scholarly journals Timely Events in Their Interrelation to Paddlefish and Sturgeon Harvest from 1945-2010

2018 ◽  
Vol 46 (2018) ◽  
pp. 62-66
Author(s):  
Ryan N. Hupfeld ◽  
Quinton E. Phelps
Keyword(s):  
Mississippi River ◽  
Commercial Fishing ◽  
Natural Ecosystem ◽  
The Caspian Sea ◽  
Shovelnose Sturgeon ◽  
Inland River ◽  
Commercial Harvest ◽  
Inland Rivers ◽  
Fishery Collapse ◽  
International Events

Abstract Due to the high amounts of harvest of natural fish populations, overexploitation can occur and subsequently lead to depleted fisheries. This is especially true for commercially exploited roe-bearing species that exhibit late age at maturation and intermittent spawning. Overexploitation can create an imbalance in natural ecosystem function and in turn jeopardize the livelihood of commercial fishers. Despite the problems created by overexploitation, trends of commercial harvest on large inland river roe-bearing populations have received minimal attention. As such, we evaluated trends in commercial fishing data from 1945-2010 for two roe-bearing species (paddlefish Polyodon spathula and shovelnose sturgeon Scaphirhynchus platorynchus) from two of the largest inland rivers in North America (Mississippi River and Missouri River) adjacent to Missouri. Commercial sturgeon and paddlefish catch has varied from ∼160 to 35,150 kg over the course of the 55-year duration. Abnormally high catches corresponded to initiation of worldwide caviar markets, onset of extensive regulations on the Missouri and Mississippi rivers, and the Caspian Sea fishery collapse; respectively. Further, our results suggest that the harvest of sturgeon and paddlefish have increased since 1945 and may be influenced by local, regional, and international events. Despite the increase in harvest and the possibility of overharvest, commercial fishing regulations have not been thoroughly evaluated for effectiveness. Further evaluation of current management and regulations of these paddlefish and sturgeon fisheries is suggested, especially considering these fisheries may be influenced by local, regional, and international events. Taking potentially influential events into consideration when evaluating and implementing regulations and authorizing commercial harvest permits are vital in sustaining a long term commercial fishery and protecting the livelihood of commercial fishers.

Conservation, Ecology, and Management of Catfish: The Second International Symposium

2011 ◽  
Keyword(s):  
Ictalurus Punctatus ◽  
Mississippi River ◽  
Market Competition ◽  
Temporal Trends ◽  
Temporal Variations ◽  
Commercial Fishing ◽  
Substantial Portion ◽  
Black Bullhead ◽  
Commercial Harvest ◽  
Spatial And Temporal Trends

<em>Abstract</em>.—Ictalurids compose a substantial portion of the commercial harvest in the upper Mississippi River (UMR). The purpose of this investigation was to examine spatial and temporal trends in commercial harvest of ictalurids in the UMR. The study focused on four species: channel catfish <em>Ictalurus punctatus</em>, flathead catfish<em> Pylodictis olivaris</em>, blue catfish <em>I. furcatus</em>, and black bullhead <em>Ameiurus melas</em>. We described trends in yield and market value and evaluated the influence of numerous factors on commercial catfish harvest in Pools 3–26 of the UMR between 1953 and 2001. Spatial and temporal variations in commercial harvest of catfish appeared to be driven by different factors through time. Early factors included habitat loss and overexploitation, and later factors included loss of the market share and increased market competition with aquaculture. Ictalurids have maintained a consistent proportion of the total commercial harvest in the UMR, and decreases in catfish harvest may indicate larger declines in commercial fishing.

Range-wide age and growth characteristics of shovelnose sturgeon from mark–recapture data: implications for conservation and management

2015 ◽  
Vol 72 (1) ◽  
pp. 71-82 ◽  
Author(s):  
Martin J. Hamel ◽  
Mark A. Pegg ◽  
Reuben R. Goforth ◽  
Quinton E. Phelps ◽  
Kirk D. Steffensen ◽  
...  
Keyword(s):  
River Basin ◽  
Mississippi River ◽  
Missouri River ◽  
Large River ◽  
Population Connectivity ◽  
Growth Characteristics ◽  
Age And Growth ◽  
Mark Recapture ◽  
Shovelnose Sturgeon ◽  
Commercial Harvest

