Life Among the Cod: Sessile Communities on Artificial Reefs in the Baltic Sea

Clara Palmer; Lou Cloix; Josefine Larsson; Hampus  Söderberg; Hannes Kindeberg; Anders Tengberg; Anders Persson; Peter  Ljungberg; Helena L.  Filipsson

Abstract

The Baltic Sea has a generally low biodiversity, and several species are declining due to high anthropogenic pressure. One example is the Baltic Sea cod (Gadus morhua, L.), the cod has decreased since the 1980s in both biomass and abundance. One potential solution to increase the cod population is to improve settling ground and provide shelter for juveniles in artificial reefs. The
Hanö Cod Reef project aims to increase the carrying capacity of cod in the southern Baltic Sea. The man-made structures could however benefit more than cod and an increase in settling ground for example epiphytic organisms could lead to a positive bottom-up effect on the ecosystem. In this study we aimed to investigate the colonization of epiphytic organisms on Hanö Bay cod reef over
time. In February 2023 14 reefs were installed and an additional 20 reefs in 2024. The reefs were documented using an underwater ROV. The video footage was analyzed and the epiphytic organisms were categorized into groups of: blue mussel (Mytilus edulis), Hydroids (life stage of Hydrozoa spp.), Barnacles (Amphibalanus improvises), Bryozoa spp., Rhodophyta spp., Chlorophyta spp. and “No organisms”. The result showed that blue mussels are the first to colonize the reefs while macroalgae (Rhodophyta spp. and Chlorophyta spp.) had the slowest colonization rate. Blue mussel, both as migrating older individuals and as settlement by new individuals increased the competition for space. Bryozoa spp. was not detected until March 2024 emphasizing the importance of time for high biodiversity to accumulate. These findings suggest that, beyond supporting cod populations, the artificial reefs in Hanö Bay provide valuable habitat for a variety of sessile organisms, which in turn may contribute to increased biodiversity and ecosystem complexity in the area. As colonization
progresses, the reefs could attract an even wider array of species, potentially creating new niches and enhancing the resilience of local marine life.

Original language	English
Publication status	Published - 2024
Event	Swedish Society for Marine Sciences - Marine Research Days 2024: Building bridges across marine disciplines - Linneaus University , Kalmar, Sweden Duration: 2024 Nov 26 → 2024 Nov 28 https://shf.se/en/havsforskningsdagarna/havsforskningsdagarna-2024/

Conference

Conference	Swedish Society for Marine Sciences - Marine Research Days 2024
Country/Territory	Sweden
City	Kalmar
Period	2024/11/26 → 2024/11/28
Internet address	https://shf.se/en/havsforskningsdagarna/havsforskningsdagarna-2024/

Bibliographical note

Sammanhängande studie: Palmer, Clara, 2024: Other tenants then cod? – A study over sessile organisms’ composition on artificial reefs in Hanö Bay.
http://lup.lub.lu.se/student-papers/record/9155164

UN SDGs

This output contributes to the following UN Sustainable Development Goals (SDGs)

SDG 14 Life Below Water

Subject classification (UKÄ)

Environmental Sciences
Fish and Aquacultural Science (including Fish farming, Fish Genetics, Fish Ethology)
Ecology (including Biodiversity Conservation)

Access to Document

https://shf.se/public_html/wp-content/uploads/SHF-all-abstracts_2024_11_20.pdfLicence: Unspecified

1 Finished
1 Active

Hanö Torskrev
Filipsson, H. (PI), Persson, A. (PI), Larsson, J. (PI), Söderberg, H. (CoPI), Kindeberg, H. (CoPI), Tengberg, A. (Researcher) & Ljungberg, P. (Researcher)
2022/03/01 → …
Project: Research
Återhämta torskbestånd med hjälp av artificiella rev
Persson, A. (PI)
Stiftelsen J. Gust. Richerts Minne, Familjen Kamprads Stiftelse
2024/09/01 → 2025/08/30
Project: Research

Swedish Society for Marine Sciences - Marine Research Days 2024
Filipsson, H. (Presenter)
2024 Nov 26 → 2024 Nov 28
Activity: Participating in or organising an event › Participation in conference
Lou Cloix
Filipsson, H. (Host)
2024 Apr 2 → 2024 Jun 6
Activity: Hosting a visitor

