Three Nereocystus remained on the left of the pilings, and six on the right.
Bull Kelp along our shoreline are generally annual algae that are often 1 foot tall in May and 60 feet by July. These kelp have cleverly overcome a logistic problem when it comes to reproduction. Their reproductive parts are at the water's surface, but they must get their spores back down to the seafloor at the right depth in areas with nice big rocks for their holdfasts to hang on to. Bull kelp have overcome this disadvantage by dropping a dense sorus containing spores from it's blade (leaves) a few hours after dawn when the waves are usually calm. If you see a kelp washed up on the beach, look for the dark patches in the blade. The darker ones farthest from the bulb are the most mature.
http://sci.odu.edu/oceanography/directory/faculty/zimmerman/
A fun experiment to do is to cut a thumbnail size of the sorus out, gently rub off anything that might be attached, then place it in a covered glass dish filled with seawater that you have microwaved to almost a boil then chilled. Keep it in a cool place that gets low light. If all went well you will get to see the next tiny phase of the Bull Kelp life cycle that occurs on rocks or on other red algae. You may need a magnifying glass!
The Oceans, Their Physics, Chemistry, and General Biology. New York: Prentice-Hall, c1942
