Geomorphological development of aquatic mesohabitats in shore channels along longitudinal training dams

Dataset for the article 'Geomorphological development of aquatic mesohabitats in shore channels along longitudinal training dams' published in Remote Sensing in Ecology and Conservation. Abstract Longitudinal training dams (LTDs) are novel hydraulic engineering structures in the river Waal intended to facilitate intensive navigation and safe discharges in the main channel while providing sheltered habitats for aquatic biota in shore channels. Monitoring data collected using light detection and ranging (LiDAR), multibeam echosounder (MBES) and aerial photography for the years during and after to construction of the LTDs were analyzed in order to determine patterns of erosion and deposition, the retreat rate of steep eroding banks and shoreline length change through time. The LTD shore channels and two traditional groyne fields (references) were divided into nine mesohabitats based on physical attributes. Net erosion was estimated for eight out of the nine mesohabitats for the 2015-2020 period. Generally, there is a pattern of riverbed aggradation towards the LTDs and degradation or bank erosion towards the littoral zones of the LTD shore channels. This kind of continuous behavior could be indicative of current or eminent channel and thus habitat stability. The bankline erosion in shore channels had mean retreat rates of 1.4-1.6 m/yr. The shorelines were longer in sand-dominated mesohabitats, which could be key for habitat heterogeneity. The LTD shore channels offered more complex relatively natural continuous littoral zones than the traditional groyne fields while maintaining the multifunctionality of the river. Thus, the development of sandy shorelines in the LTD shore channels should be encouraged through management in order to enhance biodiversity. Geomorphological monitoring of the shore channels should continue in the future in order to detect any long-term changes in the sedimentary processes and ecological functions. For detailed methods see the Readme.txt file

Underwater Macroplastic Detection Using Imaging Sonars

Abstract: Plastic pollution in the ocean occurs mainly via riverine transport. In rivers, plastic is pervasive in sediments and in the water column. Monitoring of floating plastics in rivers is time consuming as it is usually collected using nets and classified by hand, or counted and classified visually. To make plastic detection in the water column more time- and cost-efficient, there is a need to explore remote sensing options. Here we present the results of two semi-controlled pilot tests in standing water using two imaging sonar technologies: an Adaptive Resolution Imaging Sonar (ARIS) sonar and a low-cost side-scan sonar (SSS). Additionally, the ARIS sonar was tested in flowing water at a sheltered shore channel behind a longitudinal training dam in the river Waal, the Netherlands. Both technologies were able to detect 100% of the macroplastics tested in standing water. The ARIS sonar provided higher resolution images of the targets tested due to its high operation frequency detecting macroplastics down to a size of 1 cm2. The ARIS sonar detected macroplastics in the field, however, the detection decreased to 67% in flowing water. This sonar was limited to the 2D horizontal position of targets. The SSS is a low-cost option for monitoring of plastics and is integrated with CHIRP sonar technology that combines side and down imaging providing the 3D position of targets. For future monitoring, an ARIS sonar in motion or two ARIS sonars used simultaneously may provide the necessary 3D spatial information of plastic targets

School gardening increases knowledge of primary schoolchildren on edible plants and preference for vegetables

At least 10% of children worldwide are diagnosed with overweight. Part of this problem is attributed to low vegetable intake, for which preference at a younger age is an indicator. Few studies examined long-term effects of school garden interventions on the knowledge about and preference for vegetables. Therefore, in this study, an intervention period of 7 months (17 lessons) was organized for primary school students (n = 150) of age 10–12 years in the Municipality of Nijmegen (the Netherlands). Surveys were conducted before and after the intervention period to test the ability of students to identify vegetables, to measure their self-reported preference for vegetables, and to analyze students’ attitudes toward statements about gardening, cooking, and outdoor activity. The long-term effects were measured by repeating the survey 1 year after the intervention (n = 52). Results were compared with a control group of students (n = 65) with similar background and tested for significance with α = 0.05. School gardening significantly increases the knowledge of primary schoolchildren on 10 vegetables as well as their ability to self-report preference for the vegetables. The short-term (n = 106) and long-term (n = 52) preference for vegetables increased (p  0.05). This implies that the exposure to vegetables generated by school gardening programs may increase willingness to taste and daily intake of vegetables on the long term. Students’ attitudes toward gardening, cooking, and outdoor activity were unaffected by the intervention

School gardening increases knowledge of primary schoolchildren on edible plants and preference for vegetables

