Benthic Indicator Species Index (BISI) developed for marine habitat types in Natura 2000 areas.

View on the Western Scheldt with the skyline of the harbours of Antwerp – S. Wijnhoven (2016)

Benthic Indicator Species Indices (BISIs) specifically developed for quality evaluations of marine Habitat Directive (HD) habitat types and relevant Natura 2000 areas of the Dutch Delta waters, the Wadden Sea and the coastal zone of the North Sea, are available now. Specifically BISIs have been developed for HD-habitat types H1160, H1130, H1110a, H1140a and H1140b*. BISIs have been developed according to BISI v2 (protocol update in progress), taking dominant ecotopes (defining the main distinguishing communities) as the basis to select indicator species for which internal reference occurrences (as used in the indicator) are calculated surface-ratio based. This allows application of the BISI in similar habitats beyond the current Natura 2000 areas for which the indicator has been elaborated and tested here. The developed BISIs are presented with proposals for monitoring programmes with sufficient power to detect potential quality differences, as much as possible making use of current recurring monitoring activities. Indicator development and suggested monitoring programmes for the Eastern Scheldt (Oosterschelde), Western Scheldt (Westerschelde), Wadden Sea (Waddenzee) including Eems-Dollard and intertidal areas in the coastal zone of the Dutch North Sea, are presented in:

Wijnhoven, S. & Van Avesaath, P.H. (2019). Benthische Indicator Soorten Index (BISI) voor mariene habitattypen in Natura 2000-gebieden. Uitwerking beoordelingsmethodiek inclusief monitoringvoorstel voor mariene habitattypen van de Habitatrichtlijn gelegen in de Deltawateren, het Waddenzeegebied en de kustzone van de Noordzee. Ecoauthor Report Series 2019 – 03, Heinkenszand, the Netherlands.

With Assessment Tools for the developed BISIs in Excel-format available from here. Background information on the calculations and test results as indicated in the report is available on request.

(At the moment the report is only available in Dutch)

*Respectively ‘Large shallow inlets and bays’ (H1160), ‘Estuaries’ (H1130), ‘Sandbanks permanently flooded – tidal area’ (H1110a), ‘Intertidal mud flats and sandbanks – tidal area’ (H1140a), ‘Intertidal mud flats and sandbanks – North Sea coastal zone’ (H1140b).

Lecture on non-indigenous species in estuaries

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).

Ciliate communities on macrofauna: There is a world to discover.

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.

Overview alien species monitoring in the Western Scheldt

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 are amongst others presented in the Transect Monitoring Report of 2017.

– 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. (2017). Non-indigenous species presence and distribution in intertidal hard substrate environments of the Western Scheldt: Results of Transect Monitoring inventory of 2017 compared to 2015-2016. Ecoauthor Report Series 2017-04, 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.

The overview report and the transect monitoring reports for the Western Scheldt are commissioned by the Office for Risk assessment and Research (BuRO) of the
Netherlands Food and Consumer Product Safety Authority (NVWA).