Gulf of California Sea of Cortez

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Gulf of California(Sea of Cortez)

• Katrina Mangin
• Department of Ecology and Evolutionary Biology

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Gulf of California(Sea of Cortez)

• I. Geologic History A young sea
• II. The worlds aquarium (J. Cousteau)
• III. Threats Conservation

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Part I. Geologic History Upwelling Biogeographic
Provinces Coasts
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Part I. Geologic History Sea of Cortez, view
from the north
http//www-csstudents.stanford.edu/robles/bc/baja
calif.html
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Colorado River Delta
http//www-cs-students.stanford.edu/robles/bc/baj
acalif.html
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Part I. Geologic History Upwelling Biogeographic
Provinces Coasts
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Tip of Baja California, with greenery of Sierra
de la Laguna
http//www-cs-students.stanford.edu/robles/bc/baj
acalif.html
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Movie of formation of the Gulf
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Gulf of California

• II. The worlds aquarium (J. Cousteau)
• Mini-Galapagos
• isolated sea, many coves, islands, islets,
  desert subtropical/tropical habitats
• 800 islands and islets

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Diversity

• 4839 marine invertebrates (749 endemics)
• 34 marine mammals (1 endemic)
• 5 marine turtles
• 900 fish (79 endemics)
• 530 birds, 170 sea and shore birds
• 626 macroalgae (62 endemics)
• 10 endemics
• Island land animals
• many reptiles, birds, mammals (50 endemics)
• Endemic originated in and found only in a
  certain region

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Diversity

• .008 of worlds seas Gulf of California
• Diversity of fish rivals that of Bermuda and
  Hawaii
• Biodiversity hot spot

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Marine invertebrates (almost 5000 species, 749
endemics)
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Heliaster, the sunstar, crash in 1978, now
returning
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New shark species from the Gulf of California,
2003
http//news.nationalgeographic.com/news/ 2006/03/0
313_060313_shark.html
Mustelus hacat, 1 m long, lives at 250 m
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Isla Raza
http//www.oceanoasis.org/fieldguide/islarasa.html
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Isla Raza
Heermanss Gull Nest on Isla Raza
Little Cardenoza, summer 150,000-300,000
pairs Migrate to B.C.
http//www.oceanoasis.org/fieldguide/islarasa.html
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Heermans gulls and Elegant terns breed on Isla
Rasa
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Isla Raza
Sterna elegans, Elegant tern 90 of world
population nest on Isla Raza
http//www.oceanoasis.org/fieldguide/islarasa.html
http//www.oceanoasis.org/filmclips/tern-clip.html
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Isla Raza
Sterna elegans, Elegant Tern 22,500 pairs on Isla
Raza, 2000 Other nests elsewhere (eg, San
Diego)\ 1940, 1 million birds on Raza 1960s,
25,000 birds 1973, 5000 birds 1993/4, rat
eradication program 1993, 350,000 hermanns
gulls 1994, 45,000 elegant terns 1964, declared
a legal bird sanctuary Threats egg collecting,
rats, fishing camps, 300 ecotourists per
year More noisy than royal tern
http//www.oceanoasis.org/fieldguide/islarasa.html
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Sea turtles of Baja Green turtle (aka black
turtle) Loggerhead Olive Ridley Hawksbill Leatherb
ack
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leatherback
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Loggerhead sea turtle
Green sea turtles
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Japan to Baja and back! Eat jellyfish Hooks in
throat
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Tagging loggerheads Jeff Seminoff
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Blue whale, minke whale, humpback whale34
species of marine mammal in the Gulf of
California
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Baja, Loreta, Blue whale calving ground
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Long-beaked common dolphin (Delphinus capensis)
and bottlenose dolphin (Tursiops truncatus)
Gulf of California, Bahia de los Angeles,
http//www-cs-students.stanford.edu/robles/bc/baj
acalif.html
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California sea lion (Zalophus californianus)
http//www.oceanoasis.org/fieldguide/zalo-cal.html
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Fin whale Balaenoptera physalus
http//www.exzooberance.com/virtual20zoo/they20s
wim/fin20whale/Fin20Whale20314040.jpg
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Gray whale Eschrichtius robustus
http//www.exzooberance.com/virtual20zoo/they20s
wim/fin20whale/Fin20Whale20314040.jpg
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Gray whale migration, 10,000 miles rt
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Part III. Threats and Conservation

• Coastal Development (Escalera nautica)
• Overfishing and destructive fishing
• Curio and aquarium trade
• Shrimp farming
• Pollution, land runoff
• TNC, WWF, CI, Mexican Conservation Orgs

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• Fishing pressures
• 40 of production
• for Mexico
• 60-70 of fisheries
• economy
• 10-30 kg of bycatch
• (incidental catch)
• Gill nets
• (destroy sea floor)
• Loss of large predatory fish

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Vaquita Phocoena sinus The marine mammal with
the most-est
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Vaquita little cow Phoecoena sinus The marine
mammal with the most-est Smallest Most
restricted range Most secretive Most
endangered critically endangered 125
left Endemic to Gulf
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Will vaquita go the way of the Baiji (chinese
river dolphin, R.I.P. 2007)?
http//csiwhalesalive.org/csi07205a.jpg

• Threats
• 40-60 killed each year in gillnets (fishing
  boats)
• and trawling nets (shrimp boats)
• habitat loss due to damming of Colorado River
• Solutions
• Buy out all gillnet licenses in Northern Gulf of
  Ca
• Offer alternative livelihoods

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Vaquita

• In 2007, WWF-Mexico proposes the following
  milestone
• By 2009, bycatch of vaquita in the Gulf of
  California be reduced
• to no more than one animal per year.
• To achieve this
• Establish wildlife refuge covering the
  distribution area of the vaquita
• outside of the Upper Gulf of California Biosphere
  Reserve.
• Eliminate gillnets and shrimp trawls in vaquita
  habitat
• Alternative gears and other sustainable economic
  alternatives
• for local fishermen and communities
• CEDO, The Nature Conservancy, Southwest National
  Marine
• Fisheries also helping

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Bottom Trawling for Shrimp
Bottom Trawling for Shrimp
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Shrimp trawling and bycatch
http//gallery.pictopia.com/natgeo/photo/884573/
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Drift gill nets
http//www.whaleworkshop.org/gifs/porpoisenet.jpg
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2009 Whale Trackers Cruise for Vaquita
http//www.whaletrackers.com/vaquita-media/
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• Loss of Colorado River flows
• Historic
• 250,000 acre feet of water
• 40-400 million metric tons of sediment

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• Extirpation
• of species
• Totuaba
• Sharks
• Gulf Corvina
• Sea cucumber

http//baja.divebums.com/FieldID/Inverts.html
Isostichopus fuscus (yummm!?)
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875 species of fish and 30 marine mammals killed
indiscriminately for years, Sea of Cortez is
exhausted (new york times 2002) 40-50 of all
seafood in Mexico comes from Gulf of Ca (2002)
Sharks and rays critically endangered
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Help fishers establish, manage and monitor no
take zones