Global Warming and Ocean Ecosystems By Ariel Guterman March 9, 2010 Chemistry A Block

Global Warming’s Effects on Ocean Ecosystems Rising Ocean Temperatures Effects on Currents Rising Sea Levels Effects on Marine Animals Coral bleaching Destruction of marine habitats and species relocation Altered lifestyles Acidic Oceans The Domino Effect: Disruption of the Food Chain Conservation Efforts

Rising ocean temperatures

Rising ocean temperatures Disruption of the Atlantic Meridional Overturning Circulation TheAtlantic meridional overturning circulation carries warm upper waters into far-northern latitudes and returns cold deep waters southward across the Equator As atmospheric temperature rises, arctic sea ice and the Greenland ice sheet melt; dispersing fresh water into the North Atlantic Ocean With an increased ratio of fresh water to salt water, the salinity, and therefore, density of ocean water decreases; preventing the cold water from sinking and continuing southward

Rising ocean temperatures If thermohaline circulation (THC)1 shuts down and alters climate patterns, severe winters in the North Atlantic would likely continue until conditions allow the THC to resume (decades or even centuries later). Although the earth, on average, would continue to warm, a lapse in the THC could potentially produce abrupt regional cooling (especially Europe). 1the part of the large-scale ocean circulation that is driven by global density gradients created by surface heat and freshwater fluxes Slowing Current Effects on Regional Climate

Rising ocean temperatures Within the ocean itself, many creatures (including leatherback turtles and jellyfish) depend on currents for transportation. All marine animals depend on currents for food because phytoplankton (the base of the ocean’s food chain) are transported by currents. Slowing Current Effects on Marine Animals

Rising Sea levels

Rising Sea levels Global warming rises sea levels not only by adding water (melting glaciers ad ice sheets) but also increasing the volume of water through thermal expansion It is projected that global warming will cause sea levels to rise by as much as 5 mm per year over the next 100 years (potentially up to a 69 cm increase) threatening countless island nations and coastal cities

Rising Sea levels In addition to flooding that effects wildlife on low lying land masses, sea plants and algae that depend on photosynthesis suffer as deeper water causes less light to reach them. In turn, animals depending on these plants suffer, and the food chain is further disrupted. Light Penetration INTERTIDAL ZONE IS HIGHLY AFFECTED.

Effects on marine animals Population of 274 representative marine species are tracked to calculate the Marine Living Planet Index This index shows us the current health of marine environment in 4 oceans as compared to 1970.

Effects on marine animals Coral Bleaching When the ocean warms, the colorful algae that provide nutrition to coral die. This causes corals to turn white and die within a few days if a cooler temperature is not restored. It is estimated that 27% of the planet’s reefs are now dead, half of these due to global warming. Over 25% of marine creatures depend on coral reefs as homes. Before After

Effects on marine animals The Coral Triangle Region The Coral Triangle, the global centre of marine biodiversity, is a 6 million km2 area spanning Indonesia, Malaysia, the Philippines, Papua New Guinea, Timor Leste and the Solomon Islands. Within this nursery of the seas live 75% of the world’s coral species, 6 of the world’s 7 marine turtle species, at least 3,000 marine fish species.

Effects on marine animals Destruction of habitats and species relocation Animals suited to cooler climates need to move polewards as their habitats warm; often earlier than natural migrations. 1,103 species (plants, mammals, birds, reptiles, frogs, butterflies and other invertebrates) are expected to move in response to changing temperatures and climate

Grey whales migrate farther than any other animal- a 12,000 mile round trip. When temperature change comes early, migration patterns change- causing predators to migrate at a different time from their prey.

Effects on marine animals Altered Lifestyles and Adaptations Animals suited to cooler climates need to move polewards as their habitats warm 1,103 species (plants, mammals, birds, reptiles, frogs, butterflies and other invertebrates) are expected to move in response to changing temperatures and climate

beluga whale, North Atlantic right whale , killer whale, North Pacific right whale, Atlantic salmon, coho salmon, green sturgeon, smalltoothsawfish, steelhead trout, black abalone, elkhorn coral, staghorn coral, white abalone, spotted seal, monk seal, grey whale, green turtle, fin whale, humpback whale, steller sea lion, leatherback turtle There are currently over 320 marine animals on the IUCN Red List of Threatened Species. It is projected that if global warming progresses at its present rate, by 2050, 1 out of every ten animal and plant species (on sea or land) will be extinct.

References global-warming.accuweather.com/2008/07/ http://www.whoi.edu/page.do?pid=12455&tid=1061&cid=7231&cl=6616&article=9986 http://www.nature.com/nature/journal/v438/n7068/abs/nature04385.html http://environment.nationalgeographic.com/environment/habitats/ocean-profile.html http://environment.nationalgeographic.com/environment/global-warming/ http://en.wikipedia.org/wiki/Thermohaline_circulation http://www.panda.org/about_our_earth/aboutcc/problems/rising_temperatures/sea_levels/ http://geography.about.com/od/geographyintern/a/globalmarine.htm http://www.nwf.org/News-and-Magazines/National-Wildlife/Animals/Archives/2010/How-Animals-Fight-Global-Warming.aspx