Sierra Club: Climate Change Affects Ocean Ecology

August, 2017

John Muir’s oft-quoted observation, “When we try to pick out anything by itself, we find it hitched to everything else in the Universe,” was his interpretation of the “unity of nature” argument of Muir’s mentor, naturalist Alexander von Humboldt.  We should not be surprised, then, to discover that abrupt climate change affects more than weather patterns and sea level height.  

Rapid warming of the earth from human causes (fossil-fuel use, agricultural practices, etc.)—about which one climate scientist quipped that there is now higher certainty [of human-caused warming] than there is that smoking causes cancer—is having profound effects on ocean ecology.  Jellyfish are clogging cooling-water intakes to nuclear power plants.  Other animals and plants that make up the planktonic soup that is at the base of most food chains are struggling to survive in increasingly acidic oceans.  Algal blooms in arctic waters formerly protected by ice sheets are producing anoxic “dead zones” similar to those at the Mississippi River Delta.  Corals like those on the Great Barrier Reef are turning white as the stress of warming water causes them to expel the colorful algae they contain.  

The oceans might be seen as doing us a favor by absorbing much of the extra heat reflected back to earth by the ever-increasing concentrations of greenhouse gasses in the atmosphere, and by absorbing a significant part of the carbon dioxide gas that we have only recently begun to regard as pollution. The ocean acting as a buffer in this way opens a wider window of time to allow us to get our act together to reduce the impacts of our industriousness.  But, this period of grace is not without its costs. Scientific journals are chock-a-block with reports on newly identified associations between rapid changes in the climate and increasing stresses on oceanic life.

Ocean Acidification 

Carbon dioxide absorbed by the oceans combines with oxygen to produce carbonic acid, the same club soda invented by Joseph Priestley in 1767 that we use today to make mixed drinks and Coca-Cola. The problem with soda water in the ocean is that it combines with calcium to become calcium carbonate. Calcium combined in this way is less available to zooplankton to make their shells. Then, when calcium carbonate combines to make calcium bicarbonate (which it likes to do), calcium becomes even less available to the oysters and other shellfish, including the copepods (see illustration) so vital to food chains.

Coral Bleaching

Scientists attending a recent conference on the corals of the Great Barrier Reef were reported to be crying as they shared their latest observations.  Vast areas of corals are turning white (“bleaching”) as they respond to the stress caused by rapid warming of the shallow waters where they live. Coral polyps are actually animals that feed by filtering the water, but they obtain most of their nutrients from the colorful zooxanthellae that live within them in an endosymbiotic relationship. As a survival tactic, the polyps can expel the algae in order to reduce stress.  Without the nutrients provided by the algae, however, the corals begin to starve.  Corals can recover from episodes of stress and restore their algal relationships; but with prolonged stress, corals without nutrients from their algae will eventually die of starvation.

Global warming means more than worrying about where we will live after our coastal cities have flooded, or how we will eat after the desertification of our farm lands.  It is not just about us.  All life is tied up in a web of great complexity, and we are only beginning to appreciate the dynamics of life responding to rapidly changing climate.  




One need not be a Sierra Club member to participate in these outings. Please join us!

Sunday, Aug. 13—North Group Prairie Creek Ossagon to Parkway (mile marker 130.54). We descend by the Ossagon Trail to the beach, where we may pause to explore about the impressive rocks before heading south to meet West Ridge Trail. Now turning inland, we begin a long ascent to the ridge, from which the brief Zig-Zig#2 Trail connects us back to the Parkway, where we will have shuttled vehicles for the return to Ossagon. Bring water, lunch, hiking footwear. Class M-6-B Carpools 9am Rays Valley West.10:15 am Trailhead Newton B. Drury (mm130.54) leader Melinda 707-668-4275 or Rain/wind cancels. 

Wednesday, Sept. 6—North Group Redwood National Park Emerald Ridge Loop Hike. We descend by Emerald Ridge Trail through lush forest to Redwood Creek, along which we proceed by gravel bars, with several creek crossings, to the Tall Trees area. Back on trail, we will stroll the tall Trees Loop before returning by the main trail (a climb of 700’) to our cars. Bring water, lunch, sun protection and footwear for trail, loose rock, and water. Class M-5-A. Carpools 9am Ray’s Valley West. 10:30 am Tall Trees Trailhead  (Obtain pass at Kuchel Visitor Center, hwy101 south of Orick) leader Melinda 707-668-4275 or Reservation only.

 Saturday, Sept. 16—North Group Lacks Creek/Pine Ridge Prairies Hike. Come and explore this nearby Bureau of Land Management area off Highway 299, on new and old trails created by BLM, Humboldt Trails Council, and Redwood Coast Mountain Bike Association. We will see a mix of oak savannas, old-growth conifers, and regenerating hardwood-covered slopes. Humboldt Bay and ocean views a possibility. Bring lunch and water, and dress for an early fall day at 3,600 feet elevation. Medium difficulty, about 5 miles, less than 1,000 feet elevation gain/loss. Carpools: Meet 9 a.m. Ray’s Market in Valley West. Leader Ned,, 707-825-3652 message phone. Heavy rain cancels.



Please Join Us

The North Group’s Executive Committee meets on the second Tuesday of each month in the first floor conference room at the Adorni Center on the waterfront in Eureka.  The meeting, which covers regular business and conservation issues, begins at 6:45 p.m. Members and non-members with environmental concerns are encouraged to attend. When a new person comes to us with an environmental issue or concern, we often place them first or early on the agenda. 



Subject categories: