According to “Climate Change and the Ocean”, “over 90% of the heat” produced by climate change has been consumed by the ocean. This is an alarming statistic. From the industrial revolution to today, Earth’s population has continued to rise, and more people means more fossil fuel burning and energy usage (Smithsonian Ocean). Sediment cores from the deep ocean have determined that human activity is the primary cause of climate change; more specifically, the greenhouse effect (Smithsonian Ocean). Through this effect, gases, most notably carbon dioxide, have been released into the atmosphere in record numbers (Smithsonian Ocean). These gases have absorbed heat from the Sun, and in turn, have gradually warmed the Earth (Smithsonian Ocean). The ocean, which is home to 96.5% of Earth’s water, is literally taking the heat (“How Much Water…”).

Warming Waters

The increasing temperatures of the ocean have caused coral bleaching, a process in which corals lose both their color and food source from zooxanthellae algae (Smithsonian Ocean). Coral ecosystems, which are “the most threatened of all”, have already been stressed by coral bleaching. (Oregon State University). In the Caribbean alone, 80% of reefs have been lost (Oregon State University). Warming waters have also affected fish–they continue to move to colder areas, and as a result, “coastal fisheries are expected to see a 20% decline in fish catch potential” (Petsko).

Bleached coral, courtesy of Smithsonian Ocean.

Toxic algal blooms, commonly known as red tides, are also increasing in number. They have the potential to cause paralysis and even death in humans that consume toxic shellfish. Algal blooms also have great economic impacts–more than a billion dollars have been lost because of these events worldwide (Stony Brook University).

In Florida, algal blooms caused respiratory issues in humans and the death of sea turtles, manatees, and dolphins (Liberto). Image courtesy of Phys.org.

In 2014, the “Blob” (“a large mass of warm water”) caused massive transformations to the Pacific Ocean. Primary food sources declined, causing “the largest seabird die-off in recent history” (Saccomanno). Fisheries were deemed as disasters, thousands of sea lions stranded, and the largest algal bloom on the West Cost occurred (“New Marine Heatwave…”). Even Marine Protected Areas are at risk because of warming waters–the University of North Carolina at Chapel Hill has predicted that by the year 2100, MPAs could become uninhabitable.

Recently, another “Blob” has formed in the Pacific Ocean, as shown by this graphic, courtesy of NOAA.

Acidification

The ocean absorbs “more than one quarter” of carbon dioxide, but now, it is reaching a breaking point. Ocean acidification has a major impact on marine species. Fish are sensitive to acidic conditions, causing their brain chemistry to alter dramatically. For instance, clownfish cannot easily locate themselves back to their homes when in the presence of acid. On the other hand, jellyfish thrive in acidic conditions, so they could easily overtake ecosystems. Coral skeletons are corroded by acid, making the coral more likely to erode. One major consequence of ocean acidification is the disintegration of the shells of all sorts of organisms, including oysters, mussels, sea urchins, and starfish. In fact, zooplankton (small drifting organisms), the basis of the oceanic food chain, also have shells, and if they die without their shells intact, they are not able to take carbon away as part of their role in the carbon cycle. “During the last great acidification event 55 million years ago, there were mass extinctions in some species” (Smithsonian Ocean).

Acidification causes this sea butterfly shell to disintegrate. Courtesy of Smithsonian Ocean.

Rising Seas

With glaciers and ice sheets melting and thermal expansion on full display, sea levels are rising, which means that both humans and animals are in danger. In fact, “sea level is 5 to 8 inches higher on average than it was in 1900”. The National Oceanic and Atmospheric Administration predict that hurricanes will become 2-11% stronger. With flooding becoming a popular occurrence, people all over the world could possibly lose the places they call home. In addition, saltwater intrusion could occur, reaching drinking water, crops, and plants (Smithsonian Ocean). 

To put things into perspective, by the year 2300, seas could rise 17 feet or more (Petsko). Wave power, the wave energy caused by the wind, has become 0.4% higher since the middle of the 20th century, as a result of climate change (University of California – Santa Cruz).

