Your next speech assignment just got way more exciting. The ocean covers most of our planet, but we’ve barely scratched the surface of what’s down there. That’s a goldmine of amazing stories just waiting to be told.
Whether you’re talking to students, nature lovers, or anyone who enjoys a good story, the ocean gives you so much material to work with. You’ve got everything from weird creatures that glow in the dark to people building incredible machines to clean up our mess.
These topics will help you create something your audience wants to hear.
Speech Topics about The Ocean
Here are twenty different angles you can take, each one totally different from the others. Pick what feels right for your audience and your interests.
1. The Plastic Problem: What’s Really Happening Out There
We’re basically feeding our oceans plastic for breakfast, lunch, and dinner. Every minute, a garbage truck’s worth of plastic waste ends up in the water. The crazy part? You’re probably eating some of that plastic right now—it’s in our fish, our salt, even our drinking water.
Talk about one piece of trash and follow its journey. Maybe start with a water bottle someone tossed out their car window. Show how it breaks apart, gets eaten by fish, and eventually ends up on someone’s dinner plate. People remember stories better than statistics, so make it personal.
2. Glowing Ocean Creatures: Nature’s Built-in Disco
Picture this: you’re swimming at night and suddenly everything around you starts glowing blue. That’s not science fiction—that’s just Tuesday night in many parts of the ocean. Millions of tiny creatures make their own light using chemicals in their bodies.
Start your speech in complete darkness, then slowly add some LED lights to show what bioluminescence looks like. Tell your audience about the vampire squid (yes, that’s a real thing) and how its light show scared off predators for millions of years. Then blow their minds by explaining how scientists copied this trick to create better medical treatments.
3. When Oceans Turn Sour: The Acid Problem Nobody Talks About
The ocean is getting more acidic every day because it’s soaking up all the extra carbon dioxide we’re pumping out. Think of it like adding lemon juice to milk—things start falling apart. Shellfish can’t build their homes anymore, and coral reefs are basically dissolving.
Here’s a fun demonstration: drop some chalk in vinegar and watch it bubble away. That’s exactly what’s happening to coral skeletons and clam shells right now. You can make this hit home by talking about the local seafood restaurant that might not have oysters on the menu much longer.
4. The Garbage Patch: One Kid’s Crazy Idea to Clean the Ocean
There’s a floating island of trash in the Pacific that’s bigger than most countries. For years, everyone said it was impossible to clean up. Then this teenager from the Netherlands said, “watch me” and figured out how to do it.
Tell the story of Boyan Slat, who started sketching ocean cleanup ideas in high school and now has floating systems collecting tons of plastic. Focus on how many people told him it couldn’t work, and how he proved them wrong. Your audience will love hearing about someone who didn’t take “no” for an answer.
5. Digging Up the Ocean Floor: The Fight Over Underwater Mining
Your smartphone needs special metals to work, and guess where a lot of those metals are hiding? On the bottom of the ocean, just sitting there. Companies want to go get them, but there’s a problem—we have no idea what lives down there or what we might destroy.
Set this up like a courtroom case. Present the argument for mining (we need these metals for clean energy) and against it (we might wipe out species we haven’t even discovered yet). Let your audience be the jury. This kind of back-and-forth keeps people engaged and thinking.
6. Tsunami Warnings: How We Learn to Outrun Giant Waves
When the ground shakes under the ocean, it can create waves tall as buildings that race across entire oceans faster than jet planes. The good news? We’ve gotten really good at predicting when and where they’ll hit.
Use the 2004 Indian Ocean tsunami as your main story. Explain how thousands of people died simply because no one warned them, then show how the warning systems we built afterward have saved countless lives. Make it clear that technology and cooperation between countries can prevent tragedies.
7. Whale Highways: Following the Ocean’s Greatest Travelers
Some whales travel farther in a year than most people travel in their entire lives. They somehow know exactly where to go without GPS, maps, or even stopping to ask for directions. Gray whales swim from Alaska to Mexico and back—that’s like driving from New York to Los Angeles four times.
