Data from: Sediment burial intolerance of marine macroinvertebrates

The marine environment contains suspended particulate matter which originates from natural and anthropogenic sources. Settlement of this material can leave benthic organisms susceptible to smothering, especially if burial is sudden i.e. following storms or activities such as dredging. Their survival will depend on their tolerance to, and their ability to escape from burial. Here we present data from a multi-factorial experiment measuring burial responses incorporating duration, sediment fraction and depth. Six macroinvertebrates commonly found in sediment rich environments were selected for their commercial and/or conservation importance. Assessments revealed that the brittle star (Ophiura ophiura), the queen scallop (Aequipecten opercularis) and the sea squirt (Ciona intestinalis) were all highly intolerant to burial whilst the green urchin (Psammichinus miliaris) and the anemone (Sagartiogeton lacerates), showed intermediate and low intolerance respectively, to burial. The least intolerant, with very high survival was the Ross worm (Sabellaria spinulosa). With the exception of C. intestinalis, increasing duration and depth of burial with finer sediment fractions resulted in increased mortality for all species assessed. For C. intestinalis depth of burial and sediment fraction were found to be inconsequential since there was complete mortality of all specimens buried for more than one day. When burial emergence was assessed O. ophiura emerged most frequently, followed by P. miliaris. The former emerged most frequently from the medium and fine sediments whereas P. miliaris emerged more frequently from coarse sediment. Both A. opercularis and S. laceratus showed similar emergence responses over time, with A. opercularis emerging more frequently under coarse sediments. The frequency of emergence of S. lacerates increased with progressively finer sediment and C. intestinalis did not emerge from burial irrespective of sediment fraction or depth. Finally, and perhaps unsurprisingly, the greatest ability to emerge from burial in all other species was from shallow (2 cm) burial. Although survival was consistently highly dependent on duration and depth of burial as expected, emergence behaviour was not as easily predictable thereby confounding predictions. We conclude that responses to burial are highly species specific and therefore tolerance generalisations are likely to be oversimplifications. These data may be used to inform environmental impact models that allow forecasting of the cumulative impacts of seabed disturbance and may provide mitigation measures for the sustainable use of the seabed

Sediment Burial Intolerance of Marine Macroinvertebrates

<div><p>The marine environment contains suspended particulate matter which originates from natural and anthropogenic sources. Settlement of this material can leave benthic organisms susceptible to smothering, especially if burial is sudden i.e. following storms or activities such as dredging. Their survival will depend on their tolerance to, and their ability to escape from burial. Here we present data from a multi-factorial experiment measuring burial responses incorporating duration, sediment fraction and depth. Six macroinvertebrates commonly found in sediment rich environments were selected for their commercial and/or conservation importance. Assessments revealed that the brittle star (<i>Ophiura ophiura</i>), the queen scallop (<i>Aequipecten opercularis</i>) and the sea squirt (<i>Ciona intestinalis</i>) were all highly intolerant to burial whilst the green urchin (<i>Psammichinus miliaris</i>) and the anemone (<i>Sagartiogeton laceratus</i>), showed intermediate and low intolerance respectively, to burial. The least intolerant, with very high survival was the Ross worm (<i>Sabellaria spinulosa</i>). With the exception of <i>C</i>. <i>intestinalis</i>, increasing duration and depth of burial with finer sediment fractions resulted in increased mortality for all species assessed. For <i>C</i>. <i>intestinalis</i> depth of burial and sediment fraction were found to be inconsequential since there was complete mortality of all specimens buried for more than one day. When burial emergence was assessed <i>O</i>. <i>ophiura</i> emerged most frequently, followed by <i>P</i>. <i>miliaris</i>. The former emerged most frequently from the medium and fine sediments whereas <i>P</i>. <i>miliaris</i> emerged more frequently from coarse sediment. Both <i>A</i>. <i>opercularis</i> and <i>S</i>. <i>laceratus</i> showed similar emergence responses over time, with <i>A</i>. <i>opercularis</i> emerging more frequently under coarse sediments. The frequency of emergence of <i>S</i>. <i>laceratus</i> increased with progressively finer sediment and <i>C</i>. <i>intestinalis</i> did not emerge from burial irrespective of sediment fraction or depth. Finally, and perhaps unsurprisingly, the greatest ability to emerge from burial in all other species was from shallow (2 cm) burial. Although survival was consistently highly dependent on duration and depth of burial as expected, emergence behaviour was not as easily predictable thereby confounding predictions. We conclude that responses to burial are highly species specific and therefore tolerance generalisations are likely to be oversimplifications. These data may be used to inform environmental impact models that allow forecasting of the cumulative impacts of seabed disturbance and may provide mitigation measures for the sustainable use of the seabed.</p></div

Burial tolerance data for marine macroinvertebrates

Indexed spreadshee

a-c. Multispecies assessment of emergence (%) in response to sediment burial.

