Genetic research reveals crucial need for fish habitat protections in Cyprus

In November 2017, I returned to Cyprus for the umpteenth time to continue investigating the anthropogenic impacts affecting the native Killifish (Aphanius cf. fasciatus) and its three respective habitats on the island; I connected with colleagues in the south, on both Cypriot and Sovereign British territory, as well as those based in the North. Since the conception of this project all of us on the steering committee at Freshwater Life Project have been keen to develop a bi-communal cooperation as these habitats are split on either side of the islands Greek and Turkish Cypriot territories and suffer many of the same threats.

Freshwater Life Project & S.B.A.A team members during habitat monitoring at Akrotiri Salt Lake

On this trip I had a new goal. It was not the first time the topic of genetics and the overall phylogeny of the islands three populations and their relationship with their other Mediterranean con-specifics had come to be mentioned, but after almost half a decade of observation, documenting and reporting on various issues affecting the islands only remaining native inland fish species, it was time to initiative something tangible.

Around ten months prior, following a conversation with Prof. Ferruccio Maltagliati, an ecology professor from the University of Pisa who had published work on the genetics of Aphanius fasciatus dating back to the late 1990’s, we agreed that it would be worthwhile collaborating to find out more about the identity of this under-researched Cypriot fish. The suspected outcome would tell us the relationship between the islands three populations of Killifish (one discovered by a team I led in 2015), and aim to eventually look at where they sit on the phylogenetic tree next to all of the other populations of A. fasciatus across the Mediterranean and beyond.

My task, after gaining permission from the relevant authorities was to collect genetic specimens from all three of the known Killifish habitats in Cyprus and have them shipped to Pisa for analysis by Professor Maltagliati’s team, so over two days I did exactly that.

Specimens of Aphanius cf. fasciatus from Cyprus collected on the Freshwater Life Project trip in 2017 and preserved in 90% alcohol in vials

Fast forward to June 2019 and having shipped the specimens to Italy shortly after their collection, we’re now at the point that the genetic research has been completed and has revealed some very interesting insights regarding not only the relationship of the Cypriot Killifish populations to each other, but also has demonstrated a remarkable correlation between population size (and subsequent genetic diversity) and the level of human impact on the habitats themselves.

The results of our genetic research (in Italian) which are being presented at the 50th anniversary event of the Italian Society of Marine Biology in Livorno, Italy this week.

An excerpt from our research translates to the following;

“The results of the present work highlighted different levels of genetic variability within the three populations analyzed. It is interesting that the population of the Akrotiri marsh, characterized by the highest value of haplotype diversity (Fig. 3, Tab. 1), is the only one of the three locations considered in this work to be subjected to measures of protection, as a Special Protection Area. The site of Morphou, which includes the population of A. fasciatus with the lowest genetic variability, is subject to the impact of various human activities. The site of Glapsides, with the population of A. fasciatus with medium variability genetics (Fig. 3, Tab. 1), is included in a medium-impact tourist area. It appears evident hence a close relationship between the level of human impact on the environment and genetic variability in the Cypriot populations of A. fasciatus. The other significant result obtained for A. fasciatus in Cyprus is the presence of deep genetic structuring. The three populations are in fact genetically differentiated, indicating the absence of gene flow”.

A second paragraph encourages the consideration of threat status from a local level as opposed to merely relying on global status, which currently indicates a lesser threat (A. fasciatus being listed as “Least Concern” by IUCN Red List due to its wide distribution) and perhaps being too generalised for such a broadly distributed species with multiple different threats with differing levels of impact in many locations; something I have also remarked on in the past.

“The fragmented distribution of A. fasciatus in Cyprus, the values ​​of genetic variability of the relatively low populations and the high genetic divergence present among the populations lead to conclude the following: despite the conservation status of this species a global level is considered good, at the island level the species is subject to a certain degree of threat. The conservation status of isolated or marginal populations in A. fasciatus is often precarious (Valdesalici et al., 2015) and molecular data can contribute to its evaluation, to the identification of microevolutionary processes in place and to the planning and implementation of conservation measures, as proposed by Maltagliati (2002)” 

I’d like to thank and congratulate our Italian colleagues from Università di Pisa for their dedication and on behalf of the Freshwater Life Project team wish them the best of luck at the congress this week.