Dataset: Kelp retention data from macroalgal surveys in Sitka Sound, Alaska kelp beds from 2017 to 2019

We monitored monthly growth and loss of dominant kelp species in Sitka Sound from January 2017 - February 2018 at Breast Is. and Harris Is. (M. pyrifera only), and from July 2018 - July 2019 at Harris Is., Breast Is., and Samsing Pinnacle (M. pyrifera, N. fimbriatum, H. nigripes). At each site, we identified 12 - 15 “adult” individuals of each species (M. pyrifera: at least one frond reaching the surface; N. fimbriatum and H. nigripes: maximum blade length > 20 cm) along a 5 - 6 m depth (MLLW) contour with numbered tags. Each month, we re-surveyed tagged M. pyrifera plants for frond density, with zip ties loosely bound around new fronds exceeding 1 m in height to distinguish new growth. For tagged N. fimbriatum and H. nigripes plants, each month we punched a new hole through the thallus at 10 cm from the intercalary meristem (Parke 1948), and we measured blade morphometrics (maximum blade length and width) and distance from meristem to the previous month’s punched hole. When previously tagged individuals were not re-sighted after two consecutive months, we assumed they had been physically removed from the substrate, either through grazing or abiotic factors.

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."