IN THE SEA:

1.Seashell
A sea shell is the most universally identifiable part of a creature known as a mollusk. Mollusks (Sea Shells) are invertebrate animals (think of a snail) with an un-segmented, basically symmetrical body, generally consisting of head, foot, visceral hump and mantle.

Mollusks (Sea Shells) are descendants from primitive wormlike creatures inched around in the ooze of primeval seas millions of years ago. As dissolving land masses began to feed salts and chemicals into oceans, the first Mollusks (Sea Shells) digested them and eventually used them to build durable shelters.

Mollusk (Sea Shell)
Mollusk (Sea Shell), common name for members of a phylum of soft-bodied animals are usually with a hard external shell. Familiar Mollusks (Sea Shells) include the clam, oyster, snail, slug, octopus, and squid. The mollusk phylum is the second largest in the animal kingdom, after the arthropods. Earlier estimates of the number of mollusk species sometimes exceeded 100,000, but more recently this figure has been reduced to less than 50,000; the new estimates are incorporated here.

Mollusks (Sea Shells) are highly successful in terms of ecology and adaptation, with representatives in virtually all habitats, but they are most diverse in the sea. Among them are some advanced animals, such as the octopus and squid. Giant squid are also the largest invertebrates, weighing up to 900 kg (1980 lb). Most Mollusks (Sea Shells), however, are about 1 to 20 cm (about 0.4 to 8 in) long, and some are scarcely visible.

The first Mollusk (Sea Shell) fossils appear in early Cambrian rocks, about 600 million years old. Seven of the phylum's classes have living representatives: the wormlike, shell-less aplacophorans, with 250 species; the chitons, with 600 species; the monoplacophorans, with 10 species; the bivalves, such as clams, with 7500 species; the scaphopods, or tusk shells, with 350 species; the gastropods, such as snails and slugs, with 37,500 species; and the cephalopods, such as octopuses and squid, with 600 species. Several fossil classes and thousands of fossil species are also known.

Seashell - Mollusk - General Characteristics
Although few features are common to all Mollusks (Sea Shells), the animals are not readily mistaken for anything else, and all may be treated as variants on a common theme (not to be confused with a common ancestor). A theoretical, idealized Mollusk (Sea Shell) would crawl on a single flat, muscular foot, and the body would have at least a suggestion of a head at one end and an anus at the other. Above the body would be an external shell mounted on a visceral hump containing internal organs.

This shell, secreted by a sheet of tissue called the mantle, is complicated in Mollusks (Sea Shells), being made up of calcium carbonate and other minerals in an organic matrix produced in layers by the mantle at the edge of the shell and under it. An outer layer without minerals, called the periostracum, generally covers it. The shell may be multiple, as in chitons, or paired, as in bivalves. In various Mollusks (Sea Shells) the shell is reduced in size and is sometimes lost completely; in aplacophorans there is no direct evidence that a shell ever existed.

At the posterior end of the idealized Mollusk (Sea Shell) would be a groove or depression called the mantle cavity, with gills to each side of the anus, and openings to the kidneys and reproductive structures. A single pair of gills is common, but many gastropods have only one gill. The cephalopod nautilus has two pairs, and monoplacophorans and chitons have several to many pairs.

Generally the molluscan gut is equipped with jaws and a tongue like structure, called a radula, with teeth on it. Also present are a stomach and a pair of digestive glands. The nervous system consists of a ring of nerves around the anterior part of the gut, with one pair of nerve trunks to the foot and another to the viscera. Ganglia around the gut usually are developed into a brain with various sense organs; the nervous system of cephalopods is as complex and as highly organized as that of fishes. The heart is located at the posterior end of the body; it sends blood into an open system that forms the main body cavity. Associated with the heart is a complex of organs that includes the kidneys and gonads and sometimes other reproductive structures.

Seashell - Mollusk - Scientific classification
Mollusks (Sea Shells) make up the phylum Mollusca. In the class Aplacophora, the body is wormlike. No shell exists, only a tough mantle, and the foot has virtually been lost. The three orders of the class Polyplacophora (chitons) have a series of eight shell plates (valves) in a row and are well adapted to clinging on rocks. The mainly fossil Monoplacophora is now known to have one living genus, Neopilina, discovered in deep water in 1952. The animal has a single flat shell and multiple gills. The class Bivalvia has a shell divided into two valves, and they feed with their gills. As a consequence the head is poorly developed. Members of the class Scaphopoda (tusk shells) have a long, tapered, slightly curved shell and live on sandy bottoms. Members of the class Gastropoda (snails and slugs) are asymmetrical and have only one shell or, as in slugs, are shell-less. The three subclasses of the Gastropoda are the Prosobranchia (mostly marine snails, with three orders), Opisthobranchia (sea slugs and their allies, with eight orders), and Pulmonata (lunged mollusks, largely freshwater and terrestrial, with two orders). The class Cephalopoda is modified by reduction of the foot and shell and the development of arms around the mouth. The two subclasses are Nautiloidea (Nautilus, with four gills and other archaic traits such as an external shell) and Coleoidea (octopuses, squid, and cuttlefish, with two gills and other advanced traits).

