WSDA Shrimp Coring Project

Burrowing shrimp (primarily Neotrypaea californiensis) were sampled with manual cores (70 cm depth, 12.7 cm diameter) on shellfish beds in Grays Harbor and Willapa Bay, Washington, USA. We recorded the number of holes counted in a 0.25m2 quadrat and cored 5 times (at the center and corners of the quadrat), for 10 or 20 samples on each aquaculture bed. Shrimp from each sample were counted and recorded by size class in terms of carapace length: recruit (R, carapace length <4.14 mm, dry mass 0.01 g), extra small (XS, <8.28 mm, 0.09 g), small (S, <12.49 mm, 0.4 g), medium (M, <17.42 mm, 0.91 g), large (L, >17.42 mm, 1.53 g). Sediment was collected to measure organic content by loss-on-ignition and grain size (dry-sieved, Wentworth scale). Data from each sample includes GPS location (WGS84), burrowing shrimp per 5-core sample in each size class, proportion of ashed sediment in each grain size category, and proportion organic in sediment. One site was sampled in both November and May; the other 13 sites were sampled once between September 2020 and June 2021. Sites differed in both shrimp densities and sediment properties, but not in ways related to each other. In contrast, within sites showing a range of shrimp densities, sediment organic content was negatively related to shrimp density.