denise
08-12-2008, 05:10 PM
Marine Habitats
When viewed from outer space, oceans and seas cover more than 70 percent of our planet’s surface, giving it its common name, the ‘Blue Planet’. Humans have been exploring the ocean environment with primitive snorkels and far-flung boat expeditions for many centuries, but the advance of depth sonar (1914), SCUBA (1943), and Remote Operated Vehicles (in 1950’s) has given us a bigger insight into our Ocean world than ever thought possible.
The study and knowledge of our oceans stretches across all disciplines of science:
· Marine Biology is the study of plants, animals and microbes and their interaction within the ocean
· Marine chemistry, is the study of the chemical attributes of the ocean and how the ocean chemically interacts with the atmosphere.
· Marine geology is the study of structure of the ocean floor
· Marine physics is the study of the physical aspects of the ocean; temperatures, waves, tides, currents, and how light, sound and radio waves behave in the ocean.
Our knowledge of the oceans is far from complete, even with our ongoing advances and we still know very little, in fact we know more about the surface of the moon than we know about our oceans! It is important that our ocean explorations and studies continue, as the ocean plays a crucial role in regulating the well being of our planet as a whole.
What we do know, is that this vast blue expanse hosts an immense amount of lifeforms and biodiversity, distributed throughout many different habitats. Here is a summary of the basic ocean habitats that we know of:
Coral reefs
Coral reefs are found throughout warm water oceans, covering more than 100,000 sq miles, generally between the latitudes of 30˚ North and 30˚ South. Recently deep water cold corals have been discovered, but for the most part coral reefs thrive in shallow (< 100 feet), clean, clear water. North America's only living coral barrier reef starts at Palm Beach and extends southward to the Dry Tortugas, 60 something miles west of Key West. Most of the coral reef is 30-60 feet deep, and most is within six miles seaward of the coastline.
These vitally important ecosystems, the rainforests of the sea, certainly live up to their name….Coral reefs cover less than 1% of the Earths surface, yet they provide shelter and sustenance for more than 1 million different species! Coral reefs are home to more than 25% of all known marine fish species, 32 of the 34 Animal Phyla are found on coral reefs compared to only 9 Phyla in tropical rainforests!
Mangroves
Mangroves are an ecosystem consisting of various types of trees and shrubs, that protect the coast from erosion, storms, and tsunamis. Their enormous root system dissipates wave energy, and provides a strategic safe area that is constantly replenished with nutrients.
This unique ecosystem links the terrestrial and ocean world, providing a life support system through rich feeding and safe nursing areas, for a multitude of species. Hundreds of fish, crustaceans and invertebrates are supported by mangroves, along with a variety of land animals including birds, mammals, reptiles, and insects.
Mangroves grow along coastal tropical areas, commonly between 25˚ North and 25˚ South. In the continental USA, mangroves are only found in Florida and Texas. Most of Florida’s 1200 sq miles of mangroves are along the Southern coast, extending downwards through the Florida keys, and up as far as far north as Cedar Key on the Gulf Coast, and as far north as the Ponce de Leon Inlet on the Atlantic coast of Florida.
Seagrass beds
Seagrass beds are large shallow expanses of underwater flowering plants, often closely associated with coral reefs, mangroves, salt marshes and other marine habitats. They provide habitats for many other species of plants and animals, they act as nursery areas to the larger ocean, filter coastal waters and help to dissipate wave energy. They are important food recourses to many endangered species including manatees, dugongs and green sea turtles.
Large seagrass beds occur in Australia, Alaska, the Mediterranean, Africa, and the Caribbean. In Florida, sea grass beds are one of the most productive and important habitats in shallow marine ecosystems. They cover more than 5,000 km2, from Florida Bay to Biscayne Bay, and the Keys.
