Macroinvertebrate and environmental responses to dredging and submerged macrophytes transplantation
Data files
Feb 26, 2024 version files 157.75 KB
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Environment_indices.csv
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Invertebrates_data.csv
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README.md
Abstract
Eutrophication of freshwater ecosystems is a major global problem, but restoration can be difficult due to ongoing problems relating to water pollution, sedimentary nutrient stores, and altered aquatic biodiversity. Mitigation of water quality stressors is often conducted alongside transplantation of submerged macrophytes and dredging, but knowledge of ecosystem response to post-dredging transplantation of submerged macrophytes is limited.
Here, we report a long-term (2008-2018) in-situ monitoring study to evaluate the effects of two different restoration measures: dredging only (Dredged) and dredging with post-dredging transplantation of submerged macrophytes (Dredged with macrophytes) conducted in five subtropical eutrophic lakes in Lake Taihu basin, China. Water and sediment nutrients, bloom-forming algae Microcystis, and macroinvertebrate were monitored every two years for each treatment and compared with reference areas (Control) established in unrestored parts of the same lakes.
Dredging only decreased sediment nutrients (nitrogen, phosphorus, total carbon, and water total phosphorus significantly, however, this effect diminished about five years later. Dredged with macrophytes had a stronger, longer-lasting positive effect on water quality than Dredged alone. Disturbance caused by dredging (without macrophytes transplantation) decreased the biomass of Microcystis, while transplantation of submerged macrophytes shortly after dredging did not contribute to the decrease of Microcystis biomass. The biomass of Microcystis in Dredged with macrophytes areas was always similar to Control over the period of our monitoring.
A positive effect of submerged macrophytes transplantation post-dredging was found for macroinvertebrate abundance and diversity: Dredged with macrophytes areas had significantly higher macroinvertebrate biomass and richness than Dredged areas after 9 years’ recovery. Macroinvertebrate richness in Dredged with macrophytes areas nearly doubled compared to Control; while Dredged areas were just restored to Control levels.
Synthesis and applications. Our study provides an in-situ long-term field monitoring with new findings about the benefits and caution of submerged macrophytes transplantation post-dredging, and the effect of partial restoration, which could inform eutrophic waterbody restoration schemes.
README: Macroinvertebrate and environmental responses to dredging and submerged macrophytes transplantation
https://doi.org/10.5061/dryad.gb5mkkwxj
Description of the data and file structure
All the monitoring indices of water and sediment nutrients, Microcystis were included in "Environment_indices.csv" file; biomass of each benthic macroinvertebrate species was included in "Invertebrates_data.csv" file. Each row means biomass of macroinvertebrate, macroinvertebrate biomass (wet mass) was expressed by reference to the sediment area sampled (mg/m2). NAs in the dataset means no macroinvertebrte were found in the samples, for other indices NAs means the value is missing or too low that not detected out.
Abbreviations used in the dataset: total carbon (TC), total nitrogen (TN), total phosphorus (TP), nitrate nitrogen (NO3-N), ammonia nitrogen (NH3-N), orthophosphate (PO4.P), chemical oxygen demand (COD), exchangeable phosphorus (Ex.P), aluminum-bound phosphorus (Al.P), iron-bound phosphorus (Fe.P), occluded inorganic phosphorus (Oc.P), calcium-bound phosphorus (Ca.P). Indices denoted with sediment means nutrients in the sediment, other indices all water nutrients and density of Microcystis (ind/L), biomass of Microcystis (mg fresh weight/L).