Primary production and deep-water oxygen content of two British Columbian fjords

Timothy, David A.; Soon, Maureen

doi:10.1016/s0304-4203(00)00071-2

Cited by 63 publications

(42 citation statements)

References 43 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…The relatively steep topography within these drainage basins is overlain by thick forests of conifers, cedar, and oak characteristic of this cool, moist maritime climate (Pellatt et al, 2001) with a mean annual precipitation of 846 mm. Deep water ventilation within the Saanich is limited by a -65 m deep sill at the entrance to the fjord, which combined with high surface productivity maintains deepwater dysoxia and seasonal anoxia (Anderson and Devol, 1973;Timothy and Soon, 2001), preserving annual varves below 70 -150 m depth (Gucluer and Gross, 1964). The sedimentology of this site has been well studied previously (Gucluer and Gross, 1964;Brown et al, 1972;Sancetta and Calvert, 1988;Cowie et al, 1992;Blais-Stevens et al, 1997;Tunnicliffe, 2000;Calvert et al, 2001;Johnson and Grimm, 2001;Nederbragt and Thurow, 2001;Whiticar and Elvert, 2001;Smittenberg, 2003;Smittenberg et al, 2004Smittenberg et al, , 2006.…”

Section: The Global Organic Carbon Cyclementioning

confidence: 70%

The temporal dynamics of terrestrial organic matter transfer to the oceans : initial assessment and application

Drenzek¹

2007

View full text Add to dashboard Cite

Section: The Global Organic Carbon Cyclementioning

confidence: 70%

The temporal dynamics of terrestrial organic matter transfer to the oceans : initial assessment and application

Drenzek¹

2007

View full text Add to dashboard Cite

“…Skeletonema costatum is rarely preserved in open ocean sediments (Hay et al 2007), and in particular in fjords, up to 50% of diatom frustules are dissolved within the first 50 m of the water column and fail to reach the sediment (e.g. Skjoldal & Wassmann 1986;Timothy & Soon 2001). Skeletonema costatum and other lightly silicified diatoms are therefore mainly recycled prior to incorporation into the sedimentary record, especially in Doubtful Sound where the SL is rich in nutrients but depleted in silica.…”

Section: Diatoms Dominate Plankton Remainsmentioning

confidence: 99%

“…Regression analyses showed no significant relationship between diatom abundance and depth (R 2 00.02, P00.62), however, visual inspection showed dissolution of the more delicate valves at deeper sites. In the open ocean, 90Á97% of silica is lost prior to reaching the sediment (Lisitzin 1971), and even inlets of similar depths show up to 50% silica loss during flux to the seabed (Timothy & Soon 2001). Therefore the depth of the water column can alter the diatom record in fjords through dissolution, recycling and grazing of the silica valves in the water column (Fig.…”

Section: Interpretation Of Fjord Sedimentary Recordsmentioning

confidence: 99%

Spatial distribution of diatom and pigment sedimentary records in surface sediments in Doubtful Sound, Fiordland, New Zealand

Schüller

Savage

2011

New Zealand Journal of Marine and Freshwater Research

View full text Add to dashboard Cite

Algal remains (pigment concentrations, diatom frustules) and organic matter sources (d 15 N, d13 C) in surface sediments (0Á2 cm) were quantified and related to environmental gradients in Doubtful Sound, Fiordland, New Zealand. Sedimentary pigment concentrations, in particular diatoxanthin and fucoxanthin (diatom biomarkers) were elevated near Malaspina Reach, which experiences greater incident irradiance and mixing of silica-rich freshwater with nutrient-rich marine water. In contrast, diatom frustules were recovered in low concentrations in deep basins including Malaspina Reach, most likely related to dissolution and grazing. Spatial variability in pigments in Doubtful Sound was mainly correlated with light conditions (incident irradiance, chromophoric dissolved organic matter). By contrast, diatoms were principally correlated with salinity gradients (effective freshwater depth) and water column stratification (mixing). This study highlights the importance of using complementary sedimentary proxies when reconstructing algal abundance and community composition in fjord environments.

