Hydrobiologia

Melack, John

doi: 10.1007/s10750-006-0287-9pmid: N/A

Bardavid, Rahel; Ionescu, Danny; Oren, Aharon; Rainey, Fred; Hollen, Becky; Bagaley, Danielle; Small, Alanna; McKay, Christopher

doi: 10.1007/s10750-006-0288-8pmid: N/A

Salinibacter is a genus of red, extremely halophilic Bacteria. Thus far the genus is represented by a single species, Salinibacter ruber, strains of which have been isolated from saltern crystallizer ponds in Spain and on the Balearic Islands. Both with respect to its growth conditions and its physiology, Salinibacter resembles the halophilic Archaea of the order Halobacteriales. We have designed selective enrichment and isolation techniques to obtain Salinibacter and related red extremely halophilic Bacteria from different hypersaline environments, based on their resistance to anisomycin and bacitracin, two antibiotics that are potent inhibitors of the halophilic Archaea. Using direct plating on media containing bacitracin, we found Salinibacter-like organisms in numbers between 1.4×103 and 1.4×106ml−1 in brines collected from the crystallizer ponds of the salterns in Eilat, Israel, being equivalent to 1.8–18% of the total colony counts obtained on identical media without bacitracin. A number of strains from Eilat were subjected to a preliminary characterization, and they proved similar to the type strain of S. ruber. We also report here the isolation and molecular detection of Salinibacter-like organisms from an evaporite crust on the bottom of salt pools at the Badwater site in Death Valley, CA. These isolates and environmental 16S rRNA gene sequences differ in a number of properties from S. ruber, and they may represent a new species of Salinibacter or a new related genus.

Ionescu, Danny; Lipski, André; Altendorf, Karlheinz; Oren, Aharon

doi: 10.1007/s10750-006-0289-7pmid: N/A

We have used fatty acid analyses to study the community structure of a layered endoevaporitic microbial community within a gypsum crust that covers the bottom of a saltern evaporation pond in Eilat, Israel. This community, living at a salinity of 218–238 g l−1 total dissolved salts, consists of an upper brown layer dominated by unicellular cyanobacteria, a green layer with filamentous cyanobacteria, a red-purple layer with both Chromatium and Ectothiorhodospira/Halorhodospira type of purple sulfur bacteria, and a black layer in which dissimilatory sulfate reduction occurs. An olive-green layer is sometimes present below the red-purple layer. Analysis by gas chromatography/mass spectrometry of the fatty acid methyl esters prepared from the different fractions showed characteristic patterns in each layer, and these could be related to fatty acid composition data from the literature and to fatty acid analyses of representative halophilic microorganisms isolated from the site. The nature of the fatty acids in the green layer suggests that the cyanobacteria present there use the oxygen-independent pathway for production of unsaturated fatty acids, a pathway only occasionally encountered in filamentous cyanobacteria. The facultative anaerobic nature of the cyanobacteria in the green layer was confirmed by their ability to perform anoxygenic photosynthesis with sulfide as electron donor. Specific signature fatty acids identified for each layer corresponded well with the microscopic and functional analysis of the biota present.

Timms, Brian

doi: 10.1007/s10750-006-0290-1pmid: N/A

In 1984 when Bill Williams highlighted the regionalization of salt lakes in Australia, little was known about lakes in the remote inland. It was thought the invertebrate fauna of such lakes was depauperate due to their being poor evolutionary loci associated with extreme episodicity. However, work in the last two decades, has shown the fauna of many inland lakes is relatively rich. Part of the reason for restricted faunas in the larger lakes is habitat homeogeneity. Nevertheless there is little diversification at the species level, indicating restrictions on speciation. There are also limits on diversity imposed by the harsh environment, as indicated by the lack of forms unable to survive severe desiccation, e.g. higher crustaceans. Lakes in central and the eastern inland are dominated by characteristic lower crustaceans such as Parartemia minuta, Daphniopsis queenslandensis, Moina baylyi, Trigonocypris globulosa and a new mytilocyprid ostracod, as well as some forms widespread in Australia and in salt lakes on other continents. This invertebrate fauna is just as distinct as those of other salt lake districts in southern Australia, further reinforcing the concept of regionalization in Australia. The fish fauna of central and eastern salt lakes is also largely specific, but the waterbirds are not as they have responded to the episodicity by nomadism and habitat flexibility.

McMaster, Kellie; Savage, Alan; Finston, Terrie; Johnson, Michael; Knott, Brenton

doi: 10.1007/s10750-006-0291-0pmid: N/A

In Western Australia, populations of Artemia parthenogenetica in coastal salt lakes at Rottnest Island and Lake Hayward, and in salterns at Port Hedland and Shark Bay, are widely accepted to have been introduced by humans. Further, within the past 10 years, populations of A. parthenogenetica have been found in inland playa salt lakes in the wheatbelt of south-west Western Australia, where none had been recorded in previous salt lake studies. Here we hypothesise that birds act as transport vectors for Artemia cysts both within Australia and between the Asian and Australian continents. Allozyme analysis was used to identify clonal types (multi-locus genotypes), clonal frequencies, genotypic diversities and genotypic identity of six populations (three coastal, three inland).

