INTRODUCTION
Ecology is the study of living things interacting with its environment, other species,
and its own kind. It?s a study of all external condition and factors, both biotic ( living ) and
a-biotic ( nonliving ), that affect an organism. To carry out this study, scientists observe
different ecosystems: forests, deserts, grasslands, oceans, or any kind of interaction
between organisms and their surroundings, or with each other, which are called ecosystem
effects.
There are four components within an ecosystem. The a-biotic component, which
determines the types of organisms found there, the producers, the consumers, and the
decomposers. These components cause continual change within the system; the exchange
of materials between the living and nonliving. All organisms living within an ecosystem are
dependent on other living and nonliving organisms for survival and continued growth.
Two basic kinds of processes must occur in an ecosystem: a cycling of chemical
elements and a flow of energy. The flow of energy is from the external environment
through a series of organisms and back to the external environment. To preserve the
system, we must try to conserve the specie or manage the natural resources so that they
are sustainable.
THE OCEAN
The ocean is the great body of water that surrounds each continent. Covering more
than 70 percent of the earth?s surface, it contains 97 percent of all the water on the earth
and is recognized as the earth?s greatest single unifying system.
Studies say that the sea was formed due in part of the continental drift. This theory
states that the continents were once a single great mass of land surrounded with one body
of ocean. The mass broke off into separate continents, slowly drifting apart. That explains
why these continents can perfectly fit together like a jigsaw puzzle. The continental drift
theory was questioned, and later scientist formed a new theory called sea-floor spreading,
which explained the forces that caused the continents to move. And even later, another
theory was formed, called plate tectonics, which combined the two theories together.
The coast is the edge of the land, the beginning of the sea, the brink of the beach, the
rim of the ocean. It?s the conflict between human activities and natural forces that is
widespread along the open shoreline. Humans have begun to inhabit the coastline area.
They find the ocean breeze to be so overwhelming that now, many live in houses along the
coast. It disrupts a delicately balanced environment and imperils the lives and property of
coastal dwellers.
The continental shelf belongs to the land and to the sea. It is the submerged land at
the edge of the continents; the thin strip at the edge of land and the surface of the sea. The
shelf begins at the shoreline and gently slopes underwater to an average depth of 430 feet,
having a width averaging 47 miles. In the Arctic region it extends 750 miles, while in the
Pacific region it measures only 1 mile. It encounters the land, air, bright sunlight, grasses
and trees, rain and snow, rivers and glaciers. The shelf supports every class of creature
from bacteria to mammals, both inland and in the sea.
The sea absorbs all changes and the sea creatures would always find regions of
stability and abundance. It experiences only light, sudden extinction and replacements. The
ocean has gradually accepted new types of life, but also maintained many of the old ones.
All over the world sea levels rise and fall, causing disruptive changes that greatly effects its
surroundings. Nothing can really be done to stop these changes, for its all part of nature.
CLIMATE
The surface temperature of the sea varies depending on where it is located. It?s
about 28 degrees Fahrenheit near the North and 86 degrees near the equator. In the polar
regions the surface seawater freezes and the water in the western tropical pacific is the
warmest of them all. As the currents move in the ocean, they carry warm tropical water
toward the poles. Other ocean movements bring colder, deeper water up to the surface,
which lowers the surface water temperature. The water temperature also varies with
depth. The temperature falls as the depth increases.
Oceans also affect the global cycling of chemical elements. They are a major
storehouse of carbon. It exchanges carbon dioxide with the atmosphere, therefore, playing
a major role in the rate of global warming.
LIFE IN THE SEA
There is an incredible variety of living things living in the ocean. Life in the oceans is
so diverse and abundant that you could find anything from a one-celled organism to the
largest animal that has ever lived – the blue whale. All ocean life can be divided into
groups.
THE PLANKTON
The plankton consists of plantlike organisms and animals that drift with the ocean
currents. They are formed into two groups: the phytoplankton, and the zooplankton. The
phytoplankton consists of several kinds of plantlike organisms. Algae are found mostly
anywhere in the ocean. Certain types have the ability to make their own food by
photosynthesis, and others absorb nutrients from their surroundings. Algae may
reproduce in more than one way. Some split into two or more parts, each part becoming a
new, separate plant. Others produce spores and some reproduce sexually -cells from two
different plants unite to create a new plant. Green plants are mostly found in protected
areas of the continental shelf where their roots can find soil and nutrients. Diatoms and
dinofllagellates are also numerous members. Both are one-celled but the diatom lives in
the colder regions while the dinoflagellate lives in the tropical regions.
The zooplankton consists of many kinds of animal, ranging from one-celled
organisms to jellyfish up to 6 feet wide. These animals live in surface and deep waters of
the sea and must maintain a balance in body fluids and salt levels in their blood. Majority
of zooplanktons are larva?s, copepods and hydromedusa?s. They depend primarily on the
food supply, so the lack of sudden temperature changes in the water does not effect them
greatly. In fact they find the change in their environment rather comfortable.
MARINE ANIMALS
Marine animals are classified as microorganisms, vertebrates, and invertebrates.