Seashell - Mollusk - Behavior
Although vision is poor in most Mollusks (Sea Shells), cephalopods such as squid have eyes with lenses, retinas, and other features remarkably like those of vertebrates. Some gastropods have a well-developed sense of smell and can locate food in the water at a considerable distance. Predators may similarly be detected by the chemical senses and are sometimes evaded by leaping or swimming. Some Mollusks (Sea Shells) exhibit complicated courtship behavior. Advanced cephalopods possess considerable ability to learn from experience.

Seashell - Mollusk - Reproduction
The basic Mollusk (Sea Shell) pattern is to have separate sexes, with sperm and eggs spawned into the water, where fertilization and early development occur. In most Mollusks (Sea Shells) a larval stage follows, in which the larvae swim about for a while and then settle on the bottom and mature; this stage is often modified or absent, however. Fertilization may also be internal, with glands secreting protective coverings around the eggs. Slow-moving creatures such as snails often evolve into hermaphrodites (both male and female), because this doubles the number of appropriate mates. Sometimes the mother protects the developing eggs. Some oysters are remarkable in caring for the young inside the mantle cavity and switching back and forth from being males to being females.

Seashell - Mollusk - Ecology and Importance

Mollusks (Sea Shells) are abundant and hence important in food chains in many habitats. A large number are herbivores or grazers, especially the chitons and many gastropods. Tusk shells and some other Mollusks (Sea Shells) feed on matter deposited on the bottom, whereas most bivalves filter suspended materials from the water. Many gastropods are carnivorous, most of them preying on slow-moving or attached animals. Cephalopods are active predators on larger animals such as crabs. Numerous Mollusks (Sea Shells) are important food sources for humans, but some gastropods damage crops, and others harbor disease-causing parasites.


2.Sea Sponges
Although they may look plant-like, sea sponges are the simplest of multi-cellular animals. A sea sponge is a bottom-dwelling creature, which attaches itself to something solid in a place where it can, hopefully, receive enough food to grow. The scientific term for sea sponges is Porifera, which literally means "pore-bearing." A sea sponge is covered with tiny pores, called ostia, which lead internally to a system of canals and eventually out to one or more larger holes, called oscula. Within the canals of the sea sponge, chambers are lined with specialized cells called choanocytes, or collar cells. The collar cells have a sticky, funnel shaped collar and a hair like whip, called a flagellum. The collar cells serve two purposes. First, they beat their flagella back and forth to force water through the sea sponge. The water brings in nutrients and oxygen, while it carries out waste and carbon dioxide. Second, the sticky collars of the collar cells pick up tiny bits of food brought in with the water. Another type of cell, called an amebocyte, takes the food to other cells within the sea sponge. Sea Sponges are very effective filter feeders, since they are able to capture and eat particles as small as bacteria as well as much larger particles.

The "skeleton" of the sea sponge is composed of tiny needle-like splinters called spicules, a mesh of protein called spongin, or a combination of both. Many sea sponges can only be identified by microscopic examination of the skeleton, which makes certain identification from photographs difficult.

Sea Sponges � Reproduction
Most sea sponges are hermaphroditic (having both sexes in one), but produce only one type of gamete per spawn. (i.e. some play the male role and the other plays the female role, even though they are both capable of playing either role). The sperm is released into the water column by the "male" sponge and finds its way to the "female" sponges, where fertilization occurs internally. Eventually, the planktonic larvae are released from the female sponge and float around in the water column as plankton for only a few days. They then settle down and start growing. The next time the sponges reproduce, they may change sexual roles.

There are many different types of sea sponges in the world's oceans, and, contrary to popular belief, they can be quite colorful and beautiful. Sea Sponges come in two basic types: encrusting or freestanding. Although neither of these names are part of the true classification of sea sponges, it does make it a bit easier to organize them.

Encrusting sea sponges typically cover the surface of a rock in the same manner that moss covers a rock on land. Freestanding sea sponges are a bit more interesting. These sponges have more inner volume compared with their outside surface area and sometimes grow into strange shapes, often reaching gigantic proportions.

Many of the freestanding sponges are well known to most people. For example, nearly everyone has heard of the barrel sea sponge, a large tropical sponge that sometimes grows large enough to fit a whole person inside. Equally well known are the tube sponges of the tropics, coming in nearly every color of the rainbow.

While not all sea sponges are as colorful or as large as those found in the tropics, sponges are an ancient and efficient design, which will probably continue to populate the world's oceans longer than people will populate the Earth.

Famous Sea Sponges
Tube Sponge
(Callyspongia vaginalis)
The Tube Sponge is one of the most common varieties of sea sponge to be found on the reef. It is distinguished by its long tube-shaped growths, and ranges in color from purple to blue, gray, and gray-green. Filtered water is ejected through the large openings on the ends. This is one of the few reef invertebrates that is blue in color.

Vase Sponge
(Ircinia campana)
The Vase Sponge is a common species found in the Caribbean off the eastern coast of Florida. A large bell shape with a deep central cavity characterizes it. This sea sponge grows up to 2 feet wide and 3 feet high. It ranges in color from purple to red and brown, and is found attached to rocks near the sandy bottoms.

Yellow Sponge
(Cleona celata)
This small Yellow Sponge species is commonly found throughout the Pacific coastal waters of the United States. It is found growing in small colonies, and ranges in color from orange to bright yellow. This sea sponge and can be found encrusting rocks on the reef face.

