Marine sediment core EW0408-33JC (57.162°N, 135.357°W, 146 m water depth) was recovered from Katlian Bay, a temperate fjord near Sitka, Alaska, in August 2004. This jumbo piston core, along with its accompanying multicore EW0408-32MC and trigger core EW0408-33TC, preserve a continuous sedimentary record of the last 2,000 years. This data release collection encompasses the age control for this core set (doi:10.1594/PANGAEA.980871), as well as a scanning X-ray fluorometry dataset for the elements bromine (Br) and chlorine (Cl) which are used as a proxy for past primary productivity (doi:10.1594/PANGAEA.980864). Lastly, these geochemical data are compared to a statistical model of net primary productivity developed for the Southeast Alaska region (doi:10.1594/PANGAEA.980872).