We decided to survey the Belfast Lough Foreshore at Jordanstown to investigate the habitat, and establish the types of creatures living there along a fixed straight line reaching approximately 21 metres from the upper shore (not usually covered with water) to the Lower Shore (covered with water unless there are very low tides)
Based on existing knowledge, I expected to find mussels, sandworms, seaweed, crabs, periwinkles, and limpets. I expected these organisms to live mainly in damp areas, rather than in dry areas
We decided that when we got to the beach, we would select points at equal intervals marked out along a straight line. This would be marked out by rope. We would position a quadrant (0.5m2) at each of these points and count the number of organisms in each area or estimate the percentage coverage of the area if the organism was seaweed. The temperature and light intensity was to be recorded on a “LogIT Datameter 1000” We made sure it was a fair test by everyone using the same size of quadrant, measuring at equal distances along the rope and everyone measuring with the quadrant touching the rope. We also chose an area that was partly dry, partly damp and partly wet.
We chose a line of approximately 21 metres long and marked it out with rope. We then chose a starting point, plugged the sensors into the dataloggers and switched them on. We then placed our quadrants (0.5m2) on a point against the line and either count the number of organisms in each area or estimate the percentage coverage of the area if the organism was seaweed. We then recorded temperature, light intensity and the organisms present. We chose points at equal intervals along the line. I recorded points every 2 metres. The results of my investigation are shown in the table and graph below.
Distance in metres
(1 metre – upper shore, 21 metres – lower shore)
Temperature in Degrees Celsius
Percentage Coverage / Number of organisms in area, living/ non-living
Organisms Found in Area
5 (2 alive)
3 Periwinkles + 2 Sandworms
10 (1 alive)
9 Mussels + 1 Sandworm (Sandworm alive)
27 (3 alive)
6 and 5%
(4 organisms alive), seaweed + mussels dead
2 Carpetshells, 4 mussels, seaweed, 2 periwinkles
2 Periwinkles + 4 mussels
Interpretation and Analysis:-
From the data recorded, we found that the area had a relatively steady temperature as it only had a range of 1.7 degrees and it had a light intensity range of 12%. The most live organisms were recorded in the area between 7 metres and 15 metres which is the Middle shore area and is not totally dry, but is not submerged either. This would indicate that these organisms prefer moderately damp areas.
The results of the investigation were not exactly as I had predicted. I expected to find mussels, sandworms, seaweed, crabs, periwinkles, and limpets. However I didn’t find crabs or limpets, but I found 2 carpetshells which I hadn’t expected to find.
I expected these organisms to live mainly in damp areas, rather than in dry areas. This was mainly true, but there were not as many animals in areas completely underwater as there were in areas where the tide would just wash over. The results of this investigation may have been inaccurate due to pollution caused by a stream running nearby to the area we were studying.
Recommendations for a further study:-
If I was to carry out this study again, I would go later in the year when the water and shoreline would be warmer to establish if this had any effect on the marine population. Also, I would study an area where the area was damp, but not totally submerged underwater, as the results showed that there were more living organisms in the middle shore areas.