Production efficiency of mussel bottom culture

Research output: Thesisinternal PhD, WU

Abstract

Mussel bottom culture is an extensive type of aquaculture; it depends on natural resources for feed, seed and space. It consists of the translocation of seed from natural beds to designed culture areas, where mussel farmers try to improve production efficiency. Production efficiency is measured by the relative biomass production (RBP) expressed as units of biomass harvested from one unit of biomass seeded, it increases with mussel growth and decreases with mussel mortality. Mussel bottom culture makes use of nature and also depends on nature. Cultured mussels are subject to similar environmental factors that influence growth and mortality on natural mussel beds, with additional effects of anthropogenic factors. In this thesis we focus on dynamics of mussel beds and the impact and effectivity of culture activities on mussel production yield. The major objectives are stated as: (1) to better understand the population dynamics of subtidal mussel populations, (2) to analyze what factors determine production efficiency in mussel bottom culture and how this can be improved. On natural mussel beds mussels organise in patterns that enhance food delivery and resilience of the bed. On culture plots mussels are seeded in concentric seeding patterns. Seeding techniques concentrate mussels locally within the culture plot area, resulting in high local mussel densities; this increases competition and limits the spatial re-organisation of mussels in the bed. Consequently, seeding on culture plots is followed by a large size and density dependent seeding loss that ranges from about 40% for seed from fishery to 69% for smaller SMC seed. This loss was the major factor in determining the maximum RBP. Losses in the grow-out stage were substantially lower, a subsequent density dependent loss was found for smaller mussels (<30 mm), and a non-density dependent loss for larger mussels (>30 mm). Shore crab predation is an important factor contributing to the higher losses at seeding. The effect of shore crab predation on mussel biomass production is higher than expected from previous studies. In an experiment on an intertidal culture plot in the Oosterschelde (NL), we observed that shore crab predation peaks directly after seeding and accounted for 33% of the total losses within five weeks after seeding. Spatial patterns in the survival rates of natural mussel beds in the Wadden Sea show better seed survival in areas with intermediate salinity (mean annual salinity 17.5-22.5 mg l-1). This suggests that mussel survival is negatively related to sea star distribution, which is largely controlled by salinity. Natural beds that escape predation are found at lower salinities and mussels on these beds showed low growth rates, also because of a lower food quality in these areas. Mussel culture strongly affects the population dynamics of the subtidal mussel population, through relaying of mussels from natural mussel beds to culture plots. Culture plots are located in more saline regions of the Wadden Sea (mean annual salinity 25.8 mg l-1), compared to natural mussel beds. This activity increased mussel growth and survival because food quality on culture plots is high and predation is prevented. As a result, average biomass production is higher on culture plots than on natural mussel beds and this difference increases over time. A more efficient seed use on the available area, that can be obtained by reducing seeding losses will increase RBP, maximum biomass production and increases maximum profit. Our results suggest that this can be achieved by seeding homogeneously in low densities.

Original languageEnglish
QualificationDoctor of Philosophy
Awarding Institution
  • Wageningen University
Supervisors/Advisors
  • Smaal, Aad, Promotor
  • Herman, P.M.J., Promotor, External person
  • Wijsman, Jeroen, Co-promotor
Award date10 Mar 2017
Place of PublicationWageningen
Publisher
Print ISBNs9789463430869
DOIs
Publication statusPublished - 2017

Fingerprint

seeding
biomass
seed
predation
salinity
mussel culture
crab
food quality
population dynamics
mortality
loss
translocation
aquaculture
environmental factor
natural resource
fishery
food

Keywords

  • mussels
  • mussel culture
  • bottom culture
  • efficiency
  • population dynamics
  • culture techniques
  • biomass production
  • improvement
  • shellfish culture
  • aquaculture

