Sea Lettuce
Ulva lactuca · Also known as: green seaweed, ulva
Bright green sheet algae of bays and beaches. Common summer wrack on Assateague and in Isle of Wight Bay shallows.
Quick facts
| Group | Seaweed / algae |
|---|---|
| Likelihood nearby | ★★★★★ |
| Habitats | Ocean beach, Coastal bays, Inlet, Assateague State Park, Assateague National Seashore |
| Seasons (this coast) | spring, summer, fall |
How to recognize them
- Thin, bright green sheets like wet lettuce; can be ruffled or torn by waves.
- Sometimes in tangled clumps with other algae; bleaches to white when dried on the beach.
Biology notes
- Fast-growing green alga that thrives where nutrients are high; blooms can signal runoff events.
- Provides food for snails and some fish; decomposing wrack feeds beach invertebrates.
Where to see them around Ocean City
- Assateague and Ocean City beach wrack lines after summer southerlies and bay chop.
- Shallow bay edges and dock pilings in West Ocean City harbor on calm days.
- Kayak floats over green clouds in warm, calm coastal bays.
When to look
- Most obvious warm months; fresh green wrack after storms and algal blooms.
Viewing tips & etiquette
- Slippery when fresh—watch footing on algae-covered rocks at the Inlet.
- Large blooms can smell at low tide; still normal coastal ecology, not always “pollution.”
