An integrated approach to characterize deep sediment toxicity in Genoa submarine canyons (NW Mediterranean)

Abstract. Submarine canyons are sites of intense energy and material exchange between the shelf and the deep adjacent basins. To test the hypothesis that active submarine canyons represent preferential conduits of available food for the deep-sea benthos, two mooring lines were deployed at 1200 m depth from November 2008 to November 2009 inside the Blanes canyon and on the adjacent open slope (Catalan Margin, NW Mediterranean Sea). We investigated the fluxes, biochemical composition and food quality of sinking organic carbon (OC). OC fluxes in the canyon and the open slope varied among sampling periods, though not consistently in the two sites. In particular, while in the open slope the highest OC fluxes were observed in August 2009, in the canyon the highest OC fluxes occurred in April–May 2009. For almost the entire study period, the OC fluxes in the canyon were significantly higher than those in the open slope, whereas OC contents of sinking particles collected in the open slope were consistently higher than those in the canyon. This result confirms that submarine canyons are effective conveyors of OC to the deep sea. Particles transferred to the deep sea floor through the canyons are predominantly of inorganic origin, significantly higher than that reaching the open slope at a similar water depth. Using multivariate statistical tests, two major clusters of sampling periods were identified: one in the canyon that grouped trap samples collected in December 2008, concurrently with the occurrence of a major storm at the sea surface, and associated with increased fluxes of nutritionally available particles from the upper shelf. Another cluster grouped samples from both the canyon and the open slope collected in March 2009, concurrently with the occurrence of the seasonal phytoplankton bloom at the sea surface, and associated with increased fluxes of total phytopigments. Our results confirm the key ecological role of submarine canyons for the functioning of deep-sea ecosystems, and highlight the importance of canyons in linking episodic storms and primary production occurring at the sea surface to the deep sea floor.

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Bioavailability of sinking organic matter in the Blanes canyon and the adjacent open slope (NW Mediterranean Sea)

Biogeosciences Discussions ◽

10.5194/bgd-9-18295-2012 ◽

2012 ◽

Vol 9 (12) ◽

pp. 18295-18330 ◽

Cited By ~ 3

Author(s):

P. Lopez-Fernandez ◽

S. Bianchelli ◽

A. Pusceddu ◽

A. Calafat ◽

A. Sanchez-Vidal ◽

...

Keyword(s):

Mediterranean Sea ◽

Deep Sea ◽

Phytoplankton Bloom ◽

Statistical Tests ◽

Sea Surface ◽

Submarine Canyons ◽

Mooring Lines ◽

Entire Study ◽

Nw Mediterranean ◽

Nw Mediterranean Sea

Abstract. Submarine canyons are sites of intense energy and material exchange between the shelf and the deep adjacent basins. To test the hypothesis that active submarine canyons represent preferential conduits of available food for the deep-sea benthos, two mooring lines were deployed at 1200 m depth from November 2008 to November 2009 inside the Blanes canyon and on the adjacent open slope (Catalan Margin, NW Mediterranean Sea). We investigated the fluxes, biochemical composition and food quality of sinking organic carbon (OC). OC fluxes in the canyon and the open slope varied among sampling periods, though not consistently in the two sites. In particular, while in the open slope the highest OC fluxes were observed in August 2009, in the canyon the highest OC fluxes occurred in April–May 2009. For almost the entire study period, the OC fluxes in the canyon were significantly higher than those in the open slope, whereas OC contents of sinking particles collected in the open slope were consistently higher than those in the canyon. This result confirms that submarine canyons are effective conveyors of OC to the deep sea, particles transferred are predominantly of inorganic origin, significantly higher than that reaching the open slope at a similar water depth. Using multivariate statistical tests, two major clusters of sampling periods were identified: one in the canyon that grouped trap samples collected in December 2008, concurrently with the occurrence of a major storm at the sea surface, and associated with increased fluxes of nutritionally available particles from the upper shelf. Another cluster grouped samples from both the canyon and the open slope collected in March 2009, concurrently with the occurrence of the seasonal phytoplankton bloom at the sea surface, and associated with increased fluxes of total phytopigments. Our results confirm the key ecological role of submarine canyons for the functioning of deep-sea ecosystems, and highlight the importance of canyons in linking episodic storms and primary production occurring at the sea surface to the deep sea floor.

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Contamination and toxicity trends for sediments — case of the elbe river

Water Science & Technology ◽

10.2166/wst.1998.0740 ◽

1998 ◽

Vol 37 (6-7) ◽

pp. 95-102 ◽

Cited By ~ 1

Author(s):

P. Heininger ◽

J. Pelzer ◽

E. Claus ◽

P. Tippmann

Keyword(s):

Sediment Toxicity ◽

Sediment Quality ◽

Integrated Approach ◽

Reference Sites ◽

Case Scenario ◽

Elbe River ◽

Worst Case ◽

Seasonal Factors ◽

River Elbe ◽

The Elbe River

The paper deals with sediment studies in the Upper and Middle Elbe between 1991 and 1996. Hydrological and seasonal factors are discussed with respect to trends in sediment contamination. An investigation programme is described including periodical measurements of inorganic and organic pollutants at monitoring stations as well as in-depth case studies. In these studies reference sites represent background conditions. Heavily contaminated reaches are taken as the worst case scenario. An integrated approach is applied combining chemical and ecotoxicological investigations. Factors are defined which must be taken into account in order to draw reliable conclusions for sediment quality. Contamination trends and trends in sediment toxicity are derived for the river Elbe.