Cite this

Capelle, Jacob J.. / Production efficiency of mussel bottom culture. Wageningen : Wageningen University, 2017. 240 p.
@phdthesis{1dac6b81d7b143daa8e2605ffb657bf9,
title = "Production efficiency of mussel bottom culture",
abstract = "Mussel bottom culture is an extensive type of aquaculture; it depends on natural resources for feed, seed and space. It consists of the translocation of seed from natural beds to designed culture areas, where mussel farmers try to improve production efficiency. Production efficiency is measured by the relative biomass production (RBP) expressed as units of biomass harvested from one unit of biomass seeded, it increases with mussel growth and decreases with mussel mortality. Mussel bottom culture makes use of nature and also depends on nature. Cultured mussels are subject to similar environmental factors that influence growth and mortality on natural mussel beds, with additional effects of anthropogenic factors. In this thesis we focus on dynamics of mussel beds and the impact and effectivity of culture activities on mussel production yield. The major objectives are stated as: (1) to better understand the population dynamics of subtidal mussel populations, (2) to analyze what factors determine production efficiency in mussel bottom culture and how this can be improved. On natural mussel beds mussels organise in patterns that enhance food delivery and resilience of the bed. On culture plots mussels are seeded in concentric seeding patterns. Seeding techniques concentrate mussels locally within the culture plot area, resulting in high local mussel densities; this increases competition and limits the spatial re-organisation of mussels in the bed. Consequently, seeding on culture plots is followed by a large size and density dependent seeding loss that ranges from about 40{\%} for seed from fishery to 69{\%} for smaller SMC seed. This loss was the major factor in determining the maximum RBP. Losses in the grow-out stage were substantially lower, a subsequent density dependent loss was found for smaller mussels (<30 mm), and a non-density dependent loss for larger mussels (>30 mm). Shore crab predation is an important factor contributing to the higher losses at seeding. The effect of shore crab predation on mussel biomass production is higher than expected from previous studies. In an experiment on an intertidal culture plot in the Oosterschelde (NL), we observed that shore crab predation peaks directly after seeding and accounted for 33{\%} of the total losses within five weeks after seeding. Spatial patterns in the survival rates of natural mussel beds in the Wadden Sea show better seed survival in areas with intermediate salinity (mean annual salinity 17.5-22.5 mg l-1). This suggests that mussel survival is negatively related to sea star distribution, which is largely controlled by salinity. Natural beds that escape predation are found at lower salinities and mussels on these beds showed low growth rates, also because of a lower food quality in these areas. Mussel culture strongly affects the population dynamics of the subtidal mussel population, through relaying of mussels from natural mussel beds to culture plots. Culture plots are located in more saline regions of the Wadden Sea (mean annual salinity 25.8 mg l-1), compared to natural mussel beds. This activity increased mussel growth and survival because food quality on culture plots is high and predation is prevented. As a result, average biomass production is higher on culture plots than on natural mussel beds and this difference increases over time. A more efficient seed use on the available area, that can be obtained by reducing seeding losses will increase RBP, maximum biomass production and increases maximum profit. Our results suggest that this can be achieved by seeding homogeneously in low densities.",
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author = "Capelle, {Jacob J.}",
note = "WU thesis 6592 Includes bibliographic references. - With summaries in Dutch and English",
year = "2017",
doi = "10.18174/404677",
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isbn = "9789463430869",
publisher = "Wageningen University",
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Capelle, JJ 2017, 'Production efficiency of mussel bottom culture', Doctor of Philosophy, Wageningen University, Wageningen. https://doi.org/10.18174/404677

Production efficiency of mussel bottom culture. / Capelle, Jacob J.

Wageningen : Wageningen University, 2017. 240 p.

Research output: Thesisinternal PhD, WU

TY - THES

T1 - Production efficiency of mussel bottom culture

AU - Capelle, Jacob J.

N1 - WU thesis 6592 Includes bibliographic references. - With summaries in Dutch and English

PY - 2017

Y1 - 2017

N2 - Mussel bottom culture is an extensive type of aquaculture; it depends on natural resources for feed, seed and space. It consists of the translocation of seed from natural beds to designed culture areas, where mussel farmers try to improve production efficiency. Production efficiency is measured by the relative biomass production (RBP) expressed as units of biomass harvested from one unit of biomass seeded, it increases with mussel growth and decreases with mussel mortality. Mussel bottom culture makes use of nature and also depends on nature. Cultured mussels are subject to similar environmental factors that influence growth and mortality on natural mussel beds, with additional effects of anthropogenic factors. In this thesis we focus on dynamics of mussel beds and the impact and effectivity of culture activities on mussel production yield. The major objectives are stated as: (1) to better understand the population dynamics of subtidal mussel populations, (2) to analyze what factors determine production efficiency in mussel bottom culture and how this can be improved. On natural mussel beds mussels organise in patterns that enhance food delivery and resilience of the bed. On culture plots mussels are seeded in concentric seeding patterns. Seeding techniques concentrate mussels locally within the culture plot area, resulting in high local mussel densities; this increases competition and limits the spatial re-organisation of mussels in the bed. Consequently, seeding on culture plots is followed by a large size and density dependent seeding loss that ranges from about 40% for seed from fishery to 69% for smaller SMC seed. This loss was the major factor in determining the maximum RBP. Losses in the grow-out stage were substantially lower, a subsequent density dependent loss was found for smaller mussels (<30 mm), and a non-density dependent loss for larger mussels (>30 mm). Shore crab predation is an important factor contributing to the higher losses at seeding. The effect of shore crab predation on mussel biomass production is higher than expected from previous studies. In an experiment on an intertidal culture plot in the Oosterschelde (NL), we observed that shore crab predation peaks directly after seeding and accounted for 33% of the total losses within five weeks after seeding. Spatial patterns in the survival rates of natural mussel beds in the Wadden Sea show better seed survival in areas with intermediate salinity (mean annual salinity 17.5-22.5 mg l-1). This suggests that mussel survival is negatively related to sea star distribution, which is largely controlled by salinity. Natural beds that escape predation are found at lower salinities and mussels on these beds showed low growth rates, also because of a lower food quality in these areas. Mussel culture strongly affects the population dynamics of the subtidal mussel population, through relaying of mussels from natural mussel beds to culture plots. Culture plots are located in more saline regions of the Wadden Sea (mean annual salinity 25.8 mg l-1), compared to natural mussel beds. This activity increased mussel growth and survival because food quality on culture plots is high and predation is prevented. As a result, average biomass production is higher on culture plots than on natural mussel beds and this difference increases over time. A more efficient seed use on the available area, that can be obtained by reducing seeding losses will increase RBP, maximum biomass production and increases maximum profit. Our results suggest that this can be achieved by seeding homogeneously in low densities.

