Influence of bottom trawling on sediment resuspension in the ‘Grande-Vasière’ area (Bay of Biscay, France)

Mengual, Baptiste; Cayocca, Florence; Hir, Pierre Le; Draye, Robin; Laffargue, Pascal; Vincent, Benoît; Garlan, Thierry

doi:10.1007/s10236-016-0974-7

Cited by 63 publications

(60 citation statements)

References 67 publications

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“…9). Large clouds of suspended sediments can be generated by a trawl, resulting in plumes that are 200 m wide, 10 m tall and 1.5 km long, depending on the substrate (Churchill 1989, Durrieu De Madron et al 2005, Boutillier et al 2013, Mengual et al 2016. The model used in our study suggests that plumes of this size could easily pass over the present protective boundaries of the MPA.…”

Section: Long-term Effects Of Suspended Sediments On Spongesmentioning

confidence: 62%

“…Understanding the extent to which anthropogenic activities influence abiotic conditions like suspended sediments is crucial for management of reefs and species in the HSQCS-MPA. Resuspension of sediments is a well-known consequence of bottom-contact fishing (Schubel et al 1978, Puig et al 2012, Mengual et al 2016, an activity that is common near the sponge reefs (Fisheries and Oceans Canada 2017). The sediment concentrations known to be resuspended by trawl gear are above the levels that cause arrests in glass sponge reef species (Fig.…”

Section: Long-term Effects Of Suspended Sediments On Spongesmentioning

confidence: 99%

“…The 2 most commonly (Fig. 9) (Schubel et al 1978, Mengual et al 2016. Trawls designed to re duce the impact on and contact time with the seafloor, such as those with Jumper doors (Morgère), can resuspend 20 to 110 mg l −1 of sediments into the water column (Mengual et al 2016).…”

Section: Suspended Sediments Influencing the Hecate Strait Mpamentioning

confidence: 99%

“…9) (Schubel et al 1978, Mengual et al 2016. Trawls designed to re duce the impact on and contact time with the seafloor, such as those with Jumper doors (Morgère), can resuspend 20 to 110 mg l −1 of sediments into the water column (Mengual et al 2016). All of these methods generate sediment plumes with concentrations above what is currently known to induce arrests in glass sponges and would take considerable time and distance to dissipate to concentrations below the thresholds of response reported in this study.…”

Section: Suspended Sediments Influencing the Hecate Strait Mpamentioning

confidence: 99%

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Effect of suspended sediments on the pumping rates of three species of glass sponge in situ

Grant¹,

Matveev²,

Kahn³

et al. 2019

Mar. Ecol. Prog. Ser.

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The largest known glass sponge reefs in Canada are within the Hecate Strait and Queen Charlotte Sound Glass Sponge Reefs Marine Protected Area (HSQCS-MPA) in British Columbia. However, human activities outside the core MPA boundaries, such as trawling, can create plumes of suspended sediments capable of travelling large distances. We studied the response of 3 glass sponge species to changes in suspended sediment concentrations (SSCs) at 170 m depth inside the HSQCS-MPA. Two species reduced excurrent flow rate in response to natural and experimentally induced increases in suspended sediment. Background suspended sediment levels were low and showed little variation (2.71 ± 0.09 mg l −1 , mean ± SD). Species varied in the threshold of SSCs that triggered arrests. Sediment concentrations of 2.8− 6.4 mg l −1 caused arrests in Rhabdocalyptus dawsoni, while Heterochone calyx did not arrest until concentrations reached 5−10 mg l −1. Very small, but prolonged increases of suspended sediments (<1 mg l −1 for R. dawsoni and 3.2 mg l −1 for H. calyx) caused arrests of several hours in R. dawsoni and prolonged periods of reduced flow in H. calyx. No arrests were observed in Farrea occa, even after repeated exposures up to 57 mg l −1. A sediment transport model showed that sediment concentrations can remain high enough to affect sponge behaviour as far as 2.39 km from the source of the plume. The results highlight the importance of understanding the biology of different species for establishment of adequate boundaries in MPAs.

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Section: Long-term Effects Of Suspended Sediments On Spongesmentioning

confidence: 62%

Section: Long-term Effects Of Suspended Sediments On Spongesmentioning

confidence: 99%

Section: Suspended Sediments Influencing the Hecate Strait Mpamentioning

confidence: 99%

Section: Suspended Sediments Influencing the Hecate Strait Mpamentioning

confidence: 99%

See 2 more Smart Citations

Effect of suspended sediments on the pumping rates of three species of glass sponge in situ

Grant¹,

Matveev²,

Kahn³

et al. 2019

Mar. Ecol. Prog. Ser.