Kelp Beds
Kelp beds occur worldwide in temperate and polar coastal oceans, in a depth range of 18 to 90 feet, thriving along coastlines that have a temperature of about 68 degrees Fahrenheit. Kelp is a type of brown algae, that use their root-like structures (holdfasts) to anchor onto rocky bottoms. Long strands of kelp grown from these holdfasts towards the surface, each having a gas bladder at the end to keep the plant upright. Dense stands of these brown algae are called kelp forests.
Kelp forests are one of the most productive and dynamic ecosystems on Earth. They provide a unique 3D habitat for countless marine species, that use it as a source of food and/or shelter……a limited list includes whales, sea otters, jellyfish, dolphins, sea urchins, rays and sharks. The most well known kelp forests are the kelp forests off the coast of California.
Sandy shores
Sandy shores are tidally influenced areas of coastline, made up of tiny grains of sand or crushed shells and rock. Regular wave action deposits sand and other sediments regularly on sandy shores, and move their contents around, constantly shaping and reshaping the beaches.
When seen from above, sandy beaches seem to be devoid of life, but in reality, the play host to a great diversity of life, that is merely hidden from our view, buried in the sand or even living between the grains of sand! Larger animals also use sandy beaches for shelter, for example in Florida, sandy beaches of west Palm Beach are the nesting grounds for sea turtles.
Rocky Shores
Rocky shores are exposed areas of bedrock on the coastline that are tidally influenced. These are very tough places to live in, and have many extremes in environmental conditions. Rocky shores are exposed to two low and two high tides per day. Thus, water is not always available, and when it is, it varies from fresh (rain) to saline, and dry salt as the area drys out between tidal cycles. Frequent wave action can dislodge animals and plants and sweep them away. The temperature range varies constantly, from hot midday sun, to cold nighttime temperatures, again on a daily basis.
However, for those animals and plants that can adapt, the rocky shore offers many advantages; these areas are constantly replenished with fresh nutrients from the sea, wastes, eggs and larvae are quickly dispersed. The rocky shore also offers a variety of micro-habitats for their residents. As a result, many species have adapted to this area, and rocky shores are richly inhabited.
Rocky shores are divided into the splash zone (only covered by water only during storms), the intertidal zone, (which lies between the high and low tidal extremes), and the low tide zone (constantly covered by water). Each of these different areas has a different pattern of life forms, each with their own adaptations to live in their area.
Estuaries
An estuary is a semi-enclosed coastal area, connected to the sea, that has one or more streams or rivers flowing into it. They are usually silty or heavily sedimented areas, this material is constantly carried in from land or washed in from offshore. They have brackish water (mix of fresh and salt).
Estuaries are among the most productive ecosystems. As rivers and streams drain into them, they bring large amounts of nutrients from upstream. Plants use these nutrients to manufacture food, and start food chains. A wide variety of land and sea birds, marine fish and invertebrates make estuaries their home. Some major estuaries in Florida are in Charlotte Bay and Tampa Bay on the west coast, and Lake Worth and the end of the St Johns River on the East coast.
Open Ocean
The open ocean begins where the continental shelf drops off to the deep sea floor. Unlike richly productive near-shore waters, the open ocean is far less fertile, and productivity drops further and further away from shore. Long river-like currents flow through the open ocean, and these influence everything from the variety and amount of marine life to the weather that we have here on land!
The open ocean also has distinct “zones” down through its depths. The top sunlit surface water is called the photic zone, this meets the dimly lit “twilight zone” underneath (mid level), and gradually fades into the “dark zone”, a place of almost complete darkness and crushing pressures.
Some parts of the open ocean are teeming with life, while others are almost lifeless. Despite the vastness of the open ocean, approximately only 10% of all marine species live here. The species that do live here are the world’s biggest, fastest, deepest diving, and well traveled. They include many species of fish, whales, dolphins, porpoises, sharks, plankton and floating seaweed.