Red Tree Sponge
(Haliclona compressa)
This bright red sponge species is very common throughout the Caribbean Sea. This sea sponge usually grows to a height of about 8 inches. This is one species that is easy to keep and can do relatively well in a home aquarium environment. These sponges require a moderate water flow and dim light to do well.

Common Sea Squirt
(Didemnum molle)
This species of sea squirt is verry common on the reef, and is usually found in deep water. It can be found encrusting the rocks in large colonies. This squirt's leathery bag-like body has a white and gray or brown spotted exterior with a bright green interior. It is sometimes introduced into the aquarium on live rock.

Painted Tunicate
(Clavelina picta)
The tunicates are very similar to sea squirts. They take water in through a large opening where nutrients are filtered out. The water is then expelled through another opening. Painted tunicates are about 3/4 inch long and commonly grow in colonies. They are found in translucent red, purple, and yellow colors.
Skin rash from sea sponges
Sea sponges produce a large variety of toxin, which are present, either on the surface of the sponge or released into the water. The intended function of these toxins is to ward off predators that would otherwise feed on the sponges, but humans can become the unintended targets by handling sponges or by abrading against sponges. Small particles from the sponge surface (spicules) may also dislodge and remain adherent to the skin surface of the unfortunate traveler causing local inflammation.

Symptoms of Sponge Toxins

* Localized area of redness at the site of injury
* Pain
* Tingling at the site of injury (paresthesia)
* Itching (puritis)
* Swelling (localized edema)
* Small raised areas may form (papules) which may go on to form small fluid-filled bumps (vesicles)
* Although less common, systemic symptoms of nausea, malaise, and fainting (syncope) have also been reported.

Treatment of Skin injuries from Sponges

The above listed local reactions may be caused by either the sponge toxin itself or by an inflammatory reaction from the small sponge particles (spicules) that are adherent to the skin.

* Treat the affected area of the skin by applying a vinegar-soaked cloth for about 15 minutes. If you're out in the middle of nowhere and didn't bring any vinegar with you, your own urine will do in a pinch.
**NOTE: if you have a choice in the matter, use urine from a male, because male urine is consider more or less "sterile", females, are more prone to have occult urinary tract infections, and thus using female urine could introduce bacteria into the wound.
* Pat the skin dry with a nonabrasive cloth.
* Pat the skin with the sticky side of some adhesive tape to remove any fine particles (spicules) of sponge that may be present.
* Again soak the area with a vinegar soaked cloth for another 5 minutes.
* If the skin remains inflamed or itchy, you can apply over the counter
* Hydrocortisone cream 0.5% twice day the area for several days until the inflammation subsides.
* If symptoms persist for more that a three days seek medical attention.

Sea Sponges � Medical Research
The World Health Organization (WHO) estimates that 300 million to 500 million cases of malaria occur annually, mostly in developing countries near the equator, and that the disease claims a million lives a year. Tuberculosis infects about a third of the world's population and kills an estimated 3 million people each year.

Several sponge species e.g. Sigmosceptrella and Prianos produce compounds that show great promise as a drug to combat malaria, tuberculosis and other infectious diseases.

Many compounds extracted from sponges have also anti-viral, anti-neoplastic and anti-cancer properties. Back in the 1950s, chemists found compounds in a sponge in the waters off the coast of Florida that wound up as antiviral drugs Acyclovir (Zovirax®), to treat herpes, and Cytarabine (Cytosar®), to treat non-Hodgkin's lymphoma6.

Novartis Pharma AG licensed Discodermolide, a metabolite of the deep-sea sponge, Discodermia dissolute, discovered by Pomponi in the waters off the Bahamas, in 1998 for development as a candidate agent for treatment of cancers.

Halichondrin B, first isolated from the Japanese sponge Halichondria okadai, has shown promise in vivo as a treatment for melanoma and leukemia and is currently in pre-clinical trials at the NCI with material obtained from the New Zealand deep-water sponge Lissodendoryx.

Debromohymenialdisine (DBH), one of several constituents of the common Palauan shallow-water sponge Stylotella aurantium is an interesting druglike molecule that is easily synthesized and is being developed for treatment of osteoarthritis.

Sea Sponges � Biological and Economic Uses
Harvesting of sponges was once carried out by near-naked divers who were reputed to be able to dive to great depths while holding their breath for minutes at a time. Today sponges are harvested by hooking, harpooning in shallow waters, or by skin-diving.

Fossil evidence has led many scientists to believe sponges have remained relatively unchanged since around 500 million years ago. And, the way things are going; they will probably still inhabit the waters of the world long after all evidence of human occupation has gone.


3.Sea Caves
The forces of the sea form the sea-caves, waves seething at the rock face of a coastline, sometimes produce huge caverns, which are typically not very long. They are as long as the water reaches. The existence of this caves is not dependent on the kind of rock. Of course, it helps if the rock is weaker.

Typically sea caves are formed using a weakness in the rocks, like faults, other sediments or weaker layers. Faults in the rock sometimes produce chains of caves; everywhere the fault reaches the seashore.

The coastal erosion opens already existing caves and the water starts to widen the cave. Typically those caves are karst caves. Many karst areas at the coast have caves opening to the sea, where the entrance is widened by the waves. They are often called sea caves, which is only partly true.

