The following is a description of the data files associated with Strayer, D.L., Adamovich, B.V., Adrian, R., Aldridge, D.C., Balogh, C., Burlakova, L.E., Fried-Petersen, H., G.-Tóth, L., Hetherington, A.L., Jones, T.S., Karatayev, A.Y., Madill, J.B., Makarevich, O.A., Marsden, J.E., Martel, A.L., Minchin, D., Nalepa, T.F., Noordhuis, R., Robinson, T.J., Rudstam, L.G., Schwalb, A.N., Smith, D.R., Steinman, A.D., and J.M. Jeschke. 2019. Long-term population dynamics of dreissenid mussels (Dreissena polymorpha and D. rostriformis): a cross-system analysis. Ecosphere. Contact for questions about these data: David Strayer (strayerd@caryinstitute.org). WARNING. We caution that the data presented and analyzed in this paper came from a wide range of sources, were collected using a wide range of sampling designs and methods, and are expressed in several different measurement units. To avoid problems with data incompatibility, users of these data should consult “strayer_etal_dreissena_site_and_data_characteristics.csv”, as well as the original data sources (which are listed in “strayer_etal_dreissena_site_and_data_characteristics.csv”) before running analyses. LIST OF INCLUDED DATA FILES (all are tables of data in .csv format) strayer_etal_dreissena_site_and_data_characteristics.csv (overview of site characteristics and data, with lists of primary sources and links to online data sets) strayer_etal_dreissena_fig1.csv (data contained in Fig. 1) strayer_etal_dreissena_fig2.csv (data contained in Fig. 2) strayer_etal_dreissena_fig3.csv (data contained in Fig. 3) strayer_etal_dreissena_fig 4.csv (data contained in Fig. 4) strayer_etal_dreissena_fig5.csv (data contained in Fig. 5) strayer_etal_dreissena_figsS1+S2+S3.csv (data contained in Supplementary Figures S1, S2, and S3) strayer_etal_dreissena_figsS4+S5.csv (data contained in Supplementary Figures S4 and S5) strayer_etal_dreissena_figS6.csv (data contained in Supplementary Figure S6) strayer_etal_dreissena_figS7.csv (data contained in Supplementary Figure S7) strayer_etal_dreissena_figsS9+S10.csv (data contained in Supplementary Figures S9 and S10) strayer_etal_dreissena_fig S11.csv (data contained in Supplementary Figure S11) strayer_etal_dreissena_fig S12.csv (data contained in Supplementary Figure S12) strayer_etal_dreissena_figsS13+S14.csv (data contained in Supplementary Figures S13 and S14) DESCRIPTIONS OF INDIVIDUAL DATA SETS Dataset: “strayer_etal_dreissena_site_and_data_characteristics.csv” Site = name of body of water Location = country or state in which the body of water is located Habitat = broad category of habitat (lake, Great Lake, reservoir, river) First detection of zebra mussel = year in which zebra mussels were first reported (approximate for records before the year 1900) First detection of quagga mussel = year in which quagga mussels were first reported Years of study = range of years over which samples were taken (samples were not always taken in every year within this range) Study length (yr) = number of years of the study range Number of years with data = number of years within the study range for which samples were taken Type of data = demographic variable for which data were collected; four broad classes: adult density (density of settled animals, sometimes excluding the smallest animals; sometimes at one or a few selected places, and sometimes a system-wide mean using a formal sampling design); adult biomass (mass per area of settled animals; same caveats as adult density; biomass sometimes dry mass, sometimes ash-free dry mass, sometimes wet mass; may include or exclude shells; sometimes not actually biomass but a biomass-type variable such as biovolume); veligers (density of planktonic larvae, annual mean of several samples; frequency of sampling varies); recruitment (density of young-of-year animals recruited onto bare substrata, often on artificial substrata; sometimes a single measurement at the end of the growing season, sometimes mean of multiple measurements made throughout the growing season) Maximum depth (m) = maximum depth of body of water, taken from various sources Area (km^2) = surface area of body of water, taken from various sources Trophic status = broad categorization (oligotrophic, mesotrophic, eutrophic, hypereutrophic) of the trophic status of the body of water, taken from various sources, and following the guidelines of Table 13-18 of Wetzel’s 2001 textbook; text in quotes was provided in emails from co-authors Notes about trophic status = self-explanatory Source = primary sources of data on Dreissena populations for that body of water Link to data = links to primary data, if they are available on line Collection method = brief description of field method used to collect samples Size of sampling unit = self-explanatory Sampling design = brief description of statistical design Number of sites = number of sites within the body of water from which samples were taken Samples per site = number of replicate samples taken from each sampling site Depths = depth of water at points where samples were taken Threshold size for mussels (y/n) = some investigators disregard mussels smaller than some threshold shell length; this column summarizes the use of such thresholds Biomass type = indicates whether biomass was reported as wet mass (wm), dry mass (dm), ash-free dry mass (afdm), or biovolume, and whether biomass data included or excluded the shell Seasons sampled = seasonal timing of sampling Notes = any other pertinent information about the site, sampling methods, or data Dataset: “strayer_etal_dreissena_fig1.csv” panel = panel in the published paper that include the data variable = which variable about Dreissena populations is being plotted starting_year = year from which change in Dreissena populations is calculated, expressed as years since zebra or quagga mussels first appeared median_change = median change the focal Dreissena population over the study period n = number of datasets used to calculate the median Dataset: “strayer_etal_dreissena_fig2.csv” panel = panel in the published paper that include the data variable = which variable