Primary production in estuaries

Nitrogen pollution has received far more attention than that of phosphorus for two reasons. First, it has been considered as the nutrient-limiting primary production in estuaries and coastal waters. Second, its loading into the coastal zone has been far greater than that of phosphorus (Figure 24.21). It is also more efficiently exported into the ocean due in part to formation of iron phosphate minerals in anoxic estuarine sediments. 

As for lakes, primary production in estuaries tends to be nutrient dependent and can vary with nutrient load from 30 to 1000 g C m 2yr 1 (Gilmartin, 1964 Cadee and Hegeman, 1974 Cadee, 1978, 1986 Sirois... 

Benthic macroalgae and microphytobenthos are important sources of primary production in estuaries and have significant effects on the seagrass, tidal flat, and intertidal marsh habitats. 

In many estuarine systems primary production by phytoplankton and other autotrophs is affected by N inputs and concentrations (e.g., Cloem, 2001 Howarth, 1988 Kelly, 2001 Nixon, 1992 Smith, 2003). For this review, we have compiled estimates of annual primary production and simple models used to relate production to nutrient conditions. We also discuss the evolution of thinking concerning nutrient limitation of pelagic primary production in estuaries. Finally, we review the conceptual models concerning benthic and pelagic primary production and consider the influence of N on these different autrotrophic components. 

Boyer, J. N., R. R. Christian, and D. W. Stanley. 1993. Patterns of phytoplankton primary productivity in the Neuse River estuary, North Carolina, USA. Marine Ecology Progress Series 97 287-297. 

Fisher, T. R., P. R. Carlson, and R. T. Barber. 1982. Carbon and nitrogen primary productivity in three North Carolina estuaries. Estuarine, Coastal and Shelf Science 15 621—644. 

Randall, J. M., and J. W. Day, Jr. 1986. Effects of river discharge and vertical circulation on aquatic primary production in a turbid Louisiana (USA) estuary. Journal of Sea Research 21 231-242. 

Sirois, D. L., and S. W. Fredrick. 1978. Phytoplankton and primary production in the Lower Hudson River Estuary. Estuarine, Coastal and Shelf Science 7 413—423. 

Tomasko, D.A., and Dunton, K.H. (1995) Primary productivity in Halodule wrightii a comparison of techniques based on daily carbon budgets. Estuaries 18, 271-278. 

Filippino, K. C., Bernhardt, P. W., and MulhoUand, M. R. Nutrient dynamics and primary productivity in the Chesapeake Bay outflow plume during 2005 and 2006. Estuaries and Coasts (submitted). 

Paerl, H. W., and Fogel, M. L. (1994). Isotopic characterization of atmospheric nitrogen inputs as sources of enhanced primary production in coastal Atlantic Ocean waters. Mar. Biol. 119, 635—645. Paerl, H. W., Dennis, R. L., and Whitah, D. R. (2002). Atmospheric deposition of nitrogen Implications for nutrient over-enrichment of coastal waters. Estuaries 25, 677—693. 

Harding, L. W., Jr., MaUonee, M. E., and Perry, E. S. (2002). Toward a predictive understanding of primary productivity in a temperate, partially stratified estuary. Estuar. Coast. Shelf Sd. 55, 437—463. 

Pennock, J. R., and Sharp, J. H. (1994). Temporal alteration between light- and nutrient-limitation of phytoplankton primary production in a coastal plain estuary. Mar. Ecol. Prog. Ser. Ill, 275-288. 

The very productive macrophyte fringe of the ocean can make a major contribution to the input of primary production in bays and estuaries. In St. Margaret s Bay, Nova Scotia — east Atlantic Canadian coast — with a total area of about 130 km, the annual productivity of the seaweeds is estimated at three times that of the annual phytoplankton productivity (Mann, 1972a). 

Chen YLL (2005) Spatial and seasonal variations of nitrate-based new production and primary production in the South China Sea. Deep Sea Res I 52(2) 319-340 Chen ZL, Liu J, Xu SY, Wang DQ, Zheng XM (2005). Impact of macrofaunal activities on the DIN exchange at the sediment-water interface along the tidal flat of Yangtze River Estuary. Environ Sci 26(6) 43-50 (in Chinese with English abstract)... 

Jassby AD, Cloem JE, Cole BE (2002) Annual primary production patterns and mechanisms of change in a nutrient-rich tidal estuary. Limnol Oceanogr 47 698-712... 

Moreover, both river induced up-welling and river discharge of nutrients create a fertile environment which enhances the primary production of organic matter in off-shore direction of estuaries. It can be predicted from these observations that heterogeneous reactions between dissolved and both mineral phase and biota will be predominant in estuaries and coastal zones. These reactions will primarily affect those elements and compounds which are located at the particulate surface. The determination of surface properties of particles appear to be an important key to understand the interactions of trace elements and organic compounds between particulate and dissolved phases in estuarine and coastal systems. 

This major input of DOM from macrophytes is not restricted to lakes, but is also realized in other aquatic ecosystems. DOM export from watersheds in lotic ecosystems is directly related to annual runoff, but significantly greater in swamp-draining streams compared with upland-draining streams (Mulholland and Kuenzler, 1979 see Chapter 2 and 6). In the Hudson Estuary, planktonic bacterial production is 3 to 6 times greater than primary production (Findlay et al., 1992). DOC derived from submerged aquatic plants in part supports the difference in bacterial carbon uptake and planktonic primary production. 

Cadee, G. C. 1978. Primary production and chlorophyll in the Zaire River, estuary and plume. 

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