Biogeography Guest lecturer: Dr. Ana irovi (asirovic@ucsd.edu) SIO - PowerPoint PPT Presentation

Biogeography Guest lecturer: Dr. Ana Širović (asirovic@ucsd.edu) SIO 133: Marine Mammal Biology

Is the ocean homogenous?

Tagging of Pacific predators (TOPP) Yellow: females • Northern elephant Red: males seal distribution: – Pupping on beaches – Foraging in open ocean

Biogeography • Determined by: – Ecology: food availability, temperature – Evolutionary biology: historical range

Ocean zones

Seasonal variability of ocean zones • Temperate region – Wind important factor

Seasonal variability: coastal upwellings • California Current system Blue whale tracks Bailey et al. 2010

Seasonal variability: coastal upwellings • California Current system Blue whale tracks Bailey et al. 2010 Block et al. 2011

Seasonal variability: polar region • Light important – Productivity high in summer • Seasonal presence common

Prey aggregation • Affected by oceanographic features: fronts, eddies, ocean bottom Blue whale catches Krill concentration From Tynan et al. 1998

Species distribution • Cosmopolitan species – E.g. Killer whales ( Orcinus orca ) From Hoelzel 2002

Blue whale stocks From McDonald et al. 2006

Species distribution • Anti-tropical distribution – E.g.: Long-finned plot whales ( Globicephala melas ) From Hoelzel 2002

Anti-tropical distribution From Hoelzel 2002

Species distribution • Pan-tropical species – E.g. Spinner dolphins ( Stenella longirostris) From Hoelzel 2002

Species distribution • Circumpolar species – E.g. Beluga whales ( Delphinapterus leucas ) From Hoelzel 2002

Species distribution • Endemic species – E.g. River dolphins From Hoelzel 2002

Migratory species • Prey driven: Most rorquals Block et al. 2011 • Ice driven: polar species – e.g. beluga, narwhal, bowhead Month of year

Temperature-defined distribution • E.g. Short and long-finned pilot whales Source: Duke University, OBIS-SEAMAP

Gender-variable distribution • E.g. Sperm whales ( Physeter macrocephalus ) Source: whaletrackers.com

Coastal species • E.g. Porpoises From Hoelzel 2002

Plate tectonics & early records 1 – early cetaceans 2 – early sirenians From Berta et al. 2006

Evolutionary biogeography: cetaceans Geologic events | Marine mammal events | Location Tethys Southern hemisphere From Berta et al. 2006

Evolutionary biogeography: pinnipeds Geologic events | Marine mammal events | Location Walrus | Sea lion | Phocid N Pac. Pan. seaway N Pac. N Atl. N Pac. Arctic From Berta equator N Atl. et al. 2006 S Pac.

Origins of anti-tropical distribution? Globicephala melas From Hoelzel 2002