Scientists Identify Cause of Starfish Plague

Post by : Monika

Around 2013, people started noticing something very strange happening to sea stars—from the shores of Mexico all the way up to Alaska. These sea creatures, also called starfish, began to fall apart right before their eyes.

Many beach visitors, kids, and teachers saw sea stars with white sores all over their bodies. Their arms curled up in strange ways, and soon, the bodies started turning soft and mushy. The worst affected was a species called the sunflower sea star. In just five years, nearly all of these sunflower sea stars disappeared from many parts of the coast. Scientists believe that more than five billion sea stars died because of this illness.

This was one of the largest die-offs ever recorded in the ocean. Sea stars are important predators in their environment. When they died, sea urchins—small spiny creatures that sea stars usually eat—began to multiply quickly without any natural checks on their numbers.

These urchins then started eating away at kelp forests, which are underwater forests made of large seaweed. Kelp forests play a very important role in protecting coastlines from storms and waves, and they also provide homes for many ocean animals.

Finding the Cause
For many years, scientists tried to find out what was causing the sea stars to get sick and die. They thought it might be a virus or pollution or even changes in the ocean’s water. But nothing seemed to explain all the strange symptoms.

After long and careful research, scientists finally discovered the real cause—a special kind of bacteria. This bacterium has a complicated name, called Vibrio pectenicida (strain FHCF‑3). They found it inside the liquid that fills the sea stars’ bodies, known as coelomic fluid. Sick sea stars had this bacteria, but healthy sea stars did not.

To be sure, the scientists took this bacteria from sick starfish and grew it in their laboratories. Then, they exposed healthy sea stars to the bacteria. Soon, those healthy sea stars also became sick and showed the same symptoms. This proved beyond doubt that the bacteria was causing the disease that was killing so many sea stars.

How the Disease Affects Sea Stars
Once a sea star catches this disease, the effects are terrible and fast. Its arms start twisting and sometimes fall off completely. The sea star’s body becomes soft and gooey, and it can fall apart in just a few days. Sometimes, even after an arm falls off, it continues to move as if it is still alive. It looks like the sea star is melting from the inside out.

Why This Is Important
This problem is not just about sea stars. These creatures are a key part of the ocean’s food chain, especially because they eat sea urchins. When sea stars die, sea urchin numbers grow without control, and these urchins eat the kelp forests faster than they can grow back.

Kelp forests are very important—they provide shelter for many types of fish and other sea life, protect coastal areas from erosion and waves, and help absorb carbon dioxide from the air, which slows climate change.

When kelp forests die, it upsets the whole ecosystem. Fish populations may drop, and the shoreline becomes less protected. This also affects humans who rely on fishing, tourism, and healthy oceans.

Hope for the Future
Now that scientists know the cause of the sea star disease, they have hope for the future. They can test the water and the sea star habitats for this bacteria to help protect the sea stars that are still healthy.

Scientists and conservation groups have already started projects to breed sea stars that might be resistant to the bacteria. These sea stars can be raised safely in aquariums and then returned to the wild to help repopulate damaged areas.

Researchers are also exploring new treatments. For example, some helpful bacteria might protect sea stars from the harmful bacteria that causes the disease.

The Role of Climate
Scientists are also studying how water temperature affects the disease. There is evidence that warmer ocean water helps the bacteria grow faster and spread more easily. Outbreaks of the disease often happen after periods when the water is warmer than usual.

In cooler places, like deep fjords in British Columbia, sunflower sea stars are doing better and surviving the disease more often. This suggests that colder water may help protect sea stars from getting sick.

What Still Needs to Be Done
Even though scientists have made great progress, there is still a lot to learn. They want to know how common this bacteria really is in the ocean and why some sea stars are able to survive the disease.

Long-term plans include closely watching sea star populations to spot outbreaks early and testing new treatments that could help sick sea stars recover. Helping kelp forests recover is also a big part of the work. The healthier the kelp forests, the better the ocean environment will be for all kinds of sea life.

Why Kids Should Care
You might think sea stars are just simple animals, but they play a very important role in keeping the ocean healthy. When sea stars disappear, it causes big changes in the underwater world. The number of sea urchins grows too much, kelp forests shrink, and many fish lose their homes.

Healthy oceans are important for everyone—not just animals, but also for people who fish, visit beaches, or simply enjoy nature. Now that scientists understand what caused this huge problem, they can work on solutions to bring sea stars back and keep the ocean balanced.

• Starting in 2013, millions of sea stars started getting sick and dying along the Pacific coast.
• Scientists discovered the cause was a bacteria named Vibrio pectenicida.
• The disease causes sea stars’ arms to fall off and their bodies to turn mushy.
• Without sea stars to eat them, sea urchin numbers grew too large and damaged kelp forests.
• Kelp forests are important for ocean health, protecting coastlines, and supporting many animals.
• Researchers are working on ways to help sea stars survive and recover.
• Warmer water helps the bacteria spread, but cooler water can protect sea stars.
• Scientists still need to learn more to protect these important ocean creatures.

Sea stars may seem small, but their health affects many creatures and even people. This discovery is a big step toward fixing a problem that changed the Pacific coast’s ocean life for many years. It reminds us how important it is to understand nature and work together to protect it.

Pacific coast sea star die-off