Cite this

Palmer, C., Cloix, L., Larsson, J., Söderberg, H., Kindeberg, H., Tengberg, A., Persson, A., Ljungberg, P., & Filipsson, H. L. (2024). Life Among the Cod: Sessile Communities on Artificial Reefs in the Baltic Sea. Abstract from Swedish Society for Marine Sciences - Marine Research Days 2024, Kalmar, Sweden. https://shf.se/public_html/wp-content/uploads/SHF-all-abstracts_2024_11_20.pdf

@conference{e082d34065e447279b6505de57be0ade,

title = "Life Among the Cod: Sessile Communities on Artificial Reefs in the Baltic Sea",

abstract = "The Baltic Sea has a generally low biodiversity, and several species are declining due to high anthropogenic pressure. One example is the Baltic Sea cod (Gadus morhua, L.), the cod has decreased since the 1980s in both biomass and abundance. One potential solution to increase the cod population is to improve settling ground and provide shelter for juveniles in artificial reefs. The Han{\"o} Cod Reef project aims to increase the carrying capacity of cod in the southern Baltic Sea. The man-made structures could however benefit more than cod and an increase in settling ground for example epiphytic organisms could lead to a positive bottom-up effect on the ecosystem. In this study we aimed to investigate the colonization of epiphytic organisms on Han{\"o} Bay cod reef over time. In February 2023 14 reefs were installed and an additional 20 reefs in 2024. The reefs were documented using an underwater ROV. The video footage was analyzed and the epiphytic organisms were categorized into groups of: blue mussel (Mytilus edulis), Hydroids (life stage of Hydrozoa spp.), Barnacles (Amphibalanus improvises), Bryozoa spp., Rhodophyta spp., Chlorophyta spp. and “No organisms”. The result showed that blue mussels are the first to colonize the reefs while macroalgae (Rhodophyta spp. and Chlorophyta spp.) had the slowest colonization rate. Blue mussel, both as migrating older individuals and as settlement by new individuals increased the competition for space. Bryozoa spp. was not detected until March 2024 emphasizing the importance of time for high biodiversity to accumulate. These findings suggest that, beyond supporting cod populations, the artificial reefs in Han{\"o} Bay provide valuable habitat for a variety of sessile organisms, which in turn may contribute to increased biodiversity and ecosystem complexity in the area. As colonization progresses, the reefs could attract an even wider array of species, potentially creating new niches and enhancing the resilience of local marine life.",

author = "Clara Palmer and Lou Cloix and Josefine Larsson and Hampus S{\"o}derberg and Hannes Kindeberg and Anders Tengberg and Anders Persson and Peter Ljungberg and Filipsson, \{Helena L.\}",

note = "Sammanh{\"a}ngande studie: Palmer, Clara, 2024: Other tenants then cod? – A study over sessile organisms{\textquoteright} composition on artificial reefs in Han{\"o} Bay. http://lup.lub.lu.se/student-papers/record/9155164; Swedish Society for Marine Sciences - Marine Research Days 2024 : Building bridges across marine disciplines ; Conference date: 26-11-2024 Through 28-11-2024",

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language = "English",

url = "https://shf.se/en/havsforskningsdagarna/havsforskningsdagarna-2024/",

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Palmer, C, Cloix, L, Larsson, J, Söderberg, H, Kindeberg, H, Tengberg, A, Persson, A, Ljungberg, P & Filipsson, HL 2024, 'Life Among the Cod: Sessile Communities on Artificial Reefs in the Baltic Sea', Swedish Society for Marine Sciences - Marine Research Days 2024, Kalmar, Sweden, 2024/11/26 - 2024/11/28. <https://shf.se/public_html/wp-content/uploads/SHF-all-abstracts_2024_11_20.pdf>

TY - CONF

T1 - Life Among the Cod: Sessile Communities on Artificial Reefs in the Baltic Sea

AU - Palmer, Clara

AU - Cloix, Lou

AU - Larsson, Josefine

AU - Söderberg, Hampus

AU - Kindeberg, Hannes

AU - Tengberg, Anders

AU - Persson, Anders

AU - Ljungberg, Peter

AU - Filipsson, Helena L.

