International Society for Diatom Research
  • Home
  • About
    • About ISDR
    • Council Members
    • Society People
    • Diatom Research
    • Contact Us
  • Membership
  • ISDR Meetings
  • ISDR Grants
    • About
    • How to apply
  • Announcements
    • News
    • Meetings
    • Opportunities
    • Networking
  • Diatom Of The Month
    • About
    • DOM
  • Young ISDR
    • About
    • Young ISDR Blog
  • Log in
Select Page

Characteristics and growth forms of diatom communities in restored rivers at the Emscher catchment

by Mimoza Dani |

The Emscher is a river, that flows through the Ruhr area in North Rhine-Westphalia in western Germany. Its overall length is 83 kilometres. Emscher and its tributaries had the reputation until the middle of 20th century of being the catchment with the greatest pollution in Germany. Since the 1860s and the beginning of the industrialisation, the streams were canalized and used to discharge the untreated wastewater of industries, agriculture and coal mining. When coal mining came to an end, Emscher and its tributaries started being restored with the aim to reach a good ecological status, as part of the effort directed towards the European Water Framework Directive (2000/60/CE). Underground sewers were built to transport the wastewater, the stream beds and the riparian areas were restored.

In order to assess the effect of restoration based on benthic diatom communities, we sampled 9 sites in five restored rivers of the Boye, a tributary catchment of the Emscher (Fig 1). The sites differ in time since restoration and were sampled between 9 and 27 years after restoration. The main aim of this study was also to assess the ecological status and to show the seasonal differences between samplings in summer and spring.

We also observed the functional groups and the behaviour of diatoms in restored rivers at the Boye catchment. The diversity of diatoms makes them an excellent bioindicator especially of rivers. The biological metrics of biomonitoring are life-forms, size classes and ecological guilds. The diversity of life-forms can be regrouped in larger groups, so called ecological guilds.  An ecological guild is a group of taxa belonging to the same functional group that live in the same environment but may have adapted differently to abiotic factors.  Three kinds of ecological guilds were taken into account in this study: low-profile guild, high-profile guild and motile guild.

The diatom communities at the Boye catchment in summer comprised 119 species. Downstream more species richness were found comparing to upstream and middle stream, which could be due to a higher concentration of nutrients permitting a higher number of species to survive. Moreover, there was a high diversity and dissimilarity between the sites according to the species.

To see the seasonal differences between the samplings, we observed the most common species in summer and in spring (Fig 2). In summer the pioneer species dominated, which occurred with a lower number in spring. But according to the permutation test, the season did not have a significant effect on diatom community composition and on abundance at the Emscher/Boye catchment, because the p value was greater than 0.05.

Both in summer and in spring very tolerant species occurred, which can resist different abiotic factors, so this could be the reason, why we didn’t have seasonal differences of the diatom community composition and abundance at the Boye catchment. As we saw, the ecological status was in summer as good as in spring, so this could be an effect of restoration.

The pioneer species are R-strategists, this means that they are very small species and have a very short time of reproduction. They also can easily adapt to new habitats and are more competitive there, so this explains their high number in summer comparing to spring.

Several trophic and saprobic diatom indices according to the trophic level and organic pollution showed, that the samples at the Boye catchment in summer and in spring were in a good ecological status, except of one sample, which was in a very good ecological status in summer and one other sample, which was in a mediocre ecological status in spring.

In nutrient poor sites, the low-profile guild dominated, because they do not tolerate nutrient enrichment. In nutrient rich sites, the motile and the high-profile guild should dominate, because they favour environments with high nutrients, but this was not the case.

According to the trophic level and organic pollution in rivers, the low-profile guild dominated in almost all of the sites at the Boye catchment. In nutrient-rich sites dominated the variable guild instead of high-profile and motile guilds. The variable guild can build the taxa, which can change their life-form during their life, to survive interspecies competition or to resist different abiotic factors.

Time since restoration, had a significant effect on abundance of diatom communities at the Boye catchment. The analysis of variance (ANOVA) showed a p-value lower than 0.05.

The species richness of diatom communities showed variation, it went up and down between the sites, which were restored in different years. Most of the samples improved during the time of restoration, except of one sample in spring, which was restored in year 2005, because the sample was in a mediocre ecological status, comparing to the others (Fig 3).

We didn’t have seasonal differences between the diatom communities and the abundance at the Boye catchment by this observation. The next step will be to observe more different years of restoration in order to have better results, including recently restored and reference rivers (never canalized), so we can see more precisely the differences between the time of restoration.

Figure 1. The location of the study area. V_43 (Vorthbach_unten), V_57 (Vorthbach mitte), V_42 (Vorthbach_oben), B_45 (Boye_unten), B_46 (Boye_oben), H_41(Haarbach unten), H_60 (Haarbach oben), W_48 (Wittringer-Mühlenbach_unten), K_39 (Kirchschemmsbach_unten)

Figure 2. Low-profile: Achnanthidium minutissimum (a), Achnanthidium saprophilum (b), Meridion circulare (f), Encyonema silesiacum (d), Planothidium lanceolatum (g), Planothidium frequentissimum (i). High profile: Gomphonema saprophilum (e). Motile: Caloneis lancettula (c), Surirella brebissonii var kuetzingii (h)

Figure 3. Species richness in spring and in summer since time of restoration

References:

Berthon V., Bouchez A., Rimet F. (2011): “Using diatom life-forms and ecological guilds to assess organic pollution and trophic level in rivers: a case study of rivers in southeastern France” (DOI 10.1007/s10750-011-0786-1). Hydrobiologia (2011) 673: 259–271.