Sometimes faults, existing caves or weaknesses in the rock produce a small hole to the surface. The water swashing into the sea caves build up a high pressure inside the cave, which emerges in form of water and air of the small hole. This is called a blowhole. They are found all over the world along the coasts.

The biggest sea cave of the world is Painted Cave on an island belonging to California, U.S.A. The island, called Santa Cruz Island belongs to the Channel Islands National Park. The cave is 402 meters long.

Sea caves are formed by the power of the ocean attacking zones of weakness in coastal sea cliffs. The weak zone is usually a fault, or fractured zone formed during slippage. Another type of weak zone is formed where dissimilar types of rocks are inter-bedded and one is weaker than the other. Typically this is a dike, or intrusive vein of more easily eroded rock found within a stronger host rock. The cave may begin as a very narrow crack into which waves can penetrate and exert tremendous force, cracking the rock from within. Sand and rock carried by waves produce additional erosive power on the cave's walls.

Sea caves rarely have formations like solution caves or lava tubes. Occasionally some flowstone or small stalagmites are seen, formed much as in solution caves. Typically these occur in caves formed in sandstone or basalt.

Sea caves are found all over the world, and may be one of the most numerous type of caves. Areas known for large concentrations of sea caves include the Pacific coast states of the USA (Washington, Oregon, and California, and especially, California's Channel Islands); the Na Pali coast of Kauai; the Greek Isles; and many other places with good solid rock to host the caves.

The Entrance Zone

Sea caves may be explored in several ways: with kayaks or other small boats; by swimming in; or in some caves, by wading or walking if the cave empties out at low tide. When entering a cave where the surf is active, it's best to wear a helmet and study conditions carefully before entering. Remember that the power of waves and swell will be amplified in the cave interior!

Inside a Sea Cave

Inside, a sea cave may be dry or wet, depending on the tide, time or year, or the locale. On the left is a long cave formed along a fault, visible along the sloping wall on the right. The white material on the walls is calcite deposit. On the right is a sea cave floored with just sand, having emptied out at low tide. Colorful marine algae adorn the ceiling.

Life in a Sea Cave

Sea caves may abound with life, both on their walls and floors. Besides the kind of critters seen in normal tide pools, such as anemones, starfish, and sponges, sea caves with dark zones may harbor organisms not commonly seen. In California, the Giant Anemone is normally green because of algae that live inside of it; but in sea caves with dark zones, these anemones may be white because the green algae don�t get enough sunlight to grow.

Famous Sea Caves

Famous sea caves include the Blue Grotto of Capri, and Fingal's Cave on the British island of Staffa (formed in columnar basalt). While spacious inside, they are only moderate in length, neither of them exceeding 250 feet from end to end.

Sea Caves - Painted Cave

Painted Cave, so called because of its colorful rocks, lichens, and algae, is the longest sea cave in the world. Unfortunately it is rather difficult to visit this cave, as there are no regular tours or boat trips. The cave belongs to the Channel Islands National Park and it is allowed to visit it. Of course it is recommended to talk to the rangers first.

It is also possible to kayak to the cave, but it is not recommended. The water currents and waves are rather difficult and the advice of the rangers must be obeyed.

Sea Caves - Merlin Cave

Tintagel Castle is, according to Geoffrey of Monmouth in his History of the Kings of Britain, written 1139, the birthplace of King Arthur, son of Uther Pendragon and Queen Igraine. But this is just legend. There is no evidence to either prove or disprove this story.

According to the archaeologists, this place was a Roman settlement and military outpost, most likely called Durocornovium.

There was some kind of monastic settlement here in the 5th or 6th century, maybe the stronghold of a Celtic king. This would seem entirely possible, as the site would have made an impressive fort and would be almost impenetrable to any enemies attempting to storm the headland.

A finding during a 1998 excavation increased the possibility of a connection with King Arthur: a slate of 20 by 30 cm with the inscription ARTOGNOV, the Latin version of the British name Arthnou. It�s from the 6th century, which is most likely the time when Arthur lived.

This castle fits the legend very well, because of another fact: Merlin's Cave below the castle. Merlin is said to have lived in a cave below the fortress of Tintagel while King Arthur grew up, to be his teacher. In one version of the legend, Merlin found Arthur washed ashore in a cave below the castle.

Below Tintagel Castle a fault or a layer of weaker rocks crosses the Tintagel Head, the castle is built on. It also crosses several other heads to the north and south, as can be seen from the castle. The rocks were eroded by the sea so several irregular sea caves were formed, all in one row.

Two caves are easy to access from the footpath to Tintagel Castle. Both are high enough to walk through, both are going through the whole head to the other side.

Sea Caves - Grotta Azzurra

The Grotta Azzurra is one of the most famous caves of the world! And the reason why it is famous, led to its today name: the blue light shining through the salt water of the Mediterranean Sea and filling the cave with blue reflections.

So the cave is called Grotta Azzurra, which means Blue Grotto. Once, the locals called Grotta Azzurra Gradola after the nearby landing place of Gradola. It was said to be inhabited by witches and monsters and was avoided.

But the cave was well known much earlier by the Romans, as proved by antique statues found in the Grotto. This discovery, the remains of an ancient landing place and the work on an underground tunnel, creates an image of a natural cavern adorned by statues: a nymphaeum built around the intense and brilliant blue of the sea.

