Ready for a quick kelp lesson?
Kelp forests, like this one in Channel Islands National Marine Sanctuary, are held down by holdfasts anchored to rocky substrates. Growing up towards the surface, gas bladders, called pneumatocysts, keep even the tallest kelp afloat. A giant kelp plant will have these bladders at the base of each blade, whereas bull kelp plants have only one that supports several blades near the surface. Can you tell which kelp plant is featured here? (Photo: Robert Schwemmer/NOAA. Image Description: Kelp forest moving with the waves and surrounded by schools of fish.)

















