LIFE+ LIMNOPIRINEUS: CONSERVATION OF AQUATIC HABITATS AND SPECIES IN HIGH MOUNTAINS OF THE PYRENEES LIFE+ LIMNOPIRINEUS: CONSERVATION OF AQUATIC HABITATS AND SPECIES IN HIGH MOUNTAINS OF THE PYRENEES COORDINATION Empar Carrillo Josep Maria Ninot Teresa Buchaca Marc Ventura GRAPHIC DESIGN creativadisseny.cat PRINT GoPrinters ISBN 978-84-18199-17-2 Coordination: Associated beneficiaries: Co-financier: ~ Lake Delluí Nord ~ Removal of introduced fish as a restoration 06 measure in high mountain lakes POU-ROVIRA et. al Changes in lakes after the reduction of fish 28 densities BUCHACA et. al Rapid recovery of amphibian populations 42 in eight high mountain lakes linked to the eradication of exotic fish MIRÓ et. al Alterations and changes that affect the 54 conservation of the biodiversity of Estanho de Vilac (Aran Valley) CARRILLO et. al The Trescuro mire system: how sharp environ- 72 mental gradients and climatic events constrain the local distribution of plant community types COLOMER et. al Habitats of Community Interest in the mires of Aigüestortes and Alt Pallars: distribution, 84 impacts and threats PÉREZ-HAASE et. al Evaluation of the perception of high mountain aquatic ecosystems by visitors and nearby 100 residents of the National Park ROMAGOSA et. al Conservation status of the Pyrenean sculpin 108 (Cottus hispaniolensis) in the Aran Valley ROCASPANA et. al Recovery of mires at the reservoir of font 114 grossa, Espot NINOT et. al CONSERVATION STATUS OF THE PYRENEAN SCULPIN (COTTUS HISPANIOLENSIS) IN THE ARAN VALLEY Rafel ROCASPANA (1), Enric APARICIO (2), Quim POU-ROVIRA (3), Eloi CRUSET (3), Jenny CANER (4), Federica LUCATI (4), Teresa BUCHACA (4), Ivan AFONSO (5) & Marc VENTURA (4) 1. GESNA Estudis Ambientals, 25240 Linyola, Catalonia, Spain. 2. GRECO, Institute of Aquatic Ecology, University of Girona, 17071 Girona, Catalonia, Spain. 3. Sorelló, estudis al medi aquàtic. Parc Científic de la UdG, 17300, Girona, Catalonia, Spain. 4. Integrative Freshwater Ecology group, Centre for Advanced Studies of Blanes (CEAB-CSIC). Accés Cala St. Francesc, 14, 17300, Blanes, Girona, Catalonia, Spain. 5. Conselh Geneau d’Aran. Passeg dera Libertat, 16, 25530 Vielha, Catalonia, Spain. — • — ABSTRACT strong flash flood in June 2013 in the Garonne and its tributaries further debilitated the precarious status of the The Pyrenean sculpin (Cottus hispaniolensis) is one of the Pyrenean sculpin (Rocaspana & Aparicio, 2017). For this most threatened freshwater fish in Catalonia and Spain. reason, the species is currently listed as endangered on Its status in the Aran Valley drastically deteriorated as a the Catalonia and Spanish red lists of Endangered Species result of the floods of 2013, to the point of reaching its (Doadrio et al., 2011; Aparicio et al., 2016). Just like Cot- practical disappearance. Since then, their populations tus gobio (former synonym), it is also included in Annex have been progressively recovering, with a slow increase II of the European Directive on habitats 92/43. EEC. in their average density and occupied localities. In part, In 2004, a first global diagnosis was made of the this recovery has been produced thanks to actions framed conservation status of the Pyrenean sculpin population within the LIFE+ LimnoPirineus project, which have in the Aran Valley (Rocaspana et al., 2004). Subsequently, been specifically designed for the recovery of this spe- periodic inventories were carried out that provided a cies within the Natura 2000 network space “Aigüestortes” guide to its evolution. However, the conditions caused by (ES0000022). the strong floods of June 2013 led to the start of various diagnostic projects and conservation actions for the Pyrenean sculpin (Aran, 2014a, 2014b) that consisted of population censuses, the analysis of the degree of affectation of the flood and the evolution of populations INTRODUCTION throughout the year and a half following the flood. Alongside these latest studies, the LimnoPirineus he Pyrenean sculpin (Cottus hispaniolensis project (LIFE+ Natura LIFE13 NAT/ES/001210) was Bǎcescu and Bǎcescu-Meşter) belongs to the initiated to improve the conservation status of species Cottidae family (O. Scorpaeniformes) which and aquatic habitats of European interest in the Pyrenean is made up of freshwater benthic fish species high mountains. This project had the Pyrenean sculpin as that mainly inhabit cold and oxygenated riv- one of its target species, planning various actions focused Ters and lakes (Tomlinson & Perrow, 2003). It is endemic on the improvement and conservation of this species to the basin of the Garonne River (southwest France and within the Natura 2000 “Aigüestortes” network space Aran valley, northern Catalonia) and is restricted to its headwaters (Freyhof et al., 