Deep sea
The deep sea is the lowest layer of the ocean, a dark, cold environment, where little or no light penetrates. Despite the lower extreme in temperature, crushing pressures, and the scarcity of food, life is abundant in the deep sea, by far the largest of all habitats on Earth. Far from the reaches of sunlight, no plants survive, so photosynthesis is not possible, instead food chains rely on organic matter known as marine snow, falling into the depths from above. Animals here are mostly bottom feeders such as starfish, anemones, sponges, and sea cucumbers. Scavengers like crabs and lobsters make their living by decomposing carcasses that fall down from the upper layers.
The only light in the deep sea is area is produced by biolouminescence, a chemical reaction in a creature's body that creates a low level light. Not all deep sea animals are bioloumincent, instead most have other adaptations to their dark environment. Some deep sea fish have large eyes to capture what little light exists. Most are equipped with a powerful sense of smell and well adapted tactile (touch) organs to compensate for lack of vision. Deep sea animals have adapted to pressure by developing bodies with no excess cavities, such as swim bladders, that would collapse under the intense pressure. Their flesh and bones are soft and flabby, which helps them withstand the crushing pressures.
Some parts of the sea bed in the deep sea have vents and fissures that result from tectonic plate activity. These vents release rich minerals which are consumed by the bacteria, and consequently form self-sustaining food chains deep within the dark depths.
Hydrothermal Vents
A hydrothermal vent is a deep volcanic spring, usually located along mid-ocean ridges, where super hot (650F), mineral laden water pours out from underneath the ocean floor's surface. This water does not boil because it is under so much pressure from the tremendous weight of the ocean above, but when it meets the surrounding cold seawater (35F) it cools quickly, and the minerals in the fluid settle around the vent opening creating chimneys or “black smokers”. Some vents produce "white smokers". Their color depends on the minerals present in the fluid. Some chimneys have been known to grow as tall as 2 miles! Their growth continues as long as there is a supply of hydrothermal fluid.
This hydrothermal fluid is used by chemosynthetic bacteria, to make food and form the base of vent food webs. All hydrothermal vent animals depend on the bacteria in one way or another for food. Some tiny animals such as amphipods and copepods feed directly on the bacteria. Other larger animals, such as grazers (limpets and snails), scavengers (shrimp and crabs), and predators (fish and octopi) feed on these animals and form a complex food chain that is endemic to hydrothermal vents.
As well as feeding directly on bacteria, some vent animals (tube worms and giant clams) form a symbiotic (mutual) relationship with food producing bacteria. The bacteria live inside the animals exchange a built-in food supply for protection and shelter from the elements.
The first hydrothermal vent was discovered in 1977 along the Galapagos Rift in the Pacific Ocean. Since then, many more have been discovered in the Atlantic, Indian, and most recently, the Arctic Ocean, at depths varying from 4,500 to 12,000 feet.
Cold seeps
A cold seep is an area of the sea floor where abundant amounts of hydrogen sulfide, iron, manganese, silica and methane seep out from deep within the rock layers. These energy rich fluids are used by bacteria to make food (chemosynthesis), which in turn is shared with other animals. Large gutless tubeworms, mussels and clams form a symbiotic relationship with these bacteria, they get a constant high volume of food from the bacteria, and in return they offer protection and house the tiny bacteria. Recently the "ice worm" was discovered at a depth of 1500 feet in a cold seep in the Gulf of Mexico. It excavates and lives in burrows around cold seeps. It is believed that the ice worms graze around the cool seeps, feeding on nutrient rich sediments and bacteria.
Animals at cold seeps grow in great abundance since energy is never in short supply. In fact, cold seep tubeworms may be the oldest (150+ years!) and fastest growing marine animals in the world. Cold seeps were discovered in 1984 on the Florida Escarpment in the Gulf of Mexico at a depth of 9,000 feet. Since then many more have been discovered. The deepest known cold seep community is located in the Sea of Japan at a depth of 19,000 feet.
These communities are unique as they operate completely independently of light energy (all other food webs in the world use sunlight to form their building blocks). Along with hydrothermal vents, cold seeps are being studied as the possible sites where life first began on Earth!
