Bioavailable organic matter in seston modulating differential absorption rates by mussels

Autor: Uxío Labarta, María José Fernández-Reiriz, Diana Zúñiga
Přispěvatelé: Ministerio de Ciencia e Innovación (España), Consejo Superior de Investigaciones Científicas (España), Xunta de Galicia, European Commission
Rok vydání: 2017
Předmět:
Zdroj: Aquaculture. 479:161-168
ISSN: 0044-8486
DOI: 10.1016/j.aquaculture.2017.05.038
Popis: 8 pages, 5 figures, 3 tables
This study aims to analyze the seasonal variations in seston biochemical compounds (biopolymeric organic carbon (C-BPC), i.e. the sum of proteins, carbohydrates and lipids) in order to infer the bioavailable organic fraction controlling food absorption by mussels cultured in a Galician Ria. Different proxies for high-quality food (including C-BPC) vs. energy absorbed by mussels were explored to elucidate the validity of each proxy in an embayment of intensive mussel cultivation. Our results showed a strong correlation between C-BPC and both the organic fraction (f) and the carbon equivalent of Chloropyll-a (C-Chl-a) in the seston. This fact points to variations in C-BPC (predominantly composed of proteins) are strongly linked with the phytoplankton fluctuations, which in turn are modulated by the seasonal upwelling regime. Maximum total energy absorbed by mussels (about 97%) occurred during the spring phytoplankton bloom, when high-quality organic carbon (high C-BPC) dominated the seston. Minimum energy absorbed (56%) occurred during winter, when continental runoff and local resuspension of surface sediments reintroduce into the water column more refractory organic compounds not favourable to the mussel diet. These results allowed us to establish that parameters such as f, C-Chl-a, and C-BPC have close correlations with physiological responses in mussels and could be used as proxies for food quality. Nonetheless, the use of these high-quality food estimations should be considered according to particularities of each ecosystem.
This study was supported by the project Ecological Sustainability of Suspended Mussel Aquaculture (ESSMA) Spanish Ministry of Science and Innovation (ACI2008-0e780) and by the project FIGEBIV (AGL2013-49144-C3-2-R). D.Z. was funded by a postdoctoral fellowship (Jae-Doc) from the CSIC and a postdoctoral fellowship from Xunta de Galicia 2011-2015 (Plan 12C).
Databáze: OpenAIRE
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