Present status of commercial stocks of sturgeons in the Caspian Sea basin

A global perspective of fragmentation on a declining taxon—the sturgeon (Acipenseriformes)

“…However, many populations have become decimated despite their historical abundance and widespread distribution across the Northern Hemisphere (Birstein 1993, Bemis & Findeis 1994, DeVore et al 1995. Nonregulated harvests for the highly sought caviar and meat of many sturgeon species initiated their decline in the mid-1800s in North America (Birstein 1993, Bemis & Findeis 1994, Pikitch et al 2005, exacerbated stock declines from the Caspian Sea in the early 1960s (Khodorevskaya et al 1997, Ivanov et al 1999, Khodorevskaya & Krasikov 1999) and continue to depress or limit the recovery of some populations (Khodorevskaya et al 1997, Williamson 2003, Peterson et al 2007, Johnson & Iyengar 2015. Major alterations to many rivers were concurrent with, or subsequent, to overharvests.…”

“…More recently, water quality conditions in many regions have improved (Hensel & Holcik 1997, Schram et al 1999, Kampa et al 2014) and stricter harvest controls have been implemented (Khodorevskaya et al 1997, Baker & Borgeson 1999, Peterson et al 2007) in addition to the enforcement of import restrictions on many sturgeon species through the Convention on International Trade in Endangered Species (Williamson 2003, Lenhardt et al 2006, Ludwig 2006. However, poaching purportedly remains a conservation concern for all sturgeon species, given the exorbitant prices of caviar (Cohen 1997, Pikitch et al 2005; this seems to be especially relevant for European stocks (Khodorevskaya et al 1997, Ivanov et al 1999, Ludwig 2006).…”

Kemp's Ridley Sea Turtle Saga and Setback: Novel Analyses of Cumulative Hatchlings Released and Time-Lagged Annual Nests in Tamaulipas, Mexico

“…Pollution from industrial, agricultural, and municipal activities is believed responsible for a suite of physical, behavioral, and physiological impacts to sturgeon worldwide (Agusa et al 2004;Barannikova 1995;Barannikova et al 1995;Bickham et al 1998;Billard and Lecointre 2001;Kajiwara et al 2003;Karpinsky 1992;Khodorevskaya et al 1997;Khodorevskaya and Krasikov 1999). Although little is known about contaminant effects on Gulf Sturgeon, a review estimating potential reactions has been performed (Berg 2006).…”

“…It was found that loss of habitat associated with pollution and contamination has been documented for sturgeon species Shagaeva et al 1993;Verina and Peseridi 1979). Specific impacts of pollution and contamination on sturgeon have been identified to include muscle atrophy, abnormality of gonad, sperm and egg development, morphogenesis of organs, tumors, and disruption of hormone production (Altuf'yev et al 1992;Dovel et al 1992;Georgi 1993;Graham 1981;Heath 1995;Khodorevskaya et al 1997;Kruse and Scarnecchia 2002;Romanov and Sheveleva 1993)). …”

Stock Enhancement of Sturgeon Fishes in Iran

“…Economic analysis is essential to evaluate the viability of investment, determine the efficiency of resource allocation, improve existing management practices, evaluate new culture technology, assess market potential, and identify areas in which research success would have high potential payoffs (Shang, 1990). Several factors such as illegal fishing, damaging aquatic habitats, dam construction, sand exploitation from river beds, petroleum pollution, industrial, agricultural and domestic pollution cause decline in aquatic habitat quality and affect in one way or another the fish stocks, including the sturgeons of the Caspian Sea (Khodorevskaya et al,1996, Lukyanenko et al,1999, Ivanov et al,1999Salehi, 2006;Pourkazemi, 2006;and Moghim et al, 2006). As a result, the harmful human impact has grown at an especially rapid rate.…”