Native and non-native species of the Dutch Wadden Sea in 2014 Issued by the Office for Risk Assessment and Research, The Netherlands Food and Customer Product Safety Authority of the Ministry of Economical Affairs A. Gittenberger M. Rensing R. Dekker P. Niemantverdriet N. Schrieken H. Stegenga GiMaRIS report 2015_08 Date: May 2015 Report nr.: GiMaRIS 2015_08 Title: Native and non-native species of the Dutch Wadden Sea in 2014 Authors: Dr. A. Gittenberger (GiMaRIS) Drs. M. Rensing (GiMaRIS) Drs. R. Dekker (NIOZ) Drs. P. Niemantsverdriet (GiMaRIS) Drs. N. Schrieken (BiOrganized) Dr. H. Stegenga (NCB Naturalis, sectie Nationaal Herbarium Nederland) Address GiMaRIS: Address NIOZ: GiMaRIS, Leiden BioScience Park NIOZ Royal Netherlands Institute for Sea Research J.H. Oortweg 21 PO Box 59 2333 CH Leiden 1790 AB Den Burg [email protected] www.nioz.nl www.GiMaRIS.com Project leaders: Dr. A. Gittenberger (GiMaRIS) Dr. ir. C.J.M. Philippart (NIOZ) Issued by: Office for Risk Assessment and Research, The Netherlands Food and Customer Product Safety Authority of the Ministry of Economical Affairs Project leader of Office for Risk Assessment and Research: Drs. A.A.J. Smolders GiMaRIS holds no liabilities for damages resulting from the use of the data in this report. The client indemnifies GiMaRIS for claims of third parties connecting with the data in this report. GiMaRIS is NEN-EN-ISO 9001 certified by NCK for Conducting research, providing consultancy and designing management plans for the Fisheries industry and ministries of Water Management and Economical Affairs (NCK.2013.001.ISO) GiMaRIS report 2015_08 Index 1 Summary p. 5 2 Introduction p. 5 3 Materials and methods p. 6 3.1 Locations p. 6 3.2 Sampling methods p. 8 3.3 Fieldwork schedule p. 9 3.4 Reference material p. 11 4 Results p. 11 4.1. Species of non-native or unknown origin p. 25 4.1.1 Algae p. 25 4.1.1.1 Antithamnionella spirographidis p. 25 4.1.1.2 Ceramium botryocarpum p. 26 4.1.1.3 Ceramium tenuicorne p. 27 4.1.1.4 Codium fragile fragile p. 28 4.1.1.5 Colpomenia peregrina p. 29 4.1.1.6 Dasysiphonia japonica p. 30 4.1.1.7 Gracilaria vermiculophylla p. 31 4.1.1.8 Neosiphonia harveyi p. 32 4.1.1.9 Sargassum muticum p. 33 4.1.1.10 Ulva pertusa p. 34 4.1.1.11 Undaria pinnatifida p. 35 4.1.2 Annelida p. 36 4.1.2.1 Alitta virens p. 36 4.1.2.2 Aphelochaeta marioni p. 36 4.1.2.3 Ficopomatus enigmaticus p. 37 4.1.2.4 Marenzelleria viridis p. 37 4.1.2.5 Neodexiospira brasiliensis p. 38 4.1.2.6 Streblospio benedicti p. 39 4.1.3 Ascidiacea p. 40 4.1.3.1 Aplidium glabrum p. 40 4.1.3.2 Botrylloides violaceus p. 41 4.1.3.3 Didemnum vexillum p. 42 4.1.3.4 Diplosoma listerianum p. 43 3 Native and non-native species of the Dutch Wadden Sea in 2014 4.1.3.5 Molgula manhattensis /Molgula socialis p. 44 4.1.3.6 Styela clava p. 45 4.1.4 Bryozoa p. 46 4.1.4.1 Bugula stolonifera p. 46 4.1.4.2 Smittoidea prolifica p. 47 4.1.4.3 Tricellaria inopinata p. 48 4.1.5 Cnidaria p. 49 4.1.5.1 Cordylophora caspia p. 49 4.1.5.2 Diadumene cincta p. 50 4.1.5.3 Diadumene lineata p. 51 4.1.6 Crustacea p. 52 4.1.6.1 Amphibalanus improvisus p. 52 4.1.6.2 Austrominius modestus p. 53 4.1.6.3 Caprella mutica p. 54 4.1.6.4 Eriocheir sinensis p. 55 4.1.6.5 Hemigrapsus sanguineus p. 56 4.1.6.6 Hemigrapsus takanoi p. 57 4.1.6.7 Jassa marmorata p. 58 4.1.6.8 Leptomysis lingvura p. 59 4.1.6.9 Melita nitida p. 60 4.1.6.10 Palaemon macrodactylus p. 61 4.1.7 Ctenophora p. 62 4.1.7.1 Mnemiopsis leidyi p. 62 4.1.8 Mollusca p. 63 4.1.8.1 Crassostrea gigas p. 63 4.1.8.2 Crepidula fornicata p. 64 4.1.8.3 Ensis directus p. 65 4.1.8.4 Mya arenaria p. 66 4.1.9 Porifera p. 67 4.1.9.1 Haliclona cf xena p. 67 4.1.9.2 Hymeniacidon perlevis p. 68 4.1.9.3 Leucosolenia somesi p. 69 5. Literature p. 70 Appendix I. The research locations searched during The Wadden Sea inventory in 2014 p. 77 Appendix II. Species found and the locations where they were found in 2014 p. 87 4 GiMaRIS report 2015_08 1 Summary In comparison to the previous non-native spe- cies inventories in 2009 and 2011, a number of non-native species has substantially expanded In the summer of 2014 a rapid assessment was their range within The Wadden Sea. The colo- done of the marine algae and macrofauna of both nial sea-squirt Didemnum vexillum for example, the hard substrata and soft substrata in the Dutch was mainly found in the marina of Terschelling