VECTORS of change in the Dutch southwestern Delta Waters: the occurrence of invading, nonindigenous

Transcription

1 Royal Netherlands Institute for Sea Research VECTORS of change in the Dutch southwestern Delta Waters: the occurrence of invading, nonindigenous and outbreak forming species Pim van Avesaath, Sander Wijnhoven, Herman Hummel NIOZ is an institute of the Netherlands Organisation for Scientific Research (NWO) 1

2 PROJECTS o Jellies: OFS (Aurelia aurita) and IAS (Mnemiopsis leidyi) o Non Indigenous Macrozoobenthos (historical analysis 2 yrs) o Pilot pest management Pacific oyster o Early Warning System IAS 2

3 Jellies: OFS and IAS Highlights Veerse Meer OFS: A. aurita IAS: M. leidyi annual periodicity of (mass) abundance of Aurelia aurita in (early) spring followed by Mnemiopsis leidyi in late summer and early autumn often leading to ongoing blooms resulting in continous predation pressure in the system M. leidyi succesfully settled in Lake Veere in 211 WP links: WP2; task Establishing the history, distribution and abundance of OFS and IAS 3

4 Non indigenous macozoobenthos SW Delta Analysis historical dataset (2 yrs) Royal Netherlands Institute for Sea Research NIS System NIS Grevelingen 16 Oosterschelde 19 Veerse Meer Westerschelde 18 4

5 Non indigenous macozoobenthos SW Delta Analysis historical dataset (2 yrs) Royal Netherlands Institute for Sea Research NIS biomass (%) System NIS Biomass % NIS Grevelingen 16 ~75 Oosterschelde 19 < 45 Veerse Meer 14 ~8 45 Westerschelde now 45 5

6 Non indigenous macozoobenthos SW Delta Analysis historical dataset (2 yrs) Royal Netherlands Institute for Sea Research NIS System NIS Grevelingen Oosterschelde Veerse Meer Westerschelde Crepidula fornicata (Crassostrea gigas 1 ) and Ensis directus Mya arenaria Ensis directus 1 out of scope for monitoring 6

7 Non Indigenous Macrozoobenthos Highlights Different trends in dominance: numbers-mainly polycheates, biomass -molluscs Soft bottom macrozoobenthos: 45 to 8% of biomass consist of NIS!(Abundance of Crassostrea gigas not taken into account) Often a single of a few species accounts for the biomass (IAS) NIS rule the soft bottom macrozoobenthos c. in the region Every 5 years a new NIS (MZB) discovered Vectors: half of NIS probably attributable to shellfish fisheries WP links NIS info -> AquaNIS (WP 3.x) Info on vectors -> WP2; task Data analysis to test the role of aquaculture as a vector for invasions 7

8 Pilot pest management Pacific oyster Veerse Meer Biomass DRW (g m-2) Clumped Single ~2 % 32% Can be sold directly 16% 12% % Spat Coverage Pacific oyster 75-1 % First estimate: Direct market value > cost of clearing Removal of P. oysters at 4 selected beaches 8

9 Pilot pest management Pacific oyster Veerse Meer - Highlights The Pilot first results initiated from public and private stakeholders (problem owners) revealed legislative, social, technical, economic, management issues indicated (direct) economic potential for the management of the species demand for P. oysters as food and as raw material 9

10 Early Warning Systemen IAS EMBOS:Marine Biodiversity Observatory System EMBOS observatories available for an IAS early warning system European Marine Biodiversity Observatory System VECTORS: to develop a procedure for an early warning system for IAS? Implementation as a Pilot? 1

11 Monitor Taskforce NIOZ- Yerseke Thank you! 11

12 o Non Indigenous Macrozoobenthos Grevelingen 75% Oosterschelde 45% Biomassa (mg/m 2 ) Indigenous NIS-Bivalvia NIS-Gastropoda NIS-Polychaeta NIS-Others Biomassa (mg/m 2 ) Indigenous NIS-Bivalvia NIS-Gastropoda NIS-Polychaeta NIS-Others Crepidula fornicata Grevelingen Crassostrea gigas and Ensis directus Mya arenaria Veerse Meer Oosterschelde Westerschelde Veerse meer 8% Westerschelde 45% Biomassa (mg/m 2 ) Biomassa (mg/m 2 ) Indigenous NIS-Bivalvia NIS-Gastropoda NIS-Polychaeta NIS-Others Indigenous NIS-Bivalvia NIS-Gastropoda NIS-Polychaeta NIS-Others 12

13 o Non Indigenous Macrozoobenthos System N alien species found Biomass Dominant alien Grevelingen 16 ~75 % alien Crepidula fornicata Oosterschelde 19 < 45 % alien (Crassostrea gigas 1 ) and Ensis directus Veerse Meer 14 ~8 % alien Mya arenaria Westerschelde 18 11% -now 45% Ensis directus 1 species out of scope for monitoring programma 13

14 o Jellies: OFS and IAS OFS IAS Aurelia aurita Noordzee Zeeuwse delta Mnemiopsi leidyi Grevelingen Veerse Meer Oosterschelde Westerschelde 14

15 o Jellies: OFS and IAS n / m t (oc) Avg A. aurita Avg M. leidyi Avg T min 5 5 Date N / m N / m