N1 - Sammanhängande studie: Palmer, Clara, 2024: Other tenants then cod? – A study over sessile organisms’ composition on artificial reefs in Hanö Bay. http://lup.lub.lu.se/student-papers/record/9155164

PY - 2024

Y1 - 2024

N2 - The Baltic Sea has a generally low biodiversity, and several species are declining due to high anthropogenic pressure. One example is the Baltic Sea cod (Gadus morhua, L.), the cod has decreased since the 1980s in both biomass and abundance. One potential solution to increase the cod population is to improve settling ground and provide shelter for juveniles in artificial reefs. The Hanö Cod Reef project aims to increase the carrying capacity of cod in the southern Baltic Sea. The man-made structures could however benefit more than cod and an increase in settling ground for example epiphytic organisms could lead to a positive bottom-up effect on the ecosystem. In this study we aimed to investigate the colonization of epiphytic organisms on Hanö Bay cod reef over time. In February 2023 14 reefs were installed and an additional 20 reefs in 2024. The reefs were documented using an underwater ROV. The video footage was analyzed and the epiphytic organisms were categorized into groups of: blue mussel (Mytilus edulis), Hydroids (life stage of Hydrozoa spp.), Barnacles (Amphibalanus improvises), Bryozoa spp., Rhodophyta spp., Chlorophyta spp. and “No organisms”. The result showed that blue mussels are the first to colonize the reefs while macroalgae (Rhodophyta spp. and Chlorophyta spp.) had the slowest colonization rate. Blue mussel, both as migrating older individuals and as settlement by new individuals increased the competition for space. Bryozoa spp. was not detected until March 2024 emphasizing the importance of time for high biodiversity to accumulate. These findings suggest that, beyond supporting cod populations, the artificial reefs in Hanö Bay provide valuable habitat for a variety of sessile organisms, which in turn may contribute to increased biodiversity and ecosystem complexity in the area. As colonization progresses, the reefs could attract an even wider array of species, potentially creating new niches and enhancing the resilience of local marine life.

AB - The Baltic Sea has a generally low biodiversity, and several species are declining due to high anthropogenic pressure. One example is the Baltic Sea cod (Gadus morhua, L.), the cod has decreased since the 1980s in both biomass and abundance. One potential solution to increase the cod population is to improve settling ground and provide shelter for juveniles in artificial reefs. The Hanö Cod Reef project aims to increase the carrying capacity of cod in the southern Baltic Sea. The man-made structures could however benefit more than cod and an increase in settling ground for example epiphytic organisms could lead to a positive bottom-up effect on the ecosystem. In this study we aimed to investigate the colonization of epiphytic organisms on Hanö Bay cod reef over time. In February 2023 14 reefs were installed and an additional 20 reefs in 2024. The reefs were documented using an underwater ROV. The video footage was analyzed and the epiphytic organisms were categorized into groups of: blue mussel (Mytilus edulis), Hydroids (life stage of Hydrozoa spp.), Barnacles (Amphibalanus improvises), Bryozoa spp., Rhodophyta spp., Chlorophyta spp. and “No organisms”. The result showed that blue mussels are the first to colonize the reefs while macroalgae (Rhodophyta spp. and Chlorophyta spp.) had the slowest colonization rate. Blue mussel, both as migrating older individuals and as settlement by new individuals increased the competition for space. Bryozoa spp. was not detected until March 2024 emphasizing the importance of time for high biodiversity to accumulate. These findings suggest that, beyond supporting cod populations, the artificial reefs in Hanö Bay provide valuable habitat for a variety of sessile organisms, which in turn may contribute to increased biodiversity and ecosystem complexity in the area. As colonization progresses, the reefs could attract an even wider array of species, potentially creating new niches and enhancing the resilience of local marine life.

M3 - Abstract

T2 - Swedish Society for Marine Sciences - Marine Research Days 2024

Y2 - 26 November 2024 through 28 November 2024

ER -

Life Among the Cod: Sessile Communities on Artificial Reefs in the Baltic Sea

Abstract

Conference

Bibliographical note

UN SDGs

Subject classification (UKÄ)

Access to Document

Fingerprint

Projects

Hanö Torskrev

Återhämta torskbestånd med hjälp av artificiella rev

Activities

Swedish Society for Marine Sciences - Marine Research Days 2024

Lou Cloix

Cite this