The flux of particulate carbon in an estuary

The major sources and sinks of suspended particulate carbon are identified for northern Chesapeake Bay, Maryland, USA. The area of the bay under consideration was divided into two sections. The northernmost section (upper bay), from the head of the bay to the vicinity of Baltimore, was characterized by a high input of particulate carbon from upland drainage. The section from Baltimore to the mouth of the Potomac River (middle bay) was dominated by an internal supply of particulate carbon from primary production. The northernmost section was characterized by major particulate carbon losses to the bottom and to benthic respiration, with slightly less than half (43%) of the particulate carbon respired in the water column or converted to dissolved organic matter. In contrast, respiration in the water column or conversion to dissolved organic matter was responsible for the loss of about 65% of the particulate carbon in the middle section of the bay, while losses to the bottom and to benthic respiration totaled only 12%. Even though the supply of particulate carbon to the upper bay was about 1.5 times the supply to the middle bay, the loss of carbon due to biological activity (biological efficiency) in each area was similar, and amounted to about 70% of the supply of particulate carbon.The research reported here was partially supported by the University of Maryland and by the U. S. Bureau of Sport Fisheries and Wildlife under Contract No. 14-16-0005-2096. Contribution No. 471 of the Natural Resources Institute, University of Maryland, USA.