Field investigation of an ecosystem Located km out of Portland; Bridgewater Bay has many secluded rock pool locations that are accessible to biologists for investigation. In this experiment, the aim was to study small sections of a rock poll that contained a distribution of organisms. These organisms that were located were found in the littoral zone of Bridgewater rocky seashore. A littoral zone is made up of a community of aquatic organisms habiting the narrow strip of coast.
The organisms that were studied included periwinkles, sea stars, algae, urchins and different types of sea weed. Periwinkles have shells to reduce water loss and radiation effects. Sea stars also have a thick, impermeable outer layer to reduce radiation effects. Urchins are able to seek small crevices for shelter to reduce the drying effects of the wind. These are some of the structural and behavioral adaptations that rocky-shore organisms have. 1. Each region on the coast has a specific group of organisms that form distinct horizontal bands or zones on the rocks.
The appearance of dominant species in these zones is called vertical conation. It is a nearly universal feature of the interstitial zone. Spiritual zone- When the tide retreats, the upper regions become exposed to air. The organisms that live in this region are facing problems like gas exchange, desiccation, temperature changes and feeding. It is only covered during storms and extremely high tides and is moistened by the spray of the breaking waves. Because of these severe conditions, only a few resistant organisms live here. Common organisms are lichens.
When compared to our transect we found only types of algae and small black inertest. Interstitial zone- The interstitial zone or littoral zone is the shoreward fringe of the sea De between the highest and lowest limit of the tides. Because the interstitial zone is a transition zone between the land and the sea, it causes heat stress, desiccation, oxygen depletion and reduced opportunities for feeding. At low tide, marine organisms face both heat stress and desiccation stress. The organisms that we studied in this zone included periwinkles, sea snails, crabs, sea stars and types of sea weed.
Subtotal zone- The subtotal zone is the region below the interstitial zone and is continuously covered by water. Temperature, water pressure and sunlight radiation remain nearly constant. Organisms do not dry out as often as organisms higher on the beach. They grow much faster and are better in competition for the same niche. More essential nutrients are acquired from the water and they are buffered from extreme changes in temperature. The organisms studied here included mussels, inertest, algae, limpets and some sea urchins. 2.
In the spiritual zone, organisms must have specific adaptations to survive. These organisms are composed of fungi and microscopic algae living together and sharing and energy to grow. The tuning trap moisture tort to b n themselves and their algal cooperative. The algae on the other hand produce nutrients by photosynthesis. Green algae are capable of surviving on the moisture of the sea spray from waves. In the interstitial zone organisms must survive in harsh temperatures. Water loss and heating is determined by the body size and body shape.
When body size increases, the surface area decreases so the water loss is reduced. Shape has a similar effect. Long and thin organisms dry up much faster than spherical organisms. Interstitial organisms can avoid overheating by evaporative cooling combined with circulation of body fluids. Higher-interstitial organisms are better adapted to desiccation than lower-interstitial organisms, because they encounter more hours of sun. The organisms are exposed directly to the air or they are enclosed in burrows. This results in oxygen depletion, so they can’t get rid of their metabolic waste.
In the Subtotal zone, organisms do not dry out as often as organisms higher on the beach. They grow much faster and are better in competition for the same niche. More essential nutrients are acquired from the water and they are buffered from extreme changes in temperature. 3. In the rock pool I studied, there were variations of organisms. I located three small brown crabs, two shrubs of Neptune necklace, around eight black periwinkles and one pod of sea lettuce. 4. The advantages that organisms have when living in a rook pool include shelter from harsh sea conditions and a reliable food source.
They offer better survival chances for animals and plants that need to be submerged all the time. Deep rock pools provide shelter from waves. 5. There are many microcircuits within a rock pool. These habitats include organisms living in rock crevices or in the stem of Neptune necklace. Organisms living in rock crevices have a reduced amount of sunlight meaning they live in cooler enraptures compared to those that live in the light. Neptune necklace must always be in the view of sunlight to carry out photosynthesis.
The micrometers refers to the climate of a small, specific place within an area as contrasted with the climate of the entire area. In our investigation, this is seen when looking at small organisms hiding in small rock crevices within the rock pool. An example of this was when we were looking at small crabs. 6. The organisms located in our rock pool where distributed in a wide range. Not one group of organisms were found together, they were all spread out. Most of the organisms were found amongst the rocks that were located in the rock pool.
You can see this in figure 1. 3. 7. Rock pools are always changing through natural processes such as recruitment, growth, mortality and disturbance by storms. The tides are constantly changing meaning the water would be disturbed, this would result in organisms having to find new rock pools, as the one they were habiting would no longer exist or is submerged under water. This will cause each organisms to Jump from rock pool to rock pool, creating a wide distribution, thus would result in some organisms dying due to lack of food resources or sunlight.
Conclusion: By investigating various rock pools along Bridgewater coast; we were able to identify, measure and describe the biotic and biotic doctors that make up and ecosystem, look at the distribution of selected organisms within a rock pool and analyses the relationship between the ecosystems. By studying these ecosystems, we have learnt that rock pools are made up of a wide variety of organisms and each pool has different types. We also found out that the closer the rock pool is to the ocean the colder the temperature of the water.