Boggs, D.; Eliot, I.; Knott, B.

doi: 10.1007/s10750-006-0292-zpmid: N/A

A survey of 11 sites covering three large (>10 km long, 6 sites) playa lakes and four pans (<1 km2, 5 sites) of the Yarra Yarra salt lake system in the Northern Agricultural Region of Western Australia commenced in 2001. These salt lakes are shallow and ephemeral, with inundation being more regular following winter rainfall, but summer inundation also occurred in 2001. Salinity was generally higher in playas (156–368 g l−1) than pans (30–284 g l−1), but salinity responded noticeably to heavy rainfall events, especially in pans. pH values in the playa lakes (6.68–7.82) were less variable than in the pans (6.81–8.08). The range of dissolved oxygen concentrations was greater in pans (3.7–14.4 mg l−1) than in playas (3.9–8.2 mg l−1). Cationic concentrations generally followed the pattern of sea water cation dominance. Benthic microbial communities comprised either cohesive to loosely mucilaginous mats, or thin films of diatoms. Five genera of diatom and two species of filamentous cyanobacteria were recorded.

Cook, Faith; Coleman, Peri

doi: 10.1007/s10750-006-0293-ypmid: N/A

Given that diatom assemblages are a well-recognised method of characterising the water quality in freshwater streams, it seems reasonable to investigate its applicability to solar saltfields. A summer collection of benthic diatoms was undertaken in the salinas of the Dry Creek solar saltfields in South Australia for this purpose. The facility inputs seawater both from a low nutrient samphire creek and poorer quality, high nutrient samphire creek. Salinity and nutrient status of the pools and concentrating salinas have been thoroughly characterized over many years. The addition of JJ periphytometers to the sampling regime in the summer of 2001–2002 allowed the collection of benthic diatoms from these sites. Of the 69 species collected during the study, 16 species occurred only in oligotrophic waters with salinities less than 70 g/l TDS (total dissolved solids). Twenty species of diatoms occurred only in the eutrophic waters with salinities less than 70 g/l TDS, eight species were restricted to the hypersaline ponds and the remainder were undiscriminating in their ecological preferences.

Zadereev, Yegor; Tolomeyev, Alexander

doi: 10.1007/s10750-006-0294-xpmid: N/A

We examined the dynamics of the vertical stratification of physical, chemical and biological factors in a brackish meromictic lake with a deep-water chlorophyll maximum (Shira Lake, Russia, Khakasia) during the growing season and estimated how the vertical distribution of these factors influences the vertical distribution of the zooplankton community. The vertical distribution of zooplankton was restricted by the anoxic hypolimnion. Nauplii and younger copepodides (C1–C3) of the copepod, Arctodiaptomus salinus, and the rotifer, Brachionus plicatilis, were found in the upper warm waters. During summer stratification the maximum of A. salinus biomass, which consisted mainly of older copepodides (C4–C5) and females, was associated with the deep-water maximum of biomass of green algae, which are the preferred diet for this species. The vertical distribution of the rotifer Hexarthra oxiuris was bimodal with numerical peaks in the epi- and hypolimnion. Reproduction peaks of dominant species were separated in time. The reproduction peak of A. salinus was at the beginning of summer when A. salinus constituted up to 99% of total zooplankton biomass. The development of rotifers was detected after the reproduction peak of A. salinus when the biomass of rotifers reached 50% of total zooplankton biomass.

Kipriyanova, Laura; Yermolaeva, Nadezhda; Bezmaternykh, Dmitry; Dvurechenskaya, Serafima; Mitrofanova, Elena

doi: 10.1007/s10750-006-0295-9pmid: N/A

Relationships among salinity and diversity, abundance, biomass of major biological components of Chany Lake (western Siberia, Russia) are examined across a salinity gradient. As salinity increased from 0.8 to 6.4 g l−1, the species richness of aquatic vascular plants decreased from 16 to 2 species, of phytoplankton from 98 to 52 species, and of zooplankton from 61 to 16 species, but changes in species diversity of zoobenthos were negligible.

Litvinenko, L.; Kozlov, A.; Kovalenko, A.; Bauer, D.

doi: 10.1007/s10750-006-0296-8pmid: N/A

The influence of salinity on 27 Artemia parthenogenetica populations in Siberia was investigated. Salinity in the lakes sampled ranged from 50 g l−1 to 265 g l−1. Artemia were characterized on the basis of biomass, number of cysts, weight and the length of females, number of cysts in brood and several biometric parameters. Average values of shrimp biomass, number of planktonic and benthic cysts and number of cysts in broods were largest in locales with salinity 77–144 g l−1. Increased salinity reduced the number of setae on the furcal branch and the length of the cephalothorax.