Nitrogen stable isotopes ( δ 15 N ) and tissue nitrogen in shallow‐water and mesophotic macroalgae differ between the Main Hawaiian Islands and the Northwestern Hawaiian Islands Limnology and Oceanography

The Hawaiian Archipelago stretches 2500 km from the Main to the Northwestern Hawaiian Islands, repre- sents a complex gradient of oceanographic and anthropogenic drivers, and has a high abundance and diversity of native and invasive macroalgae. These photosynthetic organisms occur in intertidal to mesophotic (30 – 150+m) depths and absorb nitrogen with limited fractionation associated with their physiology and source. Our goal was to examine nitrogen dynamics from shallow to mesophotic reefs using compositional patterns of two well-characterized macroalgal tissue parameters: stable isotope ratio of nitrogen and tissue nitrogen content. Grant no. NA07NOS4780188 Grant no. NA07NOS4780187 Grant no. NA07NOS4780189