Take your audience along for the ride. Describe what a whale might see and experience during its months-long journey. Talk about the dangers they face, from ship strikes to getting tangled in fishing nets. Then share how satellite tags are helping us understand these incredible journeys and protect the routes they take.
8. Growing New Coral Reefs: Underwater Gardening at Its Finest
Coral reefs are like underwater rainforests—packed with life and beautiful. When they get damaged by warming water or pollution, scientists have figured out how to regrow them piece by piece. It’s like being a gardener, except your garden is 30 feet underwater.
Walk through a typical day for a coral restoration scientist. They collect tiny coral pieces, grow them in underwater nurseries, then carefully transplant them back to damaged reefs. Show before and after photos of restoration sites. People love seeing broken things get fixed, especially when it involves underwater adventure.
9. Power from Temperature: The Ocean’s Hidden Energy Source
Hot water and cold water can make electricity when you put them together the right way. Tropical oceans have warm water on top and ice-cold water way down deep—perfect for generating power 24 hours a day, unlike solar panels that only work when the sun’s shining.
Do a simple experiment with two cups of water at different temperatures to show how this works. Talk about Hawaii’s experimental power plant that’s already making electricity this way. This is especially interesting for people worried about reliable, clean energy that doesn’t depend on whether it’s sunny or windy.
10. Ocean Safe Zones: Where Fish Get to Live in Peace
Marine protected areas are like national parks, but underwater. When we stop fishing in certain areas, something amazing happens—the fish come back, and they get bigger and have more babies. Even the areas outside the protected zones end up with more fish.
Tell success stories from places like the Great Barrier Marine Park or California’s network of protected areas. Use numbers that people can understand, like how many more fish there are now compared to before protection. Address the obvious question: Don’t fishermen get angry about being told where they can’t fish?
11. Sunken Cities: Time Machines Under the Sea
Rising seas have swallowed up entire cities throughout history, preserving them like underwater museums. Archaeologists can swim through ancient streets and explore buildings that haven’t seen sunlight for thousands of years.
Focus on one spectacular site, like the submerged city of Heracleion in Egypt or the prehistoric settlements off the coast of England. Describe what it’s like to swim through an ancient marketplace or see statues that have been underwater longer than Christianity has existed. Connect this to what might happen to our coastal cities if sea levels keep rising.
12. Jellyfish Takeovers: When the Ocean Gets Gooey
Sometimes jellyfish show up in numbers so huge they shut down entire beaches, clog up power plants, and turn parts of the ocean into a living jelly sea. These population explosions are happening more often, and they’re a sign that something’s not right with our oceans.
Start with the most dramatic examples—like the jellyfish swarm that knocked out a nuclear power plant in Japan or the one that filled an entire bay in Australia. Explain how overfishing and pollution create perfect conditions for jellyfish blooms. But don’t make it all doom and gloom—talk about countries that have turned jellyfish into a food source.
13. Robot Ocean Explorers: Sending Machines Where Humans Can’t Go
We’ve built robots that can dive deeper than any human, stay underwater for months, and make their own decisions about what to explore next. These underwater robots have discovered new species, mapped underwater mountains, and found things we never knew existed.
Compare these robots to the Mars rovers—except instead of exploring another planet, they’re exploring 95% of our planet we’ve never seen. Share recent discoveries these robots have made, like new species of deep-sea creatures or underwater volcanoes. Make it clear that artificial intelligence isn’t just for tech companies—it’s helping us understand our planet.
14. Seaweed Farming: Growing Food Without Dirt or Fresh Water
Seaweed might be the perfect crop—it grows incredibly fast, doesn’t need any fresh water or fertilizer, and you can turn it into everything from food to fuel to biodegradable plastic. Plus, it helps clean the ocean while it’s growing.
