Impact of Great Crested Grebes (Podiceps cristatus L.) on fish ponds

The study presents data on the species composition of cyanobacterial water blooms in Czech fish ponds from the 1950s to the 1990s. Since the 1950s, a shift from large-colonial Aphanizomenon flos-aquae var. flos-aquae through Microcystis aeruginosa and small-colonial species of Anabaena to single-filament species (Planktohrix agardhii, Limnothrix redekei, Aphanizomenon gracile) or single-cell forms (Microcystis ichtyoblabe), has been observed. The changes in the species composition of the water blooms are closely related to changes in fishery management (increase in fish stock, increase in application of organic fertilizers). At present the high predation of fish upon zooplankton results in elimination of large colonial blooms of A. flos-aquae associated with large filtering zooplankton (Daphnia). Low grazing pressure of zooplankton, low light conditions and low N:P ratios are suitable conditions for mass development of the small species of cyanobacteria. High pH is not necessary to achieve cyanobacteria dominance.

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Impact of Intensive Land-Based Fish Culture in Qingdao, China, on the Bacterial Communities in Surrounding Marine Waters and Sediments

Evidence-based Complementary and Alternative Medicine ◽

10.1155/2011/487543 ◽

2011 ◽

Vol 2011 ◽

pp. 1-8 ◽

Cited By ~ 6

Author(s):

Qiufen Li ◽

Yan Zhang ◽

David Juck ◽

Nathalie Fortin ◽

Charles W. Greer

Keyword(s):

Bacterial Communities ◽

Gel Electrophoresis ◽

Denaturing Gradient Gel Electrophoresis ◽

Fish Culture ◽

Fish Ponds ◽

Marine Area ◽

Gradient Gel Electrophoresis ◽

Reducing Bacteria ◽

The Impact ◽

Nitrate Reducing Bacteria

The impact of intensive land-based fish culture in Qingdao, China, on the bacterial communities in surrounding marine environment was analyzed. Culture-based studies showed that the highest counts of heterotrophic, ammonium-oxidizing, nitrifying, and nitrate-reducing bacteria were found in fish ponds and the effluent channel, with lower counts in the adjacent marine area and the lowest counts in the samples taken from 500 m off the effluent channel. Denaturing gradient gel electrophoresis (DGGE) analysis was used to assess total bacterial diversity. Fewer bands were observed from the samples taken from near the effluent channel compared with more distant sediment samples, suggesting that excess nutrients from the aquaculture facility may be reducing the diversity of bacterial communities in nearby sediments. Phylogenetic analysis of the sequenced DGGE bands indicated that the bacteria community of fish-culture-associated environments was mainly composed of Flavobacteriaceae, gamma- and deltaproteobacteria, including generaGelidibacter, Psychroserpen, Lacinutrix,andCroceimarina.

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A Neolithic Site at Abingdon, Berks.

The Antiquaries Journal ◽

10.1017/s000358150005719x ◽

1927 ◽

Vol 7 (4) ◽

pp. 438-464 ◽

Cited By ~ 15

Author(s):

E. Thurlow Leeds

Keyword(s):

Fish Ponds ◽

The South ◽

South Side ◽

The Road ◽

Neolithic Site ◽

The North ◽

Gravel Pit ◽

Animal Bones ◽

Formed Part

At the end of April of last year the Rev. Charles Overy drew my attention to the presence of broken animal bones, flints, and sherds of pottery in a gravel-pit on the south side of the road from Abingdon to Radley, about a mile out of Abingdon (fig. 1).The pit lies on the very boundary of the parish of Abingdon in a field at about 200 ft. O.D., just over half a mile north of the Thames and some 30 ft. above the river. On its eastern and southern sides it is bounded by the wide trenches which in the days of the splendour of Abingdon Abbey formed part of the Abbey's fish-ponds ; on the north is the road, and on the east the ground drops to a little brook.

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