show abstract

“…However, these mechanisms need further elucidation. For example, processes promoting or preventing anoxia are likely to be correlated with processes of water restriction, nutrient input and flux, and productivity (Timothy & Soon 2001). Results here showed that SILL, BC and SI (our predictor of local productivity) were poorly correlated (Fig.…”

mentioning

confidence: 83%

“…Because fjords are generally deep, surface waters remain highly structured throughout the fjord, and relatively stable over time compared to shallow estuaries where bottom-induced frictional forces cause continual mixing of upper layers. This well-structured surface layer and suppressed mixing with deeper water means that basin water can become statically isolated, resulting in periods of hypoxia or anoxia as a result of biological oxygen demand (Timothy & Soon 2001 (Diaz & Rosenberg 1995). In the water column, reduced oxygen may have a unifying effect on the whole benthic community by completely overpowering any smaller-scale effects.…”

Section: Sample-scale Matrix: Proportion Of Predatorsmentioning

confidence: 99%

Relative influence of processes structuring fjord deep-water macrofaunal communities across multiple spatial scales

Brewin¹,

Probert²,

Barker³

2011

Mar. Ecol. Prog. Ser.

View full text Add to dashboard Cite

We examined the processes that maintain spatially subdivided deep-basin macrobenthic communities in a New Zealand fjord. Based on previously reported quantitative taxa distribution data, we measured physical and biological processes acting at the sample scale (physical and nutritional sediment characteristics, predation), basin scale (disturbance, productivity, local connectivity) and the fjord scale (connectivity to the regional species pool). Using partial redundancy analysis (RDA), we partitioned their effects on community variability. Direct gradient analysis revealed that previously reported high-, medium-and low-diversity communities are similarly grouped according to their position along measured biotic and abiotic gradients, where 36% of community variation in niche space (i.e. after effects of distance along the fjord were removed) was explained by the full model. Variance partitioning showed that basin-scale factors explained the highest amount of variation in basin communities, followed by sample-scale and fjord-scale factors. Sample-and basin-scale factors were correlated. Examination of the residual component of community variation showed that further investigation into basin-scale processes is warranted. These data support the notion of multiscaled control of community dynamics. Fjords may be unique in representing an 'ecotone' type habitat demonstrating processes at similar scales to those maintaining shallow soft-sediment communities, and those of deep-sea systems. Furthermore, this analysis may understate the importance of connectivity to the regional species pool (fjord-scale process) in such habitats where local extinctions may be relatively frequent.KEY WORDS: Macrofauna · Fjord · Spatial scale · Ecotone · Predation · Connectivity · Trophic · Disturbance Resale or republication not permitted without written consent of the publisherMar Ecol Prog Ser 425: [175][176][177][178][179][180][181][182][183][184][185][186][187][188][189][190][191] 2011 Fjord marine habitats are often classified as estuaries based on hydrography and geomorphology (Ketchum 1983, Burrell 1988. However, fjords may also be deep (often greater than 500 m water depth) and comparatively stable over time (Pickrill 1987, Syvitski et al. 1987, reflecting deeper offshore habitats (Grant 2000, Snelgrove & Smith 2002. This suggests that community structure and related processes may span a broad range of spatial scales. Within shallow water soft-sediment communities, species pattern often shows strong spatial structure over scales of metres to 100s of metres (Thrush 1991), where biotic and abiotic processes acting over such scales are thought to be important in structuring local communities. Such processes may include microhabitat dynamics affecting interactions between individuals (e.g. Edgar & Barrett 2002), water-driven mechanical and chemical sediment processes (e.g. Probert 1984, Guichard & Bourget 1998, disturbance by benthic megafauna (e.g. Parry et al. 2003), and effects of 'ecosystem engineers' (e.g. Berkenbusch...

show abstract

Primary production and deep-water oxygen content of two British Columbian fjords

Cited by 63 publications

References 43 publications

The temporal dynamics of terrestrial organic matter transfer to the oceans : initial assessment and application

The temporal dynamics of terrestrial organic matter transfer to the oceans : initial assessment and application

Spatial distribution of diatom and pigment sedimentary records in surface sediments in Doubtful Sound, Fiordland, New Zealand

Relative influence of processes structuring fjord deep-water macrofaunal communities across multiple spatial scales

Contact Info

Product

Resources

About