Ecosystem-based design rules for marine sand extraction sites

Maarten F. de Jong*, Bas W. Borsje, Martin J. Baptist, Jan Tjalling van der Wal, Han J. Lindeboom, Piet Hoekstra

*Corresponding author for this work

Research output: Contribution to journalArticleAcademicpeer-review

4 Citations (Scopus)

Abstract

The demand for marine sand in the Netherlands as well as globally is increasing. Over the last decades, only shallow sand extraction of 2m below the seabed was allowed on the Dutch Continental Shelf (DCS). To guarantee sufficient supply and to decrease the surface area of direct impact, the Dutch authorities started to promote sand extraction depths over 2m for sand volumes over 10 millionm3. The ecological effects of deep sand extraction, however, are still largely unknown. Therefore, we investigated short-term effects (0-2.5y) of deep sand extraction (20-24m) and compared these with other case studies such as, regular shallow sand extraction on the DCS (2m) and an 8m deepened shipping lane. For intercomparison between case studies we used tide-averaged bed shear stress as a generic proxy for environmental and related ecological effects. Bed shear stress can be estimated with a two-dimensional quadratic friction law and showed a decrease from 0.50 to 0.04Nm-2 in a borrow pit in 20m deep water and extraction depths up to 24m. Macrozoobenthos in a borrow pit with a tide-averaged bed shear stress of around 0.41Nm-2 is expected to return back to pre-extraction conditions within 4-6 year. When tide-averaged bed shear stress decreases below 0.17Nm-2 enhanced macrozoobenthic species richness and biomass can occur. Below a tide-averaged bed shear stress of 0.08Nm-2, increasing abundance and biomass of brittle stars, white furrow shell (Abra alba) and plaice (platessa platessa) can be expected. Below 0.04Nm-2, an overdominance and high biomass of brittle stars can be expected whereas demersal fish biomass and species composition may return to reference conditions. Next to changes in faunal composition, a high sedimentation rate can be expected. Ecological data and bed shear stress values were transformed into ecosystem-based design (EBD) rules. At higher flow velocities and larger water depths, larger extraction depths can be applied to achieve desired tide-averaged bed shear stresses for related ecological effects. The EBD rules can be used in the early-design phases of future borrow pits in order to simultaneously maximise sand yields and decrease the surface area of direct impact. The EBD rules and ecological landscaping can also help in implementing the European Union's Marine Strategy Framework Directive (MSFD) guidelines and moving to or maintaining Good Environmental Status (GES).

Original languageEnglish
Pages (from-to)271-280
JournalEcological Engineering
Volume87
DOIs
Publication statusPublished - 2016

Fingerprint

bottom stress
Ecosystems
shear stress
Sand
Shear stress
Tides
tide
ecosystem
Biomass
biomass
sand
continental shelf
Stars
surface area
demersal fish
sand extraction
shipping
sedimentation rate
flow velocity
Freight transportation

Keywords

  • Bed shear stress
  • Demersal fish
  • Epifauna
  • Infauna
  • Macrozoobenthos
  • Sand extraction
  • Sediment characteristics
  • Sedimentation rate

Cite this

@article{e8181cafe7ba48718f715e23eae54653,
title = "Ecosystem-based design rules for marine sand extraction sites",
abstract = "The demand for marine sand in the Netherlands as well as globally is increasing. Over the last decades, only shallow sand extraction of 2m below the seabed was allowed on the Dutch Continental Shelf (DCS). To guarantee sufficient supply and to decrease the surface area of direct impact, the Dutch authorities started to promote sand extraction depths over 2m for sand volumes over 10 millionm3. The ecological effects of deep sand extraction, however, are still largely unknown. Therefore, we investigated short-term effects (0-2.5y) of deep sand extraction (20-24m) and compared these with other case studies such as, regular shallow sand extraction on the DCS (2m) and an 8m deepened shipping lane. For intercomparison between case studies we used tide-averaged bed shear stress as a generic proxy for environmental and related ecological effects. Bed shear stress can be estimated with a two-dimensional quadratic friction law and showed a decrease from 0.50 to 0.04Nm-2 in a borrow pit in 20m deep water and extraction depths up to 24m. Macrozoobenthos in a borrow pit with a tide-averaged bed shear stress of around 0.41Nm-2 is expected to return back to pre-extraction conditions within 4-6 year. When tide-averaged bed shear stress decreases below 0.17Nm-2 enhanced macrozoobenthic species richness and biomass can occur. Below a tide-averaged bed shear stress of 0.08Nm-2, increasing abundance and biomass of brittle stars, white furrow shell (Abra alba) and plaice (platessa platessa) can be expected. Below 0.04Nm-2, an overdominance and high biomass of brittle stars can be expected whereas demersal fish biomass and species composition may return to reference conditions. Next to changes in faunal composition, a high sedimentation rate can be expected. Ecological data and bed shear stress values were transformed into ecosystem-based design (EBD) rules. At higher flow velocities and larger water depths, larger extraction depths can be applied to achieve desired tide-averaged bed shear stresses for related ecological effects. The EBD rules can be used in the early-design phases of future borrow pits in order to simultaneously maximise sand yields and decrease the surface area of direct impact. The EBD rules and ecological landscaping can also help in implementing the European Union's Marine Strategy Framework Directive (MSFD) guidelines and moving to or maintaining Good Environmental Status (GES).",
keywords = "Bed shear stress, Demersal fish, Epifauna, Infauna, Macrozoobenthos, Sand extraction, Sediment characteristics, Sedimentation rate",
author = "{de Jong}, {Maarten F.} and Borsje, {Bas W.} and Baptist, {Martin J.} and {van der Wal}, {Jan Tjalling} and Lindeboom, {Han J.} and Piet Hoekstra",
year = "2016",
doi = "10.1016/j.ecoleng.2015.11.053",
language = "English",
volume = "87",
pages = "271--280",
journal = "Ecological Engineering",
issn = "0925-8574",
publisher = "Elsevier",

}

Ecosystem-based design rules for marine sand extraction sites. / de Jong, Maarten F.; Borsje, Bas W.; Baptist, Martin J.; van der Wal, Jan Tjalling; Lindeboom, Han J.; Hoekstra, Piet.