When viewed from outer space, oceans and seas cover more than 70 percent of our planet’s surface, giving it its common name, the ‘Blue Planet’. Humans have been exploring the ocean environment with primitive snorkels and far-flung boat expeditions for many centuries, but the advance of depth sonar (1914), SCUBA (1943), and Remote Operated Vehicles (in 1950’s) has given us a bigger insight into our Ocean world than ever thought possible.
The study and knowledge of our oceans stretches across all disciplines of science:
· Marine Biology is the study of plants, animals and microbes and their interaction within the ocean
· Marine chemistry, is the study of the chemical attributes of the ocean and how the ocean chemically interacts with the atmosphere.
· Marine geology is the study of structure of the ocean floor
· Marine physics is the study of the physical aspects of the ocean; temperatures, waves, tides, currents, and how light, sound and radio waves behave in the ocean.
Our knowledge of the oceans is far from complete, even with our ongoing advances and we still know very little, in fact we know more about the surface of the moon than we know about our oceans! It is important that our ocean explorations and studies continue, as the ocean plays a crucial role in regulating the well being of our planet as a whole.
What we do know, is that this vast blue expanse hosts an immense amount of lifeforms and biodiversity, distributed throughout many different habitats. Here is a summary of the basic ocean habitats that we know of:
Coral reefs
Coral reefs are found throughout warm water oceans, covering more than 100,000 sq miles, generally between the latitudes of 30˚ North and 30˚ South. Recently deep water cold corals have been discovered, but for the most part coral reefs thrive in shallow (< 100 feet), clean, clear water. North America's only living coral barrier reef starts at Palm Beach and extends southward to the Dry Tortugas, 60 something miles west of Key West. Most of the coral reef is 30-60 feet deep, and most is within six miles seaward of the coastline.
These vitally important ecosystems, the rainforests of the sea, certainly live up to their name….Coral reefs cover less than 1% of the Earths surface, yet they provide shelter and sustenance for more than 1 million different species! Coral reefs are home to more than 25% of all known marine fish species, 32 of the 34 Animal Phyla are found on coral reefs compared to only 9 Phyla in tropical rainforests!
Mangroves
Mangroves are an ecosystem consisting of various types of trees and shrubs, that protect the coast from erosion, storms, and tsunamis. Their enormous root system dissipates wave energy, and provides a strategic safe area that is constantly replenished with nutrients.
This unique ecosystem links the terrestrial and ocean world, providing a life support system through rich feeding and safe nursing areas, for a multitude of species. Hundreds of fish, crustaceans and invertebrates are supported by mangroves, along with a variety of land animals including birds, mammals, reptiles, and insects.
Mangroves grow along coastal tropical areas, commonly between 25˚ North and 25˚ South. In the continental USA, mangroves are only found in Florida and Texas. Most of Florida’s 1200 sq miles of mangroves are along the Southern coast, extending downwards through the Florida keys, and up as far as far north as Cedar Key on the Gulf Coast, and as far north as the Ponce de Leon Inlet on the Atlantic coast of Florida.
Seagrass beds
Seagrass beds are large shallow expanses of underwater flowering plants, often closely associated with coral reefs, mangroves, salt marshes and other marine habitats. They provide habitats for many other species of plants and animals, they act as nursery areas to the larger ocean, filter coastal waters and help to dissipate wave energy. They are important food recourses to many endangered species including manatees, dugongs and green sea turtles.
Large seagrass beds occur in Australia, Alaska, the Mediterranean, Africa, and the Caribbean. In Florida, sea grass beds are one of the most productive and important habitats in shallow marine ecosystems. They cover more than 5,000 km2, from Florida Bay to Biscayne Bay, and the Keys.
