biomass <-
time prefish1  obsfish1  prefish2  obsfish2
1   0.011    0.002     0.007      0.002
2   0.011             0.007
3   0.010    0.002     0.007      0.002
4   0.010             0.007
5   0.010             0.006
6   0.010    0.002    0.006       0.002

for (i in biomass[2]) {
}
for (k in biomass[3]) {

}
}  ##this will call just columns 2 and 3 as a pair.##
ggplot(biomass, aes(x= time)) +
  geom_line(aes(y=i)) +
  geom_point(aes(y=k)) +
  ggtitle(i) + ylab("biomass t/km2") +
  ##I would also like to title them using the header one of the column pairs##
  theme_classic()

for (i in biomass[c(2,4)]) {
}
for (k in biomass[c(3,5)]) {

}
}  ##this will add all of those vectors together and produce one graph, I would like 2,3 to be two lines, 4,5 to be two lines, 6,7 etc on one graph##
ggplot(biomass, aes(x= time)) +
  geom_line(aes(y=i)) +
  geom_point(aes(y=k)) +
  ggtitle(i) + ylab("biomass t/km2") +
  theme_classic()