Learn About the Theme

Marine Keystone Species

The 2025 Science Without Borders® Challenge theme is “Marine Keystone Species.” This year, we want you to create artwork that shows a marine keystone species— animals or plants that play a crucial role in keeping ocean ecosystems healthy and balanced. To enter the contest, submit your artwork featuring a keystone species that lives in the ocean, highlighting this creature’s vital role in its marine ecosystem.

 

What is a keystone species?

A keystone species is a plant or animal that plays such an important role in its ecosystem that if it were to disappear, the entire ecosystem would change dramatically. Although it might not be the most numerous or largest species, its presence or absence can have a big impact on the environment.

The term “keystone” comes from how arches are built. At the top of an arch is a special stone called the keystone. This keystone is essential because it holds the entire arch together. Without it, the arch would collapse since the other stones would not stay in place.

Similarly, a keystone species is essential for maintaining the balance of its ecosystem. Just like the keystone in an arch, these species help keep the whole ecosystem stable by supporting many other plants and animals around them.

 

What is an ecosystem?

An ecosystem is a community of living (biotic) things, like plants, animals, and microorganisms, interacting with each other and their environment. This includes non-living (abiotic) things like water, air, and soil. Everything in an ecosystem works together to create a balanced environment where each species has a role to play.

For this contest, you can explore different marine ecosystems. Choose a keystone species—either a plant or animal—that lives in the ocean to feature in your artwork. Here are some marine ecosystems you can consider:

  • Coral reefs
  • Seagrass meadows
  • Mangrove forests
  • Sandy beaches
  • Rocky shorelines
  • Salt marshes
  • Intertidal zones
  • Estuaries
  • Kelp forests
  • Polar ecosystems (Arctic and Antactic
  • Deep sea ecosystems, such as hydrothermal vents, cold seeps, and deep-sea reefs
  • Open ocean

 

How do keystone species impact ecosystems?

Keystone species are crucial because they help maintain the structure and health of their ecosystems. For example:

  • Beavers are keystone species in freshwater ecosystems. They build dams that create wetlands, which provide habitats for various plants and animals. Without beavers, these wetlands might not exist, and many species would lose their homes.
  • African elephants are a keystone species in savannah ecosystems. They are known as “ecosystem engineers” because they shape the landscape in many ways. For example, by uprooting trees, they create open areas. This prevents any one type of plant from taking over, allowing grasslands to thrive and support a variety of animals that rely on these open spaces for food and habitat. Without elephants, the savannah could become overgrown with trees.

Please note that these examples are from freshwater and savannah ecosystems and should not be used for this marine-themed art contest.

 

How do keystone species affect the food web?

A food web is a complex network of who eats whom in an ecosystem. Keystone species play a big role in these food webs. Below are two examples.

  • Regulating Populations: Keystone species help maintain balanced populations of other species, ensuring that no single species becomes too dominant or scarce. For example, wolves are keystone species in the terrestrial ecosystem. By hunting elk, wolves help control elk populations. Without wolves, elk numbers can grow excessively, leading to overgrazing of vegetation. This overgrazing can reduce plant diversity and affect other species that rely on those plants. By managing elk populations, wolves help maintain a diverse and balanced ecosystem.
  • Creating or Maintaining Habitats: Keystone species also play a role in forming or maintaining important habitats. For example, coral reefs provide essential shelter and food for many marine animals. If these reefs are damaged or destroyed, numerous species that depend on them for survival lose their homes and food sources.
     

Why are keystone species important?

Keystone species are crucial because they play a key role in keeping ecosystems balanced and healthy. They help maintain the structure of their environments by influencing food webs, regulating species populations, and creating or preserving habitats. If a keystone species disappears, it can trigger major changes in the ecosystem, potentially leading to the loss of other species and even the collapse of the entire system. By understanding and protecting these essential species, we help ensure the stability and health of natural environments worldwide. Keystone species are vital for the overall functioning of ecosystems, making their conservation critical for the survival of many other species and the health of our planet.

 

Is it possible for an ecosystem to have more than one keystone species?

Yes, an ecosystem can have more than one keystone species. Different species can have special and important jobs that help keep the ecosystem balanced and healthy. For example, in a savanna ecosystem, African elephants and lions both act as keystone species. Elephants help shape the land by knocking down trees and creating open areas, which helps different plants and animals thrive. Lions keep the number of herbivores in check, preventing them from eating too many plants and keeping the ecosystem balanced. So, multiple keystone species can work together to keep an ecosystem stable and thriving.

 

Which species are marine keystone species? 

It’s time for you to find out! Scientists have identified many species that live in the ocean that are keystone species. We encourage you to take some time to do some research and discover a marine species that you would like to feature in your artwork. Whatever species you portray must be a keystone species that lives in the ocean to be eligible to win. Feel free to use the resources we have listed below as well as others you find on your own, then dive deeper to learn more about the keystone species you have chosen to portray.

 

 

Educational Resources

There are many activities available on various marine ecosystems and keystone species. Here are a few resources that can assist in teaching these topics.

Khaled bin Sultan Living Oceans Foundation Education Portal
Our Coral Reef Ecology Curriculum offers an engaging way to explore educational concepts. Students can dive into Unit 1 to learn about the meaning of ecology, the biological hierarchy of life, and ecological levels of organizations, and Unit 16 to delve into food webs and different feeding strategies. If students select coral reefs as their ecosystem and choose a keystone species from these habitats, they can dive into 14 units dedicated to understanding these vital ecosystems.

Deep Ocean Education Project
Deep sea experts, NOAA Ocean Exploration, Ocean Exploration Trust, and Schmidt Ocean Institute teamed up to make ocean exploration education more accessible to educators and learners of all ages by combining resources to learn about and participate in ocean science and exploration.

HHMI BioInteractive
This resource explores how keystone species across various ecosystems significantly influence their environments in diverse ways. It features a map-based interface highlighting 15 keystone species—ranging from predators and herbivores to scavengers and ecosystem engineers—such as the African elephant, gray wolf, and sea otter, showcasing their critical roles in maintaining ecological balance.

National Geographic Education
Find a wide array of activities, videos, photos, and information about keystone species and marine ecosystems by entering keywords into the search bar. Resources are available for various grade levels.

National Marine Sanctuaries
This website provides a range of lesson plans and activities designed to help students explore kelp forest ecosystems. The materials offer insights into the importance of kelp forests, the animals that inhabit them, and the threats they face. Notably, one engaging activity is the kelp forest keystone species game.

PBS Learning Media
Contains various resources about keystone species, including lesson plans, videos, and vocabulary. Type “keystone species” in the search bar to look for resources.

 

OTHER RESOURCES

 

Ocean Literacy Principles

The standards met in this contest will vary depending on the keystone species and ecosystem depicted in the artwork. Below are some Ocean Literacy Principles and Fundamental Concepts that could be met through participation. While additional standards may apply, the most relevant ones are found in Principle 5: The ocean supports a great diversity of life and ecosystems. Click on the links below to see the ocean literacy principles that apply to students in different age groups.