<p>Factors assessed: a) Duration (days); b) Sediment fraction (C = course, M = medium, F = fine) and; c) Depth of burial (cm) above organism.</p

<i>Sabellaria spinulosa</i> clump with ‘emergence tubes’.

<p>‘Emergence tubes’ constructed during burial by 2 cm fine (0.1–0.25 mm) sand for 16 days. The inset (top left) shows an isolated emergence tube which breaks off the main parent colony easily, and through which an individual animal is clearly visible. The inset (bottom left) shows three tubes emerging from the sediment following burial (Image source: Kim Last).</p

Indicators of mortality used to assess organisms following burial treatments.

<p>Indicators of mortality used to assess organisms following burial treatments.</p

a-c. Multispecies assessment of mortality (%) in response to sediment burial.

<p>Factors tested: a) Duration (days); b) Sediment fraction (C = course, M = medium, F = fine) and; c) Depth of burial (cm) above organism.</p

Data from: Buried alive: the behavioural response of the mussels, Modiolus modiolus and Mytilus edulis to sudden burial by sediment

Sedimentation in the sea occurs through natural processes, such as wave and tidal action, which can be exacerbated during storms and floods. Changes in terrestrial land use, marine aggregate extraction, dredging, drilling and mining are known to result in substantial sediment deposition. Research suggests that deposition will also occur due to the modern development of marine renewable energy. The response to individual burial under three depths of sediment, three sediment fractions and five burial durations was investigated in two mussel species, Modiolus modiolus and Mytilus edulis in specialist mesocosms. Both mussel species showed substantial mortality, which increased with duration of burial and burial by finer sediment fractions. M. modiolus was better able to survive short periods of burial than M. edulis, but at longer durations mortality was more pronounced. No mortality was observed in M. modiolus in burial durations of eight days or less but by 16 days of burial, over 50% cumulative mortality occurred. Under variable temperature regimes, M. edulis mortality increased from 20% at 8°C to over 60% at 14.5 and 20°C. Only M. edulis was able to emerge from burial, facilitated by increased byssus production, laid mostly on vertical surfaces but also on sediment particles. Emergence was higher from coarse sediment and shallow burials. Byssus production in M. edulis was not related to the condition index of the mussels. Results suggest that even marginal burial would result in mortality and be more pronounced in warm summer periods. Our results suggest that in the event of burial, adult M. modiolus would not be able to emerge from burial unless local hydrodynamics assist, whereas a small proportion of M. edulis may regain contact with the sediment water interface. The physiological stress resulting in mortality, contribution of local hydrodynamics to survival and other ecological pressures such as mussels existing in aggregations, are discussed

Buried alive:The behavioural response of the mussels, Modiolus modiolus and Mytilus edulis to sudden burial by sediment

Sedimentation in the sea occurs through natural processes, such as wave and tidal action, which can be exacerbated during storms and floods. Changes in terrestrial land use, marine aggregate extraction, dredging, drilling and mining are known to result in substantial sediment deposition. Research suggests that deposition will also occur due to the modern development of marine renewable energy. The response to individual burial under three depths of sediment, three sediment fractions and five burial durations was investigated in two mussel species, Modiolus modiolus and Mytilus edulis in specialist mesocosms. Both mussel species showed substantial mortality, which increased with duration of burial and burial by finer sediment fractions. M. modiolus was better able to survive short periods of burial than M. edulis, but at longer durations mortality was more pronounced. No mortality was observed in M. modiolus in burial durations of eight days or less but by 16 days of burial, over 50% cumulative mortality occurred. Under variable temperature regimes, M. edulis mortality increased from 20% at 8°C to over 60% at 14.5 and 20°C. Only M. edulis was able to emerge from burial, facilitated by increased byssus production, laid mostly on vertical surfaces but also on sediment particles. Emergence was higher from coarse sediment and shallow burials. Byssus production in M. edulis was not related to the condition index of the mussels. Results suggest that even marginal burial would result in mortality and be more pronounced in warm summer periods. Our results suggest that in the event of burial, adult M. modiolus would not be able to emerge from burial unless local hydrodynamics assist, whereas a small proportion of M. edulis may regain contact with the sediment water interface. The physiological stress resulting in mortality, contribution of local hydrodynamics to survival and other ecological pressures such as mussels existing in aggregations, are discussed