We used mark–recapture data from shovelnose sturgeon (Scaphirhynchus platorynchus) to describe range-wide growth characteristics and developed a model to estimate ages. Data were solicited throughout much of the current distribution of shovelnose sturgeon, specifically from the mainstem Missouri and Mississippi rivers and their tributaries. Shovelnose sturgeon exhibited variable growth among locations; however, adult fish exhibited almost no growth after they reached a particular size, presumably the size at sexual maturity. Shovelnose sturgeon from the Mississippi River basin attained greater maximum sizes and ages compared with the Missouri River basin. However, two populations from the Mississippi River that received high exploitation from commercial harvest had truncated age distributions with smaller asymptotic lengths. Lower Missouri River populations were characteristic of exploited populations (i.e., smaller fish and reduced longevity), presumably a result of anthropogenic effects. Wide discrepancies in maximum age and size suggest shovelnose sturgeon are capable of displaying phenotypic plasticity in response to exploitation or environmental influences. Determining metapopulation dynamics is a priority because it is unknown how population connectivity may influence dynamic rate functions and persistence of large-river fishes. Identifying potential source–sink connections in terms of population dynamics may provide a template for direction of future restoration and recovery efforts.

scholarly journals Effects of Commercial Harvest on Shovelnose Sturgeon Populations in the Upper Mississippi River

2009 ◽  
Vol 29 (1) ◽  
pp. 84-100 ◽  
Author(s):  
Jeff D. Koch ◽  
Michael C. Quist ◽  
Clay L. Pierce ◽  
Kirk A. Hansen ◽  
Michael J. Steuck
Keyword(s):  
Mississippi River ◽  
Upper Mississippi River ◽  
Shovelnose Sturgeon ◽  
Commercial Harvest

Red Snapper: Ecology and Fisheries in the U.S. Gulf of Mexico

2007 ◽  
Keyword(s):  
Gulf Of Mexico ◽  
Fork Length ◽  
Red Snapper ◽  
Minimum Size ◽  
Minimum Length ◽  
Commercial Fishing ◽  
Lutjanus Campechanus ◽  
Commercial Harvest ◽  
Length Regulation ◽  
The U.S

<em>Abstract.</em>—Red snapper <em>Lutjanus campechanus </em>were sampled from commercial landings from the Gulf of Mexico (GOM) off Louisiana from October 2001 to May 2004. Fork length (FL), eviscerated weight, otoliths (both sagittae), and sex determinations were taken from 2,900 specimens; FL was subsequently converted to total length (TL) with the equation TL = 1.073 (FL) + 3.56. Red snapper ages (<EM>N </EM>= 2,867) estimated from counts of opaque annuli in otoliths ranged from 1 to 14 years; however, the vast majority (97.7%) of these were ages 2 to 6 years and the modal age was 3 years. Total lengths among 2,897 specimens ranged from 278 to 940 mm, modal TL was 400 mm, and 98% of all specimens were less than 600 mm TL. We also investigated the fate of red snapper regulatory discards (individuals <381 mm [15 in] TL) during 16 trips on working commercial vessels; over two-thirds of 4,839 red snapper assigned among four discard fate categories (ranging from alive and vigorous to dead) were returned to the water either in moribund or dead condition. Among 399 potential discards retained for age and length analyses, 86% were between 12 and 15 in (305–381 mm) TL and 85% were 2 years of age. The minimum size regulation appears to do little to protect juvenile red snapper from commercial fishing mortality. Heavy red snapper mortality, which begins as bycatch mortality in shrimp trawls, continues as discard mortality at sub-legal lengths when they first recruit to the offshore fishing grounds, and persists as harvest mortality among the youngest legal year- and size-classes. If the minimum size limit is intended to provide a respite from such mortality, a reconsideration of the utility of the minimum length regulation in the commercial harvest of red snapper may be warranted.

