BEGIN:VCALENDAR VERSION:2.0 METHOD:PUBLISH PRODID:-//Telerik Inc.//Sitefinity CMS 14.3//EN BEGIN:VTIMEZONE TZID:Arab Standard Time BEGIN:STANDARD DTSTART;VALUE=DATE:20230101 TZNAME:Arab Standard Time TZOFFSETFROM:+0300 TZOFFSETTO:+0300 END:STANDARD END:VTIMEZONE BEGIN:VEVENT DESCRIPTION:Advisor: Professor Danielle DaffonchioAbstract:Tropical coral r eefs are highly productive ecosystems thriving in oligotrophic waters\, a phenomenon facilitated by efficient but delicate biogeochemical cycling wi thin reef communities. Global climate change and local stressors are drivi ng phase shifts from coral- to non-calcifier-dominated states in reefs wor ldwide\, substantially altering reef biogeochemical functioning. While maj or benthic players such as coral and macroalgae have been investigated in detail regarding carbon and nutrient dynamics\, the less conspicuous “reef cryptobiome” (sensuCarvalho \;et al.\, 2019) – comprising most of ree f diversity – has only recently gained attention. Autonomous Reef Monitori ng Structures (ARMS) have recently been developed to sample coral reef cry ptobenthic communities in a non-destructive and standardised way\, allowin g exploration of these often overlooked biota. Here\, 16 ARMS were deploye d for seven months in four distinct habitats dominated by different benthi c players (i.e.\, four units per habitat) in a nearshore Red Sea coral ree f to investigate the cryptobiome associated with proxies of varying benthi c states. Two of these habitats were coral-dominated\, and one each domina ted by turf algae or coral rubble. To assess the \; biogeochemical flu xes of pioneering cryptobenthic communities\, ARMS were incubated \;in situ \;prior to retrieval using customised chambers. Subsequently\, 1 6S rRNA gene amplicon and shotgun metagenomic sequencing of the ARMS sessi le (i.e.\, encrusting) fractions were performed to link observed fluxes wi th prokaryotic taxonomic and functional profiles\, \; particularly reg arding nitrogen cycling. The results show that the pioneering cryptobiome represents a significant source of inorganic nutrients and that its associ ated microbial communities facilitate the mineralisation and assimilation of organic matter and provide crucial genetic functional pathways for nitr ogen cycling. Functional similarities among habitats suggested functional redundancy despite variation in bacterial community composition. Hence\, t he reef cryptobiome can be considered an important biogeochemical player i n coral reefs\, actively shaping the abiotic conditions within niches of t he reef \; framework and driving the recruitment and persistence of cr ytobenthic and other reef organisms. As communities associated with the al gae-dominated reef habitat were most distinct compositionally and biogeoch emically\, and as non-calcifiers are becoming more dominant in many reefs\ , this has implications for intensifying phase shifts in coral reefs \ ; worldwide. Future ARMS studies will also benefit from adjustment of samp le processing and molecular protocols\, resulting in higher sample through put and lower costs in times of \; increased application of ARMS. DTEND:20230313T073000Z DTSTAMP:20240328T172534Z DTSTART:20230313T063000Z LOCATION:Building 9 - Room 2325 Lecture Hall SEQUENCE:0 SUMMARY:The role of the cryptobiome and its associated microbial community in coral reef biogeochemical cycling UID:RFCALITEM638472543345063557 X-ALT-DESC;FMTTYPE=text/html:
Advisor: Professor
Abstract:
Tropical coral reefs are highly product
ive ecosystems thriving in oligotrophic waters\, a phenomenon facilitated
by efficient but delicate biogeochemical cycling within reef communities.
Global climate change and local stressors are driving phase shifts from co
ral- to non-calcifier-dominated states in reefs worldwide\, substantially
altering reef biogeochemical functioning. While major benthic players such
as coral and macroalgae have been investigated in detail regarding carbon
and nutrient dynamics\, the less conspicuous “reef cryptobiome” (sens
uCarvalho \;et al.\, 2019) – comprising most of reef div
ersity – has only recently gained attention. Autonomous Reef Monitoring St
ructures (ARMS) have recently been developed to sample coral reef cryptobe
nthic communities in a non-destructive and standardised way\, allowing exp
loration of these often overlooked biota. Here\, 16 ARMS were deployed for
seven months in four distinct habitats dominated by different benthic pla
yers (i.e.\, four units per habitat) in a nearshore Red Sea coral reef to
investigate the cryptobiome associated with proxies of varying benthic sta
tes. Two of these habitats were coral-dominated\, and one each dominated b
y turf algae or coral rubble. To assess the \; biogeochemical fluxes o
f pioneering cryptobenthic communities\, ARMS were incubated \;in
situ \;prior to retrieval using customised chambers. Subsequently
\, 16S rRNA gene amplicon and shotgun metagenomic sequencing of the ARMS s
essile (i.e.\, encrusting) fractions were performed to link observed fluxe
s with prokaryotic taxonomic and functional profiles\, \; particularly
regarding nitrogen cycling. The results show that the pioneering cryptobi
ome represents a significant source of inorganic nutrients and that its as
sociated microbial communities facilitate the mineralisation and assimilat
ion of organic matter and provide crucial genetic functional pathways for
nitrogen cycling. Functional similarities among habitats suggested functio
nal redundancy despite variation in bacterial community composition. Hence
\, the reef cryptobiome can be considered an important biogeochemical play
er in coral reefs\, actively shaping the abiotic conditions within niches
of the reef \; framework and driving the recruitment and persistence o
f crytobenthic and other reef organisms. As communities associated with th
e algae-dominated reef habitat were most distinct compositionally and biog
eochemically\, and as non-calcifiers are becoming more dominant in many re
efs\, this has implications for intensifying phase shifts in coral reefs&n
bsp\; worldwide. Future ARMS studies will also benefit from adjustment of
sample processing and molecular protocols\, resulting in higher sample thr
oughput and lower costs in times of \; increased application of ARMS.<
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