Effects of the Anuran Tadpole Assemblage and Nutrient Enrichment on Freshwater Snail Abundance (Physella sp.)

2012 ◽  
Vol 168 (2) ◽  
pp. 341-351 ◽  
Author(s):  
Geoffrey R. Smith ◽  
Amber A. Burgett ◽  
Jessica E. Rettig
1989 ◽  
Vol 21 (2) ◽  
pp. 205-210 ◽  
Author(s):  
B. L. Simmons ◽  
S. L. Trengove

Increasing urbanisation of coastal areas is leading to impacts on coastal lakes which decrease their amenity for recreation and tourism. Runoff and wastewater discharge cause siltation, impact seagrass beds and change the characteristics of open waters, affecting boating, swimming, fishing and the aesthetic quality of the locale. Management of urban development and wastewater disposal is required to minimise sedimentation and nutrient enrichment. This could include development restrictions, runoff controls and a strategy for wastewater treatment and discharge. The catchment of Lake Macquarie, a marine coastal lake, has been progressively urbanised since 1945. Urbanisation, through increased stormwater runoff and point source discharges, has caused a major impact on the lake in terms of sedimentation and nutrient enrichment. Losses of lake area and navigable waters have occurred. Accompanying problems include changes in the distribution of seagrass beds and nuisance growths of benthic algae. Since the 1950's, dry weather nutrient concentrations have increased and mean water clarity has decreased. Severe problems, as observed in other New South Wales coastal lakes, for example benthic algae in Lake Illawarra and Tuggerah Lakes, have not yet developed. Because of the lead time taken to implement policies and controls, trends should be identified and policies developed now so as to avoid nutrient buildup and development of sustained problems.


1994 ◽  
Vol 29 (3) ◽  
pp. 281-288 ◽  
Author(s):  
A. Siepe

The floodplain of the Upper Rhine and its biocoenoses have, through different river-regulatory activities over the last 175 years, undergone large scale degradation. At the same time flood protection for the downstream inhabitants has been greatly reduced. For reasons of flood protection, the “Polder Altenheim” in Baden-Württemberg, Germany southwest of Strasbourg, France, with so called retention flooding, was put into operation in 1987. The original floodplain had been diked for the previous 17 years, during which no flooding occurred. Since 1989 “ecological flooding” also is carried out. This has assisted in the regeneration of floodplain biotopes and promoted the floodplain biotic communities and the readaption of the bioceonosis to a regular flooding regime. The creation of new floodplain biotopes of early succession stages, particularly through geomorphodynamic processes, has followed the more than ten flood ocassions and typical biotic communities have colonised these sites. This will be presented together with selected examples of terrestrial and limnical species and communities. The following species and communities will be discussed: kingfisher Alcedo atthis, carabid communities (Coleoptera), the red alga Hildenbrandia rivularis (Rhodophyceae), the freshwater snail Theodoxus fluviatilis (Neritacea) and the freshwater bug Aphelocheirus aestivalis (Hydrocorisae).


Water ◽  
2021 ◽  
Vol 13 (9) ◽  
pp. 1149
Author(s):  
Mi-Jung Bae ◽  
Eui-Jin Kim ◽  
Young-Seuk Park

Pomacea canaliculata (known as invasive apple snail) is a freshwater snail native to South America that was introduced into many countries (including Asia and North America) as a food source or for organic farming systems. However, it has invaded freshwater ecosystems and become a serious agricultural pest in paddy fields. Water temperature is an important factor determining behavior and successful establishment in new areas. We examined the behavioral responses of P. canaliculata with water temperature changes from 25 °C to 30 °C, 20 °C, and 15 °C by quantifying changes in nine behaviors. At the acclimated temperature (25 °C), the mobility of P. canaliculata was low during the day, but high at night. Clinging behavior increased as the water temperature decreased from 25 °C to 20 °C or 15 °C. Conversely, ventilation and food consumption increased when the water temperature increased from 25 °C to 30 °C. A self-organizing map (an unsupervised artificial neural network) was used to classify the behavioral patterns into seven clusters at different water temperatures. These results suggest that the activity levels or certain behaviors of P. canaliculata vary with the water temperature conditions. Understanding the thermal biology of P. canaliculata may be crucial for managing this invasive snail.


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