{"status":"ok","message-type":"work","message-version":"1.0.0","message":{"indexed":{"date-parts":[[2026,2,10]],"date-time":"2026-02-10T20:20:14Z","timestamp":1770754814503,"version":"3.50.0"},"reference-count":43,"publisher":"MDPI AG","issue":"9","license":[{"start":{"date-parts":[[2022,4,26]],"date-time":"2022-04-26T00:00:00Z","timestamp":1650931200000},"content-version":"vor","delay-in-days":0,"URL":"https:\/\/creativecommons.org\/licenses\/by\/4.0\/"}],"funder":[{"DOI":"10.13039\/501100002347","name":"Federal Ministry of Education and Research","doi-asserted-by":"publisher","award":["03F0847A"],"award-info":[{"award-number":["03F0847A"]}],"id":[{"id":"10.13039\/501100002347","id-type":"DOI","asserted-by":"publisher"}]}],"content-domain":{"domain":[],"crossmark-restriction":false},"short-container-title":["Remote Sensing"],"abstract":"<jats:p>Rocky reefs provide complex structures in the otherwise largely sand-dominated coastal North Sea. Therefore, these reefs are highly important natural habitats for the functioning of coastal ecosystems, as they provide shelter, refuge and nursery grounds for various mobile and sessile species. In the North Sea, the spatial distribution of these habitats has been intensively investigated over recent years. However, these studies generally provide static accounts of the current state of these reef systems, but limited data exist on the temporal variations in sediment dynamics at and around natural rocky reefs. In this study, we provide observations from a multiannual time series of hydroacoustic seafloor surveys conducted at an isolated rocky reef in the North Sea. We use multibeam bathymetry and side-scan sonar backscatter data in combination with video observations, sediment sampling, and sub-bottom profiler data to assess the long-term variations of the rocky reef system. The reef is located in water depths between 11 and 17 m with an areal extent of ~0.5 km2 and is surrounded by mobile sands. The topography of the rocky reef appears to create a distinct hydrodynamic system that permits mobile sands to settle or move into bathymetrical deeper parts of the reef. Our results suggest a very dynamic system surrounding the reef with large scale scouring, sediment reworking and transport, while the shallower central part of the reef remains stable over time. We demonstrate the importance of hydrodynamics and current scouring around reefs for the local variability in seafloor properties over time. These small-scale dynamics are likewise reflected in the spatial distribution of sessile species, which are less abundant in proximity to mobile sands. The hydroacoustic mapping and monitoring of seafloor dynamics at higher spatial and temporal resolutions presents an important future direction in the study of valuable coastal habitats.<\/jats:p>","DOI":"10.3390\/rs14092069","type":"journal-article","created":{"date-parts":[[2022,4,26]],"date-time":"2022-04-26T21:37:53Z","timestamp":1651009073000},"page":"2069","update-policy":"https:\/\/doi.org\/10.3390\/mdpi_crossmark_policy","source":"Crossref","is-referenced-by-count":7,"title":["Multiannual Seafloor Dynamics around a Subtidal Rocky Reef Habitat in the North Sea"],"prefix":"10.3390","volume":"14","author":[{"ORCID":"https:\/\/orcid.org\/0000-0002-0724-0790","authenticated-orcid":false,"given":"Jasper J. L.","family":"Hoffmann","sequence":"first","affiliation":[{"name":"Alfred-Wegener-Institute, Helmholtz Centre for Polar and Marine Research, Wadden Sea Station, 25992 List, Germany"}]},{"given":"Rune","family":"Michaelis","sequence":"additional","affiliation":[{"name":"Lower Saxon Wadden Sea National Park Authority, 26382 Wilhelmshaven, Germany"}]},{"given":"Finn","family":"Mielck","sequence":"additional","affiliation":[{"name":"Alfred-Wegener-Institute, Helmholtz Centre for Polar and Marine Research, Wadden Sea Station, 25992 List, Germany"}]},{"given":"Alexander","family":"Bartholom\u00e4","sequence":"additional","affiliation":[{"name":"Senckenberg am Meer, 26382 Wilhelmshaven, Germany"}]},{"ORCID":"https:\/\/orcid.org\/0000-0003-1066-7952","authenticated-orcid":false,"given":"Lasse","family":"Sander","sequence":"additional","affiliation":[{"name":"Alfred-Wegener-Institute, Helmholtz Centre for Polar and Marine Research, Wadden Sea Station, 25992 List, Germany"}]}],"member":"1968","published-online":{"date-parts":[[2022,4,26]]},"reference":[{"key":"ref_1","doi-asserted-by":"crossref","first-page":"37","DOI":"10.2307\/1942223","article-title":"The Establishment and Development of a Marine Epifaunal Community","volume":"47","author":"Osman","year":"1977","journal-title":"Ecol. Monogr."