Wadden Sea. Between August and October the in 2009. In 2011 it was also recorded to be abun- diversity of native and non-native species was dant just south of Terschelling on a sublittoral assessed 242 times at different times and locations oyster reef, and it was spotted on the hull of a in either samples or during visual inspections of boat in the marina of Oudeschild, Texel. In 2014 specific Wadden Sea habitats. A large variety it was abundant in the marinas of both Vlieland of sampling methods was used ranging from and Terschelling, and it was found to cover large snorkeling, turning over rocks at low tide, and proportions of the subtidal oyster reefs off both dredging shellfish beds to taking bottom sam- Texel and Terschelling. It is unclear to what de- ples with a hand corer, a petit ponar and a van gree the range expansions of non-native species Veen-grab from littoral and sublittoral zones. that were recorded in 2014, are an effect of in- In total 254 species were found of which 48 are creased survival in the year 2014. As the win- probably non-native to the Netherlands. For 8 of ter of 2013 to 2014 was relatively warm, i.e. the these it remains uncertain whether they are non- second warmest winter since 1706, some non- native as their native range is unknown in lit- native species may have been able to settle and erature, i.e.they are considered cryptogenic. Five grow at locations in The Wadden Sea where they species are here recorded for the first time: the would not have survived had the winter been algal species Dasysiphonia japonica, the ascidian colder. Diplosoma listerianum, the bryozoan Tricellaria inopinata and the crustaceans Leptomysis lingvura and Melita nitida. In addition to the fieldwork, a literature study of published and unpublished 2 Introduction non-native species records in The Wadden Sea was done. On the basis of these records and the 2014 inventory, in total ten species were added The Wadden Sea area is composed mostly of salt to the list of non-native species in the Dutch marshes, mudflats and islands, where sea water Wadden Sea as presented after the last non-na- mixes with fresh water in an area stretching over tive species inventory in 2011 by Gittenberger the Netherlands, Germany and Denmark (Gitten- et al. (2012): the algal species D. japonica, the berger et al., 2010). It is known for its habitat annelid Streblospio benedicti, the ascidian D. variation and unique biodiversity. Because of listerianum, the bryozoans Smittoidea prolifica these unique characters UNESCO has placed the and T. inopinata, the cnidarian Mitrocomella Dutch and German parts of The Wadden Sea, an polydiademata, the crustaceans L. lingvura and area of about 10,000 km2, on the World Heritage M. nitida, the molluk Rangia cuneata and the List in June 2009. To make an assessment of the oyster herpes virus Ostreid herpesvirus-1 μvar. risk of introducing non-native species into this This raised the total number of species on this area by importing mussel seed from the Oost- list to 82 in 2014. Although some of the “new” erschelde in the south of the Netherlands, spe- non-natives may have been missed in prior moni- cies inventories focusing on non-native species toring efforts, others may concern recent intro- were conducted in 2009 and 2011 (Gittenberger ductions. et al., 2010, 2012). Based on these inventories that resulted in the discovery of close to twenty 5 Native and non-native species of the Dutch Wadden Sea in 2014 non-native species previously unknown for The 3 Materials and methods Wadden Sea, it was concluded that little knowl- edge existed until 2009 about the diversity of non-native species present in The Wadden Sea. 3.1. Locations Because mussel seed is imported into The Wad- To make comparisons between the inventory in den Sea from the province of Zeeland, and trilat- 2014 and the inventories in 2009 and 2011 (Git- eral discussions between the Netherlands, Ger- tenberger et al., 2010, 2012) the same locations or many and Denmark about the management of locations close by were searched for hard substra- non-native species in The Wadden Sea are ongo- tum associated species. This was done with a focus ing, the Office for Risk Assessment and Research on harbours, where most non-native species were of the Netherlands Food and Consumer Product found during previous inventories.