Harbor Seals

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Harbor Seals!
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Our Seals

• Housing nine seals
• 6 female
• 3 male

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Taxonomy

• Seals are mammals
• Live birth
• Nurse young
• Hair
• Breath air
• Warm blooded

• Seals are Pinnipeds
• Walrus
• Eared Seals
• True Seals

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Range and Populations

• 500,000 individuals world wide
• Pacific and Atlantic Oceans
• 80 decline in Alaskan populations

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Harbor Seals

• Lifespan 15-20 years in the wild, longer in
  captivity

• Females measure 4-5 ft and 120-250 lbs
• Males measure 5-6 ft and 220-330 lbs

• Predators include killer whales, sharks, Steller
  sea lions, bears, coyotes, and eagles
• Prey includes capelin, herring, Pollock, squid,
  crustaceans, eels, and mollusks

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Pupping and Rearing

• Sexual maturity reached 3-6 years
• 12 months between birth
• 2 month delayed implantation
• 10 month gestation period
• Pups born between May and June
• Pups
• 2.5 ft long
• 18-26 lbs
• Swim right after birth
• Nurse 4-6 wks
• Milk is 40 fat
• Double in weight during nursing period
• After weaning, pups are on their own

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Differences between seals and sea lions

• 16 species of sea lions
• 18 species of seals
• Size
• Ears
• Moving in water
• Moving on land

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Seal Adaptations

• Torpedo shape

• Big eyes
• Vibrissae

• Teeth
• Water conservation

• Blubber
• Countercurrent
• Circulation

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Diving Behavior

• Dive over 25 minutes
• Most last 2-6 minutes
• Can fall asleep underwater
• Dive to 600 feet
• Most dives shallower 60 ft

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Diving Behavior
(Womble Gende 2007)
Seal avoiding transient orcas
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Diving Response

• Bradycardia
• Vasoconstriction
• Increased volume in mitochondria
• More myoglobin

• 8.9 minutes physical limit without the diving
  response

• Higher CO2 tolerance
• Compressible Ribcages

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Our Seal Habitat

• Enrichment everyday
• 18 ft deep
• 95,000 gallons
• Diet includes pollock, herring, squid, and
  capelin
• 8-15 lbs/day
• Divided into 4-5 training sessions

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Enrichment

• Improves and maintains well being of animals
• Minimizes boredom
• Increases mental stimulation, activity level, and
  curiosity
• Many different types

Enrichment is a standard for our animal care staff
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Operant Conditioning

• Bridge and target training
• Capturing
• Positive reinforcement

Behaviors keep animals physically fit and
mentally stimulated
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Husbandry

• Animals present ears, eyes, mouth, flippers, and
  tail
• May ask them to lie down still for examinations
• Restraint free and less stressful

• Some husbandry behaviors include
• Standing on a scale
• Lying for an ultrasound or x-ray
• Traveling in transport crates
• Even brushing their teeth

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Marine Mammal Protection Act

• Stay 100 yards away
• Never feed or touch them
• Observe without disturbance
• Respects cultural and community values of Alaskan
  Natives

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Recycling

• Seals encounter debris on shore and in the water
• Recycling reduces waste
• Alaska SeaLife Centers has its own recycling
  program

We can all do it!
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Seafood Watch
Make informed choices

• Seals can be caught or killed in fishing gear
• Seafood Watch guide can help with many seafood
  options
• Best choices right here in Seward include the
  Alaskan wild caught salmon, halibut, and
  Dungeness crab

www.seafoodwatch.org
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Local Seal Populations

• 80 decline in the last 30 years
• Aialik Glacier counts down to 1600 seals in 1980
  to only about 200 today
• No exact cause known
• ASLC has many research projects going on right
  now investigating

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Fjord Ecology

• Icebergs from calving glaciers are excellent
  habitat for seals
• Only 45 tidewater glaciers remain in Alaska
• There are studies investigating the physical
  characteristics of these unique habitats
• Climate change

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Harbor Seal Remote Monitoring

• Installed remote video monitoring equipment at 3
  seal haul out areas
• Transmit live video the ASLC
• We receive information about
• Harbor seal numbers
• Distribution
• Presence or absence of human activity
• Changes in ice availability

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Harbor Seal Remote Monitoring

• Watch popular spots visited by
• kayakers and tour boats
• Before 1980s, there was
• minimal human activity
• Monitoring conducted from
• 1975 to today

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Vessel Interactions
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Remote Monitoring Potential Results

• How vessel disturbance affects seal populations
  (short and long term)?
• What is affecting haulout patterns?
• How pupping rates and haulout numbers relate to
  population trends and overall health of the
  entire species?

