LIFE ON THE ROCKY SHORE (CHALLANGES)

==Problems and adaptations== The continuously changing environment makes life difficult on the rocky shore. Twice a day the tide comes in and out. Living things need special features called '''Adaptations''' that help them survive in the different zones of the rocky shore. '''Life in the High Tide Zone:''' The biggest challenge here is the lack of water. Organisms found here spend most of their time out of the water and are often exposed to the sun and wind. Without adaptations to overcome these factors organisms found here would lose too much water and die (this is called desiccation). One advantage of living in the high tide is less competition and sea predators. '''Life in the Mid Tide Zone:''' This is the most changeable region. Organisms here spend approximately half their time under water. Organisms here will be faced with challenges seen at both the low & high tide. They will will be exposed to the waves, wind and sun. They will also have to deal with competitors and predators. However, they will be exposed to each of these things for a shorter period of time. '''Life in the Low Tide Zone:''' These organisms face challenges such as increased competition for food, space or light (important for plants). They are also exposed to strong waves that could wash them away if they don't have some way of holding onto the rock. They are also more exposed to sea predators such as fish. Some advantages of living here include the reduced risk of desiccation (drying out) and that food is more readily available (the tide brings food in with it). ==Environmental (Abiotic & Biotic) Factors that affect rocky shore organisms== '''Air & Wind''' Intertidal organisms are regularly exposed to air and wind. Exposure to the air and wind can increase the amount of oxygen that is available, but also increases the rate at which water is lost by evaporation. Organisms that live here need adaptations that help them to conserve water '''Light''' Sunlight is another also affects the organisms. When there is too much sunlight, organisms can dry out (desiccation) or overheat. Light can also damage certain body parts (like sunburn). However, plants need sunlight to carry out photosynthesis (a process in which they make their own food by using the suns energy). While plants need sunlight to carry out photosynthesis they also need water. Too much sunlight can increase water loss by evaporation causing the organism to dry out (desiccation) '''Temperature''' The inter-tidal zone can experience extreme temperature changes. The organisms in this zone must be resistant to these changes to survive. When the organisms are underwater, they are protected against temperature changes (the water doesn't change temperature so much). When the organisms become exposed to the air, they can experience very cool or warm temperatures. Some organisms have developed antifreeze chemicals that help them survive cooler temperature. Many organisms will move into cracks and crevices reducing their exposure to cold winds or heat from the sun. '''Salinity''' Salinity basically means saltiness. Water evaporates from rocks / rock pools leaving behind it's salt. The more water that evaporates the saltier it gets. If water gets too salty it can also cause organisms to lose water. some organisms can simply move a region that is less salty. Less mobile organisms become less active and attach more firmly to the rock, often storing water within a shell. '''Predation''' A wide variety of strategies to escape from predation exists. The first strategy is having a hard shell. It makes it more difficult for the predator to eat these organisms. some organisms produce special chemicals such as toxins that make them unappealing to predators. Camouflage is another commonly used form of protection against predators. Camouflage makes it more difficult for predators to find their prey. '''Wave action''' One way to protect organisms from waves is permanent attachment (cementation). But this strategy can not be used by organisms that have to move to feed themselves. These organisms often have a strong muscular foot to hold them onto the rock (although not as strong as permanent attachment). Another way to be protected is to burrow themselves or seek protected habitats.