Data for: Direct and indirect ecosystem responses to vehicle compaction of soft sediments

In northeastern Pacific tidal flats, a native bioturbator, ghost shrimp Neotrypaea californiensis, engineers soft-sediment habitat and interacts antagonistically with bivalve shellfish. Vehicle compaction has been used in pest control of ghost shrimp, but this disturbance lacks quantitative evidence of its efficacy and environmental impacts. Through three large (~10 ha) experiments in Grays Harbor, Washington, USA, we tested the direct and indirect impacts of compaction by a tracked vehicle (MarshMaster) on ghost shrimp density, sediment conditions, and infauna. We also examined how oyster survival (cultch seeded with Pacific oysters, Magallana gigas) and waterbird usage of tidal flats responded post-compaction. In Experiment 1, compaction occurred on 13 Aug 2022 and 19 May 2023, and sampling occurred seasonally over three years, including immediately post-compaction. In Experiment 2, compaction occurred on 2 Aug 2023, and sampling occurred seasonally over one year. Due to minimal treat..., , # Data for: Direct and indirect ecosystem responses to vehicle compaction of soft sediments Dataset DOI: [10.5061/dryad.fbg79cp8p](https://doi.org/10.5061/dryad.fbg79cp8p) ## Description of the data and file structure Intertidal flats of sandy soft-sediment dominated by ghost shrimp (*Neotrypaea californiensis*) in Grays Harbor, Washington (USA) were compacted with a tracked vehicle (MarshMaster MM 2LX, 1 pound per square inch ground pressure). Because the tracks of the MarshMaster have a gap between them, successive rounds overlapped so that all surface experienced ground pressure. In Experiment 1 (Damon Point), five 2-ha beds were established along an elevation contour of 0.2-0.6 m relative to mean lower low water (MLLW), and two beds (9 and 11) were compacted on 13 Aug 2022 and recompacted on 19 May 2023. In Experiment 2 (Westport Single), five 2-ha beds were established along an elevation contour of 0.4-0.5 m MLLW, and two beds (2 and 4) were compacted on 2 Aug 2023. In Experimen...,