At least 10% of children worldwide are diagnosed with overweight. Part of this problem is attributed to low vegetable intake, for which preference at a younger age is an indicator. Few studies examined long-term effects of school garden interventions on the knowledge about and preference for vegetables. Therefore, in this study, an intervention period of 7 months (17 lessons) was organized for primary school students (n = 150) of age 10–12 years in the Municipality of Nijmegen (the Netherlands). Surveys were conducted before and after the intervention period to test the ability of students to identify vegetables, to measure their self-reported preference for vegetables, and to analyze students’ attitudes toward statements about gardening, cooking, and outdoor activity. The long-term effects were measured by repeating the survey 1 year after the intervention (n = 52). Results were compared with a control group of students (n = 65) with similar background and tested for significance with α = 0.05. School gardening significantly increases the knowledge of primary schoolchildren on 10 vegetables as well as their ability to self-report preference for the vegetables. The short-term (n = 106) and long-term (n = 52) preference for vegetables increased (p  0.05). This implies that the exposure to vegetables generated by school gardening programs may increase willingness to taste and daily intake of vegetables on the long term. Students’ attitudes toward gardening, cooking, and outdoor activity were unaffected by the intervention

Underwater Macroplastic Detection Using Imaging Sonars

Abstract: Plastic pollution in the ocean occurs mainly via riverine transport. In rivers, plastic is pervasive in sediments and in the water column. Monitoring of floating plastics in rivers is time consuming as it is usually collected using nets and classified by hand, or counted and classified visually. To make plastic detection in the water column more time- and cost-efficient, there is a need to explore remote sensing options. Here we present the results of two semi-controlled pilot tests in standing water using two imaging sonar technologies: an Adaptive Resolution Imaging Sonar (ARIS) sonar and a low-cost side-scan sonar (SSS). Additionally, the ARIS sonar was tested in flowing water at a sheltered shore channel behind a longitudinal training dam in the river Waal, the Netherlands. Both technologies were able to detect 100% of the macroplastics tested in standing water. The ARIS sonar provided higher resolution images of the targets tested due to its high operation frequency detecting macroplastics down to a size of 1 cm2. The ARIS sonar detected macroplastics in the field, however, the detection decreased to 67% in flowing water. This sonar was limited to the 2D horizontal position of targets. The SSS is a low-cost option for monitoring of plastics and is integrated with CHIRP sonar technology that combines side and down imaging providing the 3D position of targets. For future monitoring, an ARIS sonar in motion or two ARIS sonars used simultaneously may provide the necessary 3D spatial information of plastic targets

Data from: Thermal limits in native and alien freshwater peracarid Crustacea: the role of habitat use and oxygen limitation

1. In order to predict which species can successfully cope with global warming and how other environmental stressors modulate their vulnerability to climate related environmental factors, an understanding of the ecophysiology underpinning thermal limits is essential for both conservation biology a nd invasion biology. 2. Heat tolerance and the extent to which heat tolerance differed with oxygen availability were examined for four native and four alien freshwater peracarid crustacean species, with differences in habitat use across species. Three hypotheses were tested: 1) Heat and lack of oxygen synergistically reduce survival of species; 2) Patterns in heat tolerance and the modulation thereof by oxygen differs between alien and native species, and between species with different habitat use; 3) small animals can better tolerate heat than large animals and this difference is more pronounced under hypoxia. 3. To assess heat tolerances under different oxygen levels, animal survival was monitored in experimental chambers in which the water temperature was ramped up (0.25 ˚C min-1). Heat tolerance (CTmax) was scored as the cessation of all pleopod movement, and heating trials were performed under hypoxia (5kPa Oxygen), normoxia (20 kPa) and hyperoxia (60 kPa). 4. Heat tolerance differed across species as did the extent by which heat tolerance was affected by oxygen conditions. Heat tolerant species, e.g., Asellus aquaticus and Crangonyx pseudogracilis, showed little response to oxygen conditions in their CTmax, whereas the CTmax of heat sensitive species, e.g., Dikerogammarus villosus and Gammarus fossarum, was more plastic, being increased by hyperoxia and reduced by hypoxia. 5. In contrast to other studies on crustaceans, alien species were not more heat tolerant than native species. Instead, differences in heat tolerance were best explained by habitat use, with species from standing waters being heat tolerant and species from running waters being heat sensitive. In addition, larger animals displayed lower CTmax, but only under hypoxia. An analysis of data available in the literature on metabolic responses of the study species to temperature and oxygen conditions suggests that oxygen conformers and species whose oxygen demand rapidly increases with temperature (low activation energy) may be more heat sensitive. 6. The alien species D. villosus appeared most susceptible to hypoxia and heat stress. This may explain why this species is very successful in colonizing new areas in littoral zones with rocky substrate which are well aerated due to continuous wave action generated by passing ships or prevailing winds. This species is less capable of spreading to other waters which are poorly oxygenated and where C. pseudogracilis is the more likely dominant alien species

