Challenges to Our Oceans

The oceans are our life support system ~ they are the world’s biggest free playground ~ everyone, everywhere, depends on the oceans.  

What is ailing our oceans will eventually ail us.


1. Plastic ~ A great convenience to humanity, & a great threat to our oceans

As I enter the plastic debate, I feel like a broken record, echoing the despaired voices of impassioned environmentalists before me… we’ve found over 5 trillion particles of plastic in our oceans, we know it’s harmful, we know it’s suffocating our oceans and marine life… yet a poisonous array of plastic products ~ including forks, spoons, straws, bottles, & many more ~ are still readily available for our consumption.

This garbage entangles marine organisms, is mistaken for food and consumed, transports invasive species, and even has biochemical effects on marine food webs and seafood. 

Researchers now studying the implications of plastic on our own biochemistry have found that we constantly consume plastic toxins detrimental to human health due to the bioaccumulation of plastic toxicants in marine food chains. In reality, our useful plastic products are simply well-disguised concoctions of petroleum-based polymers, flame retardants, and other carcinogenic substances. Furthermore, while adrift, plastic debris soaks up other pollutants from surrounding seawater, acting as a gateway for persistent organic pollutants (such as DDT & PCBs) to enter marine foodwebs.

What is Our Role? Cut-out, or significantly reduce, single-use plastics from your life. Some examples of ways you can do this:

1) Invest in reusable water bottles 2) Replace plastic sandwich bags with glass tupperware 3) Bring your own silverware to restaurants 4) Refuse plastic bags for produce and groceries  5) Go straw-less  

2. More on Pollution…

No matter where you are on Earth ~ on the coast, in the mountains, landlocked & hundreds of miles from the nearest ocean ~ what you do everyday will eventually affect the ocean & entire planet. 

How can you pollute the ocean if you’ve never even seen it? Because all water systems are connected ~ watersheds lead to lakes and rivers, which lead to the ocean, which circulates the globe, and transports water, nutrients, and pollutants, throughout the entire planet. This global water cycle causes pollution from terrestrial activities~ pesticides from agriculture, flame retardants in furniture and fabric, toxic metals from coal burning, pathogens from livestock ~ to eventually make their way to the ocean and circulate the the whole Earth.

Take the Mississippi Watershed, for example, which spans a massive, landlocked area rich in agriculture, stretching from Canada across the United States. Agricultural Nitrogen & Phosphorus runoff travels through this massive watershed, down the Mississippi River, and eventually to the Gulf of Mexico, causing hypoxic “dead zones” that threaten biodiversity and fisheries.

What is Our Role? Understand that we are all part of a greater Earth system. Manage your own waste responsibly, be aware of the food and products you buy, and what agricultural practices ~ like pesticide and fertilizer use ~ you support with your purchases at the grocery store & restaurants.

3. Changing seawater chemistry

Given its role as a massive carbon sink, the ocean absorbs vast amounts of carbon dioxide from the atmosphere, driving the carbon cycle and helping balance human-induced climate change. However, this service comes at a cost~ bleaching coral reefs, dissolving the shells of marine organisms, and degrading biodiversity and fisheries. As human activity causes a dramatic spike in fossil fuel emissions, we also flood our oceans with more carbon dioxide, causing the chemistry of seawater to change in a process called “ocean acidification.” 

How does carbon dioxide change seawater chemistry? When absorbed by the ocean, atmospheric carbon dioxide reacts with seawater to form carbonic acid, changing the pH of seawater and making our oceans more acidic. Shellfish, corals, and other organisms with calcium carbonate shells are directed harmed by the increased acidity. Read more about ocean acidification & its impact on marine life, fisheries, and coral reefs here.

What is Our Role? Cut carbon emissions by reducing meat & dairy consumption, install solar panels, drive an electric car ~ diminish your dependency on fossil fuels, and support renewable energy. Eat local foods that require less transportation via driving and shipping. Get an estimate of your carbon footprint by taking a quiz here.

4. Shifting currents means shifting climate

Remember Thermohaline Circulation and its role in distributing heat and nutrients, driving climate and weather, and determining marine food webs?

The melting of the polar ice caps due to increasing global temperatures could drastically change Thermohaline Circulation, altering our planet’s global conveyor belt of currents and intensifying existing climate change. Researchers predict this shift in ocean currents will cause changes such as major cooling in Europe, and extreme warming in other parts of the globe.

Read more about climate change’s impact on currents and climate here.

5. Unsustainable fishing

There once was a time when sushi was my favorite food.

While there certainly are sustainable ways to consume seafood products, the vast majority of fish we consume is not harvested or caught in a sustainable way.

80% of fish species are overfished, at least 75% of global fish stocks are overexploited or depleted, and researchers estimate that if overfishing & ocean pollution aren’t curbed, populations of all harvested seafood species will disappear by 2048.

Overfishing not only has dire impacts on fish populations, but dramatically impacts marine food webs and other organisms that depend on fish for food, or become entangled or trapped from unsustainable fishing practices.

It’s also important to recognize that while this is an environmental challenge, it is closely linked to social and humanitarian issues as well. For some individuals, sushi and fish is an added luxury to diets that also include other forms of sustenance. To others, however, the ocean provides the community’s main source of wealth, nutrition, and nourishment. As fish stocks deteriorate and our oceans become less productive, causing food insecurity and economic loss in regions heavily reliant on fishing, the unequal impacts of environmental degradation across different demographics become strikingly clear.

What is Our Role? Not all fishing is unsustainable fishing — but be very critical. Give vegetarian or vegan sushi a try ~ & seek traceable seafood. Learn more from the Monterey Bay Aquarium’s “Seafood Watch” here.


this page also includes information from:

Stephanie Moret (2016). The Ocean and Fisheries. Personal Collection of Stephanie Moret, University of California, Santa Barbara.

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