Swimming into the grotto is a unique experience. But it is only possible when no boats with visitors are frequenting the cave.

In summer this is just early in the morning and in the late afternoon. Unfortunately this time is not very good concerning the light. The blue color is best, when sunlight shines on the water in front of the cave entrance.

If you visit the cave by boat, you have to lie down on the bottom of it - in order to fit through the narrow natural opening.

The ceiling is hardly high enough to allow the low boats to enter. The waves of the sea make this a bit tricky; the gondolier has to wait for the lowest water between two waves to enter the cave. Then he hurries to drag the boat into the cave on a rope along the wall.

This situation restricts the access to the cave. Boat tours are only possible with calm sea. High waves, which are even with good weather possible, make the cave visit impossible. But cloudy weather is also a drawback. No sun on the water means no blue light in the cave. So the boats will not enter the cave is one of those weather situations takes place. Please consider this when planning a trip to the cave.

Sea Caves - Sea Lion Caves

As the name Sea Lion Caves says, this cave is used by the Sea Lions. The cave itself is a huge sea cave at the dramatic Oregon coastline. In the Sea Lion Caves region lives a herd of 200 Northern sea lions or Steller sea lions.

Steller sea lions are named after Georg Wilhelm Steller, a German naturalist, who accompanied the Russian explorer Vitus Bering in 1741 on his second Alaskan expedition. Steller was the first who studied and classified these animals.

Sea Caves for Seals
It is the use that grey seals make of the remote and extremely exposed sea-caves of Cornwall, Devonshire and Lundy, which makes their lives uniquely different from nearly all other seals of any species living along the margins of any of the world�s oceans.

Even among the grey seals, only very few breed in sea-caves. At the northernmost sites, they breed on the ice. Elsewhere, they breed on remote or uninhabited islands, usually above the high-water mark and beyond the reach of the waves. In such places, the grey seal pups remain largely untroubled by the sea. Only after weaning, the first moult and a brief period of starvation do they venture into the marine environment.

The atmosphere of the sea-caves is entirely primaeval. Most of the sea-caves used by the seals remain inaccessible to man even in moderate sea conditions. Typically, all have deepwater entrances. The waters in the cave entrance are almost always unquiet, as where the sea funnels into the cave entrance, it piles up and quickens between the walls. From outside, it is possible to peer into the gloom of the cave and glimpse or hear the breaking of the cave wave as it turns to surf around some invisible obstacle or upon the beach within.

Then, to venture as a human being into the cave, hurried in by the gathering wave, spilled with the broken water upon the unseen obstruction or upon a shore as yet unknown, can be a fearful time. It recalls something of the atmosphere and the fears, which must have become familiar to our aboriginal ancestors. Fear of the dark. Fear of what the dark might contain, of being trapped by the rising tide, that the waves may increase in size and intensity, of trapping a limb among large, unstable boulders. It is all written indelibly on the subconscious. In the sea-caves, the lettering becomes luminous. In order to study grey seals in such an environment, it is necessary to confirm which sites they use. This might be achieved by seeing them there, by hearing the eerie ululations emanating from the dark mouth of the cave, by seeing their distinctive tracks in the sand or gravel. It is even possible to smell where they have been, a musky, fishy scent lingering for a while after they have abandoned a sea-cave beach. It is essential, therefore, to where sea-caves were found to be used by seals, accurate measurements informed plan views of the cave, with the reach of water at high and low tide being included. In addition, the extent of all bedrock, sand, shingle and boulders was measured, as were the size and depth of all waters within the cave.

This included the reach of the sea at low tide as well as the location and dimensions of any landlocked pools left by the ebb-tide. The height and nature of any potentially awkward obstacles had to be described. At those caves subject to regular scrutiny, the plan view was measured and redrawn at monthly intervals.

These measurements proved conclusively that the substratum the sea-cave floor was highly mobile. Greatest changes would occur at times when heavy seas were running. A boulder beach might become a sandy beach overnight while a landlocked pool might shrink to one half of its former length and one third of its former depth. Such changes would have important implications for the seals, rendering a cave more or less accessible by humans and their dogs, and therefore unattractive to the seals.

There are also important implications for the observer. It is a habit of grey seal bulls, at certain sites during the breeding season, to rest on the bottom of a sea-cave pool. At no other time have they been found to exhibit this behaviour. The eyes of the bull are open, ever watchful. At such times it is rather like discovering a submarine.

A stealthy approach requires that boulders and cubby-holes serve as places of concealment and, where there is no hiding-place, movement be in a prone position along the base of the cave wall. It is essential to appear as little like a human being as possible and to be mindful of the excellence of their senses of smell and of hearing.

In the sea-caves, an interesting web of sounds exists, chief among which are those of the sea, of surf breaking around boulders, racing across the beach or thundering against a wall of rock. Fresh water may drip from the roof into a pool.

Questing rock pipits call as they hit between boulders inside the cave entrance where they forage for food. Nesting shags, feral pigeons, swallows, martins, kestrels and even peregrine falcons all have their voices. There are the sounds the seals make: punctuated breathing, reminiscent of scuba divers, the snoring of the sleepers, a lone and eerie moaning made by one seal toward that other who drew too close, the thin whine of a hungry pup and perhaps a snarl, uttered in threat or fear.


