Opportunities for rehabilitation of the populations of indigenous Danubian species in Hungary

Béla Halasi-Kovács – Jenő Káldy – Gyula Kovács – Gyöngyvér Fazekas – András Rónyai

Fotó: Lehoczky István

Regional Conference on River Habitat Restoration for Inland Fisheries in the Danube River Basin and Adjacent areas

13-15 November 2018, Bucharest, Romania Utilization of natural surface waters in Hungary

• The middle section of Danube drainage belong to Hungary has diverse fishfauna with 89 species. • Commercial fisheries banned from 2016 by the Act of Fisheries Management. • More than 400 000 anglers in 2017. • The area of the registered (utilized) waterbodies under fiheries management: 160 559 ha (2017). • The amount of caught fishes are 5 607 tonnes in 2017. • 4 sturgeon species are protected by the Act of Nature Conservation. • Sterlet may capture restricted way if presence certain conditions (amount: 0,7 t in 2017). Sturgeon species in Hungary

Indigenous species Non-indigenous species • (Great sturgeon) ( huso) • Siberian sturgeon ( baeri) • Stellate sturgeon (Acipenser stellatus) • (Polyodon spathula) • Russian sturgeon (Acipenser gueldenstaedtii) • Ship sturgeon (Acipenser nudiventris) • Sterlet (Acpenser ruthenus) Latest occurrence data of native sturgeon species from the Hungarian section of Danube drainage

• Beluga: 1987 – Danube (Paks) • Stellate sturgeon : 1965 – Danube (Mohács); Tisza (Hódmezővásárhely) • Russian sturgeon : 1999 – Danube (Dunakiliti, Gönyű) • Ship sturgeon: 2010 – Danube (Mohács) • Sterlet: the hilly sections of large rivers are still regular Validated occurrences of the resident sturgeon species from the Hungarian section of the Danube drainage in the last 25 years Russian sturgeon Ship sturgeon Sterlet 1992 – Danube at Dunaszekcső and 2005 – Mura at Murakeresztúr Regular, but decreasing occurrences Mohács from the hilly sections of large rivers 1997 – Danube at Dunakiliti 2010 – Danube at Mohács

1998 – Danube at Ercsi and Fajsz

1999 – Danube at Gönyű and Dunakiliti

Catches of Acipenser ruthenus 40

35

30

25

20

Tonnes 15

10

5

0 Halasi-Kovács & Váradi 2012 Validated occurrences of the resident sturgeon species from the Middle section of the Danube

Hybrids from middle section of the Danube:

• Acipenser baeri x Acipenser ruthenus • Acipenser ruthenus x Acipenser gueldenstaedtii Nature conservational status of the sturgeon species

• All species are in the IUCN Red List • Sterlet: vulnerable • Other species: critically endangered Activities for rehabilitation of sturgeon species in Hungary by HAKI

International Domestic activities cooperations

Basic research Restocking actions

Applied research Ex-situ gene bank

Conservation plans Research activities for rehabilitation of sturgeon species in HAKI

• Population-genetics research with sterlet to determine the genetic diversity of species in the Hungarian section of Danube drainage. The results contribute either to broodstock management and design of restocking programs. • Examination of stress parameters of sterlet. The tested parameters include the determination of natural immune responses, bacterial resistance to infection, hypoxia tolerance, salt tolerance as well as crowding stress. The importance of the research that intensive production and restocking to natural aquatic habitats often demand different, sometimes contradictory requirements. • Research of environmental factors (temperature, light conditions, salinity) that determine the sex of , being investigating the effects of climate change on the natural populations of the Danube sturgeons. • Investigation of occurrence of rare sturgeon species, utilize the environmental DNA analyzis. Sturgeon species conservation programs

• Sterlet species program – Ministry of Agriculture - NAIK HAKI (2016) • Ship sturgeon species program – Ministry of Agriculture - NAIK HAKI (2018-2020) • Russian sturgeon species program - Ministry of Agriculture - NAIK HAKI (2018-2020) Scheme of gene banking to preserve the endangered sturgeon species Conservation

In vivo In vitro live cryo-preserved materials • semen • oocytes • embryos • somatic cells in situ ex situ

in the natural habitat and in an artificial environment (zoo, production environment research institute, farm) Juvenile restocking Establishment of Ex-situ sturgeon gene bank in NAIK HAKI

• Established in 1988, first the sterlet was collected from the Hungarian rivers to supply the necessity of sterlet fingerlings in aquaculture research. • Later the gene bank expanded with other species: Russian sturgeon, Stellate sturgeon, Beluga, Siberian sturgeon, Paddle fish. • Today the sturgeon gene bank is the basis of rehabilitation programs. • Maintaining and developing of the gene bank is supported by the Ministry of Agriculture. Utilization of genetic resources of the gene bank by restocking actions

• The gene bank of NAIK HAKI provide the genetic material for the National Restocking Program on Sterlet in 2016 financed by the Ministry of Agriculture. • 18.000 sterlet fingerling was stocked to Danube and Tisza rivers at 6 locations. • Total weight of the restocked sterlet stock was 7 tons with 300 – 400 g average body weight. • Monitoring of occurrence of the stocked fish by tags. Sterlet restocking actions in 2018

• 400 juvenile sterlets into the Danube. • 600 juvenile sterlets into the Körös river. • 800 juvenile sterlets into the Tisza river. Measures project: Managing and restoring aquatic ecological corridors for migratory fish species in the Danube river basin

Main aims:

• To preserve the aquatic ecological corridors used by migratory fish species on the Danube River network.

• For international relations based on new results is being prepared to protect the habitat of migratory fish species.

• The entire river basin is intended to preserve the Danube catchment of migratory species as a flagship vessel and to strengthen its stocks by ex-situ gene banks and repatriations.

Project co-funded by European Union funds (ERDF, IPA, ENI) http://www.interreg-danube.eu/approved-projects/measures Step forward to strengthen the populations of Danube sturgeon species

• Distinguish short- and long-term conservational actions. • Development of operative tools to achieve and exceed at least the critical population sizes. • Coordinated sturgeon species ex-situ gene banking. • Restocking programs along the Danube river drainage. • Transnational cooperation need! THANK YOU FOR YOUR ATTENTION!