Effect of sediment type on microphytobenthos vertical distribution: Modelling the productive biomass and improving ground truth measurements

Jesus, Bruno; Mendes, Carlos; Brotas, Vanda; Paterson, David M.

doi:10.1016/j.jembe.2005.11.005

Cited by 66 publications

(60 citation statements)

References 40 publications

Supporting

Mentioning

Contrasting

Unclassified

Order By: Relevance

“…The median diameter remained the primary factor explaining MPB aggregation, but chl a content showed a significant positive correlation with percentage water content, which did not occur when examining chl a concen- , as clearly demonstrated by Perkins et al (2003). We are aware that chl a concentration is theoretically the best proxy for MPB biomass (Perkins et al 2003, Jesus et al 2006, since chl a concentration is less subject to sediment compaction of mud particles, but we obtained better results with chl a content and a lower degree of error in terms of nugget effect, cross validation and mapped errors (data not shown). A significant part of the explained variability is also lost in the spatial regression analysis when considering chl a concentration.…”

Section: Discussionmentioning

confidence: 90%

Spatial and temporal interaction between sediment and microphytobenthos in a temperate estuarine macro-intertidal bay

Orvain¹,

Lefebvre²,

Montepini³

et al. 2012

Mar. Ecol. Prog. Ser.

View full text Add to dashboard Cite

Intertidal flats of the estuarine macro-intertidal Baie des Veys (France) were investigated to identify spatial features of sediment and microphytobenthos (MPB) in April 2003. Gradients occurred within the domain, and patches were identified close to vegetated areas or within the oyster-farming areas where calm physical conditions and biodeposition altered the sediment and MPB landscapes. Spatial patterns of chl a content were explained primarily by the influence of sediment features, while bed elevation and compaction brought only minor insights into MPB distribution regulation. The smaller size of MPB patches compared to silt patches revealed the interplay between physical structure defining the sediment landscape, the biotic patches that they contain, and that median grain-size is the most important parameter in explaining the spatial pattern of MPB. Small-scale temporal dynamics of sediment chl a content and grain-size distribution were surveyed in parallel during 2 periods of 14 d to detect tidal and seasonal variations. Our results showed a weak relationship between mud fraction and MPB biomass in March, and this relationship fully disappeared in July. Tidal exposure was the most important parameter in explaining the summer temporal dynamics of MPB. This study reveals the general importance of bed elevation and tidal exposure in muddy habitats and that silt content was a prime governing physical factor in winter. Biostabilisation processes seemed to behave only as secondary factors that could only amplify the initial silt accumulation in summer rather than primary factors explaining spatial or long-term trends of sediment changes. KEY WORDS: Benthic diatoms · Benthos · Coastal ecosystems · Intertidal flats · Baie des Veys · Normandie · Spatial pattern · Geostatistics · KrigingResale or republication not permitted without written consent of the publisher Mar Ecol Prog Ser 458: 53-68, 2012 Kronkamp 1999, Perissinotto et al. 2003). Dynamics of marine systems vary widely in their temporal and spatial components due to complexity in the benthopelagic coupling (Zajac 2008). The trophic environment of benthic fauna in these systems is therefore characterised by a high degree of spatial heterogeneity, such as transition zones and patches (Deegan & Garritt 1997, Dubois et al. 2007) that are related to the landscape of their habitats. It appears very relevant to understand the spatial patterns of primary producers in relation to sediment in order to elucidate the role they play in the trophic food web and to assess the respective contributions of both components to consumer's diet (Lefebvre et al. 2009). The questions of spatial distribution of benthic primary producer are thus critical to gain new insights in the dynamics and structure of macrozoobenthos that inhabit these environments (Herman et al. 2000).There is a general consensus that MPB biomass varies along wide-scale environmental gradients and is not affected by an isolated variable but, rather, depends on a combination of factors controlling ...

show abstract

Section: Discussionmentioning

confidence: 90%

Spatial and temporal interaction between sediment and microphytobenthos in a temperate estuarine macro-intertidal bay

Orvain¹,

Lefebvre²,

Montepini³

et al. 2012

Mar. Ecol. Prog. Ser.

View full text Add to dashboard Cite

show abstract

“…Surface mud to a depth of ~1 cm was collected on 1 July 2008 from the Alcochete mudflat, located on the eastern shore of the Tagus Estuary, Portugal (38°44' N, 9°08' W), composed of slightly gravelly mud (Jesus et al 2006c). All experimental measurements were carried out on the following day, 2 July 2008.…”

Section: Methodsmentioning

confidence: 99%

Vertical cell movement is a primary response of intertidal benthic biofilms to increasing light dose

Perkins¹,

Lavaud²,

Serôdio³

et al. 2010

Mar. Ecol. Prog. Ser.

