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SEA OTTERS Life and Death

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1 SEA OTTERS Life and Death

2 Major Objectives Sea otter evolution
Relationship between sea otter and man Sea otter’s role as a keystone predator Sea otters and kelp forests Sea otter futures Which came first? The otter or the kelp forest? Sea otter ancestors occur around 20 mya Today’s otter evolved around 2 mya Kelp starts to develop around 20 mya 20 million years of evolution only to come into contact with the new species human beings a few thousand years ago and face the possible end to an epic journey Sea otters may go extinct because of humans

3 Evolution of today’s sea otter
2 million years ago…Enhydra lutris

4 Humans like sea otters Only once otters were hunted to near extinction a hundred years ago did people began to care about the animal Now they are treasured by most, protected revered, adored They are still killed, though, without mercy and with complete disregard to their right for existence by a murderous few Still in a lifelong struggle with humans

5 In the beginning… The sea otter’s range was massive compared to today’s range Consisted of all of the Northern Pacific (Japan to Russia to Alaska to the West coast of North America all the way down to midway along the Baja peninsula Roughly otters alive by the time mass genocide began to occur

6 A simple and complex life
Food, shelter, breed, avoid being eaten Before human/otter contact, sea otters lived a life as simple as it was complex Sea otters only inhabit areas where there are kelp forests Specific kelp forest habitats will only exist while the sea otter is there Sea otters have always lived a highly vulnerable lifestyle while being the controlling factor for a highly diverse ecosystem Only predators: bald eagles (otter pups), shark, perhaps the rare killer whale

7 Sea otters eat a lot of meat
Sea otters eat meat, and lots of it They are the only mammal of the Order Carnivora to be found in the sea They have an extremely fast metabolism requiring a daily intake of 30% or more of their body weight Learned innovative behavior is key to successful food gathering (complex brain allows for problem-solving, tool-using, tool-making – tools consist of everything from rocks to past prey shells to, in recent years, broken bottles) Padded paws and strong teeth allow for grasping wiggly prey or biting through hard material (able to rip open beer cans in which octopus hide

8 Work of a keystone predator
Favorite foods: urchins, abalone, mussels, octopus, fish, snails, etc. Sea otters eat the animals which, if not preyed upon, would eat the kelp Kelp forests provide a home for hundreds of different organisms (fish, invertebrates, mammals, birds) and act as nursery for many others

9 Keystone predator in action

10 Otters love urchins There are kelp forests because there are otters
In a kelp forest community where sea otters live, there is never a huge abundance of sea urchins nor are there many large specimens Without the impact of otter predation, sea urchins are witnessed to explode in body and pop. size, eating away the kelp stalks and creating an “urchin barren” All that is left is ground covered with coralline algae and thousands of urchins

11 Kelp forest stability Human hunting changes the kelp forest structure
Alaskan kelp forests are characterized by less diversity than k.f. of lower latitudes Otters are the only predator found in A. k. f., unlike other coasts For millions of years, kelp forests maintained a stable life The intervention of human hunting has resulted in catastrophic changes

12 The first otter kill 8-9000 ya, otters become an easy target
Otters live along coastal regions, and so are an easy target for hungry humans It is presumed otters were hunted by first colonies of the otter’s entire range In Alaska, first colonization est. to have occurred ya Alaskan otters estimated to have begun being hunted roughly 2500 ya Evidence comes from bones in indigenous middens Otters first hunted merely for meat and warmth These boats are seen on Kodiak island, 1888 Throwing boards were used to send harpoons in farther with more force.

13 Russians get lost in Alaska
Russians discover Alaskan wildlife in 1741 Russians sail in North Pacific, starving and lost, find a treasure of wild life living off Alaska islands Captain Berring discovers otters as well as now extinct giant sea cow in Commandeer islands and is excited by new food supply in 1741 Sea cows, which used to exist in same range of otters, now exist in a few thousand numbers only around a few islands, later to become known as Berring Islands Bering, a Danish explorer, was in the service of Russia when he discovered the Bering Strait and Sea in In 1741 he discovered Alaska and traded with the First Nations peoples, collecting large numbers of sea otter pelts which could be sold for very high prices in China. For this reason Russia established trading posts in Alaska. Alaska remained Russian territory until it was sold to the United States in 1867

14 Sea cow is easy meat Last few thousand steller’s sea cows on the planet have a hard time of it Steller’s sea cow is easier to kill than sea otter Sailors take advantage of sea cow’s close proximity to shore, extreme fearlessness and casual nature in order to wade out from shore and hack away at will Meat is really good to eat and there are many of them Slaughtered to extinction 27 (1768) years later due to fearlessness of man Sign of things to come for sea otter

15 Sea otter genocide Otters previously only hunted for warmth and food
Previously, otters only hunted for necessity Russians desire the rich coat because of greed Russians prevent indigenous Alaskans from hunting sea otters out of necessity any longer Russians force Alaskans to catch and kill otters so the pelts can be taken home

16 The massacre continues
Demand for otter fur grows throughout the world Posts are set up almost everywhere in otter’s range for hunting, from Baja peninsula to Japan Even when otters are killed and the fur is not as beautiful as others, hunters discover ways to dye the fur darker

17 The process of skinning
The fleshy pieces still attached to the fur are scraped off delicately so as not to cut into the fur The otter is trapped or clubbed, killed The fur is stripped from the otter’s body, hunters taking as much as possible with as delicate care in order to make sure every inch of fur is perfect Stretching fur out, it can reach 3 meters square, more than half the length of otter’s body The skin is oiled down The fleshy pieces still attached to the fur are scraped off delicately so as not to cut into the fur Otter fur is smoked and dried The fur is prized all over the world beyond any other fur for its rich lustrous dark color and extraordinary warmth There are estimated to be over 100 million hairs on an otter coat and these are all treasured by the humans who wear them

