littoral zone of the rocky

shore.

Stations 5 – 12 are in the mid-littoral zone.

Stations 13 – 15 are in the splash zone.

I know this through observation on the day, the amount of rock pools

and their depth etc. Consequently the splash zone had no rock pools,

the mid-littoral zone had some, but these were not very deep, the

sub-littoral zone was very close to the sea and was almost all rock

pools with lots of slippery seaweed. My results show that this was

mainly Fucus vesiculosus (Bladdder Wrack).

Analysis of Results:

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Animals

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There are several clear trends in my results, the clearest of these

being the limpet (Patella vulgata). The majority of limpets were

situated mainly in the mid-littoral zone and splash zone. They had a

peak at station 12 of 31 limpets. Their number slowly built up to this

peak from 1 limpet at station 4 to 33 limpets at station 12. The

limpets also petered out in numbers after station 12, to go 13 to 6 to

0. This tells me that they do not want to be exposed for that long

between tides. However, station 12 still has a ...

... middle of paper ...

...rocky shore. We could have done this by placing two

measuring poles at the required points on the beach and then using a

field level device, such as an Abney level, which consists of a

sighting device and a spirit level. This would have produced two

heights which when subtracted from eachother would have produced

height increase.

We could also have improved the investigation by checking more

thoroughly in the quadrats and by spending more time learning what the

species subtle differences were.

We could have ensured that the groups we took data from for the

averages had spent a decent amount of time on the investigation and

had not rushed it.

There were many aspects of the investigation that could have flawed

the results however overall I think that the practical still reliably

rejected my null hypothesis.

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