Stimulating sturgeon conservation and rehabilitation measures in Turkey: an overview on major projects (2006-2009)

Abstract

Summary The aim of this report is to provide an overview of the current status of efforts on the potential rehabilitation of sturgeon populations in Turkish waters, describing the structure and the outcome of projects carried out since 2006 and identifying the strategic needs for sturgeon conservation measures at a national level. It is well known that there were six sturgeon species occurring around Turkish Black Sea coasts while entering the rivers, mainly Kızılırmak, Yeşilırmak, Sakarya and Çoruh Rivers for spawning. Anadromous sturgeon species have been strictly protected throughout Turkey since 1997. Conservation and management measurements have been implemented since 1970s. However, this was apparently with little success as stocks continued to decline and habitats deteriorated further, threatening the stocks with extinction. At the same time the needs for survival are not well documented. A project was initiated on 30 January 2006, consisting of seven‐work packages including studies on population structure, reproduction, habitat assessment, genetic variability between and within stocks and the development of protective management strategies and plans. The work covered the Turkish Black Sea coastline and the rovers Yeşilırmak, Kızılırmak, Çoruh and Sakarya. Actively sampled and/or accidentally caught specimens have been tagged by T‐bars and released after measurements and tissue sampling for genetic analyses. In addition, broodstocks of Russian sturgeon (Acipenser gueldenstaedtii), Beluga (Huso huso), and stellate (A. stellatus) are being built by rearing fish at the Central Fisheries Research (Yomra, Trabzon, Turkey) Institute. Reproduction studies have mainly focused on sperm collection, cryopreservation and induced spawning as well as on larval rearing.

Genetic population structure of the critically endangered stellate sturgeon (Acipenser stellatus) in the Black Sea basin: Implications for conservation

“…However, population recovery and favourable conservation status cannot be achieved and sustained under the ongoing threats of habitat degradation and loss and intensified illegal sturgeon trading in the region (Akbulut et al, 2011;Jahrl et al, 2021).…”

“…This is not the case in the southern Black Sea region where there has been no restocking and the only recovery measure has been the implementation of a fishing Sporadic spawning events are known for the Danube River, downstream of the Iron Gates Dams Honț et al, 2018), where the presence of young-of-the-year stellate sturgeon has been monitored since 2000 Paraschiv et al, 2017). In contrast, spawning migration has rarely been observed or has ceased for most of the sturgeon species of the Turkish rivers (Akbulut et al, 2011). The conditions needed for Given the scarcity of the stellate sturgeon individuals available for the study and the slight signs of the population recovery in the NW-BS region, it is vital to increase the efforts to enforce and prolong the fishing ban by all Black Sea countries.…”

“…The directed fishery and the construction of dams, together with bycatch and poaching, have all contributed to this decline. In attempts to reverse this population trend, countries in the Black Sea basin have issued national regulations and imposed fishing bans (Friedrich et al, 2018) since 1997 in Turkey (Akbulut et al, 2011in Romania, 2009 in Serbia and Ukraine, and 2011 in Bulgaria (Reinartz et al, 2012). Furthermore, sturgeons are protected at the international level (CITES, Bern and Bonn Conventions, Convention on Biological Diversity, Ramsar, EU Habitats Directive), and recovery actions have been supported by various governmental and nongovernmental organizations (International Commission for the Protection of the Danube River, International Association for Danube Research, World Wildlife Fund and the World Sturgeon Conservation Society).…”

The Danube Sturgeon Acipenser gueldenstaedtii Brandt & Ratzeburg, 1833 (Actinopterygii, Acipenseridae) in the Euphrates River, Iraq

“…The sturgeon species composition in Turkey was reviewed several times (see Akbulut et al [2011] for details) and the results showed that there are seven species belonging to the Family Acipenseridae (Huso huso, Acipenser sturio, Acipenser stellatus, Acipenser gueldenstaedtii, Acipenser nudiventris, Acipenser ruthenus, Acipenser persicus). These species are distributed in the Turkish Black Sea coastal waters, with some of them entering the freshwater system [Bat et al 2005].…”

Initial evaluation of the release programme for Dabry's sturgeon (Acipenser dabryanus Duméril, 1868) in the upper Yangtze River

“…Excessive fishing and habitat degradation have impacted many sturgeon populations worldwide (Bemis and Kynard, ; Pikitch et al., ; Bloesch et al., ; Rosenthal et al., , ). Following a dramatic decline in the wild sturgeon population, hatchery‐reared fish are often released to enhance or restore threatened or extinct sturgeon populations for conservation and recreational fishing (Akbulut et al., ; Shuman et al., ). However, there are many differences between the hatchery environment and the wild (e.g.…”