4.Coral Reef and Sea Plants
Coral reefs are one of the best and busiest ecosystems that the earth has. Many types of creatures are found and build their lives around these reefs from the tiniest crustaceans to large creatures such as sharks and turtles, which use the reefs as a feeding ground.

Coral reefs can have different sizes, shapes, and colors. Coral reefs are found in shallow waters of the ocean. Hawaii and Australia are famous for their coral reefs. Some animals that live in coral reefs are starfish, sea urchins, sea anemones, fish, clams, crabs, and sea horses.

Coral reefs are the most luxuriant and complex of all benthic communities. The largest coral reef in the world, the Great Barrier Reef, stretches more than 2,000 km, from New Guinea southward along the east coast of Australia. Corals are colonial animals, and individual coral animals are called polyps. A coral polyp is very similar to a tiny sea anemone, but extracts calcium carbonate from the water and forms a calcareous skeletal cup. Large numbers of these polyps grow together in colonies of delicately branched forms or rounded masses. Most shallow-water coral colonies also have symbiotic algae living in their skeletons. The algae get protection from the coral and, in turn, provide nutrients for the coral polyps. These shallow reef-building corals require warm, clear, shallow, clean water and a firm substrate to which they can attach. Because the water temperature must not go below 18 degrees C and the optimum temperature is 23 degrees C to 25 degrees C, their growth is restricted to tropical waters between 30 N latitude and 30 S latitude and away from cold water currents. Water at depths greater than 50-100 m is too cold for significant secretion of calcium carbonate. Also, reefs usually are not found where sediments limit water transparency. Until recent legislation banned trawling in deep-sea coral beds off the coast of Norway, the existence of deep-sea corals was known only to a handful of scientists and a large number of fishermen. Along the American east coast several deep-water corals, such as the octocoral Primnoa resedaeformis and gorgonian Paragorgia arborea, are common inhabitants of the upper and middle slope faunas in the canyons south of Georges Bank. Deep-water coral colonies can be found in a variety of shapes and forms, from branched trees to conical mounds. Like shallow corals, they require a hard surface to settle on and grow.

Given that the existence of these remarkable species has been known for more than a century, it is striking that almost nothing is known about their biology, population status, the role they play in enhancing local species diversity, and their role as habitat for deep water fishes, including those recently targeted by fishermen. The rarity of encounters with octocorals during recent submersible dives across the shelf of the northeast U.S. suggests that distribution of these species has significantly declined in the past three decades. These slow-growing species may live for centuries, yet be destroyed in seconds by human activities such as trawling and dredging. Trawling with rolling gear has allowed even larger and heavier gear into their rugged canyon homes.

Sea Corals � Symbiosis
The most important part in the building of a coral reef is the symbiotic relationships with zooxanthellae. There are also many natural polymers found within the species that occupy these realms. The most commonly found polymers are protein and cellulose, and cellulose is by far the most abundant.

There are creatures called sea cucumbers, obviously because they look like cucumbers, but are really living animals. They have strong muscles that contain protein.

Sea cucumbers also have a slime trail that they secret. The slime trail is made up of mucopolysaccharides. To better understand this I will break this word down. Muco means mucus, or in other words slime. Polysaccharide is a natural polymer; in fact it is the building block for many things. It is also known as a type of sugar.

Polysaccharide can be broken down into glucose molecules, which can be found in virtually all of the food we eat!

Another creature that lives around coral reefs and also secretes a mucopolysaccharide is a nudibranch. The nudibranch uses this secretion to find prey or possibly attract a mate. They are also known to contain Glucosaminoglycans (GAGS) that is used in medical applications for treating joint, ligament and tendon conditions. Chondroiten, a Glucocaminoglycan substance, is thought to have uses in treating arthritis.

Among the many creatures living within coral reefs are plants. These plants provide photosynthetic operations. This just means that they use sunlight to make oxygen, which has to be really interesting since they are under the water. They also contain cellulose. Cellulose is not the only polymer found in plant cell walls. There are other materials, but they have not been researched completely enough to explain all of their potential uses.

The group of organisms called Sea anemones is similar to the jellyfish only these creatures don't move around as much. They mostly stay in one place, such as a coral reef, but they do have the ability to move. Sea anemones, such as Metridium senile have layers of mesoglea that are a source of collagen, a type of protein. Plus their inside core is made up entirely of protein.

Coral looks like a flower but can sting like a bee. Thousands of coral polyps live in a colony to form a coral reef. Reefs are like underwater versions of rain forests full of fantastic shapes and structures and life. The builders of the reefs, the coral polyps, have radial (rotational) symmetry. In this lesson, students will learn about radial symmetry and then have an opportunity to build symmetrical designs using pattern blocks. The lesson will take about an hour but the post viewing symmetry activities can continue as long as interest is sustained. Students will learn about coral reefs while listening to a narrator read a New England Aquarium book, Dive to the Coral Reefs. Students will discover scuba diving as a way of exploring the coral reefs. They will get a chance to "pretend" dive with a partner, check dive equipment before diving, and then explore the wonderful underwater world of the reefs!

