Effect of reef framework and bottom sediment on nutrient enrichment in a coral reef of the Gulf of Aqaba, Red Sea

Rasheed, Mohammed; Badran, Mohammad I.; Richter, Claudio; Huettel, Markus

doi:10.3354/meps239277

Cited by 96 publications

(82 citation statements)

References 42 publications

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“…Data are mean 6 SE, showing the number of values used in the calculations (n). See Table 2 focusing on specific habitats such as sediments (Capone et al 1992;Rasheed et al 2002;Al-Rousan et al 2004), coral cavities (Gast et al 1998;Scheffers et al 2004;Rasheed et al 2006), or micro atolls (Steven and Atkinson 2003), but the relevance of these habitat-specific rates at the scale of a reef community or ecosystem remains difficult to discern (Table 6). The release rates that were estimated in the present study, by assuming gross nutrient uptake was mass-transfer limited (J 2 MTL ), were on the same order as those documented in coral cavities and micro atolls, but were an order of magnitude higher than observed over carbonate sediments (generally a net sink; Wild et al 2005;Eyre et al 2008).…”

Section: Discussionmentioning

confidence: 99%

Oceanographic forcing of nutrient uptake and release over a fringing coral reef

Wyatt

Falter

Lowe

et al. 2012

Limnology & Oceanography

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Nitrate and nitrite (NO x ) and phosphate (PO 4 ) dynamics over Ningaloo Reef, Western Australia, are shown to depend on oceanographic forcing of coupled mass transfer limited (MTL) gross uptake and gross release from remineralized oceanic particulate organic matter (POM). Estimates of gross release rates increased significantly with increasing POM uptake and were of the same order as gross uptake rates. Gross uptake rates increased significantly with increasing oceanic concentrations and wave energy dissipation, were 35-80% higher over the reef crest (7-9 mmol NO x m 22 d 21 and 4-5 mmol PO 4 m 22 d 21 ), and were significantly correlated with independent estimates of POM-mediated gross NO x uptake, supporting both MTL uptake and the strong role of oceanic POM supply. The relative supply of NO x and POM was linked to the seasonal dynamics of a regional current system. In late spring, upwelling associated with seasonally strong equator-ward winds led to increased NO x concentrations (0. The autumn enhancement of oceanic POM supply to the reef can be attributed to a regional phytoplankton bloom associated with acceleration of the oligotrophic Leeuwin Current, which may result in a significant supply of dissolved nutrients to downstream communities.

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Section: Discussionmentioning

confidence: 99%

Oceanographic forcing of nutrient uptake and release over a fringing coral reef

Wyatt

Falter

Lowe

et al. 2012

Limnology & Oceanography

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“…yr -1 ) and the total surface area covered over the same time period at different population densities. The resulting sediment volumes were subsequently multiplied by 0.5 to account for the notion that approximately 50% of the coral reef habitat consists of sand; remaining habitats typically comprise hard, non-bioturbatable substrates, including live coral and coral rubble (as described by Rasheed et al 2002).To complement the data on the volume of sediment bioturbated, the total surface area of sediment in contact with the ventral foot of Holothuria whitmaei was also determined. This was calculated by multiplying the average daily rate of activity (cm d -1 ) by the average breadth of the sea cucumber's ventral surface (11.92 cm, based on n = 30 haphazard measurements) (following Uthicke 2001a).…”

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confidence: 99%

“…The data presented in Table 5 (Table 5). Multiplication of the total distance travelled by the diameter of the trivium yielded an estimate of the sediment area in contact with the base of the sea cucumber ( ), the total area of sediment contacted was estimated conservatively as approximately 2 times the total available coral reef sediment per hectare per annum (based on the assumption that sediment accounts for ~50% of the coral reef habitat area as described by Rasheed et al 2002). …”

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confidence: 99%

Aggregations and temporal changes in the activity and bioturbation contribution of the sea cucumber Holothuria whitmaei (Echinodermata: Holothuroidea)

Shiell¹,

Knott²

2010

Mar. Ecol. Prog. Ser.