One study that takes a closer look at the effect of rising seas is NOAA’s 2019 Arctic Report Card. According to the report, “Arctic sea ice extent at the end of summer 2019 was tied with 2007 and 2016 as the second-lowest since satellite observations began in 1979” (“Arctic Report Card…”). The Bering Sea is of great concern–many fish species have moved north of the region, and the people of the area have limited access to their food supply (“Arctic Report Card…”). In fact, 2/3 of polar bears could die in half a century because of rising sea levels (Smithsonian Ocean). Harp seal pups born on Arctic sea ice are forced into the water, which could cause hypothermia and starvation (Smithsonian Ocean). On top of this, Arctic terns have been forced to forage elsewhere for krill, which reside in sea ice (Newcastle University). Greenland is another location that is currently experiencing the effects of rising seas (Petsko). 

Polar bears are on the brink of climate change in the Arctic. Image courtesy of Smithsonian Ocean.

What You Can Do

Whether you live near the ocean or not, there are plenty of actions you can take to help the ocean recover from climate change and achieve a state of consistent health.

• Reduce, reuse, and recycle–in that order.
• Don’t litter!
• Eat sustainable seafood. Download the Monterey Bay Aquarium’s Seafood Watch App to gain access to an easy-to-use guide.
• Become an efficient user of energy.
• Most importantly, educate yourself and others on the ocean and its creatures. Follow oceanic news from organizations like Ocean Conservancy and Oceana, watch documentaries, visit aquariums, participate in beach clean-ups, or volunteer. 

With warming waters, acidification, and rising seas, the ocean is currently undergoing major changes. Countless nations, people, and organisms rely on the ocean to live, and together, we can save this natural beauty, so it can be around for generations to come. 

Looking for more ways you can help the ocean? Click here.

Works Cited

“Arctic Report Card: Update for 2019.” NOAA’s Arctic Program, 14 Dec. 2019, https://arctic.noaa.gov/Report-Card/Report-Card-2019. 

“Climate Change and the Ocean.” Ocean Conservancy, 14 Dec. 2019, https://oceanconservancy.org/climate/.

“How Much Water is There on Earth?” USGS, 15 Dec. 2019, https://www.usgs.gov/special-topic/water-science-school/science/how-much-water-there-earth?qt-science_center_objects=0#qt-science_center_objects. 

Liberto, Di Tom. “Harmful algal blooms linger in parts of southern Florida in July and August 2018.” Climate.gov, 16 Aug. 2018, https://www.climate.gov/news-features/event-tracker/harmful-algal-blooms-linger-parts-southern-florida-july-and-august-2018. 

Newcastle University. “Impact of climate change on Arctic terns.” ScienceDaily, 18 Nov. 2019, https://www.sciencedaily.com/releases/2019/11/191118190903.htm. 

“New Marine Heatwave Emerges off West Coast, Resembles ‘the Blob’.” NOAA Fisheries, 20 Sept. 2019, https://www.fisheries.noaa.gov/feature-story/new-marine-heatwave-emerges-west-coast-resembles-blob. 

Oregon State University. “Climate Change Has Major Impact on Oceans.” ScienceDaily, 24 Feb. 2008, https://www.sciencedaily.com/releases/2008/02/080217102140.htm. 

Petsko, Emily. “Climate change and oceans: What you need to know from the United Nations’ new report.” Oceana, 25 Sept. 2019, https://oceana.org/blog/climate-change-and-oceans-what-you-need-know-united-nations’-new-report. 

Saccomanno, Vienna. “Big Blue Blog about BLOBS in the Big Blue.” Marine Conservation Institute, 16 Oct. 2015, https://blog.marine-conservation.org/2015/10/blobs-in-the-big-blue.html. 

Smithsonian Ocean. n.d, https://ocean.si.edu/. 

Stony Brook University. “Global warming making oceans more toxic.” ScienceDaily, 24 Apr. 2017, https://www.sciencedaily.com/releases/2017/04/170424153809.htm. 

University of California – Santa Cruz. “Upper-ocean warming is changing the global wave climate, making waves stronger.” ScienceDaily, 14 Jan. 2019, https://www.sciencedaily.com/releases/2019/01/190114082847.htm. 

University of North Carolina at Chapel Hill. “Climate change threatens Marine Protected Areas.” ScienceDaily, 8 May 2018, https://www.sciencedaily.com/releases/2018/05/180508170905.htm.