Olivia Lee

Project

Presentation

Progress Log

Capstone Essay

Olivia Lee

Mr. Coussens

English 4

May 5, 2020

How Humans Impact the Pacific Ocean Food Web

I fell in love with the ocean at a very young age. The smell, sounds and sights intrigued me. The sound of the waves crashing on the shore and the ever changing tides made me wonder about the mysteries that lay beneath the surface. I have always had a desire to learn about all of the animals that live in the sea, and I care deeply about ocean conservation. My love for the ocean has inspired me to want to become a marine biologist and learn about all of the magnificent creatures that live there. Even though I knew I wanted to do something with marine animals for my capstone project, it took me a few months to figure out what I wanted to do. I finally landed on the topic of the Pacific Ocean food web. Most people learn about the food chain and food web at a young age. I needed to refresh my memory and dive deeper into what a food web is, how humans impact it and how extinction harms the ecosystem. Food webs are crucial for understanding the natural world, but with human activities causing many different species to go extinct, the food webs are collapsing under all of the sudden changes.

What is a food web?

Many people forget or never learned what the difference between a food chain and a food web is. Both a food chain and a food web show people what animals eat. A food web is restrictive and only shows one animal of each trophic level. It is made up of many different food chains (Aquatic) in the same ecosystem and it presents one or more animals of each trophic level (DiVico). A trophic level is each level of the food web. There are four levels, producer, primary consumer, secondary consumer and tertiary consumers. Food webs were created for three main reasons: the first is to show that all ecosystems start with a plant or plant-like organism, (Aquatic) the second is to be able to showcase what happens when an animal goes extinct and thirdly, it shows what affects the extinction has on the rest of the ecosystem (DiVico). Looking at the structure of food webs and food chains helps people to understand the foundations of how these three things work.

What is the structure of a food web?

Food chains and food webs have a similar structure. They both start with Producers, who are the base and lifeline of all of the food webs and chains. These mostly photosynthesize and use the sunlight for nutrition and energy. Some plants do not photosynthesize and use other ways to gain energy. This includes chemicals released from hydrothermal vents and many other geographical features. The next level of a food web is primary consumers which include zooplankton and some small fish. Zooplankton are small marine mammals and fish. They float through the different currents in the ocean and eat whatever producers they can find. Thirdly, there are two different types of predators: pursuit and ambush. Some examples of Pursuit predators include sharks, sunflower starfish, and other larger fish. These predators hunt and chase their prey. On the other hand, ambush predators hide and suddenly attack their unsuspecting prey. These animals include shrimp, octopi, and some species of eels. These predators can be secondary and tertiary consumers. Secondary consumers eat the primary consumers. Some consist of many types of filter feeders including tube worms, baleen whales and manta rays. Tertiary consumers are the animals that have little to no predators (Aquatic) Some examples of these are killer whales and great white sharks. Killer whales have no natural predators and they hunt in packs and mainly feed on salmon. Occasionally, these whales will eat sharks. This is an extremely rare occurrence and it has only been seen a few times. It is no surprise that great white sharks are one of the tertiary consumers since their keen sense of smell allows them to smell one drop of blood in 10 billion drops of water. Furthermore, they can sense movement 820 feet away (“Top of the food chain”). The last level of the food web are scavengers, and they eat decaying material. Lastly, there are the opportunistic feeders. These animals are not categorized onto a level of the food chain due to the fact that they consume almost anything in any level in the food web. In addition, they might even eat each other (Aquatic).

How are plants and animals dependent on one another?

Plants and animals need each other to survive. When one species goes extinct, an entire food web can collapse. Most types of flowers depend on bees and many other types of pollinators to help them reproduce. One of the ways that plants do this is by making seeds which is done through pollination. These seeds eventually scatter and fall onto nutrient dense soil where flowers can grow. Another example of how plants help animals is that plants consume carbon dioxide and release oxygen into the atmosphere which allows animals on land and in the sea to breathe (Mackenzie). Plants also provide shelter for animals. For example, when a sea otter is being chased by a shark they swim to a kelp forest for safety. The kelp provides shelter and it makes it harder for the shark to find the otter. Plants help animals thrive in multiple ways and animals contribute to the wellbeing of plants. Ironically, one of the greatest ways animals help plants is when they die. When animals die, they decompose into the soil which fertilizes and provides nutrients to the plants around it (Mackenzie). If bees go extinct, flowers would be unable to reproduce, and if that were to happen, many of the animals higher in the food chain would not be able to survive. If the kelp forests die off, the sea otters would not have a place to hide and they would get eaten by the sharks. If the sea otters were to become extinct, the food web will be put at risk.

How does extinction harm the food web?

Many people a long time ago lived in fear, now they live in greed. People were afraid many apex predators were going to hurt them, their family and their livestock. The people thought the only answer to their fear was to eliminate what they were afraid of. They killed off every animal that they perceived as a threat to their well being. One example of an animal people feared was the Tasmanian tiger. The people were scared that this animal was going to eat all of their livestock. They went around the land setting up traps and shooting the animal whenever it came into view. After a few years of being attacked the tiger eventually went extinct. When people hunt and kill top predators to the point of extinction, the prey that the animal used to feed on has no predator. When animals have no natural enemy, they don’t have anything to keep their numbers in check. When this happens, they eat all of the plants and shrubbery around them. This creates an imbalance with the vegetation because it is being eaten faster than it can reproduce. Furthermore, this puts stress on the food web and if there is one more extinction in that area all of the animals could die. Along with apex predators going extinct, many animals on the lower levels of the food chain can die off too. Consequently, the predators that eat this animal have to move to another food source which can put stress on the other animal's numbers (Bove). Many people only care about making money with no regard for the planet. These things put animals at risk and create climate change.