18 What the otters used fur for…
Otters can spend 50% of daylight hours cleaning their fur Otters used their fur for same purpose – to keep warm Every cuticle on the otter’s skin has 60 hairs 20 mm. long coming out along with one longer, thicker guard hair Otters can spend 50% of daylight hours cleaning their fur Fur must remain dry in water -20 below zero in order for the otter to stay alive

19 A daily life of peril Otters can die from the cold
If fur is not constantly cleaned, it gets wet – when cold water touches otter’s skin, the otter will quickly die of hypothermia Otters constantly clean their fur and blow into it in order to build a layer of air underneath fur which acts as insulation Otters do not have layer of blubber, only fur Once fur gets wet, they can also quickly drown The fur that keeps the otter alive is the same thing for which they were exterminated

20 The last of the otters 150 years after excessive hunting, people realize a mistake has been made Sea otter population drops from previous to 3 thousand by late 1800s – only found in Alaska, gone from rest of range People start to realize that the otter may go extinct after nearly 150 years of excessive hunting and decide to protect it 1911 – International Fur Treaty is established, making it illegal to kill sea otters, even for Alaskan indigenous people a. Distribution of sea otters before fur harvest began in 1741 and populations that survived the harvest, providing the nucleus for recovery of the species. Width of shaded area is not relative to sea otter habitat.

21 Otters repopulate the world
Miraculously, otter population has not been too far reduced for regrowth Although sea otters have slow gestation periods (6 months) and only usually give birth to 1 infant (twins are exceptions), pop. slowly builds up By 1980’s, pop. assessed: nearly otters alive on Earth, primarily in Alaska Pop. of 2000 discovered in California after thought to be locally extinct Worldwide population thought to be at safe equilibrium density

22 Otter death still occurs
Aleutians demand cultural hunting rights back Sea otters made into many things, including teddy bears. Not this teddy bear, but a teddy bear like it.

23 Ignorant violence Californians deliberately murder protected sea otters People are arrested off coast of California for deliberately murdering sea otters for no reason other than the act itself One man drives his motor boat through a raft of hundreds of otters while shooting several with a .22 gun One man traps and partially skins an otter, then leaves it in a ditch, only to be arrested later w/ girlfriend charged as an accomplice Many other such incidents occur throughout the years

24 Otters are loved Despite rare deaths, otters now cherished in many parts of the world Despite rare deaths, otters now cherished and protected throughout the world – become the most extensively studied marine mammal and prized exhibit in zoos Recognized as a keystone predator maintaining kelp ecosystems & a highly intelligent mammal By the late 1980’s, sea otters had rebounded from a history of devastation turned to consideration

25 A new threat emerges In 1991, first killer whale attack on Alaskan otter is witnessed In 1991, the first attack by a killer whale on a sea otter is witnessed by otter ecologists – not considered significant, just surprising In 1994, population analysis of Alaskan Islands reveals a drop of 90% in several locations By 1998, Alaskan otter population estimated to have dropped dramatically to 45,000 from previous 148,000 Scientists struggle to find answer

26 Otter killer 3 killer whales, 3-6 otters a day, ten years
Alaskan killer whales appear to have shifted their diet from Steller sea lions and fur seals to sea otters Islands without killer whale access still have healthy otter populations It is estimated that one killer whale would require three full grown 60 pound sea otters a day in order to maintain caloric requirements It is estimated that three killer whales could hypothetically have caused the reduction of nearly 100,000 sea otters within a ten year period More killer whales are likely to be causing pop. drop

27 Whale killer The reasons why

28 Red for murder Geography of reported whale harvested species in N. Pacific ocean and Berring Sea from 1946 thru 1979

29 Solutions to the problem
No solution except the impossible No obvious solution Ironically, two species once hunted to extremely low numbers have clashed due to human beings If killer whales continue to hunt sea otters until there are no more left in order to survive, Alaskan pop. will consist of only a few thousand Neither killer whales nor sea otters can be removed safely before this predator-prey interaction reaches its conclusion

30 Cetacean populations Before and after hunting.

31 A great fall Whales, seals, sea lions, sea otters
The chance that a change in fishing practices could eventually result in replenished stocks of sea lion and fur seal fish prey, resulting in change back of killer whales to natural prey, and sea otters grow again Fishing practices will not change Chances of killer whales changing back, anyway, are not high Time it takes for fish pop. to rebuild and chance for fur seals and sea lions to recover will be too long and might not be possible

32 The threat of extinction
Can the sea otter still go extinct? Killer whales ecology and behavior cannot be changed directly as making otter hunting illegal proves While perhaps the otter may not go extinct, it may at least be reduced to unhealthy numbers below 10,000, while kelp forests across Alaska will collapse Eventually, killer whales may move on or starve to death once there are no more sea otters

33 A sign of things to come Ripple effects
This killer whale/sea otter phenomenon may represent other dangers for other marine life Animals which never had conflict before currently are in conflict due to human impacts Once thought that open-water activities could not have any effect on coastal environments: proven wrong Once thought that marine fish populations were inexhaustible, endless, and could continue to forever Ignorance has resulted in tragic losses which are increasing in time over mere years

34 Rise and fall The sea otter’s life history has been shaped by human greed This is all what many people saw. They wanted the fur. The sea otter’s life has changed drastically due to human beings

35 Sea otter today A different relationship currently exists

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