Kelp Beds
Kelp beds occur worldwide in temperate and polar coastal oceans, in a depth range of 18 to 90 feet, thriving along coastlines that have a temperature of about 68 degrees Fahrenheit. Kelp is a type of brown algae, that use their root-like structures (holdfasts) to anchor onto rocky bottoms. Long strands of kelp grown from these holdfasts towards the surface, each having a gas bladder at the end to keep the plant upright. Dense stands of these brown algae are called kelp forests.
Kelp forests are one of the most productive and dynamic ecosystems on Earth. They provide a unique 3D habitat for countless marine species, that use it as a source of food and/or shelter……a limited list includes whales, sea otters, jellyfish, dolphins, sea urchins, rays and sharks. The most well known kelp forests are the kelp forests off the coast of California.
Sandy shores
Sandy shores are tidally influenced areas of coastline, made up of tiny grains of sand or crushed shells and rock. Regular wave action deposits sand and other sediments regularly on sandy shores, and move their contents around, constantly shaping and reshaping the beaches.
When seen from above, sandy beaches seem to be devoid of life, but in reality, the play host to a great diversity of life, that is merely hidden from our view, buried in the sand or even living between the grains of sand! Larger animals also use sandy beaches for shelter, for example in Florida, sandy beaches of west Palm Beach are the nesting grounds for sea turtles.
Rocky Shores
Rocky shores are exposed areas of bedrock on the coastline that are tidally influenced. These are very tough places to live in, and have many extremes in environmental conditions. Rocky shores are exposed to two low and two high tides per day. Thus, water is not always available, and when it is, it varies from fresh (rain) to saline, and dry salt as the area drys out between tidal cycles. Frequent wave action can dislodge animals and plants and sweep them away. The temperature range varies constantly, from hot midday sun, to cold nighttime temperatures, again on a daily basis.
However, for those animals and plants that can adapt, the rocky shore offers many advantages; these areas are constantly replenished with fresh nutrients from the sea, wastes, eggs and larvae are quickly dispersed. The rocky shore also offers a variety of micro-habitats for their residents. As a result, many species have adapted to this area, and rocky shores are richly inhabited.
Rocky shores are divided into the splash zone (only covered by water only during storms), the intertidal zone, (which lies between the high and low tidal extremes), and the low tide zone (constantly covered by water). Each of these different areas has a different pattern of life forms, each with their own adaptations to live in their area.
Estuaries
An estuary is a semi-enclosed coastal area, connected to the sea, that has one or more streams or rivers flowing into it. They are usually silty or heavily sedimented areas, this material is constantly carried in from land or washed in from offshore. They have brackish water (mix of fresh and salt).
Estuaries are among the most productive ecosystems. As rivers and streams drain into them, they bring large amounts of nutrients from upstream. Plants use these nutrients to manufacture food, and start food chains. A wide variety of land and sea birds, marine fish and invertebrates make estuaries their home. Some major estuaries in Florida are in Charlotte Bay and Tampa Bay on the west coast, and Lake Worth and the end of the St Johns River on the East coast.
Open Ocean
The open ocean begins where the continental shelf drops off to the deep sea floor. Unlike richly productive near-shore waters, the open ocean is far less fertile, and productivity drops further and further away from shore. Long river-like currents flow through the open ocean, and these influence everything from the variety and amount of marine life to the weather that we have here on land!
The open ocean also has distinct “zones” down through its depths. The top sunlit surface water is called the photic zone, this meets the dimly lit “twilight zone” underneath (mid level), and gradually fades into the “dark zone”, a place of almost complete darkness and crushing pressures.
Some parts of the open ocean are teeming with life, while others are almost lifeless. Despite the vastness of the open ocean, approximately only 10% of all marine species live here. The species that do live here are the world’s biggest, fastest, deepest diving, and well traveled. They include many species of fish, whales, dolphins, porpoises, sharks, plankton and floating seaweed.
