Current Status and Trends in Shovelnose Sturgeon (Scaphirhynchus Platorynchus) Management and Conservation by J
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Journal of Applied Ichthyology J. Appl. Ichthyol. 26 (2010), 491–498 Received: June 25, 2008 Ó 2010 Blackwell Verlag, Berlin Accepted: August 27, 2009 ISSN 0175–8659 doi: 10.1111/j.1439-0426.2009.01385.x Current status and trends in shovelnose sturgeon (Scaphirhynchus platorynchus) management and conservation By J. D. Koch* and M. C. Quist Department of Natural Resource Ecology and Management, Iowa State University, Ames, IA, USA Summary the Missouri, Mississippi, and Ohio river drainages, commer- The objective of this study was to update information regarding cial harvest and habitat degradation has decreased their the status of shovelnose sturgeon fisheries. Although a abundance and distribution (Keenlyne, 1997; Pflieger, 1997). substantial amount of shovelnose sturgeon research has been A comprehensive survey regarding the status of shovelnose conducted in the past decade, the study purpose was not to sturgeon has not been compiled since 1997. Keenlyne (1997) provide a comprehensive review of the literature; the primary surveyed biologists to examine changes in the distribution of interest was in the status, trends, and management of shovelnose sturgeon, trends in their populations, and to assess Scaphirhynchus platorynchus fisheries in North America. Biol- the conservation classification and major threats to S. plato- ogists were surveyed in all 24 states within the native distribu- rynchus. The author reported that most shovelnose sturgeon tion of the species; results indicate that commercial harvest is populations had declined since 1940, but that the status of the currently permitted in eight states, recreational harvest is populations since 1990 was relatively unknown. Additionally, allowed in 13 states, and that regulations vary within rivers and most survey respondents indicated that habitat alteration was jurisdictional boundaries. Although recreational exploitation the main concern to the welfare of shovelnose sturgeon of shovelnose sturgeon is thought to be low and not a populations (Keenlyne, 1997). significant threat to populations, commercial harvest is a major The objective of this study was to update information concern in states with a commercial fishery. In the last decade regarding the status of S. platorynchus fisheries. Although a harvest has increased in all states with commercial shovelnose substantial amount of shovelnose sturgeon research has been sturgeon fisheries, but recent implementation of regulations has conducted in the last decade (e.g. Morrow et al., 1998; Quist decreased harvest in some states. Approximately half of the et al., 2002; Bajer and Wildhaber, 2007; Colombo et al., 2007; states with extant shovelnose sturgeon populations conduct Kennedy and Sutton, 2007; Kennedy et al., 2007; Koch et al., routine monitoring of the species, and the understanding of 2009; Tripp et al., 2009), the purpose of the study was not to shovelnose sturgeon populations is increasing. provide a comprehensive review of the literature on the ecology of shovelnose sturgeon. Rather, we were primarily interested in describing the status and trends in the conserva- Introduction tion and management of S. platorynchus fisheries in North Sturgeons (family Acipenseridae) are ancient freshwater and America. anadromous fishes that inhabit lakes, rivers, and marine habitats in Europe, Asia, and North America. Sturgeons are Materials and methods highly-migratory, late-maturing, long-lived fishes that do not reproduce annually. Because of their unique reproductive The current status of shovelnose sturgeon was assessed with an ecology, sturgeons are highly susceptible to human activities online survey that was sent to biologists in the 24 states within such as habitat alterations, commercial harvest, and pollution the native distribution of the species. Surveys were sent to (Boreman, 1997). As such, seven of eight North American biologists identified as shovelnose sturgeon authorities in their sturgeon species and the majority of acipenserids world-wide respective state agency by their activity in the Mississippi are classified as endangered, threatened, or vulnerable (Bir- Interstate Cooperative Research Association (MICRA) and stein, 1993; Jelks et al., 2008). For example, Birstein (1993) the MICRA sturgeon–paddlefish committee. The survey was reported several sturgeon species inhabiting the former Soviet used to collect information about population trends, conser- Union and China are facing extinction, and that several vation status, and the current distribution of shovelnose European acipenserids could have similar fates. Eight sturgeon sturgeon. Additionally, information was obtained regarding species representing two genera are extant in