By Emily Vidovich. Emily has a background in environmental journalism and sustainability and is a member of the George Washington University Class of 2019.
When the oceans are healthy, they sustain life on earth by providing oxygen production, ecosystem services, and climate regulation. Over the past century, human activity has increasingly altered the environment, imposing strains on the ocean that threaten its ability to provide these crucial benefits. But if we choose to reduce our impact on the natural world, we can continue to reap the rewards that come from prioritizing a protected, thriving ocean.
While rainforests are often celebrated as the lungs of the earth, there is increasing recognition that on our blue planet—over two-thirds of which is covered in water—it is the oceans that truly deserve this title. Between 50 and 80 percent of the oxygen produced on earth originates in the ocean. Most of this is created by photosynthetic plankton, algae, and bacteria. This oxygen is then used by the marine species that are a primary food source for 3 billion people globally.
However, ocean oxygen levels are projected to decrease by an average of 3 to 4 percent by 2100 due to climate change and increased nutrient pollution. According to the International Union for the Conservation of Nature, the consequences of this deoxygenation include, “decreased biodiversity, shifts in species distributions, displacement or reduction in fishery resources and expanding algal blooms.” Ocean ecosystems require oxygen in order to support marine life, so in order for deoxygenation to not drastically alter marine systems, and consequently threaten food security, humans must reduce carbon emissions and curtail nutrient runoff from fertilizer, sewage, and aquaculture.
The oceans also benefit people by providing ecosystem services—processes that keep our planet healthy and functioning, such as pollination and filtration of air and water. In the ocean, ecosystem services include coastal protection, carbon storage, food production, and water quality enhancement. Ecosystem services are dependent on the health of the ecosystem that produces them. Since ecosystems are delicately balanced webs in which creatures and the environment interact and depend on each other, when humans disrupt or damage an ecosystem through climate change, habitat loss, species exploitation, or pollution, the ecosystem’s equilibrium is lost and ecosystem services are reduced or eliminated as a result.
Keeping oceans healthy benefits humans in numerous ways. Photo by Matt Hardy on Unsplash
In 2006, research published in an article in the journal Science analyzed the impacts of biodiversity loss on ecosystem services in the ocean and found that, “marine biodiversity loss is increasingly impairing the ocean’s capacity to provide food, maintain water quality, and recover from perturbations.” With the continued environmental damage that has occurred since that research was published, one can only imagine the extent of the impact humans are currently having on marine ecosystem services.
However, there is hope that ecosystem restoration—defined as efforts to assist the recovery of a degraded ecosystem—can help damaged ecosystems recover, and consequently recuperate the associated ecosystem services. Unfortunately, fully healing a damaged ecosystem is a time-intensive and difficult process, and some scientists think that complete recovery of a damaged ecosystem may not be possible. As such prioritizing conservation and protection of the ocean is critical, so that ecosystems can maintain their health and continue providing ecosystem services without interruption.
The oceans also keep our planet livable by regulating climate and creating weather. The oceans absorb solar radiation and distribute the heat around the globe via ocean currents, which circulate warm water from the equator and cold water from the poles. This water movement regulates global climate and counteracts the uneven distribution of the sun’s heat, while also driving much of earth’s weather. If the oceans did not absorb solar radiation and distribute heat throughout the globe, regional temperatures would be more extreme and much of earth would be unable to support life.
The oceans have absorbed approximately 93 percent of the excess heat resulting from human-induced global warming, and the resulting increase of water temperature has had several consequences. Warmer waters in the upper levels of the ocean have led to increased ocean stratification, meaning that waters of different temperatures are mixing less due to different properties of the water masses. The warming of the oceans has also changed current patterns and led to a growth of oxygen-depleted zones. As the oceans warm and its characteristics change, weather patterns are shifting and extreme weather events are occurring more frequently.
Ultimately, when the oceans are healthy, everyone benefits. That is why it is imperative that we use the coming decades to rectify our relationship with the ocean and stop climate change. Because without healthy oceans our species, and our planet, cannot survive.