Considering a species-loss domino-effect before endangered species legislation and protected area implementation

Abstract

Regulatory legislation by governments is essential for facilitating the recovery of endangered or threatened species. Protecting commercially exploited species, in particular, requires painstaking cooperation among vested parties. However, rules protecting one species may be detrimental to others. If an exploited species is only protected in a portion of its range, exploitative efforts may divert to unprotected portions or similarly valuable species. As a result, the good intentions of protecting species in a limited fashion may manifest a species-loss domino-effect. We illustrate a species-loss domino-effect using a current example from the Mississippi River basin of the United States, where roe fisheries (for caviar) have cascaded because of strict regulations and collapses of sturgeon stocks in Europe and Asia. In the Mississippi River basin the limited protection of a commercially important sturgeon species may increase exploitation in unprotected river reaches and threaten other economically important fishes. Although a species-loss dominoeffect is delineated herein using an example from a freshwater fishery in the central United States, the concept should be considered and applied to terrestrial and marine species worldwide.

Demographics of Shovelnose Sturgeon in the Lower Wabash River, Illinois

“…The restriction of sturgeon harvest around the worldparticularly the restriction of Shovelnose Sturgeon harvest in portions of the Mississippi River during recent years-is predicted to cause an increase in harvest pressure on Shovelnose Sturgeon within the LWR, where harvest is still allowed (Hintz and Garvey 2012). Commercial catch data from the Wabash River indicate that harvest has not significantly increased since 2010; however, current levels of harvest are still higher than historical (i.e., pre-2007) catches.…”

“…Fish and Wildlife Service (2010) restricted the harvest of Shovelnose Sturgeon in most reaches of the Mississippi and Missouri rivers. Such site-limited protection of this commercially important fish may increase exploitation in unprotected rivers, such as the Wabash River, Illinois (Hintz and Garvey 2012). Thus, there is a growing need to monitor Shovelnose Sturgeon populations in areas where harvest is still allowed.…”

Exploitation of paddlefish Polyodon spathula (Walbaum, 1792) in the Mississippi River

“…Consequently, the Similarity of Appearance (SOA) provision of the Endangered Species Act closed commercial harvest of shovelnose sturgeon Scaphirhynchus platorynchus , a morphologically similar species, to further protect pallid sturgeon in the open river portion of the Mississippi River (below Lock and Dam 26) and in the Missouri River (USFWS, ). Due to the closure of the shovelnose sturgeon fishery, the SOA provision has the potential to increase international demand for paddlefish caviar and thus intensify harvest (Hintz & Garvey, ). Concern over exploitation rates from sport fisheries (Combs, ; Gordon, ; Mestl & Sorensen, ; Purkett, ) and commercial fisheries (Carlson & Bonislawsky, ; Scholten & Bettoli, ) have also increased dramatically.…”

Seasonal patterns in diet composition of adult shovelnose sturgeon in a free-flowing river

“…Moreover, the U.S. Fish and Wildlife Service (2010) has recently restricted the harvest of this species in much of the Mississippi and Missouri Rivers to protect the federally endangered pallid sturgeon, S. albus (Forbes and Richardson). Such site-limited protection of this commercially important fish may increase exploitation in unprotected river reaches where pallid sturgeon does not occur (Hintz & Garvey 2012) and suggests a need for management of existing shovelnose populations to prevent overexploitation (Colombo, Garvey & Jackson et al 2007;Colombo, Garvey & Wills 2007;Koch et al 2009). However, most research has focused on shovelnose life history and ecology in the Mississippi and Missouri Rivers (e.g.…”