Karenia mikimotoi
1. Recent Event (2024)
- Location: South Australia
- Impact:
- Mass mortality of marine species (fish, crustaceans, echinoderms).
- Disrupted tourism and fishing industries.
- Cause: Algal bloom due to warm waters + nutrient influx.
2. Biological Profile
| Feature | Description |
|---|---|
| Type | Photosynthetic dinoflagellate (causes "red tides"). |
| Toxins | Hemolytic toxins (rupture blood cells) + Ichthyotoxins (target fish). |
| Adaptability | Thrives in varied light, temperature, salinity, and nutrient conditions. |
| Global Spread | Reported in India (coastal areas), Japan, Ireland, USA, Australia, Norway. |
3. Ecological & Economic Impact
| Impact Type | Consequence |
|---|---|
| Marine Mortality | Kills fish, shellfish, crustaceans via toxins or oxygen depletion. |
| Dead Zones | Anoxic conditions form as bacteria decompose dead algae. |
| Fisheries Loss | Collapse of local fishing economies (e.g., South Australia). |
| Tourism Decline | Beaches closed; foul odor deters visitors. |
Key Terms
| Term | Meaning |
|---|---|
| Dinoflagellate | Microscopic algae; some cause red tides. |
| Eutrophication | Nutrient overload in water bodies → algal blooms. |
| Anoxia | Severe oxygen depletion in aquatic systems. |
Did You Know?
India’s first HAB monitoring began after a 1981 Karenia bloom off Chennai killed 120+ fish species.