Why is the rocky shore so important to us?
The habitat of rocky shores is described in this article.It is a habitat sub- category in the section dealing with marine habitats.It gives an introduction to the type of biota that lives there, the problems and adaptations the habitat is facing with and the importance of it in the marine environment.
steep rocky cliffs, platforms, rock pools and boulder fields are some of the habitats that can be found in the rocky intertidal areas.It is characterized by erosional features because of the permanent action of tides and waves.A complex environment is created by the wind, sunlight, and other physical factors.Organisms in this area experience fluctuations in their environment on a daily basis.They need to be able to tolerate extreme changes in temperature, humidity, and wave action to survive.
There are major differences in the species composition for different elevation zones because of the physical conditions and associated stresses.Distinct horizontal bands or zones on the rocks are populated with specific groups of organisms.It's a common feature of the intertidal zone.
Most of the time, the upper regions are exposed to air.The organisms in this region are subject to a lot of stress.The splash zone is the upper region.During the highest tides and storms, it is only covered by the spray of waves.Organisms are exposed to the heat of the sun in the summer and the cold of winter.There are only a few species that can cope with these extreme conditions.Lichens are common organisms.They share food and energy with each other for their growth.Both themselves and their symbiont are trapped by the fungi.The nutrients are produced by the algae.They are able to survive on the sea spray.They are found on the intertidal rocks in the winter.When the air temperature changes, the algae on the rocks die.There are rough snails at the lower edge of the splash zone.These snails are able to live out of the water by trapping water in their mantle cavity or hiding in cracks of rocks.Other adapted animals include isopods, barnacles and limpets.
The littoral zone is the shoreward fringe of the sea between the highest and lowest tides.The upper limit is usually controlled by limits on species tolerance of temperature and drying.The lower limit is determined by the presence of animals.Because the intertidal zone is a transition zone between the land and the sea, organisms living in this zone are subject to stresses related to temperature, desiccation, oxygen depletion and reduced opportunities for feeding.Marine organisms face both heat stress and desiccation stress at low tide.The degree of heating and water loss is determined by the shape of the body.The surface area decreases when the body size increases.The shape has the same effect.The organisms dry out faster if they are long and thin.Intertidal organisms can cool themselves down with the help of body fluids.The environment in which higher-intertidal organisms have evolved is more exposed to the sun.Oxygen demand and respiration rates increase with temperature.Normal rates of aerobic respiration cannot be sustained because marine organisms exposed to the air cannot feed or carry out gas exchange with seawater.The organisms have evolved mechanisms to tolerate a wide range of body temperatures, for example by reducing their metabolism.
There are rocky pools in the intertidal zone.They are formed by weathering of less resistant rock in the shore platform.There are holes or depressions where seawater can be collected.They can be small or deep.The bigger ones are usually found in the lower intertidal zone.The pool becomes isolated when the tide retreats.New water enters the pool when the tide rises.It is necessary to avoid temperature stress and other stress factors.These pools are usually freshwater or brackish.It is different from other coastal habitats.Several taxa are abundant in pools.The taxa are part of the gastropods.High and low located pools have different composition.Whelks, mussels, sea urchins and the common periwinkle can be found in low-located pools.Rough periwinkles are found in pools.Flatworms, marine worms, rotifers, water fleas, small crustaceans and barnacles are some of the organisms found in pools.In tidal pools, vertical zonation has been documented.[6]
The subtidal zone or sublittoral zone is continuously covered by water.The intertidal zone is not as stable as this zone.There aren't strong fluctuations in temperature, water pressure and sunlight radiation.The organisms on the beach do not dry out as frequently.They are better competitors for the same niche.They don't need to deal with extreme changes in temperature.[7]
Stresses and adaptation are discussed in more detail in this section.The constant strong fluctuations in environmental conditions imply that organisms have to be tolerant of the associated stresses.The solutions to deal with these stresses are necessary to survive.
Aerobic respiration is what most intertidal animals depend on.Some limpet species that live high on the shore have a mantle cavity that is similar to a lung.Other intertidal animals can't tolerate long air exposure.These animals need to avoid desiccation since gills only function when they are moist.In response to desiccation stress, some species have adapted their gills to allow gas exchange with the air.Barnacles have air bubbles in their gills that give them oxygen.The main adaptation strategy is to slow down the metabolism and use less oxygen in the air.Mobile animals adapt by moving with the tide.
In the intertidal zone, temperature differences can be large.Most marine animals can't regulate their body temperature, they depend on the ambient temperature.They can't tolerate large temperature differences.In the air, animals can be exposed to very cold or hot temperatures.Animals with a small body weight have a hard time.
