set.seed(8)
really.messy <- data.frame(
  id = 1:4,
  trt = sample(rep(c('control', 'farm'), each = 2)),
  zooplankton.T1 = runif(4),
  fish.T1 = runif(4),
  zooplankton.T2 = runif(4),
  fish.T2 = runif(4)
)