DMSP Induction and Responses to Short-term Stress in Intertidal Ulva fenestrata

This Excel file contains data from experiments that looked at responses of an intertidal seaweed (Ulva fenestrata) to short periods of exposure to hyposaline water and emersion. In these experiments, we emersed pieces of U. fenestrata or exposed them to hyposaline water (7.5 PSU) for 3 hours in summer and winter. We then measured the palatability of the algae to Lacuna vincta snails, seaweed growth, and dimethylsulfoniopropionate (DMSP) concentrations two days later. After the grazing measurements, the remaining seaweeds were allowed to recover in an incubator in culture medium for 7 days, and their DMSP concentrations were measured. A follow-up summer desiccation experiment was conducted in which maximum quantum yields (MQYs) and DMSP concentrations were measured after 0, 15, 30, 45, and 60 mins of emersion at low tide. This study is described in the manuscript “Seasonal effects of short-term stress on susceptibility to herbivores and DMSP induction in the intertidal green alga Ulva fenestrata (Chlorophyta)” by K.L. Van Alstyne and N. Borgen, which has been submitted to Marine Biology. When citing this data set, please also cite the Marine Biology paper, which contains additional information about the experiments conducted.Information about column headings in the data set:Page 1) Size and Mass ChangeSeason: Time of the year when the experiments were done (winter = January, summer = July)Salinity (PSU): Seawater salinity in PSU (7.5 or 30)Emersion Time (h): Time in hours that U. fenestrata were emersed in the field (0 or 3)Individual: Replicate number for the piece of U. fenestrata (1-10)Lacuna?: Indicates whether the piece of U. fenestrata was placed in a container with Lacuna vincta (Yes or No = control)D2 SA: Surface area (in cm2) on day 2 after two days of grazingD2 Growth: Growth of seaweed pieces from day 0 to day 2 (%/day)Herbivory: Loss of surface area due to grazing (in cm2); calculated as the change in surface of grazed seaweeds minus the change in surface area of control seaweedsD9 SA: Surface area (in cm2) on day 9 after 7 days of recovery in an incubatorD9 Growth: Growth of seaweed pieces from day 0 to day 9 (%/day)Page 2) DMSP Day 2Season: Time of the year when the experiments were done (winter = January, summer = July)Salinity (PSU): Seawater salinity in PSU (7.5 or 30)Emersion Time (h): Time in hours that U. fenestrata were emersed in the field (0 or 3)Individual #: Replicate number for the piece of U. fenestrata (1-10)[DMSP] umol/g DM: Concentration of dimethylsulfoniopropionate (DMSP) (in µmol DMSP. g-1 dry mass of U. fenestrata) on day 2Page 3) DMSP Day 9Season: Time of the year when the experiments were done (winter = January, summer = July)Salinity (PSU): Seawater salinity in PSU (7.5 or 30)Emersion Time (h): Time in hours that U. fenestrata were emersed in the field (0 or 3)Individual #: Replicate number for the piece of U. fenestrata (1-10)[DMSP] umol/g DM: Concentration of dimethylsulfoniopropionate (DMSP) (in µmol DMSP. g-1 dry mass of U. fenestrata) on day 9Page 4) Follow-Up Field DataIndividual: Replicate number for the piece of U. fenestrata (1-10)Desiccated: Indicates whether the piece of U. fenestrata was emersed in the field (Yes or No)Exposure Time (min): Time in minutes that U. fenestrata were emersed (0, 15, 30, 45, or 60)DAY 0 Fv/Fm: Maximum quantum yield (FV/FM) on day 0 after emersion treatments were conductedDAY 7 Fv/Fm: Maximum quantum yield (FV/FM) after 7 days of recovery in an incubatorDAY 0 [DMSP] umol/g DM: Concentration of DMSP (in µmol DMSP. g-1 dry mass of U. fenestrata) on day 0 after emersion treatments were conductedDAY 7 [DMSP] umol/g DM: Concentration of DMSP (in µmol DMSP. g-1 dry mass of U. fenestrata) after 7 days of recovery in an incubatorDAY 7 Surface Area (cm2): Surface area (in cm2) on day 7 after 7 days of recovery in an incubator