Deep sea
The deep sea is the lowest layer of the ocean, a dark, cold environment, where little or no light penetrates. Despite the lower extreme in temperature, crushing pressures, and the scarcity of food, life is abundant in the deep sea, by far the largest of all habitats on Earth. Far from the reaches of sunlight, no plants survive, so photosynthesis is not possible, instead food chains rely on organic matter known as marine snow, falling into the depths from above. Animals here are mostly bottom feeders such as starfish, anemones, sponges, and sea cucumbers. Scavengers like crabs and lobsters make their living by decomposing carcasses that fall down from the upper layers.
The only light in the deep sea is area is produced by biolouminescence, a chemical reaction in a creature's body that creates a low level light. Not all deep sea animals are bioloumincent, instead most have other adaptations to their dark environment. Some deep sea fish have large eyes to capture what little light exists. Most are equipped with a powerful sense of smell and well adapted tactile (touch) organs to compensate for lack of vision. Deep sea animals have adapted to pressure by developing bodies with no excess cavities, such as swim bladders, that would collapse under the intense pressure. Their flesh and bones are soft and flabby, which helps them withstand the crushing pressures.
Some parts of the sea bed in the deep sea have vents and fissures that result from tectonic plate activity. These vents release rich minerals which are consumed by the bacteria, and consequently form self-sustaining food chains deep within the dark depths.
Hydrothermal Vents
A hydrothermal vent is a deep volcanic spring, usually located along mid-ocean ridges, where super hot (650F), mineral laden water pours out from underneath the ocean floor's surface. This water does not boil because it is under so much pressure from the tremendous weight of the ocean above, but when it meets the surrounding cold seawater (35F) it cools quickly, and the minerals in the fluid settle around the vent opening creating chimneys or “black smokers”. Some vents produce "white smokers". Their color depends on the minerals present in the fluid. Some chimneys have been known to grow as tall as 2 miles! Their growth continues as long as there is a supply of hydrothermal fluid.
This hydrothermal fluid is used by chemosynthetic bacteria, to make food and form the base of vent food webs. All hydrothermal vent animals depend on the bacteria in one way or another for food. Some tiny animals such as amphipods and copepods feed directly on the bacteria. Other larger animals, such as grazers (limpets and snails), scavengers (shrimp and crabs), and predators (fish and octopi) feed on these animals and form a complex food chain that is endemic to hydrothermal vents.
As well as feeding directly on bacteria, some vent animals (tube worms and giant clams) form a symbiotic (mutual) relationship with food producing bacteria. The bacteria live inside the animals exchange a built-in food supply for protection and shelter from the elements.
The first hydrothermal vent was discovered in 1977 along the Galapagos Rift in the Pacific Ocean. Since then, many more have been discovered in the Atlantic, Indian, and most recently, the Arctic Ocean, at depths varying from 4,500 to 12,000 feet.
Cold seeps
A cold seep is an area of the sea floor where abundant amounts of hydrogen sulfide, iron, manganese, silica and methane seep out from deep within the rock layers. These energy rich fluids are used by bacteria to make food (chemosynthesis), which in turn is shared with other animals. Large gutless tubeworms, mussels and clams form a symbiotic relationship with these bacteria, they get a constant high volume of food from the bacteria, and in return they offer protection and house the tiny bacteria. Recently the "ice worm" was discovered at a depth of 1500 feet in a cold seep in the Gulf of Mexico. It excavates and lives in burrows around cold seeps. It is believed that the ice worms graze around the cool seeps, feeding on nutrient rich sediments and bacteria.
Animals at cold seeps grow in great abundance since energy is never in short supply. In fact, cold seep tubeworms may be the oldest (150+ years!) and fastest growing marine animals in the world. Cold seeps were discovered in 1984 on the Florida Escarpment in the Gulf of Mexico at a depth of 9,000 feet. Since then many more have been discovered. The deepest known cold seep community is located in the Sea of Japan at a depth of 19,000 feet.
These communities are unique as they operate completely independently of light energy (all other food webs in the world use sunlight to form their building blocks). Along with hydrothermal vents, cold seeps are being studied as the possible sites where life first began on Earth!