This is an acoustic telemetry dataset published by Ghent University. It contains animal (fish) tracking data collected by the Permanent Belgian Acoustic Receiver Network (https://lifewatch.be/en/fish-acoustic-receiver-network) for the project/study 2015_phd_verhelst_eel, using VEMCO tags (V13) and receivers (VR2AR, VR2Tx, VR2W). In total 136 female individuals of European eel (Anguilla anguilla) were captured, tagged and released between 2015 and 2018 in the Scheldt estuary, to study their migration behaviour - especially their use of selective tidal stream transport - in a tidal system without migration barriers. Large estuaries with a complete salinity gradient from a tidal freshwater zone to marine have become rare due to water regulating constructions such as sluices, shipping locks, water pumping stations and dams. However, the Scheldt estuary in Belgium still has an extensive estuary of ca 160 km. Diadromous fish have to overcome substantial distances which come with a high energetic cost. Due to the high energetic cost of migration and the low adult survival, some of these species have developed semelparity. Consequently, a bioenergetic trade-off between migration and reproduction may exist for semelparous fish species, especially since many will stop feeding during migration: the smaller the energy expenditure during migration, the larger the amount of energy that may remain available for gonad maturation. An example where migration can have important bioenergetic repercussions is migration through strong tidal systems. To reduce energy loss in such systems, fish may perform selective tidal stream transport (STST): an animal ascends into the water column with the appropriate tide and rests on or in the bottom during the opposite tide. However, the use of STST by silver European eels is still controversial. In this study, we found strong evidence that silver European eels apply STST. The results illustrate that eels can distinguish between ebb and flood and suggest that tides play a role in orientation, either directly or indirectly. The general migration speed was higher in the downstream part of the estuary compared to the upstream part, while tidal migration speed was equal in both parts, indicating that eels migrated more consistently in the downstream part. The results of this study give insight in how a diadromous species migrates through an estuary and underline the importance of the tides. This dataset was collected using infrastructure provided by VLIZ and INBO funded by the Research Foundation - Flanders (FWO) as part of the Belgian contribution to LifeWatch. Data have been standardized to Darwin Core using the etn package and are downsampled to the first detection per hour. The original data are managed in the European Tracking Network data platform (https://lifewatch.be/etn/) and are available in Verhelst et al. (2020, https://doi.org/10.14284/434).

This is an acoustic telemetry dataset published by Ghent University. It contains animal (fish) tracking data collected by what later became the Permanent Belgian Acoustic Receiver Network (https://lifewatch.be/en/fish-acoustic-receiver-network) for the project/study 2010_phd_Reubens, using VEMCO tags (V9) and receivers (VR2W). In total 41 individuals of Atlantic cod (Gadus morhua) were captured, tagged and released in 2010 and 2011 in the C-Power wind farm in the Belgian part of the North Sea, to study their movement behaviour and assess the impacts of offshore wind farms on their movement ecology. This dataset also includes the data of the synchronisation tags present in the study. To calculate exact 2D positions using acoustic telemetry, the time difference of arrival of signals at different receivers is used. Therefore sync tags are needed to account for clock drift in the receivers. Intensive exploitation of the marine environment by mankind can alter the natural habitat of marine organisms drastically. The addition of artificial hard substrates (e.g. offshore wind turbines) to soft-sediment sandy bottoms is a pervasive example of an anthropogenic habitat change. In this study, we assess the influence of offshore wind farms on the spatio-temporal movement ecology of Atlantic cod (Gadus morhua). The results of this study will be useful for management measures for the conservation and restoration of the cod population. This study was funded by Research Foundation - Flanders (FWO). Data have been standardized to Darwin Core using the etn package and are downsampled to the first detection per hour. The original data are managed in the European Tracking Network data platform (https://lifewatch.be/etn/) and are available in Reubens et al. (2020, https://doi.org/10.14284/437).

