Paddlefish Stock Assessments Drive Regulation Changes in Tennessee

USGS Cooperative Research Unit Corner

Paddlefish Stock Assessments Drive Regulation Changes in Tennessee

In 2001, the US Fish and Wildlife Service's Division of Scientific Authority (DSA) asked scientists at the US Geological Survey's Tennessee Cooperative Fishery Research Unit to perform a stock assessment of paddlefish in Tennessee waters. A lucrative trade in the overseas export of paddlefish caviar was developing and the DSA, tasked with ensuring that species listed under international conventions are fished in a sustainable manner, was concerned over the dramatic increase in the amount of Tennessee paddlefish caviar being exported. The research documented the declining paddlefish populations in the state resulting in new fisheries management regulations that were recently approved by the Tennessee Wildlife Resources Commission.

Paddlefish caviar exports were not a concern for the DSA prior to the 1990's because there was little international interest in paddlefish caviar as a substitute for sturgeon caviar produced overseas. That changed when Eurasian sturgeon stocks crashed within a decade of the Soviet Union's collapse in 1991. The wholesale price paid to commercial fishers in Tennessee for unprocessed paddlefish eggs jumped to $200/kg because of high demand for a scarce, luxury commodity; the resultant caviar retailed for more than $350/kg ($10/ounce). A mature female paddlefish in Tennessee waters yielded about 3 kg of eggs on average and harvest initially surged with the high demand.

The promise of quick riches also led to high-profile violations of the Federal Lacey Act, which prohibits interstate trade in animal and plant products that have been illegally obtained. Convictions, stiff fines, and jail time for some Tennessee fishers soon followed. Additionally, law enforcement officials learned that paddlefish caviar obtained legally in Tennessee and elsewhere could be exported overseas and imported back into this country labelled as sturgeon caviar to fetch higher prices (or simply relabeled falsely in this country).

Against a backdrop of illegal activity, high prices for paddlefish caviar, and more requests to export paddlefish caviar, the DSA was alarmed at a 60 percent decline in the number of paddlefish harvested annually in Tennessee between 2000 and 2002, which might signal overfishing. State authorities must be able to convince the DSA that paddlefish are being managed to protect them from overfishing in order for the DSA to grant permits to export paddlefish caviar. At the request of the DSA and with funding provided by the USGS Science Support Program, paddlefish in Tennessee's largest caviar fishery were studied by Tennessee Unit scientists and students. Reports were submitted in 2005 and 2007 to the DSA and Tennessee Wildlife Resources Agency (TWRA).

Those reports concluded, among other things, that paddlefish were being overfished and provided a summary of management actions available to regulators to ensure sustainable harvest.  Imposing higher minimum harvest size limits, establishing a refuge to limit the bycatch of juveniles, enacting a limited-entry program, changing the types of gill nets fishers could use, and prohibiting fishing during warm months when bycatch mortality is excessive were among the many management alternatives discussed in those reports and subsequent peer-reviewed publications.

Tennessee Unit scientists regularly presented research findings and TWRA biologists presented management recommendations to the Tennessee Wildlife Resources Commission (TWRA's governing body), the fishing industry, regional fish management associations, and the Tennessee state legislature. However, efforts to enact more restrictive regulations to prevent overfishing met with stiff resistance from the industry and a lawsuit was filed in 2008.

In November 2014, the Commission promulgated a suite of new regulations to protect paddlefish from overfishing in Tennessee. Among those new regulations were (1) raising the minimum harvest size limit in most waters from 34 inches to 38 inches eye-to-fork length, (2) shortening the fishing season by 13 days, and (3) enacting the state's first-ever limited entry system for a commercial fishery (the number of fishers licensed to fish for paddlefish will drop, through attrition, from a high of 93 in 2002 to a target of 40 fishers). The "No Fishing" refuge originally proposed in 2005 was created soon thereafter and remains in place today. A regulation not originally proposed or discussed that required fishers to alter how they processed eggs on their vessels was also enacted in 2014 to aid law enforcement efforts.

These new regulations subsequently prompted the DSA to once again issue permits allowing the overseas export of Tennessee caviar, which some commercial fishers find to be very lucrative. The Tennessee Unit's research findings, and the actions of the TWRA, also prompted fish management agencies in adjoining states to revisit their paddlefish regulations and make changes to more closely align their regulations with Tennessee's.

Each month, the ONB features articles from Cooperative Fish and Wildlife Research Units across the country. Working with key cooperators, including WMI, Units are leading exciting, new fish and wildlife research projects that we believe our readers will appreciate reading about. This month's article was written by Phil Bettolli, PhD, with the USGS Tennessee Cooperative Fisheries Research Unit at Tennessee Tech.

May 14, 2015