Ancient Isotopes Reveal Pre-Lessepsian Invasions and Recent Overfishing in the Levant: Insights from Holocene Fish Remains

In our latest paper in the journal Mediterranean Marine Science, “Pre-Lessepsian isotopic niche spaces: using paleoecological proxies to assess the impact of ongoing bioinvasions on fishes in the eastern Mediterranean Sea” we use stable isotope data derived from fish bones from three Middle to Late Holocene Levantine archaeological sites to explore trophodynamics and foraging ecologies prior to Lessepsian invasions and the overfishing seen in more recent times. Within this paper are 137 new carbon (δ13C) and nitrogen (δ15N) values for ancient eastern Mediterranean fish (great for folks also looking to construct isotopic baselines for palaeodietary studies).

We have analysed this data using an isotopic niche space approach to compare ancient and modern data sets (modern data from Fanelli et al. (2015)). The main findings are:
1. Our historic baseline for foraging ecology indicates that modern indigenous Mediterranean fish have expanded their trophic niches beyond what was seen prior to Lessepsian invasions.
2. In a more ‘pristine’ ecosystem, middle and lower trophic levels have the highest degree of overlap in isotopic niche spaces, suggesting greater levels of competition for trophic resources.
3. An ontogenetic shift in foraging ecology to a more specialised diet with increasing size for ancient groupers (Epinephelidae).

Read the article HERE

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