This is an acoustic telemetry dataset published by Ghent University. It contains animal (fish) tracking data collected by the Permanent Belgian Acoustic Receiver Network (https://lifewatch.be/en/fish-acoustic-receiver-network) for the project/study 2015_phd_verhelst_cod, using VEMCO tags (V9, V13, V13AP) and receivers (VR2AR, VR2C, VR2Tx, VR2W). In total 106 individuals of Atlantic cod (Gadus morhua) were captured, tagged and released between 2014 and 2018 in the Scheldt estuary and Belgian Part of the North Sea, to study movement behaviour between the estuary, sand bars, shipwrecks and wind farms. Estuaries and coastal areas are subject to anthropogenic activities, as the largest harbours and economic activities are located along river banks and close to shore. Known to have a high habitat diversity, estuaries and coastal areas play a key role in the life cycle of many organisms, including marine fish. As such, these areas can serve as transport routes, foraging or nursery areas. In order to conserve these areas in a cost-efficient and sustainable way, a better understanding of the ecosystem functions and services is needed. The western Scheldt estuary and adjacent coastal area of Belgium are an important migration route and resident area for marine fish. We selected the Atlantic cod () as an economically important indicator species for marine fish species, to assess the importance of estuarine and coastal areas as a key habitat for this species. The results of this study will be useful for management measures for the conservation and restoration of the cod population. This dataset was collected using infrastructure provided by VLIZ and INBO funded by the Research Foundation - Flanders (FWO) as part of the Belgian contribution to LifeWatch. Data have been standardized to Darwin Core using the etn package and are downsampled to the first detection per hour. The original data are managed in the European Tracking Network data platform and are available in Verhelst et al. (2020, https://doi.org/10.14284/435).

An inventory was made of the alien macroinvertebrates occurring in Flanders. To this end large collections of biological samples were investigated and supplemented with own sampling campaigns. Mainly fresh and brackish surface waters were investigated. Three new macroinvertebrate species for Flanders were discovered. In total 41 alien macroinvertebrates were encountered in fresh and slightly brackish surface waters in Flanders. Additionally, 24 alien macroinvertebrate species have been reported for the Belgian part of the North Sea and its adjacent estuaries. Most alien macroinvertebrates belonged to the crustaceans and molluscs. Over 2,500 samples containing macrocrustaceans were identified to species level, which allowed us to accurately map their distribution in Flanders. Alien species found in the fresh and brackish water environment, mainly originated from the Ponto-Caspian area and North-America followed by Asia and South- and East-Europe. This overview shows that alien macroinvertebrates are widespread and abundantly present in many watercourses in Flanders. Based on observations in neighbouring countries, several additional species are expected to arrive in the near future. A follow-up of the invasive alien species together with a monitoring scheme to detect new incoming species is valuable to estimate the size of the problem and to be able to closely follow their ecological and economic impact This dataset was originally created for research on the spread and impact of alien invasive macroinvertebrate species in Flanders. However, the dataset can be reused for a variety of purposes. However, this being an occurrence dataset, it can be used for understanding species richness, distribution pattern and modelling studies such as ecological niche modelling. In order to enhance the confidence of use, we have documented the metadata as well as subjected the data records to a series of quality assessment and enhancement processes as described in the earlier section quality control description. To allow anyone to use this dataset, we have released the data to the public domain under a Creative Commons Zero waiver (http://creativecommons.org/publicdomain/zero/1.0/). We would appreciate however, if you read and follow these norms for data use (http://www.inbo.be/en/norms-for-data-use) and provide a link to the original dataset (https://doi.org/10.15468/xjtfoo) whenever possible. If you use these data for a scientific paper, please cite the dataset following the applicable citation norms and/or consider us for co-authorship. We are always interested to know how you have used or visualized the data, or to provide more information, so please contact us via the contact information provided in the metadata, opendata@inbo.be or https://twitter.com/LifeWatchINBO.

The Inventory of alien macroinvertebrates in Flanders, Belgium is a species checklist dataset published by Ghent University. It contains information on 73 alien macroinvertebrate species (mostly crustaceans and molluscs) occurring in Flemish aquatic habitats, from inland lakes to coastal harbours at the North Sea. The inventory is the result of the study Boets et al. (2016) (https://doi.org/10.3391/ai.2016.11.2.03 with occurrence data at https://doi.org/10.15468/xjtfoo) where it was originally published as supplementary material. Here it is published as a standardized Darwin Core Archive and includes for each species: the scientific name, higher classification, and stable taxon identifier (in the taxon core), the year of first introduction and last assessment in Flanders (given as a year range in the event date in the distribution extension), coarse habitat information (in the species profile extension) and the pathway(s) of introduction, native range(s), and invasion stage in Flanders (in the description extension). The dataset can be used for researching and managing aquatic invasions or compiling regional and national registries of alien species. Issues with the dataset can be reported at: https://github.com/trias-project/alien-macroinvertebrates We have released this dataset to the public domain under a Creative Commons Zero waiver. We would appreciate it if you follow the GBIF citation guidelines (https://www.gbif.org/citation-guidelines) when using the data. If you have any questions regarding this dataset, don’t hesitate to contact us via the contact information provided in the metadata or via https://twitter.com/trias_project. This dataset was published as open data for the TrIAS project (Tracking Invasive Alien Species http://trias-project.be, Vanderhoeven et al. 2017), with technical support provided by the Research Institute for Nature and Forest (INBO). It is selected as one of the authoritative sources for the compilation of a unified and reproducible checklist of alien species in Belgium.