},{"key":"ref_2","doi-asserted-by":"crossref","first-page":"449","DOI":"10.1016\/0025-3227(69)90017-6","article-title":"Gravels of the southern North Sea","volume":"7","author":"Veenstra","year":"1969","journal-title":"Mar. Geol."},{"key":"ref_3","unstructured":"Figge, K. (1981). Sedimentverteilung in der Deutschen Bucht, Deutsches Hydrographisches Institut."},{"key":"ref_4","doi-asserted-by":"crossref","first-page":"377","DOI":"10.1086\/622910","article-title":"A Scale of Grade and Class Terms for Clastic Sediments","volume":"30","author":"Wentworth","year":"1922","journal-title":"J. Geol."},{"key":"ref_5","unstructured":"European-Commission (2022, March 14). Interpretation Manual of European Union Habitats. Available online: https:\/\/ec.europa.eu\/environment\/nature\/legislation\/habitatsdirective\/docs\/2007_07_im.pdf."},{"key":"ref_6","doi-asserted-by":"crossref","first-page":"3","DOI":"10.1306\/74D70646-2B21-11D7-8648000102C1865D","article-title":"Brazos River bar [Texas]; a study in the significance of grain size parameters","volume":"27","author":"Folk","year":"1957","journal-title":"J. Sediment. Res."},{"key":"ref_7","doi-asserted-by":"crossref","unstructured":"Papenmeier, S., and Hass, C. (2018). Detection of stones in marine habitats combining simultaneous hydroacoustic surveys. Geosciences, 8.","DOI":"10.3390\/geosciences8080279"},{"key":"ref_8","doi-asserted-by":"crossref","unstructured":"Feldens, P., Darr, A., Feldens, A., and Tauber, F. (2019). Detection of Boulders in Side Scan Sonar Mosaics by a Neural Network. Geosciences, 9.","DOI":"10.3390\/geosciences9040159"},{"key":"ref_9","doi-asserted-by":"crossref","unstructured":"Michaelis, R., Hass, C., Papenmeier, S., and Wiltshire, K.H. (2019). Automated stone detection on side-scan sonar mosaics using haar-like features. Geosciences, 9.","DOI":"10.3390\/geosciences9050216"},{"key":"ref_10","doi-asserted-by":"crossref","first-page":"107","DOI":"10.1016\/j.csr.2014.05.004","article-title":"Mapping seabed sediments: Comparison of manual, geostatistical, object-based image analysis and machine learning approaches","volume":"84","author":"Diesing","year":"2014","journal-title":"Cont. Shelf Res."},{"key":"ref_11","doi-asserted-by":"crossref","first-page":"5","DOI":"10.1016\/j.marpolbul.2017.04.009","article-title":"Benefits and shortcomings of non-destructive benthic imagery for monitoring hard-bottom habitats","volume":"121","author":"Beisiegel","year":"2017","journal-title":"Mar. Pollut. Bull."},{"key":"ref_12","doi-asserted-by":"crossref","first-page":"23","DOI":"10.3354\/meps13168","article-title":"Spatial variability in subtidal hard substrate assemblages across horizontal and vertical gradients: A multi-scale approach using seafloor imaging","volume":"633","author":"Beisiegel","year":"2020","journal-title":"Mar. Ecol. Prog. Ser."},{"key":"ref_13","doi-asserted-by":"crossref","first-page":"433","DOI":"10.1007\/BF02367159","article-title":"The macrofauna of a stony sand area in the German Bight (North Sea)","volume":"50","author":"Rachor","year":"1996","journal-title":"Helgol. Meeresunters."},{"key":"ref_14","doi-asserted-by":"crossref","first-page":"61","DOI":"10.1007\/s00300-005-0055-8","article-title":"Competitive dominance among sessile marine organisms in a high Arctic boulder community","volume":"29","author":"Konar","year":"2005","journal-title":"Polar Biol."