2005). The Garonne fish com- | 2019 munity in the Aran Valley is formed almost exclusively by Pyrenean sculpin and brown trout (Salmo trutta L. 1758), although minnow (Phoxinus sp.) and Alpine char (Salve- linus umbla L 1758) have also been introduced in some reservoirs and high mountain lakes (Aparicio, 2015). The LIFE+LIMNOPIRINEUS Pyrenean sculpin was historically distributed in contin- uous populations along the main course of the Garonne River and in the lower parts of some tributaries (Sostoa et al., 1990; Doadrio et al., 2011). These populations have report technical experienced strong regression in recent decades (Doad- Figure 1. Image of a Pyrenean sculpin (Cottus hispanoliensis) indi- vidual from the river Garonne in the Aran valley. rio et al., 2011; Sousa-Santos et al., 2014). In addition, a 109 ROCASPANA et. al (ES0000022). Among these actions, the most prominent The percentage of the different mesohabitats present was the consolidation of two population nuclei in the (pools, runs and riffles) were also recorded. A multiple Ruda and Aiguamog rivers by releasing specimens from linear regression (Stepwise multiple linear regression) was populations in good condition located in other sectors used to study the effect of habitat (substrate composition, of the Aran Valley. These translocations also had to mesohabitat) on Pyrenean sculpin density. For statistical contribute to reducing the effects of genetic isolation analyses, fish densities were transformed into log10 (x + suffered by these population nuclei located within the 1) and the percentage data was standardised by a square “Aigüestortes” area. root transformation. At the same time, regular monitoring of all the valley The translocations of Pyrenean sculpin specimens populations was planned in order to determine their for the reinforcement, improvement and consolidation status and trends. In addition, this monitoring has allowed of the populations located within the Natura 2000 increased knowledge of its biological and ecological traits. “Aigüestortes” network space, they had to be delayed in relation to the initial plans, due to the precarious state of all the populations of the Aran valley. But they were finally carried out between 2017 and 2018 (see Table METHODS 2). These releases were carried out using partly wild specimens directly from the natural environment and The monitoring of the Pyrenean sculpin populations partly specimens from a captive breeding program that consisted of sampling at 16 stations from 2015 to 2018. has been developed alongside the LIFE+ LimnoPirineus The sampling stations (80 to 200 m long) were selected made by ADEFFA. according to the information of the historical distribution We were able to genetically characterize 203 of the of the Pyrenean sculpin, i.e. the main course of the captured individuals. By microsatellite analysis we were Garonne river and the lower parts of its main tributaries able to determine the distribution of the different genetic (Figure 1). Fish were captured by two pass electrofishing lineages throughout the Garonne course in the Aran (pulsating direct current). All fish captured were valley. Genomic DNA was extracted using the Hotshot anaesthetised with clove oil, identified at the species level, method (Montero-Pau et al. 2008), in a total volume of counted, measured (fork length FL, mm), weighed (g) and 100 ml. Each fish was genotyped for 24 microsatellite loci released at the same catch site. Abundance (N) of fish was selected from the literature: Cott150, Cott113, Cott144, 2 -1 estimated as N = C1 (C1 - C2) , where C1 is the number Cott164, Cot158, Cott153, Cott138, Cott105, Cott152, of fish caught in the first pass and2 C is the number of Cott173, Cott112, Cott130, Cot132, Cott154, Cott119, individuals caught in the second. The probability of Cott118, Cott170, Cott163, Cott100, Cott127, Cott146, -1 capture was calculated as p = (C1 - C2) (C1) (Seber and Cott128, Cott149, Cott175 (Nolte et al. 2005). Forward Le Cren, 1967). Fish density (individuals · ha-1) was primers were labelled using four different fluorescent dyes calculated by dividing the estimated number of fish by the and divided into three multiplexes. PCR amplification sampled area. After sampling the fish, the composition of was performed in a reaction volume of 11 ml containing the riverbed substrate was visually estimated according 1 ml of extracted DNA and 5.5 ml of Qiagen Multiplex to a modified Wentworth scale: boulder (particle size> PCR mastermix and primers. PCR amplification was 256 mm), cobble (> 64-256 mm), pebble (> 16-64 mm), performed with the Applied Biosystems 2720 thermal gravel (> 2-16 mm), sand (0.1-2 mm) and silt (<0.1 mm). cycler. The PCR cycle protocol for all three multiplexes Figure 2. Map of the Garonne