AB - Mussel bottom culture is an extensive type of aquaculture; it depends on natural resources for feed, seed and space. It consists of the translocation of seed from natural beds to designed culture areas, where mussel farmers try to improve production efficiency. Production efficiency is measured by the relative biomass production (RBP) expressed as units of biomass harvested from one unit of biomass seeded, it increases with mussel growth and decreases with mussel mortality. Mussel bottom culture makes use of nature and also depends on nature. Cultured mussels are subject to similar environmental factors that influence growth and mortality on natural mussel beds, with additional effects of anthropogenic factors. In this thesis we focus on dynamics of mussel beds and the impact and effectivity of culture activities on mussel production yield. The major objectives are stated as: (1) to better understand the population dynamics of subtidal mussel populations, (2) to analyze what factors determine production efficiency in mussel bottom culture and how this can be improved. On natural mussel beds mussels organise in patterns that enhance food delivery and resilience of the bed. On culture plots mussels are seeded in concentric seeding patterns. Seeding techniques concentrate mussels locally within the culture plot area, resulting in high local mussel densities; this increases competition and limits the spatial re-organisation of mussels in the bed. Consequently, seeding on culture plots is followed by a large size and density dependent seeding loss that ranges from about 40% for seed from fishery to 69% for smaller SMC seed. This loss was the major factor in determining the maximum RBP. Losses in the grow-out stage were substantially lower, a subsequent density dependent loss was found for smaller mussels (<30 mm), and a non-density dependent loss for larger mussels (>30 mm). Shore crab predation is an important factor contributing to the higher losses at seeding. The effect of shore crab predation on mussel biomass production is higher than expected from previous studies. In an experiment on an intertidal culture plot in the Oosterschelde (NL), we observed that shore crab predation peaks directly after seeding and accounted for 33% of the total losses within five weeks after seeding. Spatial patterns in the survival rates of natural mussel beds in the Wadden Sea show better seed survival in areas with intermediate salinity (mean annual salinity 17.5-22.5 mg l-1). This suggests that mussel survival is negatively related to sea star distribution, which is largely controlled by salinity. Natural beds that escape predation are found at lower salinities and mussels on these beds showed low growth rates, also because of a lower food quality in these areas. Mussel culture strongly affects the population dynamics of the subtidal mussel population, through relaying of mussels from natural mussel beds to culture plots. Culture plots are located in more saline regions of the Wadden Sea (mean annual salinity 25.8 mg l-1), compared to natural mussel beds. This activity increased mussel growth and survival because food quality on culture plots is high and predation is prevented. As a result, average biomass production is higher on culture plots than on natural mussel beds and this difference increases over time. A more efficient seed use on the available area, that can be obtained by reducing seeding losses will increase RBP, maximum biomass production and increases maximum profit. Our results suggest that this can be achieved by seeding homogeneously in low densities.

KW - mussels

KW - mussel culture

KW - bottom culture

KW - efficiency

KW - population dynamics

KW - culture techniques

KW - biomass production

KW - improvement

KW - shellfish culture

KW - aquaculture

KW - mossels

KW - mosselteelt

KW - bodemcultuur

KW - efficiëntie

KW - populatiedynamica

KW - kweektechnieken

KW - biomassa productie

KW - verbetering

KW - schaal- en schelpdierenteelt

KW - aquacultuur

U2 - 10.18174/404677

DO - 10.18174/404677

M3 - internal PhD, WU

SN - 9789463430869

PB - Wageningen University

CY - Wageningen

ER -