Harbor Seals
Harbor seals are marine mammals that have spotted coats in a variety of shades from silver gray, black to dark brown. They reach 5 to 6 feet in length and weigh up to 300 pounds. Harbor seals are dimorphic, with the male being slightly larger than the female. They are true, or crawling seals, which means they have no external earflaps. True seals also have small flippers, and move on land by flopping along on their bellies. They breathe at the surface and hold their breath while diving. They can dive to 1,500 feet for up to 40 minutes, although their average dive lasts 3 to 7 minutes. Their scientific name basically means 'sea calf' or 'sea dog.' This nickname is fits them well, as these seals closely resemble a dog when their head is viewed at the surface of the water.
When the harbor seal pup (baby seal) is born, it has a coat that closely resembles the adult coat. Some have a longer, softer white or gray coat (lanugo) when born, but they shed that coat within about 10 days.
Harbor seals are found across the Northern Hemisphere in both the Atlantic and Pacific Oceans. In the northeast Pacific, they range from Alaska to Baja California, in Mexico. They live near-shore coastal waters and frequent sandy beaches, mudflats, bays, and estuaries. Some harbor seals even live in certain areas of Europe such as Finland.
The total harbor seal population in the northeast Pacific is estimated to be 330,000, in California the estimated population was 40,000, and in Europe the estimated population was 6,000 in 1997.
Harbor seals spend about half their time on land and half in water, and they sometimes sleep in water. They may sleep most of the day on the beach to keep safe from the predators that hunt them, and go into the water only a couple of times each day to hunt for food. Harbor seals don?t have a permanent place to live but they usually are found in small groups, but sometimes occur in numbers of up to 100 to 500. Their average life span is around 25 years, although some have lived for over 30 years. However, males seem to live shorter lives, probably because of the added physical stress of fighting during mating season.
The Harbor Seal is both a predator and a prey. They are very vital in the food chain. Seals eat a lot of fish and prevent over population, and they are a great source of food to animals such as orca whales, great...
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... high tolerance to carbon dioxide in the tissues, they have the ability to store large amounts of oxygen in the muscle tissues, and they have the ability to make their lungs collapse when air is expelled before they dive, which helps to prevent the bends. To help see in dark and murky waters, the seals have special adapted eyes that make them able to see in such conditions. To guard against very cold water temperatures, harbor seals maintain a thick layer of fat beneath their skin, giving them a thick sausage shape. To make the harbor seals less noticeable to predators, their coats sometimes blend in with the rocks or sand they?re lying in. To help them find food easier, they have a keen sense of smell. Without these adaptations, who knows if the Harbor Seal would still exist today.
Works Cited:
*Hanan, D. (1999). Pacific Harbor Seals. Alolkoy Publishing Co. PP 12-59.
*King, J. (1983). Seals of the World. British Museum (Natural History) and Cornell University Press. PP 20-26.
*Internet: Sea World web site.
www.seaworld.org/animal_bytes/harborsealab.html April 20, 2001
*Internet: The Marine Mammal Center web site.
www.tmmc.org/harborsl.htm April 20, 2001
The California sea lion is a pinniped. A pinniped is a carnivorous aquatic mammal of the order Pinnipedia. Sea lions, like all other pinnipeds, have nostrils that they can voluntarily close while diving in the water. Inside the nose of a sea lion are bones called turbinate bones. When the sea lion inhales, these bones moisten and warm the air and stop inhaled particles from going into the trachea or the lungs. In the back of the sea lion’s nose, there are ethmoidal turbinate bones which give it its keen sense of smell. The nasal septum of a sea lion separates the nasal cavity into left and right halves.
The nature of the long- necked seal is very shy and they have retiring behavior, the features and geography of the Loch Ness fully support the animal’s reluctance and timid actions. The animals are more likely to appear on warmer days, this also results in the appearance of people which can account for the recorded findings in Scotland. The speed of these animals, over twenty knots, can also account for why their identity can be mistaken for other animals or why there are so many theories (Shovlin 28). A Weddell seal, a species of Antarctic seal, have been known to hyper oxygenate their blood stream for long dives, up to half an hour below the freezing ice. This relates to the long-necked seal because it illustrates how they could have survived the freezing temperatures of the loch for so long, and with being below the surface it accounts for the rare sightings (Shucker). The mystery of Loch Ness is slowly, but surely being uncovered by new scientific findings and the piecing together of well- known
One of the things this company claims is that the killer whales actually live longer in their care. According to the website Sea World of Hurt, this is completely false, killer whales in the wild have a similar life span to humans, they can live from anywhere to 50-100 years. Held captive, these animals hardly live past twenty-five years. In the wild, an orcas dorsal fin is straight, which is the way it should be. In captivity, you will mostly see their dorsal fins flopped over or completely collapsed.
