A critical transition zone for fan mussels (Pinna nobilis): The Dardanelles as a barrier against mass mortality

Uğur Karadurmuş; Mustafa Sarı; Mustafa Akkuş

doi:10.12714/egejfas.42.3.03

EN TR

A critical transition zone for fan mussels (Pinna nobilis): The Dardanelles as a barrier against mass mortality

Abstract

Pinna nobilis (fan mussel) is facing mass mortality event (MME) across the Mediterranean Sea due to a combination of several factors, including the pathogen Haplosporidium pinnae and other associated pathogens, as well as climate change, invasive species, habitat degradation, boat anchoring, exploitation, and disruptions in the food web. Despite a MME associated with mucilage event, the Sea of Marmara (SoM) still hosts high-density populations of fan mussels. Despite the severe impact across the Mediterranean, the persistence of populations in the SoM has raised questions about the factors contributing to their survival. This study investigates the role of salinity patterns in the survival of fan mussel populations in the Dardanelles, a critical transition zone between the Aegean Sea and the SoM. The objective is to determine whether the unique salinity patterns in the Dardanelles provide a protective effect against the MME. Underwater observations were conducted at 23 sites in the Dardanelles in August 2024, and salinity patterns were analysed. The results reveal a significant increase in mortality rates as salinity rises above 24.9 psu, with nearly 100% mortality observed at the higher salinity levels. These findings, synthesized with existing literature, suggest that the salinity patterns in the Dardanelles play a crucial role in the survival of fan mussel by either preventing the pathogen from entering the SoM or mitigating its lethal effects. The Dardanelles, which serves as a critical transition point by supporting the survival of fan mussel populations, should be the focus of additional scientific research.

Keywords

Pinalar (Pinna nobilis) için kritik bir geçiş bölgesi: Kitlesel ölümlere karşı bir bariyer olarak Çanakkale Boğazı

Öz

Pinna nobilis (Pina), Haplosporidium pinnae patojeni ve diğer ilişkili patojenlerin etkisiyle kitlesel ölüm olayı (MME) ile karşı karşıyadır, bunun yanı sıra iklim değişikliği, istilacı türler, habitat bozulması, çapalama, aşırı avcılık ve besin ağındaki bozulmalar da dahil olmak üzere çeşitli faktörlerin birleşimi nedeniyle Akdeniz boyunca kritik düzeyde tehlike altındadır. Müsilaj olayıyla ilişkilendirilen bir MME'ye rağmen, Marmara Denizi (SoM) hala yüksek yoğunluklu pina popülasyonlarına ev sahipliği yapmaktadır. Akdeniz'deki şiddetli etkiye rağmen, SoM’deki popülasyonların devam etmesi, hayatta kalmalarına katkıda bulunan faktörler hakkında soruları gündeme getirmiştir. Bu çalışma, Ege Denizi ile SoM arasında kritik bir geçiş bölgesi olan Çanakkale Boğazı'ndaki pina popülasyonlarının hayatta kalmasında tuzluluğun rolünü araştırmaktadır. Bu çalışma, Çanakkale Boğazı'ndaki benzersiz tuzluluk değerlerinin MME'ye karşı koruyucu bir etki sağlayıp sağlamadığını belirlemeyi amaçlamaktadır. Ağustos 2024'te Çanakkale Boğazı'ndaki 23 noktada su altı gözlemleri yapılmış ve tuzluluk modelleri analiz edilmiştir. Sonuçlar, tuzluluk değerlerinin 24,9 psu'nun üzerine çıktığında pinaların ölüm oranlarında önemli bir artış olduğunu ve daha yüksek tuzluluk seviyelerinde neredeyse %100 ölüm oranının gözlemlendiğini ortaya koymaktadır. Mevcut literatürle sentezlenen bu bulgular, Çanakkale Boğazı'ndaki tuzluluk değerlerinin, patojenin SoM'ne girmesini önleyerek veya ölümcül etkilerini azaltarak yelpaze midyesinin hayatta kalmasında önemli bir rol oynadığını düşündürmektedir. Pina popülasyonlarının hayatta kalmasını destekleyerek kritik bir geçiş noktası görevi gören Çanakkale Boğazı, ek bilimsel araştırmaların odak noktası olmalıdır.

Anahtar Kelimeler

Supporting Institution

The Directorate General of Protection of Natural Assets supported this work under the Republic of Türkiye Ministry of Environment, Urbanization and Climate Change under the name “Protection and monitoring fan mussel in the Sea of Marmara (MAR-PİNA) Project”.

Project Number

MAR-PİNA

Ethical Statement

No fan mussel was landed during the study. Underwater clinical examinations were performed using non-destructive methods. Therefore, formal approval is not required for this study.

Thanks

The authors thank to professional divers Birkan Yüksel and Güven Kurtuluş Arabacı who voluntarily accompanied the dives throughout the fieldwork. Also, we would like to thank the Umut Pina project, which was previously carried out with the support of Bandırma Onyedi Eylül University Scientific Projects Directorate and Borusan Holding, for the infrastructure utilized during this study.

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Details

Primary Language

English

Subjects

Ecology (Other)

Journal Section

Research Article

Authors

Uğur Karadurmuş ^*
0000-0002-5827-0404
Türkiye

Mustafa Sarı
0000-0003-2733-3254
Türkiye

Mustafa Akkuş
0000-0002-8900-9495
Türkiye

Early Pub Date

September 1, 2025

Publication Date

September 10, 2025

Submission Date

March 19, 2025

Acceptance Date

July 16, 2025

Published in Issue

Year 1970 Volume: 42 Number: 3

DOI

https://doi.org/10.12714/egejfas.42.3.03

IZ

https://izlik.org/JA68JC46LR

Cite

RIS / Bibtex

APA

Karadurmuş, U., Sarı, M., & Akkuş, M. (2025). A critical transition zone for fan mussels (Pinna nobilis): The Dardanelles as a barrier against mass mortality. Ege Journal of Fisheries and Aquatic Sciences, 42(3), 213-221. https://doi.org/10.12714/egejfas.42.3.03