Lake_ID Year    Gear    psd BioVolume
    16  2012    EF  0.370967742 0.095585695
    16  2012    GN  1   0.095585695
    16  2012    TN  0   0.095585695
    16  2012    Whole   0.375   0.095585695
    16  2017    EF  0.214285714 0.100623115
    16  2017    GN  1   0.100623115
    16  2017    TN  0   0.100623115
    16  2017    Whole   0.179487179 0.100623115

ggplot(blg.dup.year,aes(BioVolume,psd,group=Lake_ID,label=Year))+
        geom_point(aes(BioVolume,psd,colour=Year))+theme_bw()+
        facet_grid(Gear~.,scales = "free_y")+
        labs(title="Bluegill PSD",y="PSD",x="Littoral BioVolume")+
        geom_path(arrow=arrow(angle=30,length=unit(0.1,"inches"),
            type="closed"),aes(group=Lake_ID))