View full text Add to dashboard Cite

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“…This formulation could be validated by comparing with recent data in two sectors of the BoBCS [48]: bulk densities of 1540 kg·m −3 and 1380 kg·m −3 were obtained for 85% and 75% of sand, respectively, while the application of Equation (5) with sand fractions f s of 0.85 and 0.75 led to C bulk values of 1668 kg·m −3 and 1346 kg·m −3 in fair agreement. Sediment concentrations linked to each particle class were then deduced according to their respective fraction.…”

Section: Sediment Facies Initialization For the Application To The Bobcsmentioning

confidence: 92%

Modelling Fine Sediment Dynamics: Towards a Common Erosion Law for Fine Sand, Mud and Mixtures

Mengual

Hir

Cayocca

et al. 2017

Water

Self Cite

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This study describes the building of a common erosion law for fine sand and mud, mixed or not, in the case of a typical continental shelf environment, the Bay of Biscay shelf, characterized by slightly energetic conditions and a seabed mainly composed of fine sand and muddy sediments. A 3D realistic hydro-sedimentary model was used to assess the influence of the erosion law setting on sediment dynamics (turbidity, seabed evolution). A pure sand erosion law was applied when the mud fraction in the surficial sediment was lower than a first critical value, and a pure mud erosion law above a second critical value. Both sand and mud erosion laws are formulated similarly, with different parameters (erodibility parameter, critical shear stress and power of the excess shear stress). Several transition trends (linear or exponential) describing variations in these erosion-related parameters between the two critical mud fractions were tested. Suspended sediment concentrations obtained from simulations were compared to measurements taken on the Bay of Biscay shelf with an acoustic profiler over the entire water column. On the one hand, results show that defining an abrupt exponential transition improves model results regarding measurements. On the other hand, they underline the need to define a first critical mud fraction of 10 to 20%, corresponding to a critical clay content of 3-6%, below which pure sand erosion should be prescribed. Both conclusions agree with results of experimental studies reported in the literature mentioning a drastic change in erosion mode above a critical clay content of 2-10% in the mixture. Results also provide evidence for the importance of considering advection in this kind of validation with in situ observations, which is likely to considerably influence both water column and seabed sediment dynamics.

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Using ecological trajectories to track long‐term taxonomic and functional changes in benthic shallow soft‐bottom communities (Bay of Saint‐Brieuc, English Channel)

Sturbois

Cormy²,

Moal³

et al. 2021

Aquatic Conservation

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1. Taxonomic and functional trajectories of benthic assemblages were studied in shallow soft-bottom sediments in the bay of Saint-Brieuc (Western English Channel). Changes were assessed at different spatial and temporal scales using a macrobenthic dataset based on 38 stations sampled in 1987 and 2019, coupled with data from one station sampled annually between 2005 and 2019 as part of the European Water Framework Directive monitoring programme. 2. Taxonomic trajectories indicated 1) changes in the structure and distribution of benthic assemblages, 2) an homogenization of the assemblages, and 3) significant functional shifts. 3. Fishing activities and nutrient enrichment are probably strong drivers of the observed changes, as suggested by the higher mortality rate of fragile, flexible, tubiculous and burrowing species, and the increase in the abundance of opportunistic species in the assemblages. Certain populations of macroinvertebrates seem jointly controlled by climate change and by the aforementioned local factors of disturbance. 4. The Community Trajectory Analysis framework appears as a new and interesting method to track ecological changes in marine ecosystems by measuring change with respect to a baseline state, to help define ecological recovery (station returning to the initial ecological state) and departure (station presenting increased changes over time), and to analyse trajectory similarity. 5. According to the degradation of habitat over time, we identify the need for the implementation of knowledge-based conservation strategies, especially within Natura 2000 sites.

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Influence of bottom trawling on sediment resuspension in the ‘Grande-Vasière’ area (Bay of Biscay, France)

Cited by 63 publications

References 67 publications

Effect of suspended sediments on the pumping rates of three species of glass sponge in situ

Effect of suspended sediments on the pumping rates of three species of glass sponge in situ

Modelling Fine Sediment Dynamics: Towards a Common Erosion Law for Fine Sand, Mud and Mixtures

Using ecological trajectories to track long‐term taxonomic and functional changes in benthic shallow soft‐bottom communities (Bay of Saint‐Brieuc, English Channel)

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