At May the 22nd I had the opportunity to provide insight in the benthos monitoring programme for the Dutch North Sea at the ‘Exchange day Platform Marine Monitoring 2018’). I gave a presentation focussing on the potential differences in results when making choices in monitoring and evaluation methodologies. Besides I could also present and discuss some of the findings for recent developments in the quality status of sea floor habitats of specific areas in the Dutch North Sea. For those who were there, or others that are interested now; you can find the slides of the presentation here (Sorry, they are in Dutch). All presentations are available from the website of ‘Informatiehuis Marien’.
Today I had the opportunity to talk about our research findings on non-indigenous species in estuarine environments and the Western Scheldt in particular, during a guest lecture in the course ‘Marine Biology’ of the University College Roosevelt. For those interested the slides can be found here: Guest lecture UCR 110418 . Information is largely based on our Transect Monitoring reports (2016-01, 2017-04 coming available soon) and the Overview reporting on exotic species monitoring in the Western Scheldt (2017-01).
First description of epizoic ciliates on Bathyporeia including undescribed species.
Hardly visible with the naked eye, flourishing communities of epibiont species are often present on macrofauna. Examining Bathyporeia (small crustaceans of few millimeters in size, abundantly present in marine and estuarine waters) from Dutch waters showed that peritrich ciliates were present on 44% of the over 3500 specimens investigated. Although known for a range of other species including crustaceans, peritrich ciliates on Bathyporeia, when present also often abundantly present, were not described in detail before. Only d’Udekem d’Acoz (2004) mentions the common presence of ramified colonies of peritrich ciliates on appendages of Bathyporeia in his paper on the genus.
We discovered several types including solitary and colony-forming specimens, of which the most common species appeared to be Zoothamnium nanum (an epibiont species known from other small crustaceans like Gamarus species). However, also a likely sofar undescribed species of the genus Epistylis appeared to be common, and another type of Zoothamnium (that might be an undescribed species) was observed.
Findings on infestation patterns for different Bathyporeia species for different waterbodies and years and possible implications for basibionts (hosts) and epibionts are presented and discussed in a paper published in Crustaceana: Wijnhoven et al. (2018). Taking into account the common presence and large abundances on a variety of macrofauna species, indicates that epizoic ciliates might play a more important role in ecosystem functioning than is now recognized and/or understood. There is still a whole world to discover!
Photographs of peritrich ciliates on Bathyporeia sp.; a) Typical colonies of peritrich ciliates (most likely Zoothamnium nanum) attached to a peduncle of an antenna from Bathyporeia pilosa (specimen stained with Rose Bengal and preserved in formaldehyde) (1000x magnification); b) Typical colonies of peritrich ciliates (most likely Zoothamnium nanum) in detail (on a specimen stained with Rose Bengal and preserved in formaldehyde) (4000x magnification); c) Individual and small colonies of alive Zoothamnium sp. on peduncles from antenna 2 of an alive specimen of Bathyporeia sarsi (1000x magnification); d) A singular alive specimen of Zoothamnium nanum on Bathyporeia sarsi (4000x magnification) with its cilia out; e) Singular alive peritrich ciliates on Bathyporeia pilosa (4000x magnification) showing a specimen without a spasmoneme (Epistylis sp.); f) Singular and couples of peritrich ciliates on Bathyporeia pilosa (4000x magnification) where the lower specimen belonging to the genus Zoothamnium lacks transverse folds (Zoothamnium sp.).
Wijnhoven, S., Zwiep, K.L., Hummel, H. (2018). First description of epizoic ciliates (Sessilida Stein, 1933) on Bathyporeia Lindström, 1855 (Peracarida, Amphipoda) and infestation patterns in brackish and marine waters. Crustaceana 91(2),133-152.
Other study cited:
d’Udekem d’Acoz, C. (2004). The genus Bathyporeia Lindström, 1855, in western Europe (Crustacea: Amphipoda: Pontoporeiidae). Zool. Verh. Leiden 348, 3-162.