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The population density, activity and bioturbation contribution of the sea cucumber Holothuria whitmaei was investigated on Ningaloo Reef, Western Australia. Two methods, stratified manta tows and blanket manta tows, recorded population densities between 11.4 and >100 individuals (ind.) ha -1 . Further analysis revealed a heterogeneous pattern of distribution, with individuals tending to aggregate (Moran's I; 0.039; p < 0.05) on the outer reef lagoon and particularly in areas of high flow. Densities within aggregations were up to 7.2 times greater than those obtained after blanket manta tows (17.1 ind. ha -1 ), and 4.5 to 6.3 times greater than those obtained after traditional stratified manta tows (19.3 to 27.1 ind. ha -1 ). Behavioural studies, including investigations of activity and bioturbation, were conducted over a 2 yr time frame (2002)(2003) incorporating 3 monitoring periods within each year: January, April and August. Rates of activity varied diurnally, increasing between morning and afternoon, and seasonally, increasing in April, relative to January and August. Temporal patterns of feeding were more difficult to characterise; although rates of sediment egestion were in many cases higher in the morning, no conclusive diurnal or seasonal patterns could be established. Subsequent regression analysis, however, did find a significant positive correlation between the distance travelled and the volume of sediment egested. The volume of sediment bioturbated by H. whitmaei at a population level was found to represent only a small fraction of the sediments available (ca. 2 to 14% per annum), even though the contribution per individual was greater than that of smaller sea cucumber species. However, at maximum densities and typical rates of activity, H. whitmeai makes physical contact with approximately 2 times the available coral reef sediments per annum per hectare, simply by crawling. This may represent an important ecological contribution, particularly in light of previously documented links between sea cucumber activity, nutrient recycling and the enhancement of benthic microalgal communities.KEY WORDS: Aggregation · Behavioural activity · Bioturbation · Coral reef lagoon · Densitydependent effects Resale or republication not permitted without written consent of the publisherMar Ecol Prog Ser 415: [127][128][129][130][131][132][133][134][135][136][137][138][139] 2010 tributed to a 'boom and bust' cycle where high-value sea cucumbers are targeted preferentially, leading to high-value species being fished to near local extinction (Rees et al. 2003) or to levels too low to sustain the fishery (Uthicke & Benzie 2000a).Previous studies of the ecology and biology of Holothuria whitmaei centred on the Great Barrier Reef (GBR), Queensland, Australia (Uthicke & Karez 1999, Uthicke & Benzie 2000a,b, 2002) and elsewhere in the broader Pacific Ocean (Conand 1981, Martinez & Richmond 1998. Several of these provide useful descriptions of the habitat preferences of H. whitmaei, which are described broadl...

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“…The reason that the end-member of the upstream concentration varies is unclear; however, this variation is probably caused by day-to-day variation in the fl ow rate. Regarding the variation in the Cd concentration at the bay site (St. P), as Abe (2007) reported, the remineralization and release of Cd associated with organic matter from sediments (Gobeil et al 1987;Rasheed et al 2002) and atmospheric deposition from the land (Duce et al 1980;Arimoto et al 1985) could be anticipated in this study period as well. The variation in the Cd concentrations of upstream and bay water and the characteristic and amount of supplied Cd-adsorbed particles into the study sites might be infl uenced by weather conditions, such as precipitation and wind stress, which probably change each distribution pattern in Fig.…”

Section: Resultsmentioning

confidence: 99%

Behavior of dissolved cadmium in surface water of Urasoko Bay, Ishigaki Island, Japan

Abe

2008

Galaxea, Journal of Coral Reef Studies

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Effect of reef framework and bottom sediment on nutrient enrichment in a coral reef of the Gulf of Aqaba, Red Sea

Cited by 96 publications

References 42 publications

Oceanographic forcing of nutrient uptake and release over a fringing coral reef

Oceanographic forcing of nutrient uptake and release over a fringing coral reef

Aggregations and temporal changes in the activity and bioturbation contribution of the sea cucumber Holothuria whitmaei (Echinodermata: Holothuroidea)

Behavior of dissolved cadmium in surface water of Urasoko Bay, Ishigaki Island, Japan

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