Bacteria, a form of microorganism is found throughout the ocean and make up much of
the dissolved matter in the waters. They also help decompose the dead bodies of larger
organisms. It obtains food and oxygen by means of chemosynthesis; a process in which the
organism creates food using chemical nutrients as the energy source instead of sunlight.
The bacteria live in cooperation with animals unique to this region, providing them with
important nutrients.
Animals without backbones are called invertebrates. Lobsters and clams are probably
the most numerous and diverse group. Invertebrates in the ocean range from jellyfish to
worms and crabs.
Vertebrates are animals with backbones. Reptiles, fish, dolphins, whales, shark, and
seabirds can all be found in the sea. The body temperature of reptiles changes with the
temperature of their surroundings. Two kinds found in the ocean are the sea turtle, and the
sea snake. At least 15 species of snakes are found in the tropic. There are more than 350
species of shark found in the sea. Most of these live in coastal waters and only six species
favor the mid-ocean. They are most abundant in tropical and subtropical waters. But still
the three most important mammals that are truly marine are whales, porpoises, and sea
cows because they must remain in the water at all times.
BIOLOGICAL DIVERSITY
Biological diversity can be understood as the variety of life on the Earth, but it
consists of three components. The first component is genetic diversity, the total number of
genetic characteristics. The last two are species diversity and habitat or ecosystem
diversity. The most familiar level of biological diversity is species diversity, or the number
of species living in a particular habitat. It includes three concepts: species richness,
evenness, and dominance. The most species-diverse marine habitats occur in the tropical
waters, and among the tropical areas. We don?t know how many marine species are
around exactly, but we do know that there are far more species on land than in the seas.
THE IMPORTANCE OF THE OCEAN
The ocean is far more useful than just a place for swimming, boating, surfing, and
other fun activities. It serves as a source of food, energy, and minerals, and also as the
transportation route of shipping cargo. Not just that, but it also helps keep the earth?s
climate healthful by regulating the air temperature and by supplying the moisture for
rainfall. If there was no ocean, life would not even exist on our planet.
RESOURCES
Humans have depended on the oceans for food, primarily fish. Humans eat about 60
percent of the fish and the rest is used for livestock feed, and processed into pet food.
Seaweed is eaten because it is high in vitamins and minerals. Algae is used to thicken ice
creams and puddings. Sea salt is another food item taken from the ocean. The crystals are
collected, processed, and packaged. Sea water is also desalted and used by some desert
countries for drinking and irrigation.
The most valuable energy resources from the ocean are petroleum and natural gas, in
which 25 percent of the world?s oil and gas are deposited beneath the sea. Ocean tides
also provide energy. Tidal power facilities use the energy in the rise and fall of the tides to
produce electricity.
Minerals recovered in the ocean include sand, bromide, manganese, and salt.
Copper, iron and zinc can be found deeper in the sea. These minerals are used in creating
medicines and are used in vitamin pills.
POLLUTION
The ocean plays an important role in our global environment. Although we do not
live in the ocean environment, we are the ones who cause the pollution in the waters. And
if pollution constantly occurs, what would become of these great masses of water?
Because of it?s great size and natural chemical processes, the ocean can absorb some
pollutants, but it will not absorb it all. Each type of marine waste- synthetic chemicals, oil,
marine debris, exotic species, sewage- behaves in different ways and present different
threats to ocean resources. Little is known about what happens to these chemicals when
they enter the water stream. But we do know that some accumulate into the tissues and
organs of aquatic animals, others may be excreted. Oil spills are major factors of water
pollution. These spills seriously disrupt marine ecosystems, and the effect of these
disruptions can be long-lasting. These spills are disastrous towards the water and
coastlines; killing both sea and land organisms. The deliberate dumping of waste products
also play a major role. It consists of everything from left over food to chemicals. Plastics
dumped into the sea don?t easily break down. Organisms in the sea either eat the plastic,
which blocks their digestive system, and causes starvation. They can also become
entangled with them, causing them to drown. With all these problems, how do we keep
the marine animals and plants from becoming extinct? What kind of future will the seas
have?
THE FUTURE OF OUR SEAS
The ocean has a huge impact in our lives, and it should continue being that way. But
we do need to make some changes in protecting and keeping the ocean clean. In the past
some marine animals have been thought as pests so they were eliminated. It is also human
use of the coastal zone that is the most serious threat to these animals. Our coasts and
nearshore islands play a vital role in their lives, and new strategies are being processed in
protecting the endangered species.
Steps have been taken in preserving the coastal zones, but we will have to make
difficult choices. Should public access to some beaches be restricted to allow seals and sea
lions an area for hauling out water and breeding? Should fishermen be required to provide
protection for dolphins caught in nets? These are just a few questions that involve hard
decision making. Effects of pollution on these endangered species are also taken into
consideration. New laws came up with the Endangered Species Act, and the Coastal Zone
Management Act. But the problem is that little is done to follow through with them. I feel
that the dumping of anything, either harmless or harmful, into the sea should be forbidden.
This way the ocean has a better chance of staying clean.
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