Nutrient and hydrologic conditions strongly influence harmful planktonic and benthic cyanobacterial bloom (CHAB) dynamics in aquatic ecosystems ranging from streams and lakes to coastal ecosystems. Urbanization, agricultural and industrial development have led to increased nitrogen (N) and phosphorus (P) discharge, which affect CHAB potentials of receiving waters. The amounts, proportions and c...

Of all groundwater pollution sources, septic systems are the second largest source of groundwater nitrate contamination in USA. This study investigated shallow groundwater (SGW) nutrient dynamics in septic areas at the northern part of the Lower St. Johns River Basin, Florida, USA. Thirty-five SGW-monitoring wells, located at nine different urban areas served by septic systems, were used to col...

This paper presents aspects of a research investigation into nutrient fluxes into and out of an important Irish estuary, Wexford Harbour, located in the southeast of Ireland. Details of the methodology applied, the data collection and analysis and the models used are outlined. In particular, the paper addresses modelling of chlorophyll_a production in the brackish waterbody and its dependency o...

1. The surface water/groundwater (SW/GW) interface is a crucial control point for lateral nutrient ̄uxes between uplands and aquatic ecosystems and for upstream/ downstream (longitudinal) processes in lotic ecosystems. 2. Hydrological and biogeochemical dynamics of the SW/GW ecotone are linked to the degree of channel constraint and the sediment characteristics of the ̄oodplain and stream bed. 3....

Ecological researchers have long borrowed concepts from the theory of chemical kinetics to describe nutrient dynamics in ecosystems. Contemporary ecology, however, is in the process of creating its own suite of ideas to quantify how whole ecosystems develop. In particular, the theory of ecosystem ascendency can be applied to data on the simultaneous flows of various chemical constituents to det...

This overview covers the basic microbial ecology of recirculating hydroponic solutions. Examples from NASA and Soviet CELSS tests and the commercial hydroponic industry will be used. The sources of microorganisms in nutrient solutions include air, water, seeds, plant containers and plumbing, biological vectors, and personnel. Microbial fates include growth, death, and emigration. Important micr...