Riverine and Reservoir Influences on Year Class Strength and Growth of Upper Great Plains Paddlefish

Abstract

A long-term investigation (1991)(1992)(1993)(1994)(1995)(1996)(1997)(1998)(1999)(2000)(2001)(2002)(2003)(2004)(2005)(2006) was conducted on the relation between Yellowstone and Missouri River discharges, water level (elevation) changes of Lake Sakakawea, a Missouri River mainstem reservoir in western North Dakota, and the ecology of the Yellowstone-Sakakawea stock of paddlefish Polyodon spathula, a zooplanktivorous Acipenseriform fish. After impoundment in December 1953, Lake Sakakawea filled gradually over a 13-year period (1953-1966). Water levels were lowered sharply and briefly in 1977 and 1981 and for much more prolonged periods of 1988-1993 and 2000-2006 associated with drought conditions in the central United States and water management decisions by the U.S. Army Corps of Engineers.The 1995 year class of paddlefish, by far the strongest in the 16-year study period, was associated with the sharp rise in water level from August 1993 through 1995, the longest continuous rise since the initial filling and the only period since initial filling when reservoir levels rose substantially in three consecutive years. High reservoir levels were associated with higher densities of zooplankton (all taxa combined and Leptodora kindtii, the primary food of age 0 paddlefish), stronger year classes (based on counts of age 0 fish along standard transects), greater mean weight and condition of age 0 fish in August, greater mean weights of recruits, higher growth rate of adult fish, and greater weight of gonadal fat bodies (GFBs), an indicator of energy storage, in absolute weight, as a percentage of gonad weight, and as a percentage of fish weight. Sixty-three percent of the variation in the ratio of GFB weight/gonad weight was explained by reservoir level. Fish tagged as adult migrants and recaptured in succeeding years after rearing in rising and high reservoir conditions gained an average of 0.04 kg/yr, whereas fish rearing in falling-and low-reservoir conditions lost an average of 0.19 kg/yr. Missouri River discharge during spring was significantly correlated with estimated age 0 year class strength, but a similar relationship did not hold for the Yellowstone River, which is the river used by most spawning paddlefish. Results of this study are consistent with studies from Lake Sakakawea and other reservoirs indicating that trophic upsurge in recently filled (and refilled) reservoirs favors the development of stronger year classes, faster growth, better condition, and larger size at maturity of fishes. Higher riverine discharges, thought to favor paddlefish reproductive success, were also typically associated with a rising or high reservoir. In contrast, low-reservoir levels over the period [2000][2001][2002][2003][2004][2005][2006] have negatively affected paddlefish year class strength, growth, and energy storage. If, in succeeding years, Lake Sakakawea once again is allowed to rise to full pool as it did over the period 1993-1995, inundation of the shorelines and the vegetation can be expected to result in another ups...

Southern and Northern Great Plains (United States) Paddlefish Stocks Within Frameworks of Acipenseriform Life History and the Metabolic Theory of Ecology

“…Scarnecchia et al (2009) showed that both fish weight gain and GFB accumulation were greater in Yellowstone-Sakakawea stock paddlefish during years of higher reservoir levels and associated higher zooplankton abundance in the headwater region of Lake Sakakawea. Lower reservoir levels resulted in lower reservoir productivity, lower zooplankton density, smaller fish at age 9, and smaller GFBs in absolute weight and as a percentage of fish weight.…”

“…However, strong year classes would have to become much more frequent than they are at present. As of 2010, the 1995 year class is dominating the population and the harvest (Scarnecchia et al, 2009), and recruitment of subsequent year classes is thought to be poor. For the Grand Lake stock, higher metabolic demands as the fish experience even warmer waters has the potential to push the species' life history flexibility to its limits, close to where the Gulf sturgeon now exists (Sulak and Randall, 2001).…”

“…In the first three years of the roe donation program (2008)(2009)(2010), an intensive sampling protocol was implemented to collect detailed biological data from every paddlefish brought into the RPC. Data from the Grand Lake stock were collected in a form consistent with data collected at roe donation stations for the Yellowstone-Sakakawea stock in the upper Great Plains (Montana and North Dakota; Scarnecchia et al, 2007Scarnecchia et al, , 2008Scarnecchia et al, , 2009. As a result, these two Great Plains stocks have detailed, stock-specific data that allow this study to (1) describe in detail the life history of the Grand Lake Stock, (2) compare the life history of the Grand Lake stock from the southern Great Plains with the Yellowstone-Sakakawea stock of the Figure 1 The Neosho River basin, Spring River, and Grand Lake (Oklahoma, Kansas, and Missouri, USA, respectively) (color figure available online).…”

Reservoir refilling enhances growth and recruitment of an endangered remnant riverine fish

“…Nevertheless, repeated upsurge periods and subsequent population responses by remnant riverine fish are possible. Scarnecchia et al (2009) reported paddlefish populations increasing dramatically in response to the refilling of Lake Sakakawea on the Missouri River, almost 30 years after the initial filling phase.…”

“…Nevertheless, the impounded water of reservoirs can also provide benefits to remnant riverine fish species (Irz et al 2006;Ebner et al 2011;Lintermans 2012). Examples include paddlefish (Polyodon spathula) in the United States (Paukert and Fisher 2001;Scarnecchia et al 2009) and golden galaxias (Galaxias auratus) (Hardie et al 2007(Hardie et al , 2013 and Macquarie perch (Macquaria australasica) (Cadwallader 1981;Appleford et al 1998) in Australia.…”