These pieces of information allow us to evaluate
the future of harbor seal populations on the
Kenai Peninsula and how we can better work to
protect and conserve the species.
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Aerial Surveys
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How does deep diving affect marine mammal blood?

• Investigated biochemical effects of
• pressure on blood and tissue
• Blood samples obtained from sea lions
• and harbor seals
• Samples subjected to high underwater
• pressures
• Monitored metabolic rate of red blood
• cells to determine differences in cell
• metabolism during deep diving

• Will help us understand diving limitations of
  marine mammals
• May also help us understand the negative effects
  of pressure that human divers experience

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How do harbor seals respond to changes in dietary
fat?

• Investigating the potential effects of foraging
  for different fish
• Alaskan waters have warmed, causing decline in
  certain fish populations and increases in others
• Seals could be eating less fatty fish than before

Herring
Pollock
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Differences in high and low fat diets

• We are looking at effects on seals
• Growth
• Development
• Maturity
• Health of seals on high or low fat diets
• We will monitor
• Growth
• Blood chemistry
• Blubber deposits and turnover
• Food passage
• Hormone levels
• Metabolic condition and development
• Nutrient Assimilation
• Sexual development

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Thank You!
We thank you for your support of the Alaska
SeaLife Centers mission Dedicated to
understanding and maintaining the integrity of
the marine ecosystem in Alaska through research,
rehabilitation, conservation and public education.
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References

• Atkinson, S. How does the harbor seal respond to
  changes in dietary fat? Leaflet.
• Ballmann, S. and Kamrath, K. Summer 2007.
  Oceans of Fun Seal and Sea Lion Show, Milwaukee,
  Wisconsin.
• Elliott, N. M., Andrews1, R. D., Jones, D. R.
  (2002).Pharmacological blockade of the dive
  response effects on heart rate and diving
  behaviour in the harbour seal (Phoca vitulina).
  The Journal of Experimental Biology 205,
  37573765.
• Fuson, A. L., Cowan, D. F., Kanatous, S. B.,
  Polasek, L. K., Davis, R. W. (2003).
  Adaptations to diving hypoxia in the heart,
  kidneys and splanchnic organs of harbor seals
  (Phoca vitulina). The Journal of Experimental
  Biology 206, 4139-4154.
• Hoover-Miller, A., Jezierski, C., Conlon, S.,
  Atkinson, S. 2006. Harbor seal population
  dynamics and responses to visitors in aialik bay,
  Alaska. 2006 Fall Semi-annual Report to the
  Ocean Alaska Science and Learning Center and the
  National Park Service.
• Hoover-Miller, A. Harbor Seals on Ice. Ocean
  Science Lecture Series. Alaska SeaLife Center.
  June 24, 2008.

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References

• Hastings, K. K., Frost, K. J., Simpkins, M. A.,
  Pendleton, G. W., Swain,
• U. G., Small, R. J. (2004). Regional
  differences in diving behavior of harbor seals in
  the Gulf of Alaska. Can. J. Zool. 82, 17551773.
• Jobsis, P. D., Ponganis, P. J., Kooyman, G. L.
  (2001). Effects of training on forced submersion
  responses in harbor seals. The Journal of
  Experimental Biology 204, 38773885.
• Kinkhart, Edward and Pitcher, Ken. 1994. Harbor
  Seal.
• Sea World. Harbor Seals. Retrieved August 6,
  2007, from http//www.seaworld.org/infobooks/Harbo
  rSeal/hsadaptations.html.
• Tollit, D. J., Black, A.D., Thompson, P. M.,
  Mackay, A., Corpe, H. M., Wilson, B., et al.
  (1998). Variations in harbour seal Phoca
  vitulina diet and dive-depths in relation to
  foraging habitat. J. Zool., Lond, 244, 209-222.
• Womble, J. N. Gende, S. M. (2007). Dive
  Behavior of a Harbor Seal (Phoca Vitulina
  Richardii) in the Presence of Transient Killer
  Whales (Orcinus Orca) in Glacier Bay National
  Park, Alaska. Marine Mammal Science, 23(1),
  203208.