Alaska

1
Alaska
2
Alaska

• 663,268 sq miles, including territorial waters
• 21 of the size of the lower 48.
• Bound by
• Gulf of Alaska
• Bering Sea
• Chukchi Sea
• Beaufort Sea (Arctic Ocean)

3
Alaska

• Width West - East 808 miles
• Length North - South 1,479 miles
• 65 land area controlled by Federal Govt
• Shoreline 34,000 miles
• Two Time Zones
• Population 670,053

4
Alaska

• Coastline Alaska 33,904 miles
• Coastline Lower 48 54,729 miles
• Alaska has 62 total Tidal Coastline of US
• Area of Continental Shelf in Alaska is huge
• Most fish are caught near shore and on the
  continental shelf

5
Geology of Alaska

• Two Major Tectonic Plates
• North American Plate, Pacific Plate
• Plate Interactions
• Transform Boundary - sliding along
• Divergent Boundary - mid ocean ridge
• Convergent Boundary - subduction zone

6
Geology of Alaska II

• North American Plate NA Craton is the Core
• North - East corner of Alaska is NA Craton Rock
• Continental Shelf Considered Continental Plate
• All else is accreted terraines, rocks from
  further south that have been sequentially
  transported to Alaska by Plate Tectonics. And
  there are many different terraines.
• Kula Plate - Oceanic plate subducted under NA but
  a last fragment lies beneath shallow waters of
  the Bering Sea

7
Plate Tectonics

• Oceanic and Continental Plates
• Ocean Spreading Centers
• Mid-Oceanic Ridge
• Volcanic Activity - Black Smokers
• Seamounts
• Continental Plates Override Oceanic Plates
• Oceanic Plates dive into Subduction Zones

8
Alaskan Marine Regions

• Southeast Alaska Inland Waters
• Gulf of Alaska Coast
• Western Gulf of Alaska
• Alaska Peninsula
• Bering Sea
• Yukon Kuskokwim Delta
• Aleutian Islands
• Seward Peninsula Norton Sound
• Chukchi Sea
• Beaufort Sea

9
Freshwater Alaska

• More than 3 million lakes
• Marshland Wetland Permafrost188,320 sq mi
• 12,000 rivers, many with salmon runs
• 51 Tidewater Glaciers
• Many other Glaciers feed Rivers, Marshes and Lakes

10
Geology Fishing

• What does this have to do with fishing?
• 1. Nutrients eroded from rock feed food web
• 2. Ocean spreading centers provide nutrients
• 3. Volcanism from subducted plates
• 4. Freshwater and anadromos fish
• 5. Seamounts bring huge diversity
• 6. People, Fish Harvesters, live on land

11
Climate

• Latitude 51 20 North to 71 50 North
• Longitude 130 West to 172 East
• Record High 100 Fort Yukon
• Record Low -80 Prospect Creek
• Sea Ice Covers Cook Inlet - Bering, Chukchi and
  Beaufort Seas for months.

12
Global Warming

• What will be the effects of Global Warming?
• 1. Warmer water species will migrate north
• 2. Colder water species will migrate north
• 3. Ocean currents will change
• 4. Potentially profound effects on species

13
Regional Climate Change

• El Niño and La Niña are short term climatic
  fluctuations
• 1997 El Niño
• 1. Weird algal bloom in Bering Sea visible
  from space.
• 2. Implicated in protozoan infestations of
  many commercial species.

14
Pacific Decadal Oscillation

• PDO is a pattern of Pacific climate variability
  that shifts phases on at least inter-decadal time
  scale, usually about 20 to 30 years
• PDO provokes a faunal regime shift, where the
  animals found most abundantly change in cold to
  warm and warm to cold shifts.
• Cold - crab, shrimp, herring, capelin
• Warm - cod, pollock, salmon

15
Pacific Decadal Oscillation

• Cold Phase Warm Phase

16
PDO Index

• The PDO Index is calculated by spatially
  averaging monthly sea surface temperature of the
  Pacific Ocean north of 20N. The global average
  anomaly is then subtracted to account for global
  warming. Only October to March values are used
  because year-to-year fluctuations are most
  apparent during the winter months.

17
PDO Index
18
Alaska Ocean Warming