Aquatic Plant Nitrogen This is a large, confusing topic but we now have a good review Systematics: Michener RH, Kaufman L (1994) Stable isotope ratios as tracers in marine food webs. In Stable Isotopes in Ecology and Environmental Science, 2nd Edition (Michener, R. H., and Lajtha, K., eds.). Blackwell Scientific Publications, Boston, pp. 238-282. Just read the short section on N isotopes in marine systems (pages 248-252). Altabet MA, et al. (1999) The nitrogen isotope biogeochemistry of sinking particles from the margin of the Eastern North Pacific. Deep-Sea Research Part I, 46: 655-679. More of an applied study than a review, but it lays out the balance between many of the important processes, and does it in our own back yard. Montoya JP (2007) Natural abundance of 15N in marine planktonic ecosystems. In Stable Isotopes in Ecology and Environmental Science, 2nd Edition (Michener, R. H., and Lajtha, K., eds.). Blackwell Scientific Publications, Boston, pp. 176-201. At last, a review of N isotopes in marine plankton. You can skim the sections on animal fractionations and food web processes and compound specific isotopes, if you wish. We’ve done most of this already. Further Reading There is way too much written on this subject for you to keep up with. Here are a few eastern Pacific centric studies. Rau GH, et al. (1998) Suspended particulate nitrogen δ15N versus nitrate utilization: observations in Monterey Bay, CA. Deep Sea Research Part II, 45: 1603-1616. A long companion paper to Rau et al. (01) on carbon isotopes. Looks at trade off between N utilization, upwelling, and isotopes. Voss M, Dippner JW, Montoya JP (2001) Nitrogen isotope patterns in the oxygen-deficient waters of the Eastern Tropical North Pacific Ocean. Deep Sea Research Part I, 48: 1095-1921. Denitrification is a big deal in the oxygen minimum zone and it labels shallower water during upwelling. Rau GH, Ohman MD, Pierrot-Bults A (2003) Linking nitrogen dynamics to climate variability off central California: a 51 year record based on 15N/14N in CalCOFI zooplankton. Deep Sea Research Part II, 50: 2431-2447. Yet another long paper, looking up the food web a bit at N isotope labeling. Interesting effects associated with el Nino.