Tides are the vertical movement of water in a periodical oscillation of the sea, due to the gravitational pull of the sun and moon. The tides are on a semi-diurnal cycle, so there are two high tides and two low tides each day.

Due to the orbit of the moon, the tides also have a monthly cycle. This creates neap (very low) and spring (very high) tides.

The seashore can be divided into several zones, which are illustrated on the diagram below:

This is the highest zone on the shore, and lies above the EHWS mark, and therefore is never covered by seawater. However, it may be occasionally be spray wetted. Because of this, it is ma

Fucus serratus: This species of brown seaweed (Phaoephyta) was found only below the MLWN mark in stations 10, 11 and 12. It was most common in station 11 (40% cover), but there was not a lot of difference in the distributions between these three stations.

Light: Light is needed for photosynthesis, and all seaweeds must be immersed in water for this to occur. Water filters off some of the wavelengths of light and reduces the intensity that reaches the seaweeds. To maximise the light that does reach them red and brown seaweeds have accessory pigments that help to absorb different wavelengths of light. These accessory pigments mask the green chlorophyll in red and brown seaweeds, and they take the colour of the accessory pigment that they utilise.

The biotic factors that affect the rocky shore tend to affect the lower limits at which a species may live. The biotic factors that affect the distribution of organisms on the rocky shore are:

Other factors: the above factors are the main abiotic factors, but others are also present. The aspect of a slope affects the temperature and rate at which water evaporates, so south facing slopes are warmer, but dry faster, while north facing slopes are cooler and damper. The steepness of a slope also affects the rate at which it drains, as a steeper slope drains faster than a shallower one, so desiccation is more of a problem. The turbidity or cloudiness of seawater (due to plankton, sewage and other detritus) can affect the intensity of light reaching submerged seaweeds. Another factor is the seepage of freshwater onto the shore. Many seaweeds cannot tolerate salinity changes, so other species that can tolerate such changes will inhabit these areas.

1. Frond (lamina, thallus, blade) (often broad and flat)

Those species that are best adapted to take advantage of a set of conditions will do far better than those that are not adapted will. This survival of the fittest leads to wide diversity of species found on the seashore.

Some common words found in the essay are:
Light Light, Shore Wave, Sublittoral Zone, Biological Significance, SPLASH ZONE, LOWER SHORE, MLWN MHWN, UPPER SHORE, Temperature Seawater, Coursework Conclusion, middle shore, fucus serratus, upper shore, fucus vesiculosus, lower shore, species found, littorina saxatalis, rocky shore, littorina obtusata, pelvetia canaliculata, desiccation temperature change, animal species recorded, resources short supply, shore region shore, shore species seaweed,
Approximate Word count = 4623
Approximate Pages = 18 (250 words per page double spaced)