Dataset: Pisaster Counts and Sea Star Wasting Disease Incidence on Tatoosh Island, Makah Reservation, Washington 2014-2025

Standardized count data were initiated by J. Timothy Wootton on Tatoosh Island, Makah Reservation, Washington, USA in 2014 as the sea star wasting disease epidemic of 2013-2014 was progressing on the northeastern Pacific Ocean. At the time of study, signs of disease were absent from Tatoosh Island. Six sites scattered around the periphery of the island (Glacier, Glacier Control, West Island Wall, East Strawberry, Simon's Landing, Toad Point) with relatively large, uniform benches on shores with high wave exposure were selected for study areas. Surveys were carried out in the intertidal zone in late spring and summer during periods with strong spring tides to maximize population counts. The area of lower intertidal bench at each sampling site was estimated by tape measure as length x width (meters) of the lower intertidal (below lower limit of the mussel bed in 2014) assuming a rectangular area. Counts were made by the investigator by systematically walking along each site and counting each individual of Pisaster ochraceus (urn:lsid:marinespecies.org:taxname:240755) encountered, noting whether it had signs of disease (lesions/ruptured body parts, missing arms, thin profile with crossed arms), and whether it was larger than 10 centimeters in diameter. Counts at one site (West Island Wall) were made from across a large surge channel using binoculars when necessary to inspect the condition of individual sea stars.