# Amazing Underwater Forests (DD-291)

> Kelp forests are dense stands of large brown algae (kelp) that grow in cool, shallow, nutrient-rich coastal waters. NOAA notes that kelp can grow up to 18 inches (45 cm) a day in ideal conditions and is rarely found deeper than about 15 to 40 m. Giant kelp (Macrocystis) can grow 30 to 60 cm vertically per day and form a floating canopy at the surface. The forests shelter and feed fish, invertebrates and marine mammals. Kelp is an alga, not a true plant, and like other seaweeds it takes up carbon dioxide as it grows. The footage shows divers' views of tall kelp fronds with fish swimming among them.

- Department: Nature
- First published: 2024-08-06
- Last updated: 2024-08-06
- Permalink: https://detailenjoyer.com/case/amazing-underwater-forests/
- Author: Marcus Easterling (DetailEnjoyer), The Detail Department

## Quick facts

- **DD-291-F01**: Kelp can grow up to 18 inches a day. _(Write-up · Exhibit C (Fast growth))_
- **DD-291-F02**: Kelp forests grow in cool, shallow coastal waters. _(Write-up · Exhibit B (Cool, shallow water))_

## Write-up

Some forests grow underwater, and fast. Giant kelp can grow 30 to 60 cm a day.

1. **Large brown algae**: Kelp forests are dense stands of large brown algae.
2. **Cool, shallow water**: They grow in cool, nutrient-rich coastal waters, rarely deeper than about 40 m.
3. **Fast growth**: NOAA says kelp can grow up to 18 inches a day in ideal conditions.
4. **A surface canopy**: Giant kelp can grow 30 to 60 cm a day and form a canopy at the surface.
5. **Habitat**: The forests shelter and feed fish, invertebrates and marine mammals.

## Related case files

- [Concrete Reefs (DD-632)](https://detailenjoyer.com/case/concrete-reefs/): I paired it with another underwater habitat
- [Soft Coral Capital of the World! (DD-199)](https://detailenjoyer.com/case/soft-coral-capital-of-the-world/): I linked more underwater life

## Reel vs. record

- **Note**: 'Over 100 feet': right for giant kelp, which can top 100 feet. I'd add that kelp is an alga, not a true plant.

## Video: Amazing Underwater Forests: Some Forests Grow Underwater, and Fast

- Duration: 25.5 s · Published: 2024-08-06
- File: https://detailenjoyer.com/assets/videos/C-WpWGvtTcd.mp4

### Transcript

DID YOU KNOW? Kelp forests are underwater ecosystems formed by dense growths of kelp a type of large brown seaweed found in shallow nutrient-rich coastal waters. These forests provide critical habitat and food for a wide range of marine life. Kelp grows rapidly often reaching lengths of over 100 feet and forms a canopy that supports diverse species from fish to invertebrates. Their rapid growth and ability to absorb carbon dioxide make kelp forests important for marine biodiversity and climate regulation. NOW YOU KNOW!

## Questions & answers

**Q: What is kelp?**  
A: It's a seaweed, not a true plant. _(Source: Write-up · Exhibit A (Large brown algae) · NOAA Ocean Service: What is a kelp forest?; Wikipedia: Kelp forest)_

**Q: Where do kelp forests grow?**  
A: They need light and nutrients. _(Source: Write-up · Exhibit B (Cool, shallow water) · NOAA Ocean Service: What is a kelp forest?)_

**Q: How fast can kelp grow, per NOAA?**  
A: That's in ideal conditions. _(Source: Write-up · Exhibit C (Fast growth) · NOAA Ocean Service: What is a kelp forest?)_

**Q: What does giant kelp form at the surface?**  
A: It grows 30 to 60 cm a day. _(Source: Write-up · Exhibit D (A surface canopy) · Wikipedia: Kelp forest)_

**Q: Who uses kelp forests?**  
A: They're rich habitats. _(Source: Write-up · Exhibit E (Habitat) · NOAA Ocean Service: What is a kelp forest?; Wikipedia: Kelp forest)_

## Sources

- [NOAA Ocean Service: What is a kelp forest?](https://oceanservice.noaa.gov/facts/kelp.html)
- [Wikipedia: Kelp forest](https://en.wikipedia.org/wiki/Kelp_forest)

## Cite this case file

Easterling, Marcus. "Amazing Underwater Forests." The Detail Department (DetailEnjoyer), case file DD-291, last updated Aug 6, 2024. https://detailenjoyer.com/case/amazing-underwater-forests/