The continuation of human life relies heavily on how we treat our planet and most importantly our oceans since they cover the vast majority of Earth. The loss of biodiversity in the oceans is increasing drastically because of human activity and will soon reach rates to where species and ecosystems cannot recover. This is important to us because we rely on our oceans for many resources, essential goods, and services to survive and prosper. Marine life must remain stable and healthy for humans to continue to live on this planet and grow economically.

To begin with, the oceans provide so much for our planet as they cover more than 70% of the Earth. Our oceans produce more than half of the oxygen in the atmosphere and is a great absorber of carbon dioxide to help combat climate change and help phytoplankton, which increase biological productivity, grow. There are thousands of jobs in the science field to study and work with the oceans because so much is unknown about it. Fisheries provide food for billions of people and in return provide mass amounts of revenue to our economy. Food that we eat, products that we use, medicine we need, and entertainment that we pay for can all come from our oceans. Our ability to use it as transportation is just another positive aspect of having the ocean available to us. 

Even though all these points are positive ways to utilize what our oceans have to offer, we are using them to benefit ourselves with little thought to how it is effecting the environment in the long run. Over the last century there have been many large-scale advances and changes on how humans live and provide resources. Technology has become incredibly advanced just within the past few decades, allowing us to take more from our planet at faster rates without a second thought about how it may affect the Earth. With the population growing faster than ever, this means that more and more people will want and need these resources that we are already exploiting.

Currently our focus in the economy is all about numbers. Generally, we want to provide the maximum amount of goods and services that we can while making as much money as possible for our own benefit. The ocean seems endless and dispensable because of how large it is and how little we know about it. It was thought that we could never put too much waste into the ocean or take too much life out of it because of how massive it is on a global scale. Even though the ocean can get rid of waste and we are able to use it for our own benefits, this does not mean there is no cap on how much we can put in and take out.

To prove some of these points, scientists Boris Worm and Nicola Beaumont along with many other qualified scientists performed multiple experiments to test marine biodiversity and how it effects different types of ocean ecosystems. They examined 12 different coastal and estuarine areas for species diversity in each ecosystem. Areas that had higher numbers of species proved to be more stable and showed slower rates of biodiversity loss. 

 Using records from the past millennium and current data they collected, it showed a rapid decline in species diversity specifically since the industrial age began. Up until that point, the levels had been very stable. Three of the 12 sites were critically impaired by biodiversity loss, meaning that the sites could get to the point where they cannot provide the services they naturally would. The number of reliable fisheries, habitats like oyster reefs and wetlands which serve as a nursery for juvenile fish, and water filtering services from suspension feeders and wetlands all decreased significantly in these areas. All of this contributed to lowered water quality, an increase in harmful algal blooms, and oxygen depletion. Overall, their results confirm that marine biodiversity loss is associated with loss of services that marine ecosystems provide. 

They also did similar research on larger marine ecosystems regarding fisheries worldwide. They took data from all recorded fish and invertebrate catches from 1950 to 2003 within all areas that are defined as a large marine ecosystem. They found that 29% of currently fished species are collapsed which means they showed a greater than 90% decline since 1950. Relating back to their first experiment, they confirmed that these collapses occurred more frequently in ecosystems that had declined in species diversity. This proves the point that biodiversity is necessary for ecosystems to thrive and prosper. 

On the opposite side of these two experiments, they also observed marine areas that were protected and areas where fisheries had closed. Comparing what they were like before they were protected or closed, they saw on average a 23% increase in species richness since then. Because these areas had not been abused and exploited by humans, they were able to bounce back and become a more natural ecosystem again. 

If small, local ecosystems are destroyed it plays a bigger part than the average person thinks and can lead to a much larger scale very quickly. Each organism in the ocean serves a purpose and maintains a balance that must be kept. If thousands of species continue to decline at such a fast rate, it’s very possible we can lose keystone species that are essential for the oceans to function properly. If the rates continue as they have been, they predict there could be possible threats to global food security from the oceans, water quality, and ecosystem stability. 