about Dreissena populations is being plotted start_period = time from which change in Dreissena populations is calculated, expressed as years since zebra or quagga mussels first appeared; periods usually are individual years, but are aggregated into multiple years to express change after year 10 end_period = time to which change in Dreissena populations is calculated, expressed as years since zebra or quagga mussels first appeared; periods usually are individual years, but are aggregated into multiple years to express change after year 10 log(median) = log10 of the median change the focal Dreissena population over the study period Dataset: “strayer_etal_dreissena_fig3.csv” year = calendar year in which samples were taken YSA = years since the first appearance (detection) of zebra mussels in the Hudson River (1991) Adult_density = riverwide mean density of settled animals Veligers = mean density of veligers over the growing season Recruitment = density of young-of-year mussels recruited onto bare substrata (navigation buoys) by late November-early December Biomass = biomass (dry mass, excluding shells) of settled animals Dataset: “strayer_etal_dreissena_fig4.csv” site = body of water D*B_correlation = Pearson’s correlation coefficient between annual means of density of adults and biomass of adults D*B(n) = number of years for which the D*B correlation was calculated D*V_correlation = Pearson’s correlation coefficient between annual means of density of adults and density of veligers D*V(n) = number of years for which the D*V correlation was calculated D*R_correlation = Pearson’s correlation coefficient between annual means of density of adults and recruitment of young-of-year D*R(n) = number of years for which the D*R correlation was calculated B*V_correlation = Pearson’s correlation coefficient between annual means of biomass of adults and density of veligers B*V(n) = number of years for which the B*V correlation was calculated B*R_correlation = Pearson’s correlation coefficient between annual means of biomass of adults and recruitment of young-of-year B*R(n) = number of years for which the B*R correlation was calculated R*V_correlation = Pearson’s correlation coefficient between annual means of recruitment of young-of-year and density of veligers R*V(n) = number of years for which the R*V correlation was calculated Dataset: “strayer_etal_dreissena_fig5.csv” panel = panel in the published paper that include the data variable = which variable about Dreissena populations is being plotted (numbers, biomass) site = name of body of water symbol = symbol used on the graphs for each body of water YSQ = years since the first appearance (detection) of quagga mussels at the site %_quagga = % of total dreissenid numbers or biomass constituted by quagga mussels Dataset: “strayer_etal_dreissena_figsS1+S2+S3.csv” site = name of body of water year = calendar year YSA = years since the first appearance (detection) of zebra mussels at the site Zebra_mussel_density = density of settled (“adult”) zebra mussels Quagga_mussel_density = density of settled (“adult”) quagga mussels Notes = pertinent information about the sites or data Dataset: “strayer_etal_dreissena_figsS4+S5.csv” site = name of body of water year = calendar year YSA = years since the first appearance (detection) of zebra mussels at the site Units = measurement units in which biomass is expressed (WM=wet mass, DM=dry mass, AFDM=ash-free dry mass) Zebra_mussel_biomass = biomass of settled (“adult”) zebra mussels Quagga_mussel_biomass = biomass of settled (“adult”) quagga mussels Notes = pertinent information about the sites or data Dataset: “strayer_etal_dreissena_figS6.csv” site = name of body of water year = calendar year YSA = years since the first appearance (detection) of zebra mussels at the site Recruitment = density of young-of-year Dreissena (units and details vary among studies) Dataset: “strayer_etal_dreissena_figS7.csv” site = name of body of water year = calendar year YSA = years since the first appearance (detection) of zebra mussels at the site Veliger_density = mean annual density of Dreissena veligers at the study site Units = measurement units used to express veliger densities Dataset: “strayer_etal_dreissena_figsS9+S10.csv” site = name of body of water year = calendar year YSA = years since the first appearance (detection) of zebra mussels at the site Zebra_mussel_body_size = mean body size of settled zebra mussels Quagga_mussel_body_size = mean body size of settled quagga mussels Units = measurement units in which body size is expressed Dataset: “strayer_etal_dreissena_figS11.csv” site = name of body of water year = calendar year YSA = years since the first appearance (detection) of zebra mussels at the site Standardized_zebra_mussel_body_mass = body mass of zebra mussels in year i divided by the mean annual body mass of zebra mussels at that study site Dataset: “strayer_etal_dreissena_figS12.csv” site = name of body of water year = calendar year YSA = years since the first appearance (detection) of zebra mussels at the site Standardized_zebra_mussel_body_mass = body mass of zebra mussels in year i divided by the mean annual body mass of zebra mussels at that study site Standardized_quagga_mussel_body_mass = body mass of quagga mussels in year i divided by the mean annual body mass of quagga mussels at that study site Symbol = symbol (indicating study site) used to plot data in the figure Dataset: “strayer_etal_dreissena_figsS13+S14.csv” site = name of body of water variable = population variable shown in the figure (either numbers or biomass) year = calendar year zebra_mussel_mean = mean numbers or biomass of zebra mussels zebra_mussel_90%CL = half the width of the 90% confidence interval around the zebra mussel mean quagga_mussel_mean = mean numbers or biomass of quagga mussels quagga_mussel_90%CL = half the width of the 90% confidence interval around the quagga mussel mean total_Dreissena_mean = mean numbers or biomass of all Dreissena combined total_Dreissena_90%CL = half the width of the 90% confidence interval around the mean for all Dreissena combined