This project has received funding from the European Union’s Horizon 2020 research and innovation programme under grant agreement Nº [753304]
This project has received funding from the European Union’s Horizon 2020 research and innovation programme under grant agreement Nº [753304]
The application of ecogeochemistry through Stable Isotopes Analysis (SIA) of animal tissues (i.e., inorganic and organic matter) has increasingly become a powerful tool used in ecological studies to elucidate fish movements patterns, habitat use, stock structure, trophic relationships, and even dietary pattern (Francis and Campana 2004, Kerr and Campana 2014). Bones, teeth, otoliths, fin spines and scales are calcium-derived hard structures in fish that incorporate trace elements and their isotopes during formation. Otolith is the preferred bony structure for microchemical and stable isotopes analysis, but it has also drawbacks. Otolith removal from live specimens requires sacrificing the specimen which is not allowed for endangered and/or rare species. Besides, their extraction greatly affects the apearance of commercially valuable fish species such as Atlantic bluefin tuna as it can diminish their market value. In addition, otoliths do not contain high enough concentrations of organic matter to allow for the reconstruction of food-web relationships via multiple stable isotopes. In this context, alternative hard tissues such as fin spines may also provide valuable chemical information and are particularly useful as a non-lethal and minimally invasive alternative to otolith in endangered or protected species. However, we currently have very limited knowledge of the feasibility of using other body parts such as fin spines for microchemical analysis.
SIFINS project overall aims to elucidate the feasibility of dorsal fin spines as a non-lethal and minimally invasive biogenic calcified structure alternative/complement to otoliths in retaining, into its cellular matrix, isotopic signatures of ecological value used as “environmental proxies" to reconstruct life and environmental histories of highly migratory tuna species, promoting its applications in fish ecology, fisheries management, and conservation issues.
In accomplish this, the project will focus at different and consecutive levels (specific objectives):
SIFINS offer a novel multispecies and interdisciplinary approach integrating the fields of bio-chronology and isotopes chemistry into large pelagic fish species population dynamics research providing (i) a better understanding of tuna migration patterns, trophic structure, timing of ontogenic shifts, and population-stock structure of tunas across their distribution range and (ii) an original perspective of SI chemistry research in fishes, particularly relevant to support the management of commercially valuable species under the EU Biodiversity and Fisheries policies priorities. The results of the project will promote EU excellence in marine fish population dynamics, likely to be of increasing interest in the future due to climate and human-induced change to marine environments.
SIFINS project overall aims to elucidate the feasibility of dorsal fin spines as a non-lethal and minimally invasive biogenic calcified structure alternative/complement to otoliths in retaining, into its cellular matrix, isotopic signatures of ecological value used as “environmental proxies" to reconstruct life and environmental histories of highly migratory tuna species, promoting its applications in fish ecology, fisheries management, and conservation issues.
In accomplish this, the project will focus at different and consecutive levels (specific objectives):
- To caracterize the structural cellular matrices of fin spine employing Raman-X, XPS, and FTIR techniques.
- To explore two micro-sampling techniques (i.e. Micromilling-isotope gas-ratio mass spectrometry (GRMS), and the secondary ion mass spectrometry (SIMS)) to assess the spatial (i.e. temporal) resolution and the analytical precision of the two methods for sampling sequential annual fin spine growth layers used for SIA purposes.
- To analyze the chronological variation of isotopic ratios of oxygen and carbon (d18O and d13C) across annualgrowth bands in fin spines to determine whether these isotopic ratios can be used to i) assing individuals to their capture locations, and ii) vary according to tª and/or salinity in a predictable manner as it has been hypothesized in otoliths.
- Giving an increased proportion of organic matter in fin spines, SIA (d13C and d15N) will be conducted on the sequential annual fin spine growth layers to infer shifts in the diet, movement and habitat use of tropical and temperate tuna species, gaining a better understanding of their population dinamics from a multi-proxies approach.
SIFINS offer a novel multispecies and interdisciplinary approach integrating the fields of bio-chronology and isotopes chemistry into large pelagic fish species population dynamics research providing (i) a better understanding of tuna migration patterns, trophic structure, timing of ontogenic shifts, and population-stock structure of tunas across their distribution range and (ii) an original perspective of SI chemistry research in fishes, particularly relevant to support the management of commercially valuable species under the EU Biodiversity and Fisheries policies priorities. The results of the project will promote EU excellence in marine fish population dynamics, likely to be of increasing interest in the future due to climate and human-induced change to marine environments.