To capture the annual variation in nutrient concentrations around a high latitude giant kelp bed, we sampled seawater monthly (July 2018 - July 2019) from the water column adjacent to Breast Is. in Sitka Sound, Alaska. We collected seawater using a surface-deployed Niskin bottle at 0.5 m and 4.5 m depth at each of four locations: in the middle of the Breast Is. giant kelp bed canopy, at the canopy edge, 150 m away from canopy edge, and 600 m away from the canopy edge towards the open ocean (Gulf of Alaska). In addition, we collected benthic seawater samples monthly (June 2016 - July 2017) and opportunistically (Fall 2017 - Summer 2020) using a diver-deployed Niskin bottle at 8 - 10 m depth at Breast Is., Harris Is., Samsing Pinnacle and Talon Is. (57.073 N, 135.414 W). We brought collected water to the surface, immediately filtered each sample through a 0.2 µm filter and kept it frozen until analysis for dissolved inorganic nitrogen content as NOx (NO3 + NO2) on a Lachat QuikChem 8000 Flow Injection Analyzer at the University of California Santa Cruz Marine Analytical Laboratory (detection limit < 0.28 µM NOx, average run measurement error < 0.1 µM NOx).
Additional Funding Details:
In addition to primary funding from the NSF award OCE-1752600 additional funding was provided from The David and Lucile Packard Foundation and the North Pacific Research Board’s Graduate Student Research Award (1748-01) to Lauren Bell, PhD University of California Santa Cruz, Award title: "Fish Habitat, Fishes and Invertebrates, Lower Trophic Level Productivity Effect of substrate on herring roe response to global change."