Kelp forests spread
Cooling coastal seas allow large brown algae to build underwater forests along temperate shores.
- When
- —
- Duration
- 8.7 million years
- Known to
- ± 3 million years
- Era
- Miocene, Cenozoic
Kelps require cold, nutrient-rich water, and as the northern and southern oceans cool through the Miocene they expand into extensive submarine forests along temperate coasts. Kelp grows extremely fast — up to half a metre a day in giant kelp — and creates three-dimensional habitat that supports a distinct ecosystem of fish, invertebrates and, later, sea otters. The expansion of kelp is closely tied to the diversification of the marine mammals and birds that depend on those coastal ecosystems.