Ocean+period+8

**Ocean period 8**
[] **Facts/characteristics of the Biome:** This ocean zone is from the surface of the sea down to a depth of about 200 meters. As you begin your descent you see that the ocean is absolutely teeming with life forms of every sort. From the microscopic plankton and diatoms that give the ocean its murky color and limits visibility, to bony fishes of every shape and size, to starfishes, and warm-blooded, oxygen-breathing mammals. ** Epipelagic Zone  ** - The surface layer of the ocean is known as the epipelagic zone and extends from the surface to 200 meters (656 feet). It is also known as the sunlight zone because this is where most of the visible light exists. With the light come heat. This heat is responsible for the wide range of temperatures that occur in this zone. ** Mesopelagic Zone  ** - Below the epipelagic zone is the mesopelagic zone, extending from 200 meters (656 feet) to 1000 meters (3281 feet). The mesopelagic zone is sometimes referred to as the twilight zone or the midwater zone. The light that penetrates to this depth is extremely faint. It is in this zone that we begin to see the twinkling lights of [|bioluminescent] creatures. A great diversity of strange and bizarre fishes can be found here. ** Bathypelagic Zone  ** - The next layer is called the bathypelagic zone. It is sometimes referred to as the midnight zone or the dark zone. This zone extends from 1000 meters (3281 feet) down to 4000 meters (13,124 feet). Here the only visible light is that produced by the creatures themselves. The water pressure at this depth is immense, reaching 5,850 pounds per square inch. In spite of the pressure, a surprisingly large number of creatures can be found here. Sperm whales can dive down to this level in search of food. Most of the animals that live at these depths are black or red in color due to the lack of light. ** Abyssopelagic Zone  ** - The next layer is called the abyssopelagic zone, also known as the abyssal zone or simply as the abyss. It extends from 4000 meters (13,124 feet) to 6000 meters (19,686 feet). The name comes from a Greek word meaning "no bottom". The water temperature is near freezing, and there is no light at all. Very few creatures can be found at these crushing depths. Most of these are invertebrates such as basket stars and tiny squids. Three-quarters of the ocean floor lies within this zone. The deepest fish ever discovered was found in the Puerto Rico Trench at a depth of 27,460 feet (8,372 meters). ** Hadalpelagic Zone  ** - Beyond the abyssopelagic zone lies the forbidding hadalpelagic zone. This layer extends from 6000 meters (19,686 feet) to the bottom of the deepest parts of the ocean. These areas are mostly found in deep water trenches and canyons. The deepest point in the ocean is located in the Mariana Trench off the coast of Japan at 35,797 feet (10,911 meters). The temperature of the water is just above freezing, and the pressure is an incredible eight tons per square inch. That is approximately the weight of 48 Boeing 747 jets. In spite of the pressure and temperature, life can still be found here. Invertebrates such as starfish and tube worms can thrive at these depths. **Location of the Biome**: 

The [|ocean] holds the largest of Earth’s biomes. It covers 70% of the planet’s surface.

**Consumers/Animals living in the biome** :
 * Coelacanth**:oldest fish in the sea.
 * Fangtooth**:Looking like it just swam out of a horror movie is the amazing **fangtooth**. Known scientifically as Anoplogaster cornuta, this menacing creature haunts **the deep** waters of many of the world's oceans.
 * Snipe Eel:** The **snipe eel**, known to science as Nemichthys scolopaceus, is a rather peculiar looking fish. It has a long body, up to five feet in length,
 * Sixgill Shark**:The **sixgill shark**, or Hexanchus griseus, is a common species of deep water shark. It is also one of the largest sharks that feed on prey other than plankton.
 * Firefly Squid**: Of all the [|bioluminescent] life forms in the deep sea, there is one tiny creature who's light show puts all others to shame. This is the **firefly squid**, sometimes called the sparkling enope squid.