Orcinus orca is the scientific name for the massive marine mammal. Orcas are not rare, but have declining numbers in some areas (Martin.) Orcas are found from the Artic Ocean to the Antartic Ocean. (Britannica) They belong to the Delphinidae, or dolphin family, which is the largest of their species. Female orcas grow to be at the most 15 feet, and weigh up to 4 tons, but the males can grow as large as 20-30 feet, and weight up to 8 tons. (Martin) The color of the orca is white in some spots, black on the majority of the body, and gray just behind the dorsal fin. It is white on the chin, belly and the eye. The white patch above the eye is usually mistaken for the eye, and may confuse their prey, but acts as a camouflage for the eye. The name “killer whale” makes people tend to believe that this is a viscious man-eating mammal, yet it is one of the most shrewd, docile and playful species of the marine mammals. The orca is sexually mature at 10-15 years of age, much like humans, which is 12-13 years of age. They tend to mate year round, and is able to have a calf every two years. It is interesting to know that lactation of the mother lasts 12 or more months (Wynne.) The life expectancy of orcas is 45-50 years of age.
Orca whales are the largest members of the dolphin family. Orcas are very curious creatures, they like to sky hop, which is when they poke their heads out of the water and look around, and they can also dive to as much as a hundred feet. These social animals live in pods and stay with them for their whole lives. They are so family oriented that they can may sleep together in a tight circle and have synchronized breathing. Orcas can grow up to thirty-two feet and can weigh nine tons. They typically eat five percent of their body weight and are amazing hunters. The lifespan of an orca in their natural habitat is about fifty years. This lifestyle for them is wonderful because they can swim as far as they want to and are free. Orcas should not be held captive because the capture process is dangerous, it is not good for their health, and their trainers are at risk. Free Willy. Dir Simon Wincer. 1993.Video. Warner Bros Home Video
Jefferson, T. A, M. A. Webber, and R. L. Pitman. (2008). Marine Mammals of the World, A Comprehensive Guide to their Identification. Amsterdam, Elsevier. p. 241-244.
Today, in addition to the bottlenose dolphins, the Navy program includes sea lions and white beluga whales. The sea lions have excellent hearing and can dive much deeper than dolphins. They are trained for marking mines and retrieving torpedoes or practice mines, all while being more efficient than human divers. The white beluga whales dive deeper than the sea lions to recover inert torpedoes and are currently on loan from Sea World.
Killer whales have a recognizable coloration with a black back and white belly. They also have a noticeable o...
Although they are fish, seahorses are not great swimmers. In fact, they prefer to rest in one area, sometimes holding on to the same coral or seaweed for days.
...ls, it does not only affect the size of seal population but also it affects the Inuit people because it decreases the amount of seal oil and seal pelts being produced, and it also causes species that depend on baby seals to have a loss in their diet too. The seal population may not seem like it is diminishing however at this rate, the baby seals are faced with the possibility of becoming extinct. If the seal hunt was to continue at this frequency and with global warming also playing a major role into the death of seals as ice glaciers are melting, the population of seals can become extinct within the next few decades. Each year, there are hundreds of thousands of baby seals killed by the Canadian government and even though, the government is making profit from this industry, they failed to consider how is poses a significant long-term threat to their whole specie.
The wide paws prevent sea ice from breaking by distributing weight while walking. Their paws allow them to pull a 600 pound seal out of its breathing hole (Rosing, 20). The webbed feet result in making polar bears, unlike other bear species to be considered as marine mammals along with seals, sea lions, walruses, whales and dolphins (Polar Bear). According to Rosing, Polar bears are excellent swimmers and have been known to swim up to six miles an hour and as far as 60 miles at a stretch. Bears paddle with their front feet and steer with their back feet.
Orcas, or killer whales are majestic giants of the sea. They are actually the largest type of dolphin. They have long black bodies with distinct white patches near their eyes. A killer whale can be up to 32 feet or more in length, and weigh up to 12,000 pounds. Females are a bit smaller, but live longer (Gorman). The name “killer whale” apparently came not because it is a vicious whale, but because it preys on whales. They do not have any natural predators, and they are considered the “top dog” of the ocean. Not even the great white shark stands a chance against these superb killers. “Unlike sharks, killer whales are cautious hunters, sometimes spending hours harassing a 1,000-pound sea lion so it can easily be drowned” (Francis). Orcas use many hunting tactics that are unique to their species, which is what makes them invincible.
The history of warships goes back in history to the ancient Greeks and Romans. Their ships were called galleys. The galleys were powered by oarsmen. The galley had a sharp point in the front for ramming other ships. In the A. D. 700's, the Vikings invented the long ship. It weighed less than the galley and was stronger and more seaworthy. The Viking's controlled the seas until the 1000's. By the 1500's most warships carried guns, and later became heavily armed ships.
The Orca is irrefutably one of the most fascinating animals in the ocean. Killer whales, or Orca, are aquatic mammals which live in almost every ocean on Earth. Their black and white color pattern makes them one of the most easily recognized animals on Earth, and their intelligence and strength makes them apex predators. Though the killer whale sounds like an aggressive animal, Orcas are very social and are very sensible in what they kill.
Did you know in the world there are more than 90 species of whales, dolphins, and porpoises? (WDC) The dolphin is a very important animal to the ocean and there are many different types to discover. In order to learn about dolphins, it is important to discuss where they live, their appearance, and what they eat. Some helpful words to understand are “dorsal fin”, a dorsal fin is the top pointed fin on the dolphins back, “flippers”, a flipper is a flat fin that dolphins use to swim, and “echolocation” is a tool dolphins use to find food by sounds bouncing off of objects (dictionary.com).