Zones and Classifications Divisions Intertidal Zone I Habitat

Zones and Classifications Divisions

Intertidal Zone I. Habitat largely consists of rocky shores A. Organisms adapted to tolerate pounding waves, changes in salinity, and periods of exposure to air I. Along the Rocks: A. Barnacles - live attached to rocks i. Close shells when water recedes, trapping a drop of water inside to see them through the dry period until

B. Limpets - live on rocks i. A large, muscular foot allows them to hold tightly to the rocks ii. Release a drop of mucus around the edge of their shell to seal it

III. The Pools: A. Water that remains in a hole during low tide, creating pools of sea water B. Organisms tolerate pounding waves, changes in temperature and salinity i. Sea stars, which cling to rocks with rows of tiny suction cups on their arms

ii. Sea urchins use their spines to dig holes, burying themselves for protection during times of heavy surf iii. Some sea anemones survive for up to two weeks out of water by pulling in their tentacles and folding up into what looks like a round blob

IV. Estuaries: coastal inlets and bays where fresh water from rivers meets salty water from the ocean A. Have brackish water - US wetlands mainly in the form of mangrove forests or salt marshes

B. Mangrove Forests: i. Most along the west coast of Florida ii. Home to roseate spoonbill bird and American crocodile iii. Prop roof of the mangrove tree anchors it to sandy soil, withstanding all but hurricane winds, and protecting the coastline

iv. Trap sediment, creating a protected nursery, rich in nutrients, for many young organisms C. Salt Marshes: i. Most along the east coast of Florida ii. Mud, though smelly, is rich in nutrients iii. Home to many fish, crabs, shrimp, and oysters after they hatch and before they enter the ocean

iv. Mud flats are exposed during low tide, allowing carnivorous organisms to eat the seafood v. Cordgrass - surviving in salt water by releasing salt through small openings in long, narrow leaves

Neritic Zone I. Zone with the most organisms, including most of the world’s fisheries A. Due to the shallow water receiving a steady supply of sunlight, allowing photosynthesis to occur, as well as a steady supply of nutrients washed from land into the ocean

i. Light and nutrients allow algae to grow and serve as a food source and shelter for other organisms ii. Kelp Forest Habitat: large, floating mats of algae a. Most often found in cooler waters above rocky floors b. Possess air bladders, which keep the long, heavy stalks upright in the water

c. Young grey whales hide from predators among kelp while mothers feed d. Sea otters help keep kelp forests healthy, eating the sea urchins that eat the kelp B. Upwelling currents bring additional nutrients from cold bottom to the surface

i. Nutrients support the growth of large numbers of plankton, which feed many fish a. Monterey Canyon fishery off the coastline of California, Grand Banks of the coast of Newfoundland, and Georges Bank off the coast of New England

C. Coral Reef habitat: i. Looks like rock, but actually is made up of living organisms, each tiny coral animal is about the size of an eraser at the end of a pencil ii. Each organism makes a hard structure to surround and protect its soft body, and the hard shell remains, even after the organism dies

iii. New coral animals, called polyps, attach atop the empty shells, causing coral reefs to be built over many years iv. Algae lives in the bodies of the polyps, providing food for them v. Coral polyps need warm temps and sunlight, so they only form in shallow, tropical ocean waters

D. Atoll: forms where the seafloor is sinking and a ringshaped reef surrounded by a shallow lagoon may form i. Begins as a reef close to an island’s coastline, but the coral continues to grow upward, even as the island sinks ii. Soft sand is formed by parrotfish scraping coral off the reef to eat it, and sediment falls to the sea floor

E. Coral reefs protect coastlines from erosion during violent storms, so we need to care for them i. But, dragging boat anchors through reefs harm them, as do divers who break off pieces, even accidentally brushing up against reefs can be harmful ii. Because each reef only grows a few millimeters each year

Open-Ocean Zone I. Only part of this zone receives light, and there are fewer nutrients, meaning fewer organisms live there II. There are three subcategories in this zone A. Sunlit / Surface Zone i. Algae, the base of the food web, grows here animal plankton feeds on it

ii. Orcas, killer whales, are the typical predators in this zone a. Distinctive black and white coloring b. Teeth can be 4 inches long c. Hunt in pods, or groups d. Communicate using sounds and echolocation e. Pregnancy lasts for 17 months

B. Twilight / Transition Zone i. Some light penetrates here, though not enough for photosynthesis to occur - no plants and smaller food supply ii. Organisms have larger eyes to aid sight in low lighting iii. Small, dark, thin organisms with large teeth and jaws are more easily camouflaged in surroundings

