Physical, chemical, and biological consequences of episodic aluminum additions to a stream1

Abstract

AlCl3 was added to a second‐orderroborated field results, added Al producing a 20% reduction in surface tension. We suggest that added Al may have associated with organic functional groups, rendering DOC more hydrophobic and less soluble. Some of these alumino‐organic substances subsequently may have accumulated at the air‐water interface. Terrestrial and aquatic invertebrate drift was also altered with elevated Al; we attribute drift to responses to chemical changes in the stream such as Al and H+ toxicity or to a physical change in surface film. stream to simulate episodic increases in Al concentration during acidic snowmelt. Significant decreases in pH and DOC and accumulation of foam at the surface (visible evidence of reduced surface tension) accompanied a stepwise increase in Al in the water. Laboratory experiments cor

Aluminum in acidic surface waters: chemistry, transport, and effects.

“…Hall et al (63) reported that increased rates of invertebrate drift followed Al addition to a New Hampshire stream. The drift rate of aquatic immature insects generally increased with increasing concentration of added Al, suggesting a stress-avoidance response that was a function of Al concentration.…”

“…Microcrystalline precipitate organic and inorganic solutes. The cycling or orthophosphate (13), trace metals (58,59) and dissolved organic carbon (DOC) (13,(60)(61)(62)(63) within acidic surface waters may be altered by adsorption of Al oxyhydroxides. However, few studies have addressed this specific hypothesis.…”

Identification des compartiments responsables de la qualité des eaux de surface d'un petit bassin versant du centre du Nouveau-Brunswick (Canada): application et analyse du modèle hydrochimique EMMA

“…(1988) et PLAMONDON (1993) ont montré que l'exploitation forestière expliquait localement la chute du pH des solutions de sol et des eaux de surface suite à une intensification du processus de nitrification. La chute du pH des solutions de sol favoriserait la mobilisation d'ions métalliques jusqu'au cours d'eau, particulièrement AI 3 *, lesquels sont toxiques pour certaines espèces de poissons et invertébrés aquatiques (BAKER et SCHOFIELD, 1982;HALL et al, 1985 ;SCHINDLER, 1988). D'après LIKENS étal.…”

Not really white - again: performing Jewish difference in Hollywood films since the 1980s

“…In lotic waters, the loss of intolerant taxa may be a function of increased drift (Hall et al 1985). Other responses to pH decline include an increase in the frequency of acidtolerant taxa Hall and Ide 1987;Dangles and Guérold 2000).…”

“…Acidic waters often contain comparatively high concentrations of metals, attributable to the increased mobilization of cations such as Al in acidified watersheds and aquatic sediments (Hall et al 1985;Cronan and Schofield 1990). This may result from the increased solubility of the cations under low pH conditions (Meybeck et al 1992) or through their replacement by H + ions during cation exchange .…”