Sunflower Sea Stars

Source: ET

Context: Scientists have finally identified Vibrio pectenicida as the bacterium causing sea star wasting disease (SSWD), which led to the loss of over 5.8 billion sunflower sea stars across North America since 2013.

About Sunflower Sea Star (Pycnopodia helianthoides)

• What It Is? A large, fast-moving marine predator with up to 24 arms; vital in regulating underwater ecosystems by preying on sea urchins.

• A large, fast-moving marine predator with up to 24 arms; vital in regulating underwater ecosystems by preying on sea urchins.

• Habitat: Native to the Pacific Ocean, ranging from Alaska to Baja California, dwelling on kelp beds and rocky seabeds.

• IUCN Status: Listed as Critically Endangered due to mass mortality from SSWD.

• Key Features of the Sunflower Sea Star:

• Size: Can grow up to 1 meter (3.3 feet) in diameter, making it one of the largest known sea stars.

• Mobility: Capable of moving at a speed of up to 1 meter per minute using thousands of tube feet.

• Arms: Possesses 16 to 24 soft, flexible arms, aiding rapid movement and predation.

• Feeding Habits: Acts as a top predator, feeding on sea urchins, clams, and other invertebrates.

• Habitat Range: Found in temperate coastal waters from Alaska to California, primarily on rocky reefs and kelp beds.

• Coloration: Exhibits vibrant hues—orange, purple, red, or brown, aiding in camouflage and predator avoidance.

• Respiration & Circulation: Uses a water vascular system and coelomic fluid (analogous to blood) for nutrient transport and gas exchange.

About Vibrio pectenicida:

• What Is It? A pathogenic marine bacterium, also known to affect shellfish, now linked conclusively to sea star wasting disease (SSWD).

• A pathogenic marine bacterium, also known to affect shellfish, now linked conclusively to sea star wasting disease (SSWD).

• Where It Was Found? Detected in high abundance within the coelomic fluid (internal fluid akin to blood) of infected sea stars.

• Detected in high abundance within the coelomic fluid (internal fluid akin to blood) of infected sea stars.

• Features & Effects: Strain FHCF-3 of pectenicida initiates with external lesions, leading to twisted arms, tissue decay, and death. Transforms sea stars into mucus-like goo within days, disrupting marine trophic chains. Thrives in warmer ocean conditions, raising alarm over climate-linked outbreaks.

• Strain FHCF-3 of pectenicida initiates with external lesions, leading to twisted arms, tissue decay, and death.

• Transforms sea stars into mucus-like goo within days, disrupting marine trophic chains.

• Thrives in warmer ocean conditions, raising alarm over climate-linked outbreaks.

• Ecological Significance & Broader Impact Keystone Species Loss: Sunflower sea stars kept urchin populations in check; their decline led to exploding urchin numbers. Kelp Forest Collapse: Northern California lost 95% of kelp cover, impacting fisheries, biodiversity, and coastal protection. Cultural & Economic Damage: Affects First Nations’ traditions, recreational diving, and carbon sequestration potential of kelp.

• Keystone Species Loss: Sunflower sea stars kept urchin populations in check; their decline led to exploding urchin numbers.

• Kelp Forest Collapse: Northern California lost 95% of kelp cover, impacting fisheries, biodiversity, and coastal protection.

• Cultural & Economic Damage: Affects First Nations’ traditions, recreational diving, and carbon sequestration potential of kelp.