Functional feeding traits as predictors of invasive success of alien freshwater fish species using a food-fish model

Invasions of Ponto-Caspian fish species into north-western European river basins accelerated since the opening of the Rhine–Main–Danube Canal in 1992. Since 2002, at least five Ponto-Caspian alien fish species have arrived in The Netherlands. Four species belong to the Gobiidae family (Neogobius fluviatilis, Neogobius melanostomus, Ponticola kessleri, and Proterorhinus semilunaris) and one to the Cyprinidae family (Romanogobio belingi). These species are expected to be potentially deleterious for the populations of four native benthic fish species: Gobio gobio (Cyprinidae), Barbatula barbatula (Nemacheilidae), Cottus perifretum, and C. rhenanus (Cottidae). Invasion success may be dependent on competitive trophic interactions with native species, which are enabled and/or constrained by feeding-related morphological traits. Twenty-two functional feeding traits were measured in nine species (in total 90 specimens). These traits were quantitatively linked to the mechanical, chemical and behavioral properties of a range of aquatic resource categories, using a previously developed food-fish model (FFM). The FFM was used to predict the trophic profile (TP) of each fish: the combined capacities to feed on each of the resource types. The most extreme TPs belonged to three alien species, indicating that they were most specialized among the studied species. Of these three, only P. kessleri overlapped with the two native Cottus species, indicating potential trophic competition. N. fluviatilis and R. belingi did not show any overlap, indicating that there is low trophic competition. The two remaining alien goby species (N. melanostomus and P. semilunaris) had average TPs and could be considered generalist feeders. They overlapped with each other and with G. gobio and B. barbatula, indicating potential trophic competition. This study suggests that both generalist and specialist species can be successful invaders. Since the FFM predicts potential interactions between species, it provides a tool to support horizon scanning and rapid risk assessments of alien species.</p

Data underlying the publication: The conservation paradox of critically endangered fish species: trading alien sturgeons versus native sturgeon reintroduction in the Rhine-Meuse river delta

The data underlies the publication Brevé et al. (2022). This dataset has data on the industry of sturgeon aquaculture and the occurrences of alien sturgeons in garden ponds and angling ponds and hydrologically connected waters in the Rhine-Meuse river delta. The incentive of this study was a reintroduction of the native and critically endangered European sturgeon (Acipenser sturio). By analysing the data we found the spread of alien sturgeons in cultivation and natural waters to be unexpectedly high, which poses risks (diseases and parasites, hybridisation, predation and competition) to their novel environment and its native biodiversity

Biodiversity recovery following delta-wide measures for flood risk reduction

Biodiversity declined markedly over the past 150 years, with the biodiversity loss in fluvial ecosystems exceeding the global average. River restoration now aims at flood safety while enhancing biodiversity and has had success locally. However, at the scale of large river distributaries, the recovery remained elusive. We quantify changes in biodiversity of protected and endangered species over 15 years of river restoration in the embanked floodplains of an entire river delta. We distinguish seven taxonomic groups and four functional groups in more than 2 million field observations of species presence. Of all 179 fluvial floodplain sections examined, 137 showed an increase in biodiversity, particularly for fast-spreading species. Birds and mammals showed the largest increase, that is, +13 and +3 percentage point saturation of their potential based on habitat. This shows that flood risk interventions were successfully combined with enhancement of biodiversity, whereas flood stage decreased (−24 cm)

Life cycle greenhouse gas benefits or burdens of residual biomass from landscape management

The use of residual biomass for the production of bioenergy and biomaterials is often suggested as a strategy to avoid negative effects associated with dedicated biomass production. One potential source is biomass from landscape management. The goal of this study was to find the lowest net greenhouse gas (GHG) emissions of various applications of residual biomass from landscape management. GHG balances of thirteen residual biomass applications were calculated and compared to their respective conventional counterfactuals. As a case study, the potential contribution to climate change mitigation through the use of residual biomass available from vegetation management in floodplains of the Dutch Rhine delta were quantified. The greatest GHG benefits are achieved when using woody biomass to produce heat (−132 kg CO 2 -eq./tonne wet biomass) and grassy biomass to produce growth media (−229 kg CO 2 -eq./tonne wet biomass). In contrast, composting grassy biomass for fertiliser replacement on agricultural fields results in the largest GHG burdens of 62 kg CO 2 -eq./tonne wet biomass. The findings imply that residual biomass from landscape management can contribute to both GHG benefits and burdens, depending on the application. Higher benefits were found for bioenergy than for biomaterial applications. Biomass applications should be chosen with care and consideration of their counterfactuals