Download Sea Otters: Adorable but Threatened

Sea Otters:
Adorable but
Threatened
Sentinel Species at Risk
Due to Pollution and Over-fishing
By Jim Fiddes
Danbury HS & PNWBOCES, Yorktown, NY
Threats to Sea Otter Population
• Disease : EPM &
toxoplasmosis
• Contaminants: in water
& in prey
• Starvation: hi food need
• Entanglement &
Entrapment: lines/nets
• Predation
• Oil Spills: ExValdez 5K
• Difficult Environment
Sea Otter Biology
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Enhydra lutris; Mustelidae
150K Alaska; 1.3K Calif.
>60 lbs; >20 years; >4’ long
high metabolism: 20% body
weight in food daily; 3x human
dense fur: ~100K/sq in;
grooming critical
semi-retractable claws; rear
outside toe is longest
lungs 2x : other mammals
whiskers locate prey, feel
vibrations
Sea Otter Anatomy
•Muscles for grasping &
swimming; side to side on
back, vertical
•flexible spine, longer outer
toe; hips hold legs for
swimming, more than walking
Sea Otter Biology 2
• Body temp: 100 F. hold paws
& feet up to conserve heat
• extremely flexible spine; can
reach all body to groom-• no blubber, oils & bubbles in
fur insulate
• pouches near back feet to
store food
• tool user: breaks shells with
rock, on sternum
• can dive to 300’; 4 minutes
Sea Otter Biology 3
• Related to weasels & skunks
• Social learning: mother
teaches pup foraging skills;
recognizes unique pup’s call
• playful & intelligent as dogs
• “raft” = group of sea otters
• strong jaws & sharp teeth:
canines to break, incisors to
scoop meat from shells
• frequent short naps, feed
day & night
Sea Otter
Ecology 1
Sea Otter
Ecology 2
Sea Otter
Ecology 3
Sea Otter
Ecology 4
•rugged coastline
•steep shore contour
•bay collects run-off
Polluted Food--eat hearty & die...
• Shellfish concentrate
pollutants, which
accumulate in otters, &
otter milk
• Sea urchins eat kelp
holdfasts, but also are a
cash crop; abalone are
expensive--fishermen
complain: otters eat both
• urchins destroy kelp forest-clear-cut = habitat loss
Otters & Diseases...
• Pollutants weaken
immune systems
• Butylin is a biocide in
anti-fouling boat paint
• Concentrations of DDT
& PCB correlate with
diseases in otters
http://www.nwhc.usgs.gov/images/seaott99.gif
Predators: Part of the Problem
• Fur hunters nearly wiped
out sea otters; 1911 law
stopped sea otter fur trade
• Over-fishing reduces prey
fish species in Alaska;
Orcas eat otters
• California shark
population increases,
otters now on menu
Other Otter Problems & Perils
• Female injured
during mating
• It’s tough work, being
an otter:
• Other, 3
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California: 17 to 38 % foraging 50 to 68 % resting
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Amchitka Island, AK: 51 to 58 %
time foraging - 32 to 34% resting
• High infant mortality
We Can Fix This: Ways to Help
• Monterey Bay Aq.’s
orphan otter recovery &
rehab program
• Fewer feral cats!!
• Public support &
contributions
“Sea Otters Threatened”--Annotated Works Cited
http://www.the-scientist.com/yr2001/feb/research_010219.htm
•Details toxoplasmosis & protozoal meningococcus infections from
feral cats & opossums--good details & pix
http://www.enn.com/news/enn-stories/1999/06/062499/seaotter_3930.asp
•One good illus.--short article links pop. decline to fishing nets
http://www.defenders.org/wildlife/new/marine/otters/images/dowil_se
a-otter_even-more-final.html
•Cute animation on otter problems w/links to Defenders of Wildlife
http://www.discovery.com/stories/nature/otters/otters.html
•Good site w/live cams & recovery program profiles, sounds & videos
Zoobooks: Sea Otters Wildlife Education, Ltd. 0-937934-70-4 c.1995
•Excellent illus. & photos; detailed text, interesting, inexpensive
http://www.mbayaq.org/
•Excellent site w/live otter cam; detailed info, interesting, authoritative
www.fso.org •Friends of the Sea Otter--pix, history, videos, &c
“Sea Otters Threatened”--Annotated Works Cited 2
www.otterproject.org
•Colorful & interesting site, with good links to scientific studies, charts
http://www.enn.com/news/enn-stories/1999/06/062499/seaotter_3930.asp
•One good illus.--short article links pop. decline to fishing nets
http://www.nwhc.usgs.gov/research
•Pdf article & some pix , plus good links, & scientists to call
http://www.marinemammalcenter.org/
•Links & articles on all marine mammals; colorful, easy, searchable
response.restoration.noaa.gov/ bat/images
•Extensive database & analysis of Exxon Valdez oil spill; lots of
links, images, charts & graphs; NOAA site is great resource itself!
We need your help!!
Thank you & take care!
Now--the Quiz!!!
Sea Otter Screen Quiz 1
1. Name & describe at least three
things making sea otters sick.
2. List & describe two ways sea otters
keep warm.
3. Describe at least two other
adaptations of the sea otter that enable
it to live successfully in the ocean.
4. What is the sea otter’s role in the
ecology of the kelp forest?
5. Three reasons people should
concern themselves with the sea otter.
(one hint: define “sentinel species”)
No Peeking, Now!!
1. Cat feces & litter, possum feces,
oil, insecticides, pollutants in food &
water
2. Air bubbles in fur, fur density,
high metabolism & lots of food
3. Grasping front claws, 2x lungs,
spine & rear feet adapted for
swimming, frequent naps, wraps in
kelp…etc
4. Predator, control urchins to
preserve kelp
5. Sentinel species-”canaries”;
preserve important ecosystem; bring
in lots of cash...
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