Freshwater snail and shrimp differentially affect water turbidity and benthic primary producers

The increase of temperature might affect the distribution and reproduction of seagrass. This research aims to determine the seagrass bed coverage and the ecosystem condition. Three line transects were established perpendicular to the coastal line with the distance of 50-100 m, or up to the border of the intertidal area. In each transect, sampling points were determined with a distance of 10-20 m. At the sampling points, a plot of 50 cm x 50 cm was established to measure the coverage percentage of seagrass vegetation. The seagrass species were also observed and recorded along the line transects. The percentage of seagrass coverage was measured using a method from Saito and Atobe (1994). The results showed that the coastal area of Jelenga has the highest percentage of seagrass coverage (>60%, healthy) among other coastal areas. This may be caused by the characteristic of Jelenga coast which was relatively calm, few visitors, low water turbidity, and high light penetration. While, other transects have percentage coverage of less than 60% (less healthy). There was one transect on Maluk coast which has coverage percentage of less than 29% (lack of seagrass species). The small coverage percentage on Maluk coast can be caused by the high number of visitors and high activity of fishing boats around the coast which results in high turbidity. Keywords: coverage, ecosystem condition, seagrass bed, west Sumbawa.

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TRANSFER EFFICIENCY FROM PRIMARY PRODUCERS TO RUDITAPES PHILIPPINARUM ON AN INTERTIDAL FLAT IN HIROSHIMA BAY, JAPAN

Proceedings of International Conference "Managinag risks to coastal regions and communities in a changinag world" (EMECS'11 - SeaCoasts XXVI) ◽

10.31519/conferencearticle_5b1b93b4af8c32.73166623 ◽

2017 ◽

Author(s):

Sosuke Otani ◽

Akira Umehara ◽

Haruka Miyagawa ◽

...

Keyword(s):

Stable Isotope ◽

Secondary Production ◽

Isotope Ratios ◽

Ruditapes Philippinarum ◽

Transfer Efficiency ◽

Food Sources ◽

Stable Isotope Ratios ◽

Primary Producers ◽

Nitrogen Stable Isotope ◽

Carbon And Nitrogen

Fish yields of Ruditapes philippinarum have been decreased and the resources have not yet recovered. It needs to clarify food sources of R. philippinarum, and relationship between primary and secondary production of it. The purpose on this study is to reveal transfer efficiency from primary producers to R. philippinarum and food sources of R. philippinarum. The field investigation was carried out to quantify biomass of R. philippinarum and primary producers on intertidal sand flat at Zigozen beach in Hiroshima Bay, Japan. In particular, photosynthetic rates of primary producers such as Zostera marina, Ulva sp. and microphytobenthos were determined in laboratory experiments. The carbon and nitrogen stable isotope ratios for R. philippinarum and 8 potential food sources (microphytobenthos, MPOM etc) growing in the tidal flat were also measured. In summer 2015, the primary productions of Z. marina, Ulva sp. and microphytobenthos were estimated to be 70.4 kgC/day, 43.4 kgC/day and 2.2 kgC/day, respectively. Secondary production of R. philippinarum was 0.4 kgC/day. Contribution of microphytobenthos to R. philippinarum as food source was 56-76% on the basis of those carbon and nitrogen stable isotope ratios. Transfer efficiency from microphytobenthos to R. philippinarum was estimated to be 10-14%. It was suggested that microphytobenthos might sustain the high secondary production of R. philippinarum, though the primary production of microphytobenthos was about 1/10 compared to other algae.

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Regeneration of Floodplain Biotopes on the Upper Rhine – The “Polder Altenheim” Case

Water Science & Technology ◽

10.2166/wst.1994.0121 ◽

1994 ◽

Vol 29 (3) ◽

pp. 281-288 ◽

Cited By ~ 6

Author(s):

A. Siepe

Keyword(s):

Large Scale ◽

Freshwater Snail ◽

Red Alga ◽

Flood Protection ◽

Flooding Regime ◽

Theodoxus Fluviatilis ◽

The Creation ◽

Early Succession ◽

Upper Rhine

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).

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Remote turbidity measurement with a laser reflectometer

Water Science & Technology ◽

10.2166/wst.1998.0549 ◽

1998 ◽

Vol 37 (12) ◽

pp. 255-261 ◽

Cited By ~ 1

Author(s):

Mark Johnson

Keyword(s):

Water Surface ◽

Free Water ◽

Optical Scattering ◽

Flowing Water ◽

Water Stream ◽

Water Turbidity ◽

Water Colour ◽

Contact Measurement ◽

Optical Instruments ◽

Better Than

A simple, laser-based reflectometer is described for the measurement of water turbidity via 180° optical scattering. Applications exist both in clean source waters (0-1000NTU) with a minimum detectable turbidity better than 1NTU, and in dense wastewater primary-clarifier sludges. The non-contact measurement is performed from a distance at least up to 10m, substantially avoiding the usual window fouling problems of optical instruments. By measuring directly in the process, through a free water surface or on the side of a flowing water stream, the difficulties of transporting sample to the instrument are also avoided. Extensions to be described allow measurement also of water colour.

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EVALUATION OF CARBON STRAGE OF PRIMARY PRODUCERS IN YODO RIVER MOUTH TIDAL FLAT

Journal of Japan Society of Civil Engineers Ser B2 (Coastal Engineering) ◽

10.2208/kaigan.74.i_1207 ◽

2018 ◽

Vol 74 (2) ◽

pp. I_1207-I_1212

Author(s):

Sosuke OTANI ◽

Taiga YASUHARA ◽

Daichi TSUJI

Keyword(s):

Tidal Flat ◽

River Mouth ◽

Primary Producers

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Differential impacts of alternate primary producers on carbon cycling

Ecology ◽

10.1002/ecy.3455 ◽

2021 ◽

Author(s):

Khashiff K. Miranda ◽

Brooke L. Weigel ◽

Sophie J. McCoy ◽

Catherine A. Pfister

Keyword(s):

Carbon Cycling ◽

Primary Producers

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Comparison of Invasive Apple Snail (Pomacea canaliculata) Behaviors in Different Water Temperature Gradients

Water ◽

10.3390/w13091149 ◽

2021 ◽

Vol 13 (9) ◽

pp. 1149

Author(s):

Mi-Jung Bae ◽

Eui-Jin Kim ◽

Young-Seuk Park

Keyword(s):

Water Temperature ◽

Farming Systems ◽

Freshwater Snail ◽

Freshwater Ecosystems ◽

Pomacea Canaliculata ◽

Activity Levels ◽

Self Organizing Map ◽

Apple Snail ◽

Temperature Changes ◽

Organic Farming Systems

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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