The metabolism of most animals increases at high temperatures.The animals can't absorb oxygen when the tide is low.The homeoviscous adaptation is one way of adaptation.The rates of metabolism and respiration decrease at high temperatures.At low temperatures, the opposite happens.The production of heat shock proteins is an adaptation to high ambient temperatures.Many intertidal molluscs such as mussels, limpets, top shells and periwinkles produce these proteins.Intertidal animals can tolerate more temperature changes than their estuarine relatives.Light colors can be used to reflect light or a large surface to diffuse heat.Desiccation can lead to problems when it is cooled.
The organisms have to deal with cold stress when the temperature is too low.In polar and temperate latitude coastal zones, this can be the case.Ice crystals can form when the body fluids reach their freezing point.The osmotic concentration of the nonfrozen fluid increases.There are organisms that have developed anti-cryoprotectants.The freezing tolerance is increased by the concentration of osmolytes in the body fluids.It is possible to control the formation and spread of internal ice crystals.When the ice formation is outside, it is not lethal.In saltwater of high salinity, invertebrates are more tolerant of cold.acclimating the animals to higher salinities can increase the cold tolerance in molluscs.Increased concentrations of intracellular solutes may be the reason for this.
Mobile organisms can avoid extreme temperatures by moving to more suitable places.
Dehydration is the main environmental factor in the supralittoral and high intertidal zones, and the green macroalgae living in these zones are exposed regularly to air, yet still survive.Desiccation tolerance is the ability to survive drying to less than 10% of the water content.Maintaining homeostasis during dehydration involves repairing any damage as quickly as possible.Highly mobile organisms can avoid desiccation by moving to a region that is more suitable.Reduced metabolism is restricted by less mobile organisms.The deployment of desiccation-resistant egg cases for embryonic development, reduction of the exposed surface areas across which water loss takes place, and temporary depression in metabolism are among the Physiological Features to tolerate Water Loss.Some organisms can anticipate emersion by storing water in their bodies.
Many intertidal animals have a biological clock that allows them to anticipate changes as a result of tides or light.Different signals play a role in the setting of rhythmicity in some crustaceans and crabs.After a few tidal periods, the rhythmicity is maintained.The animals can adapt in time thanks to the biological clock.
The organisms are influenced by Sunlight.Light energy can be weakened when there is too much sunlight.Damage to subcellular structures can be caused by the light that is not used or dissipated.Non-photochemical quenching (NPQ) is a process in which the light energy absorbed by the chlorophyll is dissipated in the form of heat or fluorescence.NPQ can be used to prevent damage from excess sunlight.Suppressing free radicals produced from an excess of light is one of the mechanisms.The growth and reproduction of the organisms are affected by too little sunlight.
The organisms living in pools that are not regularly refreshed with new seawater can be subjected to varying salinity.The rain can cause the salinity to fall.The cells of the body tissues swell or shrink when the osmotic pressure in the cells is changed.Organisms living in estuaries have adapted to deal with this.Most intertidal organisms can't control the salt in their body.The environment that they evolved in and are adapted to is similar to that of normal seawater.Most intertidal organisms adapt to salinity variations by producing organic osmolytes that keep fluids at the same pressure as the marine environment.
There are a lot of strategies to escape.The first strategy is to make it harder for the predator to eat these organisms.The strategy is applied by algae.It makes them less healthy.The production of chemicals is a second one.Toxic chemicals can be produced all the time, but other chemicals are only produced in response to stimuli.It is possible to have two distinct forms within one life cycle.This can be something.When the predator is present, there is a more delicate form.The predator is absent.The shape of the body can be an evolutionary advantage.Another strategy is bioluminescence.There are many predator that are looking visually.The light is used to warn or scare.Camouflage is a form of protection.This can be either visual or chemical.The prey becomes invisible to the predator by using the same colors as the environment.Chemical camouflage is the act of removing chemicals from the environment.The predator doesn't smell the prey anymore because the smell is masked.Some animals can hide between seaweed and crevasses to escape seabird attacks.Beach crabs bury themselves under the rocks.
Permanent attachment protects organisms from waves.This strategy can't be used by organisms that have to feed themselves.The organisms compromise between mobility and attachment.Different structures can be used for attachment.Bivalves use threads to attach to rocky surfaces or other organisms, but they can also use a foot.Cementation is another one.Bivalves include oysters, scallops, and some other forms.The lower valve was put firmly to the bottom.Reduction or enlargement of certain muscles can be combined.If you want to be protected from waves, you can burrow into the sand or seek shelter in a crevasse.
There are four cliff types that are considered to be composed of 'Hard' rock in the European Union's habitat classification.
Although they can be considered to be included in 1230 above, the 'Soft' rock sea cliffs are not classified.