Derivation of a water quality guideline for aluminium in marine waters

Abstract

Metal risk assessment of industrialized harbors and coastal marine waters requires the application of robust water quality guidelines to determine the likelihood of biological impacts. Currently there is no such guideline available for aluminium in marine waters. A water quality guideline of 24 µg total Al/L has been developed for aluminium in marine waters based on chronic 10% inhibition or effect concentrations (IC10 or EC10) and no-observed-effect concentrations (NOECs) from 11 species (2 literature values and 9 species tested including temperate and tropical species) representing 6 taxonomic groups. The 3 most sensitive species tested were a diatom Ceratoneis closterium (formerly Nitzschia closterium; IC10 = 18 µg Al/L, 72-h growth rate inhibition) < mussel Mytilus edulis plannulatus (EC10 = 250 µg Al/L, 72-h embryo development) < oyster Saccostrea echinata (EC10 = 410 µg Al/L, 48-h embryo development). Toxicity to these species was the result of the dissolved aluminium forms of aluminate (Al(OH4 (-) ) and aluminium hydroxide (Al(OH)3 (0) ) although both dissolved, and particulate aluminium contributed to toxicity in the diatom Minutocellus polymorphus and green alga Dunaliella tertiolecta. In contrast, aluminium toxicity to the green flagellate alga Tetraselmis sp. was the result of particulate aluminium only. Four species, a brown macroalga (Hormosira banksii), sea urchin embryo (Heliocidaris tuberculata), and 2 juvenile fish species (Lates calcarifer and Acanthochromis polyacanthus), were not adversely affected at the highest test concentration used.

Evaluating the effects of pH, hardness, and dissolved organic carbon on the toxicity of aluminum to freshwater aquatic organisms under circumneutral conditions

“…This is consistent with known mechanisms of toxicity from precipitated forms of Al in fish that are related to smothering of gill surfaces and increased mucus production at the gills, thereby limiting respiratory gas exchange [29][30][31][32]. Similar mechanisms are likely responsible for toxicity from exposure to precipitated forms of Al in invertebrates [5], and both precipitated and dissolved forms of Al have been shown to contribute to algae toxicity [5,33]. Therefore, Al toxicity under circumneutral conditions should best be expressed and modeled on the basis of both dissolved and precipitated Al, rather than dissolved or monomeric Al, as would be preferred at more acidic pH [16].…”

The increasing aluminum content affects the growth, cellular chlorophyll a and oxidation stress of cyanobacteria Synechococcus sp. WH7803

“…Vrieling et al (1999) found that the increased Al positively affected the growth and final cell density of pennate Navicula salinarum, but not of centric species Thalassiosira weissflogii; while Saçan (2007) found that Al negatively affected the growth of diatom Minutocellus polymorphus and green alga Dunaliella tertiolecta. However, a limited Al effect was observed for the growth of diatom Skeletonema costatum (Stoffyn 1979); and no significant effects were detected on the brown macroalga Hormosira banksii, sea urchin embryo Heliocidaris tuberculata and 2 juvenile fish species of Lates calcarifer and Acanthochromis polyacanthus, even at an extremely high Al level (37 μmol l -1 ) (Golding 2014).…”

Aluminium, gallium, and molybdenum toxicity to the tropical marine microalga Isochrysis galbana

“…Aluminium (Al), gallium (Ga), and molybdenum (Mo) are 3 metals for which there is little chronic toxicity information available for marine species and which are of relevance to tropical marine waters. A recent study has derived a high-reliability guideline value of 24 mg/L Al for marine waters [5]. However, in some regions, including tropical northern Australia, dissolved Al in coastal seawater can range from 10 mg/L to 16 mg/L in the dry season to 20 mg/L to 29 mg/L in the wet season depending on the vicinity to freshwater inputs [4].…”