Matching the trend seen among the major large rivers of the globe, the Amazon River and its tributaries are facing aquatic ecosystem disruption that is affecting freshwater habitats and their associated biodiversity, including trends for decline in fishery resources. The Amazon's aquatic ecosystems, linked natural resources, and human communities that depend on them are increasingly at risk fro...

Invertebrates and plants are among the most ubiquitous and abundant macroscopic organisms in aquatic ecosystems; they dominate most habitats in both diversity and biomass and play central roles in aquatic food webs. Plants regulate and create habitats for a wide array of organisms (Cooke et al. 2005). Snail grazing and bivalve filtering profoundly alter habitats and communities (Harvey and Hill...

The purpose of this introductory paper is simply to bring together in a general way some of the more important factors influencing riparian ecosystems. Riparii'.n ecosys­ tems are defined as those "on or by la."ld bordering a stream, lake, tidewater, or other body of water." Open water is the key to this definition and to the context of this paper. A riparian system is the interface between ter...

This paper describes the design, development, and initial application of a sensor-actuated network for sensing and sampling microbial communities in aquatic ecosystems. The network consists of ten stationary buoys and one mobile robotic boat for real-time, in situ measurements and analysis of chemical and physical factors governing the abundance and dynamics of microorganisms at biologically re...

Picocyanobacteria are extremely important organisms in the world's oceans and freshwater ecosystems. They play an essential role in primary production and their domination in phytoplankton biomass is common in both oligotrophic and eutrophic waters. Their role is expected to become even more relevant with the effect of climate change. However, this group of photoautotrophic organisms still rema...

H. T. Odum’s influential Limnology and Oceanography 1956 publication compared gross primary production (GPP) and ecosystem respiration (ER) among aquatic ecosystems. Few syntheses of aquatic ecosystem metabolism have been completed since. We used Odum’s conceptual framework to compare GPP and ER from open-water diel oxygen curves in lakes, wetlands, estuaries, and streams (n 5 350). We also doc...

The use of seabirds as sentinels of the condition of aquatic ecosystems has been well-established. Large environmental perturbations to aquatic food webs (e.g., chemical contamination, overfishing, particulate pollution) have all been detected or monitored by tracking seabirds at colonies. However, seabirds may elicit more subtle, sublethal responses that can also be used to track ecosystem hea...

Recently, commercial nanometer sized silver is extensively used for its antibacterial effect; however, nanoparticles may also have ecotoxicological effects after being discharged into aquatic ecosystems. Nanometer sized silver can flow into water ecosystems, where it can exert a variety of physiologically effects in aquatic animals, including fish. The current research aimed to examine the effe...

Many freshwater ecosystems receive allochthonous resource subsidies from adjacent terrestrial environments. In eastern North American forests, geographic broods of periodical cicadas emerge every 13 to 17 y to breed, and local abundances can sometimes be .300 individuals/m. Most individuals avoid predation, senesce after breeding, and become a resource pulse for forest ecosystems; some cicada c...

Anthropogenic sedimentation has various detrimental effects in many freshwater ecosystems. Sedimentation is most often caused by erosion following deforestation or development of pristine areas that expose the soil surface to precipitation and surface runoff. Accumulation of eroded sediments in the benthic zone of aquatic ecosystems has a variety of adverse effects on the fauna (Cohen et al. 19...