},{"key":"ref_15","doi-asserted-by":"crossref","first-page":"84","DOI":"10.1016\/j.seares.2015.06.010","article-title":"Reefs, sand and reef-like sand: A comparison of the benthic biodiversity of habitats in the Dutch Borkum Reef Grounds","volume":"103","author":"Coolen","year":"2015","journal-title":"J. Sea Res."},{"key":"ref_16","doi-asserted-by":"crossref","first-page":"78","DOI":"10.1016\/j.seares.2018.11.009","article-title":"Hard-substrate habitats in the German Bight (South-Eastern North Sea) observed using drift videos","volume":"144","author":"Michaelis","year":"2019","journal-title":"J. Sea Res."},{"key":"ref_17","doi-asserted-by":"crossref","first-page":"30","DOI":"10.1016\/j.csr.2019.01.011","article-title":"Epibenthic assemblages of hard-substrate habitats in the German Bight (south-eastern North Sea) described using drift videos","volume":"175","author":"Michaelis","year":"2019","journal-title":"Cont. Shelf Res."},{"key":"ref_18","doi-asserted-by":"crossref","first-page":"183","DOI":"10.1007\/s00367-019-00599-7","article-title":"Hydrodynamics and hydroacoustic mapping of a benthic seafloor in a coarse grain habitat of the German Bight","volume":"40","author":"Capperucci","year":"2020","journal-title":"Geo-Mar. Lett."},{"key":"ref_19","doi-asserted-by":"crossref","first-page":"106343","DOI":"10.1016\/j.margeo.2020.106343","article-title":"Detecting shifts of submarine sediment boundaries using side-scan mosaics and GIS analyses","volume":"430","author":"Galvez","year":"2020","journal-title":"Mar. Geol."},{"key":"ref_20","doi-asserted-by":"crossref","first-page":"193","DOI":"10.1016\/0025-3227(79)90080-X","article-title":"Wreck marks: Indicators of net sand transport","volume":"33","author":"Caston","year":"1979","journal-title":"Mar. Geol."},{"key":"ref_21","doi-asserted-by":"crossref","unstructured":"Reineck, H.-E., and Singh, I.B. (1973). Scour Marks. Depositional Sedimentary Environments, Springer.","DOI":"10.1007\/978-3-642-96291-2"},{"key":"ref_22","doi-asserted-by":"crossref","first-page":"409","DOI":"10.1016\/j.ecss.2009.07.011","article-title":"The impact of scour processes on a smothered reef system in the Irish Sea","volume":"84","author":"Callaway","year":"2009","journal-title":"Estuar. Coast. Shelf Sci."},{"key":"ref_23","doi-asserted-by":"crossref","unstructured":"Von R\u00f6nn, G.A., Kr\u00e4mer, K., Franz, M., Schwarzer, K., Reimers, H.-C., and Winter, C. (2021). Dynamics of Stone Habitats in Coastal Waters of the Southwestern Baltic Sea (Hohwacht Bay). Geosciences, 11.","DOI":"10.3390\/geosciences11040171"},{"key":"ref_24","first-page":"459","article-title":"Mobility and transport directions of residual sediments on abrasion platforms in front of active cliffs (Southwestern Baltic Sea)","volume":"I","author":"Schrottke","year":"2006","journal-title":"J. Coast. Res."},{"key":"ref_25","unstructured":"(2020, May 08). BSH Meeresboden DGM. Available online: http:\/\/www.geoseaportal.de\/."},{"key":"ref_26","first-page":"1","article-title":"Geological development of the North Sea and the Baltic Sea","volume":"74","author":"Schwarzer","year":"2008","journal-title":"Die K\u00fcste"},{"key":"ref_27","unstructured":"Ehlers, J., Ehlers, J., Gibbard, P.L., and Hughes, P.D. (2011). Quaternary Glaciations-Extent and Chronology: A Closer Look, Elsevier."},{"key":"ref_28","first-page":"134","article-title":"Nordsee und K\u00fcstenlandschaft-Beispiel einer dynamischen Landschaftsentwicklung","volume":"20","author":"Streif","year":"2002","journal-title":"Nat. und Landsch. Zwischen K\u00fcste und Harz"},{"key":"ref_29","doi-asserted-by":"crossref","unstructured":"Papenmeier, S., and Hass, C. (2020). Revisiting the paleo elbe valley: Reconstruction of the holocene, sedimentary development on basis of high-resolution grain size data and shallow seismics. Geosciences, 10.","DOI":"10.3390\/geosciences10120505"},{"key":"ref_30","first-page":"431","article-title":"Mass balance study of Holocene sediment accumulation on the Lower Saxony coastal region","volume":"148","author":"Hoselmann","year":"1997","journal-title":"Z. Dtsch. Geol. Ges."