Graduate Research Course
Seal Biophysics & Biochemistry
Pinnipedia — phocids, otariids, walruses — from 96-min Weddell breath-holds to the 60%-fat milk of hooded seals. Comprehensive coverage of all 33 species.
About This Course
Pinnipeds are the most fully aquatic carnivores short of cetaceans. A Weddell seal holds its breath for 96 minutes; a hooded-seal pup doubles its weight in 4 days on 60%-fat milk; a walrus suction-feeds clams through 3-m-deep Arctic bottom sediments; a harbor seal tracks a minnow’s hydrodynamic wake seconds after it has passed. This course covers diving physiology, thermoregulation, sensory biology, reproduction, and conservation across all 33 extant species.
Cross-links: Polar Seals (polar-region focus),Cetacean Biophysics,Polar Penguins,Climate M9.
Nine Modules
M0
Pinniped Diversity & Evolution
33 extant species across Phocidae, Otariidae, Odobenidae; divergence ~30 Mya, Enaliarctos fossil, monophyletic origin, ursid sister clade.
M1
Diving Physiology
ADL theory, bradycardia to 4-6 bpm, peripheral vasoconstriction, spleen as O2 reservoir, myoglobin content, Scholander mammalian dive response.
M2
Blubber, Fur, Thermal Biology
Blubber k=0.15 W/m/K, fur-seal vs. true-seal insulation, lanugo, thermal conductance allometry, Kvadsheim 1994, Folkow 2008 cold tolerance.
M3
Countercurrent & Vascular
Flipper countercurrent heat exchangers, renal portal system, hepatic sinus reservoir, rete mirabile vs. ring arrangement, blood partitioning.
M4
Sensory Systems (Vibrissae)
Vibrissae wake-tracking (Dehnhardt 1998), undulated harbor-seal whisker vortex suppression, underwater vision tapetum, amphibious hearing.
M5
Locomotion: Land vs. Water
Phocid caterpillar crawl, otariid forelimb walking, vertebral axial undulation swimming, Fish 1996 thrust, fluid-mechanic Reynolds regimes.
M6
Reproduction & Lactation
Hooded-seal pup gains 7 kg/day on 60% fat milk (Oftedal 1987), delayed implantation, fasting lactation in true seals, annual vs. biennial cycles.
M7
Walrus & Sea Lion Comparative
Odobenus tusks (1-meter canine), foraging suction clam feeding, Steller & California sea lion, pinniped phylogeny revisited, sexual dimorphism.
M8
Conservation & Human Impact
Mediterranean monk seal Monachus most-endangered, Hawaiian monk seal, fishery bycatch, marine plastic, oil spills, PCB biomagnification.