Sea Coral Research
In recent years scientists have discovered deep-sea corals and/or coral reefs in Japan, Tasmania, New Zealand, Alaska, California, Nova Scotia, Maine, North Carolina, Florida, Colombia, Brazil, Norway, Sweden, UK, Ireland and Mauritania. Because research submarines and remotely operated vehicles suitable for studying the deep sea are few and expensive to operate, scientific investigation of these remarkable communities is in its very early stages. But it is increasingly clear that deep-sea corals usually inhabit places where natural disturbance is rare, and where growth and reproduction appear to be exceedingly slow. Deep-sea corals and sponges may live for centuries, making them and the myriad species that depend on them extremely slow to recover from disturbance.

Sea Coral Conservation
Unfortunately, just as scientists have begun to understand the diversity, importance and vulnerability of deep-sea coral forests and reefs, humans have developed technologies that profoundly disturb them. There is reason for concern about deep-sea oil and gas development, deep-sea mining and global warming, but, at present, the greatest human threat to coral and sponge communities is commercial fishing, especially bottom trawling. Trawlers are vessels that drag large, heavily weighted nets across the seafloor to catch fishes and shrimps. Scientific studies around the world have shown that trawling is devastating to corals and sponges. As trawlers become more technologically sophisticated, and as fishes disappear from shallower areas, trawling is increasingly occurring at depths exceeding 1,000 meters.

It is not too late to save most of the world's deep-sea coral and sponge ecosystems. It is commendable that nations including Australia, New Zealand, Canada and Norway, which have already taken initial steps towards protecting some coral and sponge ecosystems under their jurisdiction. United Nations and appropriate international bodies should establish a moratorium on bottom trawling on the High Seas. Similarly, individual nations and states should ban bottom trawling to protect deep-sea ecosystems wherever coral forests and reefs are known to occur within their Exclusive Economic Zones. They should prohibit roller and rock hopper trawls and any similar technologies that allow fishermen to trawl on the rough bottoms where deep-sea coral and sponge communities are most likely to occur. They should support research and mapping of vulnerable deep-sea coral and sponge communities. It is expected of them to establish effective, representative networks of marine protected areas that include deep-sea coral and sponge communities.


5.Sea Cucumber
The shape of the sea cucumber is an elongate cylinder with a mouth and anus on opposite sides. It has a worm like body that lays parallel to the ocean's floor. The external surface of the sea cucumber is very soft because it is an invertebrate (without a spine), it also has five rows of tube feet that are all along the length of their body. Around the mouth there can be more than ten ambulacral appendages, branched, oral tentacles, and ambulacral feet that can be on all sides.

The internal structure of sea cucumbers consists of an alimentary canal, which is a long tube that runs from the mouth of the sea cucumber at the forward end to the anus, which is at the posterior end of the sea cucumber. The posterior end of the sea cucumber is enlarged and becomes narrower towards the anterior end. There are two types of respiratory organs; they are the respiratory trees and the curvier's organ. These organs function as a pair to pump water through the system. The body wall of the cucumber consists of powerful longitudinal muscles running along the radii and transverse muscles in the inter-radii.

Sea Cucumber - Reproduction
Sea cucumbers tend to be having separate sexes. Spawning behavior tends to be seasonal. Many sea cucumbers on the Great Barrier Reef spawn during the mass spawning events seen in November. During spawning, sea cucumbers travel to the top of reef structures and release their gametes into the surrounding currents. A range of developmental modes is seen among sea cucumbers. Development via feeding larvae (Planktotrophy) or non-feeding larvae (lecithotrophy) occurs in a large number of species. In others, embryos and larvae may be brooded by the female. The feeding larva of sea cucumbers (when present) is very distinctive and is called an auricularia larva. It swims for about 10-40 days before settling on the bottom and metamorphosing into a baby sea cucumber.

Sea Cucumber - Distribution and Habitats
The sea cucumbers are found in most oceans and in all depths. Some move over the bottom of the sea, some swallow sand and or mud and others catch small organisms. Most of the sea cucumbers live near rocks, corals or seaweeds. Although most of the sea cucumbers live among the sea grasses some do live in the mud or in the sand.

Predators
Sea cucumbers have tough skins that probably lessen the risk of predation. However, they do face the problem of being eaten by large fish. Sea cucumbers, however, don�t just lie around and let this happen. They have a number of neat tricks. The first is that some sea cucumbers have the ability to throw up their entire digestive systems! They do this to distract the predator that generally focuses on the yummy bits thrown up with the stomach. The sea cucmber then crawls away and regrows its entire digestive tract over the next couple of months. Amazing huh! The second trick is that some other sea cucumbers have fine sticky threads that they are able to eject out their bottoms when trouble brews. These threads are called Cuverian Tubules and are as sticky as any glue you can buy in a shop. These threads are thrown out over the potential predator who gets them stuck all over it. This usually makes the potential predator desist from attacking the sea cucumber.

Sea Cucumber as Food

To prepare the sea cucumber after it is collected, the internal organs are removed, and dirt and sand are washed out of the cavity. It is then boiled in salty water and dried in the air to preserve it. When readied for use in making food, it is softened in warm water and then boiled.

According to analysis by principles of traditional Chinese medicine, the sea cucumber nourishes the blood and vital essence (jing), tonifies kidney qi (treats disorders of the kidney system, including reproductive organs), and moistens dryness (especially of the intestines). It has a salty quality and warming nature. Common uses include treating weakness, impotence, debility of the aged, constipation due to intestinal dryness, and frequent urination. Sea cucumber is traditionally served in the form of a soup.

