Climate Change Effects On Fish and Fisheries

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How Climate Change is Impacting Fish

Brief Summary: While wildfires and hurricanes are impacting our lives on land due to climate change, fish and marine organisms are also influenced by climate change. What is happening to Earth’s waters, and how is climate change affecting fish? Why should you care, and what can you do to help? We’ll answer these questions in this blog post.
Estimated reading time: 7 minutes By Kim DeGracia

You spent all summer planning the perfect beach getaway, and the day of your trip has finally come! You decide to arrive early to enjoy the cool, ocean breeze and to watch the sunrise. As the morning progresses the sun begins to scorch your skin, so you unpack your family’s beach canopy to stay cool. Your friends that came along decide to go back to the beach house to cool down and eat lunch. They’re not as fond of hot weather as you are, but you’re happy that they can enjoy their day in an air conditioned home.

As humans, we are able to use resources or change our environment to adapt to stressors. Animals that hibernate such as the groundhog and animals that migrate such as the snow goose are also able to change their environments or adapt to stressors. One stressor that is impacting our whole planet is climate change.

If you search your local and national news outlets, you’ll find headlines on:

1. Wildfires raging in California, Oregon and Washington
2. Intense hurricanes causing strong winds and flooding 
3. Desert locusts swarming Africa and Asia that attack humans’ food sources and farms

While we can visibly see the effects of climate change on land, climate change is also affecting aquatic ecosystems. Dry land only accounts for less than 30% of the Earth’s surface; the majority of the Earth is covered with water. So, the effects of climate change on species that live in the water are even greater than we realize!
Let’s explore how climate change is affecting fish populations and what you can do to help.

Impact Of Climate Change On Fisheries Sector

Climate change has led to rising sea levels, warming water temperatures, decreasing oxygen levels, and changing levels of salinity. These changes have forced the need for fish to adapt to their environments or to migrate to new parts of the ocean altogether. Since aquatic environments are changing, the variety of fish in a given area is also changing.

How Does Water Temperature Affect Fish

In the recent past, male blacktip sharks migrated between Florida and North Carolina annually to mate. But because the East Coast waters are warming, the blacktip sharks adapted to the warm waters. They no longer need to migrate to Florida. The absence of blacktip sharks endangers Florida’s ecosystem because the sharks are no longer around to eat Florida’s sick fish. The whole food chain is affected, from the fish to coral reefs to aquatic plants. 

The red hake and black sea bass have moved northward by almost 120 miles (193 km) since the 1960s. The Alaskan Pollock and Pacific halibut have moved northward by 14 miles (23 km) since the 1980s. The movement of these fish towards the North Pole shows that they are escaping to cooler environments. Conservation Scientist Miranda C. Jones and Environmental Scientist William Cheung studied 802 marine species and estimated that they shift poleward almost 16 miles (26 km) every 10 years. Warmer water temperatures cause fish to escape to cooler temperatures or adapt to the warm temperatures.

Fish Diversity is Changing

Scientists from Texas A&M University and Texas Parks & Wildlife Department studied the distribution of 141 fish and invertebrate species along the Texas coast. They found that tropical and subtropical fish such as spotted seatrout, Spanish mackerel and Atlantic croaker that traveled to the region increased the diversity of fish in the Gulf of Mexico. 

Climate change can affect the saltiness of water and change sea levels. These changes affect the reproduction, development, growth and migration patterns of fish. Climate change may explain why fish diversity increased by the Gulf of Mexico. Aquatic organisms introduced into new areas leave their former habitats and alter the ocean food web. Altered food webs can impact the survival of aquatic organisms.

What Can I Do To Help Save The Oceans

While the effects of climate change on fish may remain invisible to humans on land, they should not be ignored. The challenges we are facing from climate change show the interconnectedness between our environments of land and water. While we struggle with the negative effects from climate change, we can take actions to reduce the impact climate change has on our waters.

Educate Students and Their Communities

Ocean Blue Project founded the Blue Schools Program to teach K-12 students ecology lessons about their local watershed. The students also learn about the connection humans have to our One World Ocean. One World Ocean refers to the Earth’s 5 ocean basins connected in one great ecosystem. The Earth’s 5 ocean basins are the Pacific, Atlantic, Indian, Southern, and Arctic. The Blue Schools Program is divided into 4 segments:

1. Classroom Learning and Outdoor Field Experience
2. Stewardship Action Projects
3. Synthesis
4. Community Integration

So far, Ocean Blue Project has worked with hundreds of students in Oregon and Florida. Together, we clean beaches, plant trees for streams, test for water quality, and do a range of Stewardship Action Projects to improve water quality and wildlife habitats. 

Ocean Blue has also provided Marine Debris Kits for dozens of classrooms around the world. The kits feature recovered plastics, styrofoam, rope, and other debris. Students can see what goes into the ocean so they can be inspired to keep it out of waterways that flow to the ocean. 

Now, Ocean Blue Schools is expanding with a goal to instill values and a love for nature in the next generation of stewards. In the next year, Ocean Blue plans to roll out year long lesson plans for classroom, virtual platforms, and homeschoolers. 

“The goal is to get students outside and continually coming back to the same Outdoor Field Experience place,” says Karisa Boyce, Development Director and Ocean Blue and creator of The Blue Schools program. “When they’re connected to nature, students notice the subtle differences and become aware of the difference they can make in the natural world. Even if they live inland, they can understand how they affect the ocean from where they live and play.” 

Raising awareness through education is the first step we can take in shaping human values for nature and raising awareness about ocean pollution and its effects on fish. From there, they will understand the importance of habitat restoration projects and simple things like bringing your own cup and straw with you everywhere you go. 

Join Habitat River Restoration Projects
Ocean Blue Project and help removing microplastics from local rivers or ocean sandy beaches. We work with small and large groups to lead cleanups to help make larger impacts for our environment. Create a cleanup today!

Just as we are living through the consequences of climate change on land, fish are affected by climate change in aquatic ecosystems. The consequences of climate change include: 

1. Increasing water temperatures
2. Changing fish diversity
3. Decreasing oxygen levels in waters
4. Rising sea levels


These changes in water temperatures cause harm to aquatic life and coral reefs. While work needs to be done to reverse the consequences from climate change, we can do our part by educating our students, parents, teachers and communities and participating in habitat river restoration projects.

For information about climate change and its effects on our oceans, please check our previous blog post.

Author Bio

Kim DeGracia is a writer, researcher, scientist and clean-water advocate based in the Washington D.C.-Maryland area.