Examining the production, export, and immediate fate of kelp detritus on open‐coast subtidal reefs in the Northeast Atlantic. Issue Volume 67:Issue S2(2022) (1st November 2021)

• Record Type: Journal Article
• Authors: Smale, Dan A.; Pessarrodona, Albert; King, Nathan; Moore, Pippa J.
• Other Names: Santos Isaac R. guestEditor.; Hatje Vanessa guestEditor.; Serrano Oscar guestEditor.; Bastviken David guestEditor.; Krause‐Jensen Dorte guestEditor.; Mullarney Julia C. guestEditor.
• Is Part Of: Limnology and oceanography. Volume 67:Issue S2(2022)
• Page Start: S36
• Page End: S49
• Publication Date: 2021-11-01
• Subjects: Limnology -- Periodicals; Oceanography -- Periodicals; Océanographie; Limnologie; Limnology; Oceanography; Computer network resources; Périodique électronique (Descripteur de forme); Ressource Internet (Descripteur de forme); Periodicals; 551.4805
• DOI: 10.1002/lno.11970
• Languages: English
• ISSNs: 0024-3590

Abstract

Abstract: Kelp forests are highly productive coastal habitats and are emerging as important sources of organic matter for other ecosystems. Although their high rates of productivity and detritus release are expected to lead to substantial export of carbon, few studies have actually quantified rates of export or the persistence of detritus. We addressed this in eight subtidal kelp forests ( Laminaria hyperborea ) spanning the length (9° of latitude) of the United Kingdom. Specifically, we quantified detritus production, retention/export from source and adjacent habitats, and in situ decomposition rates. Detritus released via both dislodgment of whole plants and "May cast" shedding of old growth was highly variable between sites with greatest values recorded in our colder, northern sites. This was attributable to greater plant size biomass in northern regions, rather than plant density or dislodgement rates. On average, the annual production of kelp detritus was 4706 ± 700 g FW m −2 yr −1 or 301 g C m −2 yr −1 . Low retention of detritus within the kelp forest and adjacent sedimentary habitats indicated very high rates of export (> 98% across the study). A litterbag experiment showed detritus may take > 4 months to decompose, suggesting great potential for long distance transport. Overall, our findings suggest that L. hyperborea forests export large amounts of detritus subsidies across their range, which can potentially shape the structure of distant benthic communities and constitute a relevant and largely overlooked flux in the coastal carbon cycle, which may represent an important component of natural carbon sequestration.