2 Major Objectives Sea otter evolution Relationship between sea otter and manSea otter’s role as a keystone predatorSea otters and kelp forestsSea otter futuresWhich came first? The otter or the kelp forest?Sea otter ancestors occur around 20 myaToday’s otter evolved around 2 myaKelp starts to develop around 20 mya20 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 journeySea otters may go extinct because of humans
3 Evolution of today’s sea otter 2 million years ago…Enhydra lutris
4 Humans like sea ottersOnly once otters were hunted to near extinction a hundred years ago did people began to care about the animalNow they are treasured by most, protected revered, adoredThey are still killed, though, without mercy and with complete disregard to their right for existence by a murderous fewStill in a lifelong struggle with humans
5 In the beginning…The sea otter’s range was massive compared to today’s rangeConsisted 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 peninsulaRoughly otters alive by the time mass genocide began to occur
6 A simple and complex life Food, shelter, breed, avoid being eatenBefore human/otter contact, sea otters lived a life as simple as it was complexSea otters only inhabit areas where there are kelp forestsSpecific kelp forest habitats will only exist while the sea otter is thereSea otters have always lived a highly vulnerable lifestyle while being the controlling factor for a highly diverse ecosystemOnly 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 itThey are the only mammal of the Order Carnivora to be found in the seaThey have an extremely fast metabolism requiring a daily intake of 30% or more of their body weightLearned 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 kelpKelp forests provide a home for hundreds of different organisms (fish, invertebrates, mammals, birds) and act as nursery for many others
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 specimensWithout 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 latitudesOtters are the only predator found in A. k. f., unlike other coastsFor millions of years, kelp forests maintained a stable lifeThe 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 humansIt is presumed otters were hunted by first colonies of the otter’s entire rangeIn Alaska, first colonization est. to have occurred yaAlaskan otters estimated to have begun being hunted roughly 2500 yaEvidence comes from bones in indigenous middensOtters first hunted merely for meat and warmthThese boats are seen on Kodiak island, 1888Throwing boards were used to send harpoons in farther with more force.
13 Russians get lost in Alaska Russians discover Alaskan wildlife in 1741Russians sail in North Pacific, starving and lost, find a treasure of wild life living off Alaska islandsCaptain Berring discovers otters as well as now extinct giant sea cow in Commandeer islands and is excited by new food supply in 1741Sea 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 IslandsBering, 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 meatLast few thousand steller’s sea cows on the planet have a hard time of itSteller’s sea cow is easier to kill than sea otterSailors 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 willMeat is really good to eat and there are many of themSlaughtered to extinction 27 (1768) years later due to fearlessness of manSign of things to come for sea otter
15 Sea otter genocide Otters previously only hunted for warmth and food Previously, otters only hunted for necessityRussians desire the rich coat because of greedRussians prevent indigenous Alaskans from hunting sea otters out of necessity any longerRussians 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 worldPosts are set up almost everywhere in otter’s range for hunting, from Baja peninsula to JapanEven 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 furThe otter is trapped or clubbed, killedThe 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 perfectStretching fur out, it can reach 3 meters square, more than half the length of otter’s bodyThe skin is oiled downThe fleshy pieces still attached to the fur are scraped off delicately so as not to cut into the furOtter fur is smoked and driedThe fur is prized all over the world beyond any other fur for its rich lustrous dark color and extraordinary warmthThere 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 furOtters used their fur for same purpose – to keep warmEvery cuticle on the otter’s skin has 60 hairs 20 mm. long coming out along with one longer, thicker guard hairOtters can spend 50% of daylight hours cleaning their furFur 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 hypothermiaOtters constantly clean their fur and blow into it in order to build a layer of air underneath fur which acts as insulationOtters do not have layer of blubber, only furOnce fur gets wet, they can also quickly drownThe fur that keeps the otter alive is the same thing for which they were exterminated
20 The last of the otters150 years after excessive hunting, people realize a mistake has been madeSea otter population drops from previous to 3 thousand by late 1800s – only found in Alaska, gone from rest of rangePeople start to realize that the otter may go extinct after nearly 150 years of excessive hunting and decide to protect it1911 – International Fur Treaty is established, making it illegal to kill sea otters, even for Alaskan indigenous peoplea. 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 regrowthAlthough sea otters have slow gestation periods (6 months) and only usually give birth to 1 infant (twins are exceptions), pop. slowly builds upBy 1980’s, pop. assessed: nearly otters alive on Earth, primarily in AlaskaPop. of 2000 discovered in California after thought to be locally extinctWorldwide population thought to be at safe equilibrium density
22 Otter death still occurs Aleutians demand cultural hunting rights backSea otters made into many things, including teddy bears. Not this teddy bear, but a teddy bear like it.
23 Ignorant violenceCalifornians deliberately murder protected sea ottersPeople are arrested off coast of California for deliberately murdering sea otters for no reason other than the act itselfOne man drives his motor boat through a raft of hundreds of otters while shooting several with a .22 gunOne man traps and partially skins an otter, then leaves it in a ditch, only to be arrested later w/ girlfriend charged as an accompliceMany other such incidents occur throughout the years
24 Otters are lovedDespite rare deaths, otters now cherished in many parts of the worldDespite rare deaths, otters now cherished and protected throughout the world – become the most extensively studied marine mammal and prized exhibit in zoosRecognized as a keystone predator maintaining kelp ecosystems & a highly intelligent mammalBy the late 1980’s, sea otters had rebounded from a history of devastation turned to consideration
25 A new threat emergesIn 1991, first killer whale attack on Alaskan otter is witnessedIn 1991, the first attack by a killer whale on a sea otter is witnessed by otter ecologists – not considered significant, just surprisingIn 1994, population analysis of Alaskan Islands reveals a drop of 90% in several locationsBy 1998, Alaskan otter population estimated to have dropped dramatically to 45,000 from previous 148,000Scientists 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 ottersIslands without killer whale access still have healthy otter populationsIt is estimated that one killer whale would require three full grown 60 pound sea otters a day in order to maintain caloric requirementsIt is estimated that three killer whales could hypothetically have caused the reduction of nearly 100,000 sea otters within a ten year periodMore killer whales are likely to be causing pop. drop
28 Red for murderGeography 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 impossibleNo obvious solutionIronically, two species once hunted to extremely low numbers have clashed due to human beingsIf 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 thousandNeither killer whales nor sea otters can be removed safely before this predator-prey interaction reaches its conclusion
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 againFishing practices will not changeChances of killer whales changing back, anyway, are not highTime 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 provesWhile 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 collapseEventually, 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 lifeAnimals which never had conflict before currently are in conflict due to human impactsOnce thought that open-water activities could not have any effect on coastal environments: proven wrongOnce thought that marine fish populations were inexhaustible, endless, and could continue to foreverIgnorance has resulted in tragic losses which are increasing in time over mere years
34 Rise and fallThe sea otter’s life history has been shaped by human greedThis 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 todayA different relationship currently exists
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