An overview on monitoring activities providing information on the presence of alien species among macrofauna, macro-algae and plankton in the Western Scheldt has been prepared by Ecoauthor, GiMaRIS and eCOAST. Almost a hundred alien species were observed during the last 25 years, for which vectors of introduction are indicated. The study gives a nice overview of the efficiency of techniques to detect certain alien species groups and the habitats where new alien species are most likely be encoutered. In the meanwhile new alien species have been detected in the Western Scheldt and will amongst others be presented in the Ecoauthor Transect Monitoring report for 2017 coming available soon.
– Wijnhoven, S., Gittenberger, A., Faasse, M., Schellekens,T. (2017). Overview alien species monitoring in the Western Scheldt: Current status of monitoring efforts and presence of alien species among macrofauna and algae. Ecoauthor Report Series 2017 – 01, Heinkenszand, the Netherlands.
– Wijnhoven, S. (2016). Non-indigenous species presence and distribution in intertidal hard substrate environments of the Western Scheldt: Results of Transect Monitoring inventory of 2016. Ecoauthor Report Series 2016 – 01, Heinkenszand, the Netherlands.
Both, the Overview report as the Transect monitoring in the Western Scheldt are commissioned by the Office for Risk assessment and Research (BuRO) of the
Netherlands Food and Consumer Product Safety Authority (NVWA).
Foto: ©Bert Ooms/WWF
WWF – The Netherlands (WNF) has published a nice report showing the recent trends in species richness in amongst others the Dutch North Sea, Wadden Sea and Delta waters. Ecoauthor also made a modest contribution to the interpretation of findings here.
The entire report:‘Wereld Natuur Fonds. 2017. Living Planet Report. Zoute en zilte natuur in Nederland. WNF, Zeist.’ (written in Dutch) can be found here.
Additional information can be found on the website of WNF (www.wnf.nl).
At the moment Ecoauthor is monitoring the presence of non-indigenous species in the intertidal zone along the Western Scheldt (‘Westerschelde’). Besides valuable information on the distribution of exotic species (results will follow later this year), the monitoring also gives insights in populations of indigenous species. For the second year in row Myosotella denticulata (‘Meertandig muizenoortje’ in Dutch) is found to be common in the high intertidal parts near Bath. Myosotella denticulata is specifically found in the spaces between the blocks that pave the dikes. The ecological atlas (De Bruyne et al., 2013) records the species for just one 10×10 km gridcell in the entire South-western Dutch delta, although it is already mentioned that the species might be more common than suggested. We did also observe the species near Breskens and Hansweert in a similar habitat before (Wijnhoven et al., 2015).
Research is part of the Transect Monitoring project commissioned by the Netherlands Food and Consumer Product Safety Authority (NVWA).
De Bruyne, R., van Leeuwen, S., Gmelig Meyling, A., Daan, R. (2013). Schelpdieren van het Nederlandse Noordzeegebied. Ecologische atlas van de mariene weekdieren (Mollusca). Uitgeverij Tirion, Utrecht en Stichting ANEMOON, Lisse, 414 p.
Wijnhoven, S., Engelberts, A., Dekker, A. et al. (2015). Non-indigenous species inventory of estuarine intertidal areas; a comparison of estuaries and habitats using a hard substrte transect methodology. Pilot study wthin the frame of the INTERREG IV A 2 Seas project SEFINS commissioned by the NVWA. Monitor Taskforce Publication Series 2015-07, NIOZ-Yerseke, the Netherlands.
Last February the 8th, a trinational workshop on joint monitoring, evaluation and knowledge exchange concerning the Doggerbank was held in Hamburg. With several participants from Germany and the UK, Ecoauthor represented the Dutch government. Although monitoring programmes in the three countries are quite different, it is clear that cooperation will have benefits for each of the countries. As a first step, benthic monitoring data will be exchanged, and the various indicators in use will be applied on each others datasets. The tuning of evaluations should lead to a joint evaluation of the international Doggerbank region in the near future. Also joint monitoring activities are foreseen.
This gallery contains 4 photos.
As a follow-up on the last years monitoring of hard substrate related macrofauna and macro-algae communities in the intertidal zone of a selection of estuaries with the focus on exotic species within the frame of SEFINS (Safeguarding the Environment from … Continue reading