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Vertical distribution of microbial communities abundance and biomass in two NW Mediterranean Sea submarine canyons

Progress In Oceanography ◽

10.1016/j.pocean.2019.03.005 ◽

2019 ◽

Vol 175 ◽

pp. 14-23 ◽

Cited By ~ 1

Author(s):

Tommaso Diociaiuti ◽

Fabrizio Bernardi Aubry ◽

Serena Fonda Umani

Keyword(s):

Vertical Distribution ◽

Microbial Communities ◽

Mediterranean Sea ◽

Submarine Canyons ◽

Nw Mediterranean ◽

Nw Mediterranean Sea

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Development of submarine canyons after the Mid-Pleistocene Transition on the Ebro margin, NW Mediterranean: The role of fluvial connections

Quaternary Science Reviews ◽

10.1016/j.quascirev.2017.01.006 ◽

2017 ◽

Vol 158 ◽

pp. 77-93 ◽

Cited By ~ 11

Author(s):

Marie-Aline Mauffrey ◽

Roger Urgeles ◽

Serge Berné ◽

Jason Canning

Keyword(s):

Submarine Canyons ◽

Nw Mediterranean

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Natural vs. trawling-derived transport of sediment and particulate organic matter in a submarine canyon

10.5194/egusphere-egu2020-978 ◽

2020 ◽

Author(s):

Sarah Paradis ◽

Marta Arjona-Camas ◽

Miguel Goñi ◽

Pere Masqué ◽

Pere Puig

Keyword(s):

Fatty Acids ◽

Organic Matter ◽

Amino Acid ◽

Particulate Organic Matter ◽

Benzoic Acids ◽

Submarine Canyons ◽

Natural Sediment ◽

Bottom Trawling ◽

Nw Mediterranean ◽

Autumn And Winter

Deep bottom trawling often occurs in the vicinities of submarine canyons since these morphological features act as nursery areas for commercial species. Previous studies in the submarine canyons incising the NW Mediterranean margin have highlighted that bottom trawling resuspends large volumes of sediment which are partly transported downcanyon as sediment gravity flows. To assess the contribution of downward particle fluxes in La Fonera Canyon (NW Mediterranean) linked to natural sediment transport events and bottom trawling, a near-bottom mooring equipped with a 24-cup sediment trap, a current meter, and a turbidimeter was deployed during 2017 in its axis (1200 m water depth), next to a trawling ground. Temporal variations in the quantity and composition of trapped particulate organic matter were assessed through the analysis of organic carbon (OC), total nitrogen (TN) and several biomarkers (lignins, cutin acids, p-hydroxybenzenes, benzoic acids, amino acid-derived products, dicarboxylic acids, and fatty acids).High downward particle fluxes (60-100 g&#183;m-2&#183;d-1) were registered in autumn and winter associated to torrential river discharges, seasonal storms and dense shelf water cascading. During these natural events, sediment transported downcanyon had high organic matter contents that were mostly terrigenous in origin. However, the highest downward particle flux (>140 g&#183;m-2&#183;d-1) was recorded in the onset of the bottom trawling season in March, after a 2-month seasonal trawling closure. During the following summer months no major natural sediment transport events occurred, but the high frequency of bottom trawling activities (10-26 hauls&#183;week-1) near the sediment trap caused considerably high downward particulate fluxes (80-125 g&#183;m-2&#183;d-1) during this season. Compared to autumn and winter months, sediment transferred downcanyon caused by trawling had lower organic matter contents, mostly consisting in refractory compounds (i.e. lignins, p-hydroxybenzenes and benzoic acids) with similar concentrations to those observed in the bottom sediments of the trawling grounds, confirming that this material originates from these areas. During periods with less trawling activity, lower sediment fluxes (30-50 g&#183;m-2&#183;d-1) with higher organic matter contents enriched in labile compounds (i.e. amino acid-derived products, di-carboxylic acids, and fatty acids) were recorded. These results highlight how bottom trawling activities on the flanks of submarine canyons modify the supply of sediment and organic matter downcanyon. The low-quality of organic matter transferred by bottom trawling activities may ultimately affect the fragile ecosystems dwelling in these deep environments.

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GEOCHEMICAL AND ECOTOXICOLOGICAL EVALUATION OF AN ESTUARINE SEDIMENT SECTION AT PACOTI RIVER/CE, BRAZIL

HOLOS - ISSN 1807-1600 ◽

10.15628/holos.2016.4741 ◽

2016 ◽

Vol 7 ◽

pp. 151

Author(s):

Ivanildo Surini De Souza ◽

Priscila Araújo Da Silva

Keyword(s):

Marine Invertebrates ◽

Biological Effects ◽

Sediment Toxicity ◽

Sediment Quality ◽

Integrated Approach ◽

Toxicity Tests ◽

Sources Of Pollution ◽

Toxic Risk ◽

Contaminant Sources ◽

Moderate Change

Pacoti estuary is located on the East coast of Ceará State/Brazil and is influenced by several sources of pollution. The sediment quality in three sampling stations was evaluated through an integrated approach. The sediments obtained were analyzed geochemically with respect to texture, organic matter, phosphorus, nitrogen and concentration of metals (Fe, Pb, Cu and Zn). Additionally, the metal loading in the sediment was determined considering a toxic risk quotient (RQ) and enrichment factor (EF). The ecotoxicological approach consisted of acute and chronic toxicity tests with species of marine invertebrates. The geochemical and ecotoxicological data were integrated using qualitative and technical criteria for multivariate analysis. The analyses showed a moderate change in the quality of the sediment Pacoti and there are influences of different contaminant sources. For this reason, one cannot disregard the input of other contaminants, not measured in this study, which probably may also have been relevant for sediment toxicity. Nonetheless, the data suggest that Pb and Cu metals as well as N tended to quality degradation in depositional areas and the sediment had some influence on the biological effects observed.

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