SBC LTER: Reef: Kelp Nitrogen uptake in Carpinteria and Mohawk kelp forests, 2016-2017

A large on-going time-series monthly water samples have been taken at 1m, 5 m and 10 m depth from the offshore edge of five kelp forests near Santa Barbara, CA, USA (Arroyo Burro, Arroyo Quemado, Carpinteria, Mohawk, Naples). See dataset: http://sbc.lternet.edu/cgi-bin/showDataset.cgi?docid=knb-lter-sbc.10. Two datasets are presented here. One is a field study conducted in two of the sites (Mohawk or Carpinteria) to test the N uptake of giant kelp (Macrocystis pyrifera) and phytoplankton from May 2016 to October 2017. In situ rates of urea, ammonium and nitrate uptake by giant kelp blades and phytoplankton, which were enclosed together within polyethylene blade bags, from the surface canopy of Mohawk or Carpinteria kelp forests. The second dataset has the results of laboratory experiments for testing the direct uptake of urea by whole blades and natural phytoplankton communities entrained in surface canopy waters.