To cite wq in publications use:

  Alan D. Jassby and James E. Cloern (). wq: Some tools for exploring
  water quality monitoring data. R package version 1.0.1.
  https://cran.r-project.org/package=wq

A BibTeX entry for LaTeX users is

  @Manual{jassbywq,
    title = {wq: Exploring water quality monitoring data},
    author = {Alan D. Jassby and James E. Cloern},
    note = {R package version 1.0.1},
    url = {https://CRAN.R-project.org/package=wq},
  }