Jv. Klump et al., SEDIMENTARY PHOSPHORUS CYCLING AND A PHOSPHORUS MASS-BALANCE FOR THE GREEN BAY (LAKE MICHIGAN) ECOSYSTEM, Canadian journal of fisheries and aquatic sciences, 54(1), 1997, pp. 10-26
The tributaries of Green Bay have long been recognized as major source
s of phosphorus in the Lake Michigan basin. The status of Green Bay as
a sink or source of phosphorus for Lake Michigan proper has been less
well defined. The bay receives nearly 70% of its annual load of phosp
horus (700 metric tons (t).year(-1)) from a single source: the Fox Riv
er. Most of this phosphorus is deposited in sediments accumulating at
rates that reach 160 mg.cm(-2).year(-1) with an average of 20 mg.cm(-2
).year(-1). The phosphorus content of these sediments varies from <5 t
o >70 mu mol.g(-1). Deposition is highly focused, with similar to 70%
of the total sediment accumulation and at least 80% of the phosphorus
burial occurring within 20% of the surface area of the bay. Diagenetic
and stoichiometric models of phosphorus cycling imply that >80% of th
e phosphorus deposited is permanently buried. External phosphorus load
ing to the bay is combined with sediment fluxes of phophorus to arrive
at a simple phosphorus budget. Green Bay acts as an efficient nutrien
t trap, with the sediments retaining an estimated 70-90% of the extern
al phosphorus inputs before flowing into Lake Michigan.