DOI: 10.5061/dryad.p0r3v
title: Data from: Atmospheric rivers and the mass mortality of wild oysters: insight into an extreme future?

description: Climate change is predicted to increase the frequency and severity of
 extreme events. However, the biological consequences of extremes remain
 poorly resolved owing to their unpredictable nature and difficulty in
 quantifying their mechanisms and impacts. One key feature delivering
 precipitation extremes is an atmospheric river (AR), a long and narrow
 filament of enhanced water vapour transport. Despite recent attention, the
 biological impacts of ARs remain undocumented. Here, we use biological
 data coupled with remotely sensed and in situ environmental data to
 describe the role of ARs in the near 100% mass mortality of wild oysters
 in northern San Francisco Bay. In March 2011, a series of ARs made
 landfall within California, contributing an estimated 69.3% of the
 precipitation within the watershed and driving an extreme freshwater
 discharge into San Francisco Bay. This discharge caused sustained low
 salinities (less than 6.3) that almost perfectly matched the known oyster
 critical salinity tolerance and was coincident with a mass mortality of
 one of the most abundant populations throughout this species' range.
 This is a concern, because wild oysters remain a fraction of their
 historical abundance and have yet to recover. This study highlights a
 novel mechanism by which precipitation extremes may affect natural systems
 and the persistence of sensitive species in the face of environmental
 change.
description: Cheng et al PRSB Oyster
 Density Dataset 1Oyster density data from
 Village North, Rat Rock, and Weber Point. Columns are variables and rows
 are replicate data points. Date = date of survey in month/day/year format.
 Site = one of the above described sites. Recorders = initials of
 surveyors. Mini-quadrat = quadrat number within the larger quadrat. Height
 = tidal height where Low = 0.0 m, Mid = 0.05 m, High = 0.10 m above mean
 lower low water. Distance = position of the quadrat in meters along the
 transect. Alive = number of live Olympia oysters. Ostrea.25m = number of
 live oysters per 0.25 meters squared. Notes = notes for each
 replicate.Cheng et al PRSB Oyster
 Density Dataset 2Oyster density data from
 Bullhead Flat. Site = Bullhead Flat (all data from this file is from this
 site). Date = date of survey in month/day/year format. Year = year in full
 year format. Quadrat = quadrat number. OstreaLive = number of live oysters
 within the quadrat. OstreaDead = number of dead oysters within the
 quadrat.Cheng et al PRSB Oyster
 Size Frequency DataOyster size frequency
 data from field quadrat surveys at Bullhead Flat. Date = date in
 month/day/year format. Site = Bullhead Flat for all rows. Recorders =
 initials of surveyors. Quadrat = quadrat number. Oyster.Length = oyster
 length in mm.Cheng et al PRSB Oyster
 Recruitment DataOyster recruitment data
 from Bullhead Flat. Ceramic tiles were deployed on racks in the intertidal
 zone. Timeframe = frequency of sampling (Quarterly or Monthly). Date.In =
 date of tile outplant in month/day/year format. Date.Out = date of tile
 recovery in month/day/year format. Approximate.season = season that tile
 was deployed during. Year = year in full year format. Site = site that
 tiles were deployed at (China Camp = Bullhead Flat). Site Code = code for
 site (all values = CC). Frame = the frame number that the tile was
 attached to. Tile = letter for each tile per frame. oyster.count = number
 of oyster recruits per tile. count.m2 = number of oysters recruits
 extrapolated to a meter squared. days.in.field = the number of days that a
 tile was deployed for. count.m2.day = count.m2 column divided by the
 days.in.field column.