Sea sparkle is a single-celled of coasts worldwide that flashes blue when waves break, boats pass, or you splash through the water at night. Each cell is a clear sphere about 0.02–0.06 in (0.4–1.5 mm) across, just big enough to see with the naked eye. Big blooms can turn coastal water pink or orange by day.
Appearance
- Appearance
- A translucent ball with a single short tentacle-like extension. It floats near the surface by adjusting the salts inside its cell.
Look-alikes
The famous glowing blue waves of Southern California, like those off San Diego, mostly come from this much smaller , whose cells are only 35–60 micrometers across and far too small to see. Sea sparkle cells are about 0.4–1.5 mm, just big enough to see with the naked eye.
Why they get mixed upBoth glow blue when waves break at night, and both can tint the water during big daytime blooms.
Where it lives
- Typical habitats
- Coastal waters
- Bays
- River mouths
- Range
- Found along coasts worldwide from temperate to tropical seas, especially near shore and around river mouths. In the US, blooms have been recorded in Puget Sound, Washington.
- Preferred conditions
- Blooms build up in nutrient-rich coastal water, mostly in warm seasons. The red form handles water of about 50–77°F (10–25°C).
Behavior
- Diet
- The common red form can't photosynthesize. It eats diatoms and other , small protists, and copepod and fish eggs, and can go more than three weeks without food.
- Activity
- When the water is disturbed, a chemical reaction (luciferin and luciferase, like in fireflies) inside tiny packets in the cell gives off a blue flash lasting less than a tenth of a second. It glows most strongly at night.
Life cycle
- Reproduction
- Mostly reproduces by splitting in two. When cells get crowded and food runs short, some switch to producing swimming sex cells that fuse.
Cautions
- Cautions
- It doesn't make toxins. But very dense blooms can kill fish and shellfish because ammonium builds up and oxygen in the water drops.
Name and classification
- Varieties and forms
- There's a widespread red form and a green form that houses photosynthetic green algae inside its cell. The green form lives in warm tropical seas such as the Arabian Sea and Southeast Asia.
Conservation
- IUCN Red List
- NENot EvaluatedNot yet assessed
- Threats
- Big blooms may be a sign of nutrient pollution along the coast, though the link to nutrient levels isn't always clear.
More species to explore
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