30 years’ eutrophication in shallow brackish waters — lessons to be learned

Author(s):  
U. Schiewer
Keyword(s):  
1938 ◽  
Vol 29 (3) ◽  
pp. 251-251 ◽  
Author(s):  
Theodore Stephanides

The following mosquitos should be added to the list given in my earlier paper on this subject (Bull. Ent. Res. 28, 1937, pp. 405—407).1. Anopheles elutus, Edwards.The larvae are found in the same habitats as those of A. maculipennis, but seem to show a greater preference for waters near the sea-shore. A. elutus appears to be considerably rarer in Corfu than A. maculipennis, but sufficient data are not yet to hand to settle this question.2. Anopheles plumbeus, Stephens.Not common. I have obtained the larvae from the rot-holes of oak, elm and white poplar, but never so far from those of olive-trees. They favour deep holes containing plenty of rotting material.3. Aëdes (Ochlerotatus) caspius, Pallas.The larvae are sometimes present in fresh, but more frequently in slightly brackish waters. They are often gregarious with the larvae of O. detritus, Hal., but are much less abundant than the latter.4. Aëdes (Ochlerotatus) pulchritarsis, Rondani.The larvae live in rot-holes of oak, elm and white poplar, and are sometimes met with in considerable numbers in the same hole. They prefer holes in which the collected water has become thick and very dark amber in colour owing to the presence of decaying wood debris.5. Orthopodomyia pulchripalpis, Rondani.The larvae are found in the same habitats as those of O. pulchritarsis and are often gregarious with the latter. They are less plentiful, on the whole, than O. pulchritarsis and prefer somewhat clearer water.Note.—In my paper referred to above I mentioned that Finlaya echinus, Edw., is commoner in Corfu than F. geniculatus, Oliv. This statement is due to an error of determination arising from the fact that in many of the Corfu larvae of F. geniculatus the bristles of the abdominal tufts are somewhat more developed than those described in some text-books.


Author(s):  
P. Tongiorgi ◽  
E. Fregni ◽  
M. Balsamo

During 1996–1997 a systematic sampling programme was carried out in brackish coastal lakes and lagoons and in the delta of the River Po. In six of the nine collecting locations, 12 species of Gastrotricha were identified. One species, Chaetonotus ichthydioides, is new to science; another three species, the chaetonotidans Heterolepidoderma foliatum and the macrodasyidans Dendrodasys ponticus and Turbanella cf. pontica, and one macrodasyidan genus, Paradasys (P. subterraneus), were found in Italy for the first time. The unusual morphology of some of the species identified shows that Gastrotricha colonized brackish waters from both marine and freshwater habitats.


Desalination ◽  
2001 ◽  
Vol 139 (1-3) ◽  
pp. 327-331
Author(s):  
V.V. Goncharuk ◽  
D.D. Kucheruk ◽  
V.F. Skubchenko ◽  
V.P. Badekha ◽  
V.M. Kochkodan
Keyword(s):  

2003 ◽  
Vol 20 (4) ◽  
pp. 309-319 ◽  
Author(s):  
Bronson P. Guilbeau ◽  
Frederick P. Harry ◽  
Robert P. Gambrell ◽  
F.Carl Knopf ◽  
Kerry M. Dooley

Author(s):  
S. Seoane ◽  
P. Riobó ◽  
J. Franco

The genus Prymnesium includes several species that produce toxins with cytotoxic, ichthyotoxic, neurotoxic and haemolytic activity. Bloom episodes of Prymnesium species have been reported from several parts of the world (North America, Europe, Africa, Asia and Australia), especially from temperate and subtropical regions and most of them from brackish waters. Blooms cause great economic losses to aquaculture and fisheries around the world. The ichthyotoxic and allelopathic effects of Prymnesium have been linked to the presence of Haemolysin 1, Prymnesins 1 and 2 and, more recently, fatty acids and fatty acid amides. The toxicology of this genus with regard to different growth conditions such as light, nutrients and other parameters has been well documented. It is unknown, however, whether different species and strains from the Prymnesium genus all produce the same types and level of toxins. In this study, we have determined the haemolytic activity of eight different strains from the genus Prymnesium in both exponential and stationary phases of growth. We have also evaluated the efficiency of the extraction solvent.


2020 ◽  
Vol 44 ◽  
Author(s):  
Carlos Donato da Silva Souza ◽  
Geronimo Ferreira da Silva ◽  
Sirleide Maria de Menezes ◽  
José Edson Florentino de Morais ◽  
José Amilton Santos Júnior ◽  
...  

ABSTRACT Cultivation using brackish waters can result in nutritional and metabolic imbalances in several plant species, consequently reducing the production of dry matter (DM) and accumulation of toxic ions (Na+ and/or Cl-) in plants. We evaluated the DM production, and nutrient and inorganic solute (Na+ and Cl-) content in green onion plants (cv. Todo Ano Evergreen - Nebuka) under different levels of nutrient solution salinity in combination with circulation frequencies of this solution. Two experiments were conducted in a hydroponic system, using a completely randomized design, in a 6 × 2 factorial scheme, with five replicates: six levels of nutrient solution salinity (1.5, 3.0, 4.5, 6.0, 7.5, and 9.0 dS m-1) and two solution circulation frequencies (twice and thrice a day). In Experiment I, the evapotranspired depth was replaced using brackish water that was used to prepare each of the salinity levels (used exclusively), whereas in Experiment II, brackish water was used only to prepare each of the salinity levels and public water was used (electrical conductivity [ECw] = 0.12 dS m-1) for replacement in all treatments. The increase in the nutrient solution salinity reduced the production of DM and accumulation of nutrients; the reductions were more pronounced when brackish waters were used exclusively (Experiment I). However, the circulation of solutions thrice a day resulted in the harmful effects of the salinity effect. Replacing the evapotranspirated blade with water supply (Experiment II) mitigated the deleterious effects of salinity. Moreover, three circulations of the nutrient solution daily resulted in lower accumulation of inorganic Na+ and Cl- solutes and increased accumulation of nutrients N, P, K+, Ca2+, Mg2+, and S in the culture.


2000 ◽  
Vol 57 (3) ◽  
pp. 610-615 ◽  
Author(s):  
M B Edlund ◽  
C M Taylor ◽  
C L Schelske ◽  
E F Stoermer

Microfossil analysis of sediment cores collected in 1994 and phytoplankton collected in 1998 from Lake Ontario indicated that the diatom Thalassiosira baltica (Grunow) Ostenfeld was introduced and became established ca. 1988 according to 210Pb date estimates and has remained a predominant component of the phytoplankton since its establishment. Thalassiosira baltica is an exotic species in the Laurentian Great Lakes and is more commonly found in coastal brackish waters in western and northern Europe and only rarely reported from North American coastal waters. The probable vector for introduction of T. baltica was ballast water exchange and the successful establishment attributed to this taxon's euryhalinity tolerance.


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