What is climate change?

Climate change is caused by carbon dioxide and methane being released into the atmosphere and these greenhouse gasses are covering the earth like a blanket. This warms the earth and the land and oceans are affected by it. Many marine plants including phytoplankton and algae need cooler oceans to survive. Due to the warming of our planet the nutrients in the water can't drift upward into the sunlight which makes the phytoplankton and algae unable to turn carbon dioxide into oxygen. Consequently, marine life is harmed (Lindell).

How are plants and animals affected by climate change?

Animals and plants are drastically affected by climate change. When the temperature of the air rises the oceans become less dense and the water separates from the nutrients. Many plants including phytoplankton are starting their growth season earlier which affects the ecosystem. Animals that used to travel to the surface to find food are now having to find new areas to eat. Climate change can also cause animals to migrate at different times of the year. Many species that are heat tolerant like shrimp are migrating north and species that are intolerant to heat like clams and flounders are retreating from the north. This reduces the food supply for predators causing them to move to a different food source. Carbon dioxide changes the ocean's chemistry by making it more acidic. The acidity reduces plankton and can also threaten coral and shellfish (Lindell).

How does plastic pollution harm animals?

Plastic pollution also harms marine ecosystems. Plastics were made to package things like food and toys. The reason why plastics are used by manufacturers in such massive amounts is due to their inability to break down or decay. A large percentage of plastic is not recyclable and ends up being dumped into our oceans. Additionally, plastic can be taken by the wind and drop into the ocean. About 5.3 million tons of plastic are dumped into the oceans each year (“Plastic Pollution”). The plastic floats on the ocean and gets taken by the currents. The floating plastic forms floating garbage patches in the ocean. The biggest garbage patch is called the Pacific Ocean garbage patch which is the size of Texas. The plastic severely harms and even kills marine life. Many animals have been seen tangled in lost fishing gear and soda springs. Consequently, they get stuck in the garbage and either starve to death, suffocate or drown. Animals have also been seen dead with plastic in their stomach including sea turtles and many filter feeders like manta rays. Plastic bags look like jellyfish which are sea turtles' main food source. The sea turtles mistake the bags for jellyfish and when they consume the plastic they die from indigestion. Another type of plastic that is extremely damaging to our oceans are Micro plastics. Micro plastics are small pieces of plastic that have broken off of a larger piece of plastic. This affects filter feeders who swim with their mouth open. Filter feeders have little control over what they consume and end up eating many pieces of micro plastics. As a result, this can end up killing the animal.

Through my research I have learned about the delicacy of food webs, the extent of plastic pollution in our oceans and climate change. Many human activities are putting food webs and marine life at risk. Climate change and plastic pollution are creating devastating circumstances in our oceans which could make them become uninhabitable. This information helped me realize that food webs desperately need our help. If we as human beings don’t change our ways, all species will be at risk. I will use all of the information I gathered about the food web to create paintings of some of the animals in the Pacific Ocean. My paintings will be designed to show the food cycle and illustrate what happens to the food web when one animal goes extinct. My goal is to reveal the delicate nature of food webs and food chains in the Pacific Ocean. Most importantly, I hope that people will be inspired to take action in caring for our planet.

Works cited

“Aquatic Food Webs” NOAA, February 2019,

https://www.noaa.gov/education/resource-collections/marine-life-education-resources/aquatic-food-webs. April 2, 2020.

Bove, Jennifer “Why it Matters When Species go Extinct” Thought Co, May 6, 2019

https://www.thoughtco.com/why-it-matters-when-species-go-extinct-1182006. April 9, 2020

DiVico, Taylor “Why is the Food Web Important?” Sciencing, March 14, 2018.

https://sciencing.com/food-important-5525614.html. April 6, 2020.

Gohd, Chelsea “Marine Food Webs are on the Brink of Collapse Because of Climate Change”

Futurism, January 9, 2018,

https://futurism.com/marine-food-webs-brink-collapse-because-climate-chan. April 9, 2020.

Lindell, Nicole “A Distant Sea: Global Warming and its Effect on Marine Populations” Thought

co, March 08,

https://www.thoughtco.com/global-warming-effect-on-marine-populations-1434916. April 22, 2020

Mackenzie, Ashley. “How do Plants and Animals Depend on Each Other?” Sciencing, July 21,

2017, https://sciencing.com/causes-destruction-ecosystem-5594776.html. April 2, 2020

“Plastic Pollution” Britannica School, n.d,

https://school.eb.com/levels/high/article/plastic-pollution/477253. April 8, 2020.

“Top of the Food Chain: 5 Deadly Marine Predators “Eaglewingtours””

https://www.eaglewingtours.com/articles/top-of-the-food-chain-5-deadly-marine-

predators/. April, 6 2020.