. The Biological bulletin. Biology; Zoology; Biology; Marine Biology. Childs River. June July August •— NO3 + POJ enriched Summer 1995 —»— N°3 enrkhed —•— PO4 enriched Figure 1. Left panels: Initial ambient chlorophyll concentrations for Sage Lot Pond. Quashnel River, and Childs River, three estuaries of llut/uoir Bay. Massachusetts. Right panels: Phytoplankton growth rates with nitrate + phosphate, nitrate, and phosphate enrichment in water samples from Sage Lot Pond. Quashnet River, and Childs River. Nutrient enrichment experiments were completed in June. July, and August. 1995. and initial
. The Biological bulletin. Biology; Zoology; Biology; Marine Biology. Childs River. June July August •— NO3 + POJ enriched Summer 1995 —»— N°3 enrkhed —•— PO4 enriched Figure 1. Left panels: Initial ambient chlorophyll concentrations for Sage Lot Pond. Quashnel River, and Childs River, three estuaries of llut/uoir Bay. Massachusetts. Right panels: Phytoplankton growth rates with nitrate + phosphate, nitrate, and phosphate enrichment in water samples from Sage Lot Pond. Quashnet River, and Childs River. Nutrient enrichment experiments were completed in June. July, and August. 1995. and initial concentrations in the enriched treatments, and d is the number of days of incubation). The calculation normalizes growth, compensating for the difference in chlorophyll that oc- curs over time in the estuary (Fig. 1, left panel). Phytoplankton growth rates for water samples enriched with NO3^ and NOr + PO43 peaked during mid-July in the three estuaries (Fig. 1, right panel). The phytoplankton was primarily nitrogen-limited: nitrogen addition stimulated growth (in both NOr and NO3~ + PO43~ enrichments), but PO43~ addition alone did not (Fig. 1, right panel). There was some degree of secondary limitation by PO43~ when NOr was available, as suggested by the moderate increase of chlorophyll growth in NO3~ + PO43 treatment compared to NO," treatment (Fig. 1, right panel). Surprisingly, the growth response (largely due to nitrogen supply) was most pronounced where the algal cells were chron- ically exposed to greater nitrogen loading. Compare, for example, the response in Childs River (Fig. 1, bottom right) to that in Sage Lot Pond (Fig. 1. top right). The differences in growth re- sponse may be attributed to the threefold higher initial ambient concentration of chlorophyll in Childs River than in Sage Lot Pond (Fig. 1, top and bottom, left panel). The enriched samples from different estuaries differ in phy- toplankton species composition. A bloom of the chain-fo
Size: 1641px × 1522px
Photo credit: © Library Book Collection / Alamy / Afripics
License: Licensed
Model Released: No
Keywords: ., bookauthorlilliefrankrat, booksubjectbiology, booksubjectzoology
