Conservation Implications of Sabellaria spinulosa Reef Patches in a Dynamic Sandy-Bottom Environment

Conservation Implications of Sabellaria spinulosa Reef Patches in a Dynamic Sandy-Bottom Environment

van der Reijden, Karin J. (University Medical Center Groningen)
Koop, L. (TU Delft Aircraft Noise and Climate Effects)
Mestdagh, S.M.F. (NIOZ Royal Netherlands Institute for Sea Research)
Snellen, M. (TU Delft Aircraft Noise and Climate Effects; Deltares)
Herman, P.M.J. (TU Delft Hydraulic Engineering; TU Delft Environmental Fluid Mechanics; Deltares)
Olff, Han (University Medical Center Groningen)
Govers, Laura L. (University Medical Center Groningen; NIOZ Royal Netherlands Institute for Sea Research)

Hydraulic Engineering

2021

Biogenic reefs form biodiversity hotspots and are key components of marine ecosystems, making them priority habitats for nature conservation. However, the conservation status of biogenic reefs generally depends on their size and stability. Dynamic, patchy reefs may therefore be excluded from protection. Here, we studied epibenthos and epifauna density, richness, and community composition of patchy, dynamic Sabellaria spinulosa (ross worm) reefs in the North Sea. This study was conducted by comparing boxcore (endobenthos) and video transect (epifauna) data from two research campaigns in 2017 and 2019 to the Brown Bank area on the Dutch Continental Shelf, where S. spinulosa reefs were first discovered in 2017. The Brown Bank area is characterized by dynamic, migratory bedforms at multiple scales which potentially affect biogenic reef stability. We showed that S. spinulosa habitats had a patchy distribution and alternated with habitats comprised of plain sand. Average S. spinulosa habitat patch size was 5.57 ± 0.99 m and 3.94 ± 0.22 m in 2017 and 2019, respectively (mean ± SE), which especially in 2019 closely resembled the small-scale megaripple bedforms. Contrary to the endobenthos communities that were unaffected by S. spinulosa, epifauna density and species richness were at least two times higher in S. spinulosa habitats compared to sandy habitats, resulting in different community compositions between the two habitat types. We showed that S. spinulosa persisted in the area for almost 2 years. Although the stability of individual patches remained unclear, we demonstrated that even patchy biogenic reefs may promote density and local biodiversity of mobile, epibenthic species, very likely as a result of increased habitat heterogeneity provided by reef habitat patches. This indicates that patchy biogenic reefs that occur in dynamic environments may also have high ecological value and their conservation status should be (re)considered to ensure their protection.

biogenic reefs
ecosystem engineering
habitat heterogeneity
marine management
megaripples
North Sea
patchiness
ross worm

http://resolver.tudelft.nl/uuid:90c5bb67-3f49-42ff-8f04-cb066a0d9881

https://doi.org/10.3389/fmars.2021.642659

2296-7745

Frontiers in Marine Science, 8

Institutional Repository

journal article

© 2021 Karin J. van der Reijden, L. Koop, S.M.F. Mestdagh, M. Snellen, P.M.J. Herman, Han Olff, Laura L. Govers