In: Ecological Engineering, Vol. 87, 2016, p. 271-280.

Research output: Contribution to journalArticleAcademicpeer-review

TY - JOUR

T1 - Ecosystem-based design rules for marine sand extraction sites

AU - de Jong, Maarten F.

AU - Borsje, Bas W.

AU - Baptist, Martin J.

AU - van der Wal, Jan Tjalling

AU - Lindeboom, Han J.

AU - Hoekstra, Piet

PY - 2016

Y1 - 2016

N2 - The demand for marine sand in the Netherlands as well as globally is increasing. Over the last decades, only shallow sand extraction of 2m below the seabed was allowed on the Dutch Continental Shelf (DCS). To guarantee sufficient supply and to decrease the surface area of direct impact, the Dutch authorities started to promote sand extraction depths over 2m for sand volumes over 10 millionm3. The ecological effects of deep sand extraction, however, are still largely unknown. Therefore, we investigated short-term effects (0-2.5y) of deep sand extraction (20-24m) and compared these with other case studies such as, regular shallow sand extraction on the DCS (2m) and an 8m deepened shipping lane. For intercomparison between case studies we used tide-averaged bed shear stress as a generic proxy for environmental and related ecological effects. Bed shear stress can be estimated with a two-dimensional quadratic friction law and showed a decrease from 0.50 to 0.04Nm-2 in a borrow pit in 20m deep water and extraction depths up to 24m. Macrozoobenthos in a borrow pit with a tide-averaged bed shear stress of around 0.41Nm-2 is expected to return back to pre-extraction conditions within 4-6 year. When tide-averaged bed shear stress decreases below 0.17Nm-2 enhanced macrozoobenthic species richness and biomass can occur. Below a tide-averaged bed shear stress of 0.08Nm-2, increasing abundance and biomass of brittle stars, white furrow shell (Abra alba) and plaice (platessa platessa) can be expected. Below 0.04Nm-2, an overdominance and high biomass of brittle stars can be expected whereas demersal fish biomass and species composition may return to reference conditions. Next to changes in faunal composition, a high sedimentation rate can be expected. Ecological data and bed shear stress values were transformed into ecosystem-based design (EBD) rules. At higher flow velocities and larger water depths, larger extraction depths can be applied to achieve desired tide-averaged bed shear stresses for related ecological effects. The EBD rules can be used in the early-design phases of future borrow pits in order to simultaneously maximise sand yields and decrease the surface area of direct impact. The EBD rules and ecological landscaping can also help in implementing the European Union's Marine Strategy Framework Directive (MSFD) guidelines and moving to or maintaining Good Environmental Status (GES).

AB - The demand for marine sand in the Netherlands as well as globally is increasing. Over the last decades, only shallow sand extraction of 2m below the seabed was allowed on the Dutch Continental Shelf (DCS). To guarantee sufficient supply and to decrease the surface area of direct impact, the Dutch authorities started to promote sand extraction depths over 2m for sand volumes over 10 millionm3. The ecological effects of deep sand extraction, however, are still largely unknown. Therefore, we investigated short-term effects (0-2.5y) of deep sand extraction (20-24m) and compared these with other case studies such as, regular shallow sand extraction on the DCS (2m) and an 8m deepened shipping lane. For intercomparison between case studies we used tide-averaged bed shear stress as a generic proxy for environmental and related ecological effects. Bed shear stress can be estimated with a two-dimensional quadratic friction law and showed a decrease from 0.50 to 0.04Nm-2 in a borrow pit in 20m deep water and extraction depths up to 24m. Macrozoobenthos in a borrow pit with a tide-averaged bed shear stress of around 0.41Nm-2 is expected to return back to pre-extraction conditions within 4-6 year. When tide-averaged bed shear stress decreases below 0.17Nm-2 enhanced macrozoobenthic species richness and biomass can occur. Below a tide-averaged bed shear stress of 0.08Nm-2, increasing abundance and biomass of brittle stars, white furrow shell (Abra alba) and plaice (platessa platessa) can be expected. Below 0.04Nm-2, an overdominance and high biomass of brittle stars can be expected whereas demersal fish biomass and species composition may return to reference conditions. Next to changes in faunal composition, a high sedimentation rate can be expected. Ecological data and bed shear stress values were transformed into ecosystem-based design (EBD) rules. At higher flow velocities and larger water depths, larger extraction depths can be applied to achieve desired tide-averaged bed shear stresses for related ecological effects. The EBD rules can be used in the early-design phases of future borrow pits in order to simultaneously maximise sand yields and decrease the surface area of direct impact. The EBD rules and ecological landscaping can also help in implementing the European Union's Marine Strategy Framework Directive (MSFD) guidelines and moving to or maintaining Good Environmental Status (GES).

KW - Bed shear stress

KW - Demersal fish

KW - Epifauna

KW - Infauna

KW - Macrozoobenthos

KW - Sand extraction

KW - Sediment characteristics

KW - Sedimentation rate

U2 - 10.1016/j.ecoleng.2015.11.053

DO - 10.1016/j.ecoleng.2015.11.053

M3 - Article

VL - 87

SP - 271

EP - 280

JO - Ecological Engineering

JF - Ecological Engineering

SN - 0925-8574

ER -