ECOSYSTEM RESTORATION WITH ARTIFICIAL HABITAT STRUCTURES:
EXPERIENCES AND FUTURE POTENTIAL
T.M. Van der Have,
K. Didderen, W. Lengkeek & M. Dorenbosch Bureau Waardenburg
Who are we?
Bureau Waardenburg
Over 35 years independent research, consultancy and design in the field of ecology, nature and
landscape.
Around 70 staff in three departments:
Aquatic and Marine Ecology
Nature and Landscape
Bird Ecology
Challenges:
• Apparent irreversible loss of estuarine and marine habitats, in particular biogenic reefs
• flat oysters Ostrea edulis
• blue mussels Mytilus edulis
• Loss / degradation of ecosystem services:
• filtration capacity & biodeposition
• ecosystem productivity
• protection immature fish
• natural hard substrate
• Loss of positive feedback for recruitment
150 – 200 sp. epifauna Grevelingen
Photo’s: Hans Waardenburg
Olsen (1883)
Oyster dredging & bottom trawling
Houziaux et al. (2008)
1883 – North Sea bottom map Olsen
2014- flat oyster reefs functionally extinct in North sea
But flat oysters still occur in the Dutch Delta...
De Bruyne et al. (2013)
Mussel beds – self organisation
Dankers & Fey – Hofstede, 2015
Mussel spatfalls are rare events
Wadden Sea mussel bed growth
Dankers & Fey-Hofstede, 2015
Rare or absent in Delta area....
Alternative stable states soft-sediment habitats
Eriksson, van der Heide, van de Koppel, Piersma, van der Veer & Olff, 2010
How to tackle the challenge?
• Provide artificial hard substrate AND predator exclusion for successful shellfish recruitment
Breakthrough moment?
• Provide biodegradable hard substrate
Recovery estuarine
blue mussel banks Wadden Sea Fully biodegradable structure
BESE-elements ®:
Biodegradable Ecosystem Engineering Elements
STW-project Radboud University (T. van der Heide et al. 2015 – 2018 with Bureau Waardenburg & NIOZ.
Over ons Sectoren en werkvelden Opdrachtgevers Aanpak
Innovatie in natuurbouw - Rifballen - Kwelders - Stapsteen - Dood hout - Mosselkratten Service
Nader onderzoek Natuurwetgeving
Oyster recruitment - reef balls / reef domes
Restoration shellfish habitats Voordelta project 2015-2018 WFN / ARK
© Cor Kuyvenhoven
Reef domes in the Grevelingen – Dutch Delta
Principles of working
• Historical reference for inspiration
• Robust ecological observation & theory
• Proof of principle with small scale pilots
• Learning by doing
Proposition
“Proactive ecosystem restoration with artificial structures is allowed if natural recovery is slow (decades or centuries)”
(and policy cycles are measured in years...)