From the nutritional viewpoint, sea cucumber is an ideal tonic food. It is higher in protein (at 55%) than most any other food except egg whites (at 99%), and it is lower in fat than most foods (less than 2%). For nourishing essence and blood in persons who suffer from emaciation, it is combined in soup with pork. For impotence, frequent urination, and other signs of kidney deficiency, sea cucumber is cooked with mutton. For yin and blood deficiency, especially manifesting as intestinal dryness, sea cucumber is combined with tremella (yiner, the silvery tree mushroom).

For modern applications, the dried or extracted sea cucumber is useful as a nutritional supplement, prepared in capsules or tablets. The fully dried material has a protein concentration as high as 83%. From the Western medical viewpoint, the reason sea cucumber is valuable is because it serves as a rich source of the polysaccharide condroiton sulfate, which is well-known for its ability to reduce arthritis pain: as little as 3 grams per day of the dried sea cucumber has been helpful in significantly reducing arthralgia. Its action is similar to that of glucosamine sulfate, which is useful for treating osteoarthritis. Sulfated polysaccharides also inhibit viruses; there is a Japanese patent for sea cucumber chondroitin sulfate for HIV therapy.

Economical Uses and Biological Significance

Although about 200 species of sea cucumber have been recorded from Australian waters, only a few large tropical species were collected for processing as b�che-de-mer. The process itself involved boiling the body in salt water, gutting it, smoking it and finally sun-drying it. The finished product is hard, dry and a fraction of the weight of the live animal. Although there is still considerable demand for b�che-de-mer throughout much of Asia, there is very little commercial fishing for it in Australia today. The local industry wound down in the late 1940s largely because of lesser demand and poor prices.

There are a number of animals that live with sea cucumbers. Tiny polychaete worms that look almost identical to the skin of the sea cucumbers crawl across the skin and are probably responsible for cleaning the surface of the sea cucumber in return for getting a place to live. There are also some very strange relationships. There is a little fish that lives in the back end of sea cucumbers. Again, in return for being a cleaner, the fish gets a pace to live and something to eat.

The many varieties and species of Sea Cucumbers around the world are an essential part of the ecosystem of the ocean. They are both predators and prey to many different organisms. Their main food source is plankton (incredibly small drifting organisms in the sea,) they also provide food for certain Sea Stars. Because they are living animals, they are part of the ecosystem and will become a food source one way or another. As mentioned previously, the most fascinating characteristic of the sea cucumber is their ability to eviscerate their guts, thus providing food for their predators while still being able to survive themselves. The ability to provide food for other organisms labels the Sea Cucumber as a provider (of food) in their marine environment.

Chinese studies reveal that sea cucumbers also contain saponin glycosides. These compounds have a structure similar to the active constituents of ginseng, ganoderma, and other famous tonic herbs. Additional Chinese studies indicate anticancer properties of both the sea cucumber saponins and the polysaccharides.

Sea cucumbers are harmless. Unfortunately, they are good to eat and are considered a delicacy by many cultures. Did you know that a ton of dried sea cucumbers will fetch as much as a million dollars in some countries? This has lead to uncontrolled exploitation of sea cucumbers around the world. In some places they have almost completely disappeared. Several projects (e.g. Solomon Island) are currently underway to start growing sea cucumbers in aquaculture farms to try and reduce the fishing pressure on sea cucumbers. Sea cucumbers are seriously endangered in many parts of the world. As all other marine creatures, it is essential to protect both the Sea Cucumbers themselves, and their environment to ensure the continuing survival of diversity in the oceans.

Parastichopus Californicus
Common Name: California Sea Cucumber
The Parastichopus Californicus can be identified by their prominent, stiff, conical papillae (cone-shaped spines). They also have tube feet on their ventral side. They are dark red or brown in color and have an approximate length of 40 cm (16 inches). They are found on the Northwest coastal waters from Alaska to Isal Cedros in Baja, California. They live in a sub tidal habitat, as well as feeding on detritus and small organisms. They are currently the only Sea Cucumber harvested in British Columbia, however only every three years to control population decline. They are eaten for their five muscle strips and body wall. One California Sea cucumber is shown below, this one is currently being kept at the Bamfield Marine Station and we have nick named him "Mike."

Cucumaria Miniata
Common Name: Burrowing Sea Cucumber
This bright orange sea cucumber has ten branched tentacles and five rows of tube feet. They are 25 cm (10 inches) long and live along the western coast from Gulf of Alaska to Avila Beach in California. They live in rocky areas with lots of crevices to hide from their predators, particularly the Sea Star Solaster Stimpsonii. They live in the intertidal zone all the way out 24 m (80 ft) or so. Their branched tentacles are used to collect drifting food. The photograph below shows a Burrowing Sea Cucumber, along with sea grass, its favorite environment.

Eupentacta Quinquesemita
Common Name: White Sea Cucumber
These Sea Cucumbers cannot completely contract their tube feet. They have ten yellow or white-branched tentacles, eight long and two short. They are ten cm (four inches) in length and live both off the coast of Japan, as well as the Sacramento Reff, Baja, California. They like rocky places ranging from lower intertidal to 15m off shore. Their tentacles remain retracted during daylight hours. A White Sea cucumber is shown below, lying on a