Overall, they concluded and confirmed that biodiversity in all marine ecosystems fuels the natural services that the oceans provide for us. They also acknowledge that it is almost entirely human activity that is causing these mass changes to the marine environment and that we need to better manage fisheries, control pollution input, maintain essential habitats, and increase the number of marine reserves. They end the report with the statement that we are negatively affecting our current generation and that we will affect future generations even worse if we do not change our relationship with the oceans now.

Specifically, one of the worst and most prevalent issues with our oceans is the amount of pollution that goes in and cannot be broken down. Pollution in the ocean is defined as “marine litter” and throughout history has ranged from many different types such as trash, plastic, pharmaceuticals, dead animals, chemicals, large structures (ships), carbon dioxide, sewage waste, dredge waste, mining waste, fishing waste, and radioactive waste. From that list, dead animals and carbon dioxide are the only two that occur naturally and even with those, we boost them to unhealthy rates.

When it comes to pollution, most people think of plastic floating on the surface. The deep ocean is often overlooked because there is less known about it. All other pollutants that do not float must go somewhere, and they sink straight to the ocean floor. The deep sea is typically very cold, nutrient rich water that makes up roughly 95% of the oceans and contributes a lot more than what was expected by early scientists. One of many services it provides is that it continues to break down carbon dioxide as it gets lower in the water which reduces the impact that humans are contributing. It also is a recycling center for nutrients, meaning that the nutrients such as silica, phosphorus, hydrogen, sulfur, and nitrogen are transported by deep ocean currents up to the open ocean and surface waters where they are needed, which is called “upwelling.” 

One of the most important nutrients in the ocean, nitrogen, is fixed through the nitrogen cycle by deep sea organisms so that it can be properly used by other organisms. It is also already a limiting nutrient, meaning that it is supplied at the lowest rate to organisms that need it. When chemicals, sewage, and other pollutants sink to the bottom in mass amounts it can interfere with this process. This can cause the deep-sea dwelling organisms to not be able to fixate as much nitrogen which then means that organisms in the open ocean and near the surface may not receive the nutrients they need.

 In the deep ocean, the water temperature and salinity change very little and it is always pitch black with the only exception being fish that are bioluminescent. Even though there is no sunlight in the deep ocean, there is a surprisingly high amount of biodiversity featuring many unique organisms that live there that are all accustomed to very specific living conditions. When pollution covers non-mobile organisms on the sea floor, warms the water, or changes the chemical makeup of the water even slightly it can prevent these organisms from doing their natural job. 

All ocean functions are easily linked together and will not properly function if humans continue to take advantage of it. The loss of one species can directly affect another significant species and set off a chain reaction that will only continue to happen with the way we treat our planet. Pollution is one of the largest human impacts on the ocean along with climate change that affects it negatively and on a large scale in many ways. 

Regarding climate change, it is one of the most commonly talked about subjects in the environmental field today. It drastically affects the oceans by warming water temperatures, causing sea level rise, and increasing ocean acidification to name a few. With the warming of the water surface winds from the ocean will contribute warmer atmospheric temperatures as well. Polar organisms along with all organisms that require certain temperatures may not be able to adjust to changes as quickly they are happening, which is another reason some species are heading towards extinction.

 With the amount of research done and the results provided it seems hard to deny that climate change and biodiversity loss is happening. It is also hard to reject that it is almost entirely caused by humans. A woman named Judith Curry is one of the most known climatologist who rejects that climate change is mostly caused by humans. She received a PhD in geophysical sciences and was chair of the School of Earth and Atmospheric Sciences at Georgia Institute of Technology, which shows she is educated on the topic and that both sides can be argued. 

She acknowledges that humans affect the environment, but she does not believe to the extent most people do. She states that linking climate change and its effects on the environment to humans is unsupported by evidence. Curry believes that climate change and its effects such as rising sea temperatures and species loss are from natural Earth processes. She basically believes that humans causing climate change is a mainstream belief that people follow blindly without proper knowledge. She says that all who study in this field need to go back and have a better understanding of the fundamental interactions between the ocean and atmosphere because she believes that is the driving force behind climate change. 

 