DOI: 10.5061/dryad.gb5mkkwxj
title: Macroinvertebrate and environmental responses to dredging and submerged macrophytes transplantation

description: 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.
description: # Macroinvertebrate and environmental responses to dredging and submerged
 macrophytes transplantation
 ## 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).