12:44 A Estuaries Estuaries are semi-enclosed, transition areas Where fresh water mixes with salt water (called brackish). U.S. has nearly 900 estuaries, most of which Wee formed at the end of the last glacial period by rising sea level. Seawater flooded the land and was trapped By barrier island bays, river deltas and earthquakes

Productivity and biomass are extremely high. Species diversity is directly related to fluctuations in the characteristics of estuaries. Salinity – more euryhaline (0-30%) salinity) than stenohaline (30-32%) organisms. Infauna have a more stable environment than the epifauna because mud traps salt. Salt wedges of seawater from under river runoff when the tide comes in. This layers the salinity.

2.temperature – higher in summer; production Is increased. 3. light/silt – primary producers are sea grasses who need good light and low sediment. 4. oxygen – depletion can occur in the mud or In the water column and limits growth 5.Nutrients - come from river runoff and And provides for a detritus based food chain, Inverted energy pyramid increases productivity

12:45 A ORDER SIRENIA - MANATEES Phylum Chordata; Class Mammalia Manatees have been protected By law since 1893 by the state Of Florida and by the Endangered Species Act of 1973 – but only About 1200 still survive There were 5 populations in the order Sirenia

1. West Indian – Trichechus manatus migrates from Brazil to Florida in the ocean, and often spends winter in warm rivers 2.West African Manatee 3.Amazonian Manatee 4.Dugong – found in Australia and Indonesia, Has a tail shaped like a mackerel, only horizontal 5.Stellar Sea Cow – hunted to extinction within 27 6.Years of its discovery in 1741 in the Bering Strait

Manatees are related to the elephant through Biochemistry and external features. 12:45 B The average manatee is 10 feet long and weighs 1000 pounds. Calves are Around 4 ft. and weigh 60 pounds. These herbivores may eat 100 pounds of sea grass a day or 10% of their total body weight. They have large lips to hold plants and replaceable back molars

Manatees like warm shallow water and need fresh water to drink. Their constant eating helps clear navigational channels of water weeds. However, by inhabiting rivers they encounter boats where 50% of their deaths are from human-related boating accidents Many manatees are identified by their propeller scars.

Flicker Waving bye-bye

Mammal characteristics: 1.Whiskers (vibrissae) on snout used to rake plants 2.Mammary glands cows nurse young for a year. The glands are located under the flippers. 2.Live births gestation period, 13 months, produce one calf every 3-5 years. They do not reach sexual maturity until 5-9 years old and may live up to 60 years.

4.Large brain, but poor vision 5.Warm blooded with a 4 chambered heart 6.Stomach has compartments and it ruminates 7.Breathes air – may dive for 20 minutes 8.Marine mammal tail – horizontal 9.Can produce high pitched whistle for communication Because they have no predators, they have no social structure, not territorial. Herds have no leader and no permanent bonds are formed for mating

Adopt me please!!!

West Indian With calf Dugong

The Chondrichthyes or cartilaginous fishes are jawed fish with paired fins, paired nostrils, scales, two-chambered hearts, and skeletons made of cartilage. They consist of several orders:fish Subclass Elasmobranchii (sharks, rays and skates)Elasmobranchii Superorder Batoidea (rays and skates), containing the orders:Batoidea RajiformesRajiformes (common rays and skates) PristiformesPristiformes (Sawfishes)Sawfishes TorpediniformesTorpediniformes (electric rays)electric rays

The shark’s skeleton is entirely composed of cartilage. The skin is covered with tiny scales called denticles. They are similar in structure to teeth and cause the skin to be very abrasive if rubbed in the wrong direction. Most have gray, brown, white or black coloring; Are not camoflauged but may be counter-shaded. 12:46 A CLASS CHONDRICHTHYES Sharks and Rays

Only predators are toothed whales and man. Puffer fish can accidentally suffocate a shark by blocking water from entering the fills resulting in death for both fish and shark. Predation: Efficient, top carnivore of the sick, weak, old and injured. Sharks will not eat Moses sole.

Jaw is lined with rows of teeth like a conveyor belt. Teeth can be replaced ever 24 hours and are used to identify species Jaw can be extended out of the mouth for extra reach

With there diet, it is unusual that they are somewhat resistant to tumors and cancer Mote Marine Laboratory in Sarasota, FL is leading research center in shark immunology Sharks cartilage has not been proven to prevent cancer, and sharks with tumors have been observed

Circulation: 2 chambered heart; cold- blooded Respiration: Gills are located in muscular slits behind the mouth. They exchange oxygen from the water into the blood. Sharks lack swim bladders and must constantly swim upwards to balance their weight. They do sleep

Senses: Vision is good in clear water. Eyelids close from the bottom upwards to prevent injury during an attack. Smell is excellent. Olfactory lobes compose 2/3 of the brain. Sharks can detect a drop of blood ¼ mile away in the water and can determine the Direction of the source. Hearing is excellent. Sound vibrations can be Detected by the lateral line from 3,000 ft away

The electrical impulses of breathing from a prey can be picked up through the pores in the face. Reproduction sexual, internal fertilization. Most sharks have live births – dogfish have 4-10 pups, tiger sharks may have At one time. A few species lay eggs

Attacks on humans are rare, but a surfer in a wet-suit paddling out on a board, may look like a seal to interest a shark

12:46 C Largest shark: The whale is over 50 ft. long. It is a filter-feeder with baleen instead of teeth Most dangerous: Great white sharks are found in temperate and tropical oceans worldwide

Largest Ray: Manta rays may have a 25 foot wide wing span Most dangerous: Sting rays have a venomous stinger in their tail. Shuffle your feet when wading to avoid stepping on it