C. Midnight / Deep Zone i. Cold, black water under high pressure and with less dissolved oxygen (more dense) ii. Many organisms are bioluminescent, meaning they make their own light - either a chemical reaction or glowing bacteria live on them

a. Light used for finding food, finding a mate, and confusing predators b. Greenland shark: eyes glow in the dark iii. Other organisms use counterillumination, lighting from only underneath, to help them camouflage, as predators from above do not see glowing prey below

iv. Animals feed on: plant matter and algae that falls into this zone, animals that stray into this zone, and each other v. Some migrate up to feed and then return to this zone vi. Even with such a small food supply, hydrothermal vents, cracks in the ocean floor out of which hot water is emitted, support life

a. Water headed by magma and carries gases and minerals to the ocean from the interior of the earth b. Bacteria feed on these nutrients, producing a food source for other organisms c. Giant clams feed on the bacteria d. Tube worms contain bacteria in them, which feed the worms

Categories of Organisms I. Classified into three main categories according to where they live and how they move A. Plankton: tiny plants, animals, and bacteria that float in the water, carried by waves and currents i. Phytoplankton: single-celled photosynthetic plants that perform 3 jobs necessary for life on earth

a. Provide about 70% of the earth’s oxygen b. Regulate levels of carbon dioxide in both the water and atmosphere c. Producers of all food chains and webs d. Consist of consumers (eaters) and decomposers 1. Food chain: single pathway connecting producer with several levels of consumers

ii. Zooplankton: single or many-celled animals that feed on phytoplankton (including tiny young fish and microscopic crustaceans) a. Some can photosynthesize, though most are decomposers, feeding on dead organisms

iii. Nekton: free-swimming animals that can move through the water column (includes squid, most fish, whales, seals, etc. ) iv. Benthos: inhabitants of the sea floor a. Some move place to place (crabs, sea stars, octopi, lobsters) b. Some are stationary (sponges and sea anemones)

II. A second way biologists classify living things is according to: A. Kingdom, Phylum, Class, Order, Family, Genus, Species (King Phyl of Class Ordered his Family to be a Genius Species) B. As relating to the study of marine biology, we look at creatures in the Animal Kingdom

i. Animals: many-celled organisms that feed on other organisms C. Chordata Phylum within the Animal Kingdom: i. Bilateral symmetry, meaning there is a mirror image ii. A “front end” with sense organs iii. A notocord - stiff rod of cartilage - running down the body, developing into the spine, and allowing marine animals to swim through the flexing of a tail

D. Classes under the Chordata Phylum: i. Osteichthyes (bony fish in Greek) make up half the animals in the phylum (parrot fish, barracuda, eel) ii. Chondrichthyes (cartilaginous fish in Greek) have skeletons made of cartilage rather than bone (sharks, rays)

iii. Reptilia (creeping in Greek) - reptiles, usually coldblooded, egg-laying vertebrates with dry, scaly skin (crocodile, alligator, turtle) iv. Mammalia (milk in Latin) - because they are fed by milk from the mammary glands of the mother for a short time; usually give birth to live young

E. Orders under the Mammalia class, Chordata phylum: i. Pinnipeds (winged feet in Latin) classified by: a. Otariidae family: sea lions b. Phocidae family: seals c. Odobentidae family: walruses

ii. Pinnipeds have adaptations for both air and water: a. Large, compact bodies with a layer of fat and covered in fur; spending most of their time in water, typically cold; keep from overheating by putting sand onto their backs, panting, digging holes to expose cooler layers of soil to rest in

b. Sleep in the water, as they often spend months at sea; sleeping for minutes at time, slowly drifting downward in a belly-up position; half of their brain is awake so they can see and escape predators; on land, both sides of the brain go to sleep

c. Can dive to great depths, first emptying their lungs of hair and closing their nostrils and throat cartilage; lungs and trachea collapse and even heart flattens somewhat; remaining air is stored in the bronchioles to prevent decompression sickness (the “bends”); middle-ear squeeze is prevented in seals, probably, by sinuses filling with blood during dives

ii. Sirenia (from the sirens in Greek mythology) a. Slow-moving herbivores found in areas of shallow water along warm coastlines b. Categorized - the two look alike but are very different: 1. Trichechidae family: manatees 2. Dugongidae family: dugongs (sea cows)

c. Their habitats/where they live, tails, nostrils, mouths/snouts, teeth III. Invertebrate Phyla for marine animals: A. Porifera (“pores” in Greek and “to bear” in Latin) i. Sponges, which usually have no body symmetry and never have tissues or organs

B. Cnidarians (“stinging nettle” in Greek) i. Stinging cells capture food and act as a mode of defense a. Polyp: vase-shaped body (anemone and coral) b. Medusa: bowl-shaped body (jellyfish)

C. Echinoderms (“spiny skinned” in Greek) i. Live in salt water ii. Have radial symmetry, meaning they are able to be folded in half and the sides line up iii. Have an internal skeleton and a water vascular system (sea star, sea urchin, brittle star, sea cucumber)