Paddlefish Management, Propagation, and Conservation in the 21st Century

2009 ◽  
Keyword(s):  
Gravid Female ◽  
Primary Source ◽  
Commercial Fishing ◽  
Natural Mortality ◽  
Ultrasonic Telemetry ◽  
Spawning Habitat ◽  
Arkansas River ◽  
Kaplan Meier ◽  
Commercial Harvest ◽  
Gravid Females

<em>Abstract</em>.—We assessed potential impacts of harvest and proposed channel modifications on the paddlefish <em>Polyodon spathula </em>fishery of Ozark Lake, Arkansas River, Arkansas. Ultrasonic telemetry was used to determine commercial and recreational exploitation rates, survival, spawning locations, and habitat use of gravid female paddlefish. Monthly searches were conducted for 40 tagged fish and we recorded 862 locations in Ozark Lake from January 2004 through December 2005. Adjacent reservoirs (i.e., Pool 13 and Lake Dardanelle) were tracked periodically, but interpool movement was not detected. Commercial fishing exploitation was determined at a mandatory check station and was estimated to be 30% during a 5-d special season. Annual recreational snag-fishing exploitation estimates were 8% (2004) and 3% (2005). Survival was different between years and was much lower the year (2004) with a commercial fishing season. Kaplan-Meier staggered-design survival estimates (±95% confidence interval [CI]) for 2004, 2005, and 2004 through 2005 were 0.60 ± 0.19, 0.92 ± 0.11, and 0.55 ± 0.18, respectively. With commercial and recreational harvests omitted from the analysis, the estimated 2-year survival rate was 0.91 ± 0.13 (±95% CI), which corresponds to 5% annual natural mortality. Gravid females migrated a median distance of 33 and 32 km in the spring of 2004 and 2005 and likely spawned in the tailwater of James W. Trimble Lock and Dam from late March to early April. Successful paddlefish reproduction was verified by capture of 23 prolarvae. Paddlefish selected tributary mouth habitat in all seasons (59% of locations). Tailwater and inundated creek channel habitats were selected in spring and summer, respectively. A navigation project to deepen the channel from 2.7 to 3.7 m will impact approximately 50% of the tailwater spawning habitat. Channel modifications (i.e., dredging and dike construction) near the mouth of the Mulberry River may disturb an important tributary mouth habitat for paddlefish where 55% of all locations were recorded. Our study identified biologically important habitats that need conservation and indicates that commercial harvest was the primary source of mortality for gravid female paddlefish in Ozark Lake.

Paddlefish Management, Propagation, and Conservation in the 21st Century

2009 ◽  
Keyword(s):  
Mississippi River ◽  
First Year ◽  
State Agencies ◽  
Ohio River ◽  
Independent Data ◽  
Arkansas River ◽  
Commercial Harvest ◽  
Harvest Data ◽  
Sport Fisheries ◽  
Anthropogenic Alterations

<em>Abstract</em>.—Paddlefish <em>Polyodon spathula </em>have been intensively harvested in both sport and commercial fisheries. Recent harvests (2000–2006) were surveyed from state agencies and compared to historical harvests (1965– 1975). Seven major sport fisheries had recent annual harvests greater than 1,000 fish, and most large sport fisheries appeared to have sustainable harvests due to intensive management. Recent commercial harvest was greater than sport harvest across the species’ range. Most of the commercial harvest was from Arkansas, Kentucky, and Tennessee. Annual commercial harvest from the Ohio River increased from 6,000 to 196,000 kg from 1965–1975 to 2000–2006. Annual harvest remained substantial from the Arkansas River (37,000 kg), the lower Tennessee River (121,000 kg), and the Mississippi River (103,000 kg). Harvests of paddlefish (sport and commercial) compiled from the literature were highly variable and ranged between 0.01 and 5.06 fish/ ha and 0.04–43.43 kg/ha (median = 0.12 fish/ha, 1.73 kg/ha). Stock depression has been associated with a first-year harvest as low as 1.46 kg/ha, and harvests greater than 5 kg/ha were usually associated with overfishing or opening a previously closed fishery. Case histories from the Tennessee and Ohio River systems documented that paddlefish were susceptible to overharvest in lentic waters and river reservoirs, but the threat posed by commercial harvest from large rivers will remain unresolved until more fisheries-independent data becomes available. Anthropogenic alterations to habitat, overreliance on harvest data, and lack of fisheries-independent data limit our historical understanding of the degree of threat that harvest is to paddlefish populations.

Age, Growth, and Mortality of Shovelnose Sturgeon in the Lower Mississippi River

1998 ◽  
Vol 18 (3) ◽  
pp. 725-730 ◽  
Author(s):  
James V. Morrow ◽  
James P. Kirk ◽  
K. Jack Killgore ◽  
Steven G. George
Keyword(s):  
Mississippi River ◽  
Shovelnose Sturgeon ◽  
Lower Mississippi River
Sign in / Sign up

Export Citation Format

Share Document