Who lives in a pear tree under the sea?

Activity: Talk and presentationAcademic presentationAcademic


Prior to widescale landscape domestication, downed trees reached the sea in huge numbers; more than five million cubic meters of large wood annually. Some of this wood sank and provided habitat, settlement substrate, nutrients and shelter for various animals. In modern times, this wood flux has greatly declined due to human intervention, decreasing the amount of hard substrate available for marine animals –along with other substrate removal by trawling, deadly shellfish diseases, and active removal. We have created a mimic of this historical marine wood by creating 32 artificial reefs of waste pear trees, each 3m3 in the Wadden Sea to assess their effect on biodiversity and species richness. Within six months,the tree-reefs proved to be hotspots of biodiversity: they were covered in sessile life such as bryozoans, barnacles, tunicates and hydrozoa. Fish abundance was 5x higher within reef areas, with 3x as many species when compared to only-sand control sites. Monitoring 1.5 years after placement revealed fish eggs and juvenile fish within the trees, as well as consistent and regular presence of larger predatory fish and seals. These results indicate that we can rapidly restore degraded soft-bottomed marine systems with active restoration efforts using these 3D biodegradable tree-reefs.
Event titleNetherlands Annual Ecology Meeting 2024
Event typeConference
Conference number16
Organiser Netherlands Ecological Research Network (NERN)
LocationLunteren, NetherlandsShow on map
Degree of RecognitionNational