**Producers/Plants living in the biome:**


 * [[image:http://www.mrsmacdonald.net/sealife.jpg width="180" height="237" align="middle" caption="Animals of all shapes and sizes live throughout the layers of the ocean"]] Marine animals are divided into three groups: zooplankton (those that float), nekton (those that actively swim) and benthos (those that live on or in the ocean bottom). ||

Marine animals are divided into three groups: zooplankton, nekton, and benthos. Zooplankton are drifting animals and are usually small, however, they can grow to fairly large size. For example, the jellyfish and the Portuguese man-of-war are examples of larger types of zooplankton which are unable to propel themselves effectively and are therefore at the mercy of either wind or current. The zooplankton population also includes some temporary members such as fish eggs or larval forms of organisms which may grow up and leave the planktonic community to join the nekton or benthos.

Nekton are the free swimmers and probably the largest portion of familiar animals found in the ocean belong to this class. Common fishes, the octopus, whales, eels and squid are all examples of nekton. The nekton category includes a number of very diverse creatures. The whale, dolphin and porpoise are certainly very different from codfish or trout because whales represent sea mammals whereas cod are true fishes.

The third type of sea animal spends its entire life on or in the ocean bottom. This group of marine animals is called the benthos. It includes lobsters, starfish, various worms, snails, oysters and many more. Some of these creatures, such as lobsters and snails, may be able to move about on the bottom but their lifestyle is so bound up with the ocean floor that they are unable to survive away from this environment.

** Dominant (keystone) species in the biome: **


 * [[image:http://www.reef.crc.org.au/discover/images/ClownfishAIMS-web_000.jpg width="160" height="153" caption="Clownfish"]] || Some baby anemone fish can swim at 9.5 body lengths per second just 24 hours after hatching (the Olympic swimmer, Ian Thorpe, can only swim at 2 body lengths per second). The oldest fish on the Great Barrier Reef would probably be a [|red bass] which can live to more than 50 years old. The biggest fish on the Great Barrier Reef would be the visiting whale shark which can grow to about 12m long. Five of the seven species of [|coral trout] occur on the Great Barrier Reef. Coral trout change sex as they grow � they start life as females and become males as they get larger. The average length at sex change is 42 cm. Common coral trout can live for about 16 years. All fish have ear bones called [|otoliths]. They grow every year and can be read in the same way as tree rings. Scientists can use these bones to find out how old the fish was, and even what its habitat was like. The seahorse is the slowest horse, and takes about 2.5 days to travel one kilometre. ||

Corals are colonies of made up of tiny animals called polyps. Hard corals have polyps with 6 tentacles, or multiples of 6 tentacles. Soft coral polyps have 8 tentacles. The oldest coral on the Great Barrier Reef would be a Porites sp. and is probably about 1,000 years old. Old colonies of this species are the size of a small room. These corals grow at about 1 cm in height per year and their skeleton reflects the weather conditions at the time of the growth. Hence large corals which are hundreds of years old can provide information about water temperature and rainfall patterns that pre-date European settlement. Tiny algae called zooxanthellae live in the flesh of most corals. The algae photosynthesise and transfer energy to the coral. Therefore, coral reefs (which are built mostly by these corals) are generally confined to shallow waters because like other plants, the algae require light to survive. Coral spawning happens on only a few nights of the year. Corals release their eggs and sperm into the water, where they will either meet and be fertilised, or become food for other Reef animals. **Average Temperature Range for the biome:**

The water in this region is very cold (around 3° C), highly pressured, high in oxygen content, but low in nutritional content. The abyssal zone supports many species of invertebrates and fishes. Mid-ocean ridges (spreading zones between tectonic plates), often with hydrothermal vents, are found in the abyssal zones along the ocean floors. Chemosynthetic bacteria thrive near these vents because of the large amounts of hydrogen sulfide and other minerals they emit. These bacteria are thus the start of the food web as they are eaten by invertebrates and fishes.

** Annual Precipiation for the biome: **

[[image:biomesduff/era40_arctic_prec_ann.gif]]
Total rainfall in 2004 was 57 inches with 56% of the annual total (32.4") accumulating in the four months of October, November, December and January. It is not uncommon to have 1" to 3" of rainfall accumulate in a short period of time. The average annual rainfall for past 8 years is 67.8"