},{"key":"ref_31","first-page":"11","article-title":"Ein Vierteljahrhundert sedimentologische Forschung vor der K\u00fcste Sylts\/Deutsche Bucht","volume":"46","author":"Ahrendt","year":"1994","journal-title":"Meyniana"},{"key":"ref_32","unstructured":"Mittelstaedt, E., Lange, W., and Soetje, K.C. (1983). Die Str\u00f6mungen der Deutschen Bucht, Deutsches Hydrographisches Institut."},{"key":"ref_33","doi-asserted-by":"crossref","first-page":"363","DOI":"10.1016\/S0025-3227(00)00089-X","article-title":"Mobile sand deposits and shoreface sediment dynamics in the inner German Bight (North Sea)","volume":"170","author":"Zeiler","year":"2000","journal-title":"Mar. Geol."},{"key":"ref_34","doi-asserted-by":"crossref","first-page":"141","DOI":"10.3354\/cr018141","article-title":"Expected effect of climate change on Sylt island: Results from a multidisciplinary German project","volume":"18","author":"Ahrendt","year":"2001","journal-title":"Clim. Res."},{"key":"ref_35","unstructured":"K\u00f6ster, R. (1979). Dreidimensionale Kartierung des Seegrundes vor den nordfriesischen Inseln. DFG Forschungsber. \u201cSandbewegung im K\u00fcstenraum\u201d, DFG."},{"key":"ref_36","doi-asserted-by":"crossref","first-page":"295","DOI":"10.1016\/j.csr.2003.11.001","article-title":"A new hypothesis and exploratory model for the formation of large-scale inner-shelf sediment sorting and \u201crippled scour depressions\u201d","volume":"24","author":"Murray","year":"2004","journal-title":"Cont. Shelf Res."},{"key":"ref_37","doi-asserted-by":"crossref","first-page":"31","DOI":"10.1016\/j.csr.2015.10.016","article-title":"Interannual variability of sorted bedforms in the coastal German Bight (SE North Sea)","volume":"111","author":"Mielck","year":"2015","journal-title":"Cont. Shelf Res."},{"key":"ref_38","first-page":"6","article-title":"An operational, assimilative model system for hydrodynamic and biogeochemical applications for German coastal waters","volume":"118","author":"Li","year":"2021","journal-title":"Hydrogr. Nachr."},{"key":"ref_39","doi-asserted-by":"crossref","first-page":"1237","DOI":"10.1002\/esp.261","article-title":"GRADISTAT: A grain size distribution and statistics package for the analysis of unconsolidated sediments","volume":"26","author":"Blott","year":"2001","journal-title":"Earth Surf. Process. Landf."},{"key":"ref_40","doi-asserted-by":"crossref","first-page":"19","DOI":"10.3354\/meps11763","article-title":"Seasonal sediment dynamics shape temperate bedrock reef communities","volume":"552","author":"Figurski","year":"2016","journal-title":"Mar. Ecol. Prog. Ser."},{"key":"ref_41","doi-asserted-by":"crossref","first-page":"25","DOI":"10.1007\/BF02328531","article-title":"Gezeitenstr\u00f6mungen um Sylt Numerische Untersuchungen zur halbt\u00e4gigen Hauptmondtide (M2)","volume":"40","author":"Dick","year":"1987","journal-title":"Dtsch. Hydrogr. Z."},{"key":"ref_42","first-page":"25","article-title":"Zur Geologie des Seegebietes westlich von Sylt","volume":"21","author":"Hoffmann","year":"1971","journal-title":"Meyniana"},{"key":"ref_43","doi-asserted-by":"crossref","first-page":"321","DOI":"10.1002\/aqc.2994","article-title":"The potential exceptional role of a small Baltic boulder reef as a solitary habitat in a sea of mud","volume":"29","author":"Beisiegel","year":"2019","journal-title":"Aquat. Conserv. Mar. Freshw. Ecosyst."}],"container-title":["Remote Sensing"],"original-title":[],"language":"en","link":[{"URL":"https:\/\/www.mdpi.com\/2072-4292\/14\/9\/2069\/pdf","content-type":"unspecified","content-version":"vor","intended-application":"similarity-checking"}],"deposited":{"date-parts":[[2025,10,10]],"date-time":"2025-10-10T23:01:05Z","timestamp":1760137265000},"score":1,"resource":{"primary":{"URL":"https:\/\/www.mdpi.com\/2072-4292\/14\/9\/2069"}},"subtitle":[],"short-title":[],"issued":{"date-parts":[[2022,4,26]]},"references-count":43,"journal-issue":{"issue":"9","published-online":{"date-parts":[[2022,5]]}},"alternative-id":["rs14092069"],"URL":"https:\/\/doi.org\/10.3390\/rs14092069","relation":{},"ISSN":["2072-4292"],"issn-type":[{"value":"2072-4292","type":"electronic"}],"subject":[],"published":{"date-parts":[[2022,4,26]]}}}