Class Notes (838,272)
Canada (510,817)

one ocean-a changing sea.docx

3 Pages
Unlock Document

Life Sciences
Luc Bernier

February 28 , 2013 Life Sci 2H03: Environmental Life Sciences One Ocean: The Changing Sea - impact of predatory squid on local fisheries - surveying squid using acoustical instruments to identify squid at night when they come to surface to feed - saw a large layer of squid - squid have life span of 1-2 years and can grow very fast as it constantly feeds - hunts in packs and feeds on whatever is available - changes in schooling behaviour of fish as a result of the fish - hate now seems to be spawning off of waters outside California and could pose a problem - Monterey Bay California: Northway migration - Sudden invasion of squid - Sudden predation has been fished out in the squids home range - Big fishes eat the baby squid, in response the squid population grow (exploding population) - Fisherman have seen these squid before in warmer periods - No evidence of humble squid until 1998 El Nino - 2002 little El Nino and the squid came back and have been here ever since - episodic range expansions during El Nino is a natural phenomenon - thanks to a blanket of CO El2Nino is becoming more persistent and is driving up other temperature in the global sea - world’s fish docks are swimming poleward at a rate of 40-60km - invading species aren’t the only threat - calforis are the primary ecosystem and support creatures above and below the ocean - calforis found in cool coastal water around the world and are among the most productive ecosystems in the world - kelp does best in temp 10-16 C o - in 2006 in the deep ocean off Oregon, thousands of creatures suddenly disappeared - in 2002 fisherman show dead crabs in their traps - low oxygen is the cause - why are oxygen levels dropping? - Every year there has been a reappearance of drops in oxygen in the Oregon zone - No many rivers emptying into the coast therefor it is not related to toxins - Change in the natural rhythms by upwelling - Winds from the north drive the nutrient rich waters from the deep up to the surface feeding phytoplankton at the surface - Phytoplankton is one of the most valuable ecosystems - Large phytoplankton blooms begin to form of Oregon coast - Dead phytoplankton drops to the deep ocean and bacteria feed on them burning oxygen in the process causing a 3km area lacking in oxygen, loss of all fish in the area - Only a major disruption in the upwelling cycle could cause this, climate change is the main component - Global warming drives stronger winds supercharging the upwelling process - Off Canada in the subarctic pacific, the deep ocean is also loosing oxygen – 22% decline from 150-600m - Ventilation is how the ocean breathes and is being reduces - Oxygen absorbed at the surface seas making it able to sink, transporting oxygen into the deep water - As the planet warms and the melting of ice caps causes the surface waters to be too light due to the input of freshwater and inhibits the sinking of water causing a lack of oxyge
More Less

Related notes for LIFESCI 2H03

Log In


Join OneClass

Access over 10 million pages of study
documents for 1.3 million courses.

Sign up

Join to view


By registering, I agree to the Terms and Privacy Policies
Already have an account?
Just a few more details

So we can recommend you notes for your school.

Reset Password

Please enter below the email address you registered with and we will send you a link to reset your password.

Add your courses

Get notes from the top students in your class.