North America, the presence and regulation of commercial and recreational three of which are classified as river sturgeons (genus shovelnose sturgeon fisheries. Data were also gathered regard- Scaphirhynchus). Two of the three Scaphirhynchus species are ing threats to shovelnose sturgeon persistence, as well as federally endangered: pallid sturgeon S. albus and Alabama information about current monitoring, conservation, and sturgeon S. suttkusi. Although the third member of the genus, restoration activities. Most questions required respondents to shovelnose sturgeon S. platorynchus, is currently abundant in check one, several, or the most applicable answers to survey questions, but some questions required a detailed textual explanation that was useful in interpreting answers and gaining additional insight into shovelnose sturgeon popula- *Current address: Kansas Department of Wildlife and Parks, tions. Below, questions are outlined with responses grouped Pretty Prairie, KS, USA. U.S. Copyright Clearance Centre Code Statement: 0175–8659/2010/2604–0491$15.00/0 492 J. D. Koch and M. C. Quist into broad focal areas (i.e. distribution, shovelnose sturgeon biologists indicated that only relict populations of shovelnose fisheries, current status, and outlook). sturgeon are present and recreational regulations are unnec- essary. Keenlyne (1997) reported that 12 states permitted sport fishing for shovelnose sturgeon; however, the author incor- Distribution rectly reported that Tennessee did not have a sport fishery for If there have been extirpations of shovelnose sturgeon in your shovelnose sturgeon. Recreational fishing for S. platorynchus state, approximately what percentage of the historic distribution has never been prohibited in Tennessee (G. Scholten, Tennes- of shovelnose sturgeon has been lost? Shovelnose sturgeon are a see Wildlife Resource Agency, pers. comm.). Thus, there has highly-mobile species found in large rivers of the Mississippi been no change in the number of states that allow recreational River drainage (Bailey and Cross, 1954; Keenlyne, 1997). fishing for shovelnose sturgeon since the 1997 survey by Historic records of shovelnose sturgeon exist from the Rio Keenlyne. Survey results indicate that shovelnose sturgeon are Grande and Pecos rivers as well as in the Alabama-Mobile targeted by <1% of anglers in 89% of states that provided River basin; however, survey results indicate the species is now estimates of shovelnose sturgeon recreational fishing pressure. considered extirpated from these drainages as well as from Although we are unaware of any recent data regarding four states (i.e. New Mexico, Alabama, West Virginia, and shovelnose sturgeon recreational exploitation, the vast major- Pennsylvania). Our survey results indicate that seven addi- ity of fisheries biologists indicated that recreational harvest is tional states have had local extirpations. Although limitations likely not a significant threat to shovelnose sturgeon popula- in historic data prevented some states from determining tions. Keenlyne (1997) suggested that few anglers fish specif- whether extirpations have occurred, Nebraska, Kansas, Ken- ically for shovelnose sturgeon and that most sport harvest tucky, and Iowa reported that 1–25% of the historic distribu- results from incidental catch; however, Peters and Parham tion of shovelnose sturgeon has been lost, and Tennessee (2008) reported that in April and May from 2002 to 2004, estimated that 26–50% has been eliminated. Approximately shovelnose sturgeon was the most commonly sought species 51–75% of historic shovelnose sturgeon habitat has been lost during creel surveys near the confluence of the Platte River, in Wyoming, while the historic distribution in Oklahoma has Nebraska. Although there appears to be isolated, seasonal been reduced by 76–99%. shovelnose sturgeon fisheries, our survey results indicate that the sport harvest is relatively low. Is there a shovelnose sturgeon reintroduction program in your state? Reintroduction efforts have been implemented for Is commercial fishing for shovelnose sturgeon allowed in your several North American sturgeon species including lake state? In the late 1800s, shovelnose sturgeon were considered sturgeon Acipenser fulvescens (Schram et al., 1999), shortnose an undesirable species by commercial fishermen because of sturgeon A. brevirostrum (Smith and Collins, 1996), Atlantic their low monetary value and difficulties associated with sturgeon A. oxyrhynchus (St. Pierre, 1999), white sturgeon capturing large quantities in commercial gear (Coker, 1930). A. transmontanus (Ireland et al., 2002), and pallid sturgeon However, in the early 1900s, a substantial market developed (Krentz et al., 2005). To mitigate extirpations or decreases in for shovelnose sturgeon flesh and roe, and soon (i.e. the 1920s) shovelnose sturgeon abundances, biologists