Show your audience all the things they use every day that contain seaweed products—toothpaste, ice cream, cosmetics. Explain how seaweed farms look like underwater forests that don’t take up any land that could be used for other food crops. This is especially interesting when you talk about feeding a growing world population without destroying more natural habitats.
15. Noisy Oceans: How Ship Engines Mess with Whale Conversations
The ocean used to be a pretty quiet place, but now it’s full of noise from ships, construction, and military sonar. This underwater racket is so loud it’s drowning out whale songs and messing up dolphin echolocation. Some whales are shouting to be heard over the noise.
Play recordings of what the ocean sounds like now compared to how quiet it used to be. Explain how whales use sound to communicate across hundreds of miles, and how human noise is breaking up these conversations. Talk about solutions like quieter ship engines and speed limits in whale areas.
16. Moon Power: Getting Electricity from the Tides
Twice a day, the moon pulls billions of gallons of water up and down our coastlines. That’s a massive amount of energy just going to waste. Engineers have figured out how to capture some of that energy and turn it into electricity that works whether it’s sunny, cloudy, windy, or calm.
Use simple demonstrations to show how the moon creates tides, then explain how underwater turbines work like underwater windmills. The best part about tidal energy is its predictability—we know exactly when high and low tides will happen for the next thousand years. Compare this reliability to solar and wind power, which can’t work all the time.
17. Coastal Carbon Collectors: The Wetlands That Fight Climate Change
Salt marshes and mangrove swamps are like supercharged forests when it comes to storing carbon. They suck carbon dioxide out of the atmosphere and bury it in their muddy soils faster than any land-based forest. Plus, they protect coastlines from hurricanes and provide homes for fish.
Talk about these ecosystems like they’re nature’s multitaskers—fighting climate change, protecting coastal communities, and supporting fishing industries all at the same time. Use examples of places where restoring wetlands saved communities millions of dollars in hurricane damage. Make the connection between protecting local environments and solving global problems.
18. Ocean Medicine Cabinet: Life-Saving Drugs from Sea Creatures
Some of our most important medicines come from weird sea creatures that live in places where no human has ever been. Sea sponges gave us cancer treatments, marine bacteria provide blood thinners, and we’ve barely scratched the surface of what’s out there.
Share specific examples of medicines that came from the ocean and how they’ve saved lives. Make it personal—talk about how someone’s grandmother might be alive today because of a compound discovered in a Caribbean sponge. Emphasize that we’re racing against time to discover new medicines before pollution and climate change wipe out species we haven’t even found yet.
19. Antarctica’s Melting Ice: The Biggest Player in Sea Level Rise
Antarctica holds enough ice to raise sea levels by 200 feet if it all melted. That won’t happen overnight, but even small changes in Antarctic ice can flood coastal cities around the world. Satellite images show ice sheets disappearing faster than scientists expected.
Use dramatic before-and-after satellite photos to make abstract climate data feel real. Explain how ice that’s been frozen for millions of years is now melting into the ocean. Connect Antarctic ice loss to local impacts—show which neighborhoods in your audience’s city would flood with different amounts of sea level rise.
20. Ocean Smarts: Why Everyone Should Know About the Sea
Most people know more about outer space than they do about the ocean, even though the ocean controls our weather, provides our oxygen, and affects pretty much everything about life on Earth. Ocean literacy isn’t just for marine biologists—it’s for anyone who wants to understand how their planet actually works.
Challenge your audience with some basic ocean questions that most people get wrong. How much oxygen does the ocean produce? (More than half.) Where does rain come from? (Mostly ocean evaporation.) Make the case that understanding the ocean helps people make better decisions about everything from climate policy to where to live. End with simple ways people can stay connected to ocean health, even if they live hundreds of miles from the coast.
Wrapping Up
Each of these topics connects to bigger issues that matter to everyone: climate change, food security, clean energy, and protecting the planet for future generations. The ocean touches every part of human life, whether people realize it or not.
Pick the topic that gets you excited, because your enthusiasm will be contagious. Your audience will walk away understanding something new about the incredible planet we all share.