Borcard D., Gillet F. und Legendre P. (2018): “Numerical Ecology with R” (DOI 10.1007/978-3-319-71404-2), 2. Auflage, Switzerland: Springer.

EGLV (2011): „Die neue Emscher“ (https://www.eglv.de/emscher/der-umbau/).

Kollmann J., Kirmer A., Tischew S., Hölzel N. & Kiehl K. (2019): „Renaturierungsökologie“, 1. Auflage: Springer Spektrum.

Passy I. S. (2007): “Diatom ecological guilds display distinct and predictable behavior along nutrient and disturbance gradients in running waters” (DOI 10.1016/j.aquabot.2006.09.018). Journal of aquatic botany (2007) 86: 171–178.

Peet R. (2016): “A greener tomorrow: Water management in urban redevelopment” (www.iclei.org).

Rimet F. und Bouchez A. (2012): “Life-forms, cell-sizes and ecological guilds of diatoms in European rivers” (DOI 10.1051/kmae/2012018). KMAE (2012) 406, 01.

Winking C. (2015): “Ecological evaluation of restored former sewage channels in the urbanised Emscher catchment”.

Winking C., Lorenz W. A., Sures B. und Hering D. (2015): “Start at zero: succession of benthic invertebrate assemblages in restored former sewage channels” (DOI 10.1007/s00027-015-0459-7). Aquatic Science (2016) 78:683–694.

Wittkampf P. (2012): „Die Emscher bis zum Ende des 20. Jahrhunderts” (https://www.lwl.org/LWL/Kultur/Westfalen_Regional/Naturraum/Emscher_I).

Previous Young ISDR Posts

2023

  • IDS Early Career Researcher, best oral presentation
  • ECR Report of the IDS
  • IDS – ECR Activities (and links)
  • Flash presentations and speed talks! Hybrid Yamagata IDS Event
  • Registration for Workshops and Speed Talks at the IDS in Yamagata are now open
  • First announcement: Workshops for the IDS
  • ECR activities at the Yamagata International Diatom Symposium (August 28th to September 2nd 2023)

2022

  • Characteristics and growth forms of diatom communities in restored rivers at the Emscher catchment
  • Functional and compositional responses of stream microphytobenthic communities to multiple stressors increase and decrease
  • Untangling the relationship between Rhopalodian diatoms and their nitrogen-fixing endosymbionts.
  • Loggerhead sea turtle-associated epizoic vs. non-epizoic diatoms



    Social Media ...

    • facebook
    • twitter
    • instagram
    • mail

    YoungISDR Follow

    Early Career Researcher group of the International Society of Diatom Research (https://t.co/NuEgRneCpg). Join us in our ECR diatomist network!

    Avatar
    Avatar YoungISDR @young_isdr ·
    29 Aug

    Tell me you are in a Japanese (diatom) meeting without telling me that you are in a Japanese (diatom) meeting. Our student posters are marked with this cutie and their siblings. Brilliant idea from Shinya Sato :) The persons are “tagged” with Young ISDR pins

    3

    Reply on Twitter 1696444736402559130 Retweet on Twitter 1696444736402559130 1 Like on Twitter 1696444736402559130 5 Twitter 1696444736402559130
    Retweet on Twitter YoungISDR Retweeted
    Avatar International Society for Diatom Research @isdr_diatom ·
    28 Aug

    Hybrid activities of the #IDS26 #IDS for today (time in Japanese local time):
    - ISDR Grant presentation meeting (link in ) at 15h
    - Presentation of the new discussion series at 16:15, link in membership mail!

    Reply on Twitter 1696303766603989264 Retweet on Twitter 1696303766603989264 1 Like on Twitter 1696303766603989264 1 Twitter 1696303766603989264
    Avatar YoungISDR @young_isdr ·
    28 Aug

    #IDS26 #IDS remember that today we have the hybrid grant scheme meeting at 15h local Japan time. Find the information for your timezone and the link here:

    Reply on Twitter 1696302874068910522 Retweet on Twitter 1696302874068910522 1 Like on Twitter 1696302874068910522 3 Twitter 1696302874068910522
    Retweet on Twitter YoungISDR Retweeted
    Avatar Rosa Trobajo @rosatrobajo ·
    28 Aug

    #IDS26 in Yamagata taking off with the molecular diatomology workshop organized by @young_isdr tought by @Kalipster

    Reply on Twitter 1696046868915269923 Retweet on Twitter 1696046868915269923 3 Like on Twitter 1696046868915269923 12 Twitter 1696046868915269923
    Load More

    Get In Touch

    If you’d like to know more, please contact us to get involved and learn about diatom research around the world.

    Contact ISDR

    • facebook
    • twitter

    ISDR Mission

    The International Society for Diatom Research promotes fundamental diatom research and translation of that research for public benefit throughout the world.

    The International Society for Diatom Research

    Society Details

    secretary@isdr.org
    president@isdr.org
    treasurer@isdr.org
    editor@isdr.org
    webmaster@isdr.org
    youngISDR@isdr.org

    Registered Charity (1054897)

    ISDR Constitution
    Privacy Policy

    Copyright 2023 © The International Society For Diatom Research | Site design by The Big Idea