Editing Kelp (section)

===Kelp forests===
{{main|Kelp forest}}

Kelp may develop dense forests with high production,<ref>{{Cite journal |last1=Pessarrodona |first1=A. |last2=Assis |first2=J. |last3=Filbee-Dexter |first3=K. |last4=Burrows |first4=M. T. |last5=Gattuso |first5=J-P. |last6=Duarte |first6=C. M. |last7=Krause-Jensen |first7=D. |last8=Moore |first8=P. J. |last9=Smale |first9=D. A. |last10=Wernberg |first10=T. |date=23 July 2020 |title=Global Seaweed Productivity |journal=Science Advances |volume=8 |issue=37 |page=eabn2465 |doi=10.1126/sciadv.abn2465 |pmid=36103524 |pmc=9473579 |hdl=10754/681467 |hdl-access=free}}</ref><ref>Abdullah, M.I., Fredriksen, S., 2004. Production, respiration and exudation of dissolved organic matter by the kelp Laminaria hyperborea along the west coast of Norway. Journal of the Marine Biological Association of the UK 84: 887.</ref> biodiversity and ecological function. Along the Norwegian coast these forests cover 5,800&nbsp;km<sup>2</sup>,<ref>Rinde, E., 2009. Dokumentasjon av modellerte marine Naturtyper i DNs Naturbase. Førstegenerasjonsmodeller til kommunenes startpakker for kartlegging av marine naturtyper 2007. NIVA report, 32 pp.</ref> and they support large numbers of animals.<ref name="Christie-2003">Christie, H., Jørgensen, N.M., Norderhaug, K.M., Waage-Nielsen, E., 2003. Species distribution and habitat exploitation of fauna associated with kelp (Laminaria hyperborea) along the Norwegian coast. Journal of the Marine Biological Association of the UK 83, 687-699.</ref><ref>Jørgensen, N.M., Christie, H., 2003. l Diurnal, horizontal and vertical dispersal of kelp associated fauna. Hydrobiologia 50, 69-76.</ref> Numerous [[sessile animals]] (sponges, bryozoans and ascidians) are found on kelp stipes and mobile invertebrate fauna are found in high densities on epiphytic algae on the kelp stipes and on kelp holdfasts.<ref>Norderhaug, K.M., Christie, H., Rinde, E., 2002. Colonisation of kelp imitations by epiphyte and holdfast fauna; a study of mobility patterns. Marine Biology 141, 965-973.</ref> More than 100,000 mobile invertebrates per square meter are found on kelp stipes and holdfasts in well-developed kelp forests.<ref name="Christie-2003" /> While larger invertebrates and in particular sea urchins (''[[Strongylocentrotus droebachiensis]]'') are important secondary consumers controlling large barren ground areas on the Norwegian coast, they are scarce inside dense kelp forests.<ref>Norderhaug, K.M., Christie, H., 2009. Sea urchin grazing and kelp re-vegetation in the NE Atlantic. Marine Biology Research 5, 515-528.</ref>