View full text Add to dashboard Cite

Intertidal soft sediment microphytobenthic biofilms are often dominated by diatoms, which are able to regulate their photosynthesis by physiological processes (e.g. down-regulation through the xanthophyll cycle, referred to as non-photochemical quenching, NPQ) and behavioural processes (e.g. vertical cell movement in the sediment -biofilm matrix). This study investigated these 2 processes over a 6 h emersion period using chemical inhibitors under 2 light treatments (ambient and constant light at 300 µmol m -2 s -1). Latrunculin A (Lat A) was used to inhibit cell movement and dithiothreitol (DTT) to inhibit NPQ. HPLC analysis for chlorophyll a and spectral analysis (Normalised Difference Vegetation Index) indicated that Lat A significantly inhibited cell movement. Photosynthetic activity was measured using variable chlorophyll fluorescence and radiolabelled carbon uptake and showed that the non-migratory, Lat A-treated biofilms were severely inhibited as a result of the high accumulated light dose (significantly reduced maximum relative electron transport rate, rETR max , and light utilisation coefficient, α, compared to the migratory DTT and control-treated biofilms). No significant patterns were observed for 14 C data, although a decrease in uptake rate was observed over the measurement period. NPQ was investigated using HPLC analysis of xanthophyll pigments (diatoxanthin and the percentage de-epoxidation of diadinoxanthin), chlorophyll fluorescence (change in maximum fluorescence yield) and the 2nd order spectral derivative index (diatoxanthin index). Patterns between methods varied, but overall data indicated greater NPQ induction in the non-migratory Lat A treatment and little or no NPQ induction in the DTT and control treatments. Overall, the data resulted in 2 main conclusions: (1) the primary response to accumulated light dose was vertical movement, which when inhibited resulted in severe down-regulation/photoinhibition; (2) diatoms down-regulated their photosynthetic activity in response to accumulated light dose (e.g. over an emersion period) using a combination of vertical migration and physiological mechanisms that may contribute to diel and/or tidal patterns in productivity.KEY WORDS: Benthic · Diatom · Down-regulation · Migration · Photophysiology · ProductivityResale or republication not permitted without written consent of the publisher

show abstract

“…The combination of high values of skewness and average grain size produce larger interstitial spaces, greater water infiltration and penetration of sunlight below the top millimeters of sediment (JESUS et al, 2006). Nauplius was the most abundant group.…”

Section: Discussionmentioning

confidence: 99%

“…High chlorophyll a concentrations below the top layers of the sediment may somehow support microscopic chains and enable the proliferation of meiofauna and Nematoda in reflective beaches (JESUS et al, 2006). The combination of high values of skewness and average grain size produce larger interstitial spaces, greater water infiltration and penetration of sunlight below the top millimeters of sediment (JESUS et al, 2006).…”

Section: Discussionmentioning

confidence: 99%

Vertical distribution of meiofauna on reflective sandy beaches

2015

View full text Add to dashboard Cite

Extreme physical conditions usually limit the meiofauna occurrence and distribution in highly hydrodynamic environments such as reflective beaches. Despite sediment grains of the upper layers being constantly resuspended and deposited, the high energy of the swash zone besides depositing coarse sediments allows an ample vertical distribution of meiofaunal organisms. The effect of physical, chemical and sediment variables on the vertical distribution of meiofaunal organims and nematodes was analysed on two reflective exposed beaches. Sampling was conducted at three sampling points on each beach in the swash zone. The sediment collected was divided into four 10-cm strata (0-10 cm, 10-20 cm, 20-30 cm, 30-40 cm). The statistical differences between strata due to factors previously established (i.e. meiofaunal composition, density of most abundant taxa) were tested using a hierarchical PERMANOVA applied under similarity and euclidian distances. An inverse relation among average grain size, content of organic matter and sediment sorting was evident. Coarser sediment characterized the upper layers, while at deeper layers the sediment was very poorly sorted and presented a higher content of organic matter. A similar pattern in the vertical distribution of meiofaunal and nematofaunal composition and density was detected. The lowest densities were associated with the first stratum (0-10 cm), highly affected by hydrodynamics. The vertical distribution of organisms was statistically different only when the interaction among factors was considered. This result suggests that zonation and vertical distribution of meiofaunal organisms are determined by the within-beach variability. Descriptors: Reflective beach, Vertical distribution, Spatial distribution, Meiofauna, Nematoda, Sediment. AbstrAct Mariana de Oliveira Martins*, Tito Cesar Marques de Almeida, Maikon Di DomenicoA ocorrência e distribuição da meiofauna em ambientes com alta energia hidrodinâmica, tais como praias refletivas, são normalmente limitadas por extremos físicos. Apesar de as camadas superficiais do sedimento serem afetadas, a alta energia na zona de espraiamento e a presença de areia grossa possibilitam que a meiofauna tenha ampla distribuição vertical. Para testar o padrão de distribuição vertical da meiofauna e de nemátodos em relação às variáveis físicas, químicas e sedimentológicas, duas praias refletivas expostas foram analisadas. As coletas ocorreram na zona de espraiamento em três pontos de cada uma dessas praias. O sedimento coletado foi dividido em quatro estratos de 10 cm (0-10, 10-20, 20-30 e 30-40 cm). A diferença entre os estratos foi analisada com o uso de PERMANOVA com modelo hierarquizado. A análise foi aplicada em matrizes de similaridade e de distância euclidiana, para estudo da composição da meiofauna e densidades específicas de táxons mais abundantes, respectivamente. O padrão granulométrico evidenciado caracterizou-se pela relação inversa entre o tamanho médio do grão e o teor de matéria orgânica aliado ao grau de selecionamento. Sedime...

show abstract

Effect of sediment type on microphytobenthos vertical distribution: Modelling the productive biomass and improving ground truth measurements

Cited by 66 publications

References 40 publications

Spatial and temporal interaction between sediment and microphytobenthos in a temperate estuarine macro-intertidal bay

Spatial and temporal interaction between sediment and microphytobenthos in a temperate estuarine macro-intertidal bay

Vertical cell movement is a primary response of intertidal benthic biofilms to increasing light dose

Vertical distribution of meiofauna on reflective sandy beaches

Contact Info

Product

Resources

About