Exercise 1:
3.1 – Which barnacle species ranges into the warmest water? Chthamalus montagui
4.1 – On average, how many high and low tides will a given spot on the coast experience in a day, and why? A given spot on the coast will experience two high and two low tides each day. High tide occurs when the Moon and Earth are facing towards each other and away from each other. Low tide occurs when the Moon is facing the Earth at 90˚ and 270˚.
4.2 – What is spring tide and when does it occur? Spring tide is when the Earth, Moon and Sun are directly aligned. This occurs at new moon and full moon. The gravitational forces caused by the Sun are parallel to those of the moon. This creates a very high tide and a very low tide. This occurs about every two weeks.
4.3 – What is a neap tide and when does it occur? At half moon, the Moon and the Sun are at right angles from each other relative to the Earth. The gravitational pull of the Sun is perpendicular to that of the Moon and the ocean water is evenly distributed. This occurs about every two weeks.
6.1 – How many high and low tides are there each day? There are two high tide and two low tides each day.
7.1 – What is the height of each of the following in your study area?
Spring high tide: 4.7 m
Spring low tide: 0.5 m
Neap high tide: 3.5 m
Neap low tide: 2.0 m
7.2 – If you are an organism that must remain submerged at all times, what is your maximum height on the rock? Explain. If you must be submerged at all times, the maximum height the organism can live on the rock is 0.5 m. This is the lowest low tide that occurs and being at this level will ensure to obtain the most amount of water and the least amount of air.
7.3 – During approximately which days in the 14-day tide cycle do organisms living low on the rock experience their greatest potential exposure to air? Explain. At day 4