Voglio sapere a riguardo di…

Federal Register / Vol. 86, No. 1 / Monday, January 4, 2021 / Rules and Regulations at 50 CFR 424.11d set forth a framework for evaluating the foreseeable future on a case-by-case basis. The term foreseeable future extends only so far into the future as we can reasonably determine that both the future threats and the species responses to those threats are likely. In other words, the foreseeable future is the period of time in which we can make reliable predictions. Reliable does not mean certain; it means sufficient to provide a reasonable degree of confidence in the prediction. Thus, a prediction is reliable if it is reasonable to depend on it when making decisions.
It is not always possible or necessary to define foreseeable future as a particular number of years. Analysis of the foreseeable future uses the best scientific and commercial data available and should consider the timeframes applicable to the relevant threats and to the species likely responses to those threats in view of its life-history characteristics. Data that are typically relevant to assessing the species biological response include speciesspecific factors such as lifespan, reproductive rates or productivity, certain behaviors, and other demographic factors.
In our determination, we correlate the threats acting on the species to the factors in section 4a1 of the Act.
The following analysis examines factors currently affecting the June sucker or that are likely to affect it within the foreseeable future. For each factor, we examine the threats at the time of listing in 1986 or if not present at the time of listing, the status of the threat when first detected, the downlisting criterion pertinent to the threat, what conservation actions have been taken to meet the downlisting criteria or otherwise mitigate the threat, the current status of the threat, and its likely future impact on June sucker. We also consider stressors not originally considered at the time of listing, most notably climate change.
Habitat Destruction and Modification Loss and alteration of spawning and rearing habitat were major factors leading to the listing of the June sucker 51 FR 10851; March 31, 1986 and continue to pose a threat to the species overall resiliency and its recovery.
Suitable spawning and rearing habitat in Utah Lake and its tributaries declined due to water development, habitat modification, introduction of common carp, and urbanization, but has improved since listing due to recovery actions taken by the JSRIP.

VerDate Sep<11>2014

18:06 Dec 31, 2020

Jkt 253001

Water Development and Habitat Modification Water development and substantial habitat modifications have occurred in the Utah Lake drainage since the mid1800s. These changes include the reduction in riverine flows including the Provo River from numerous water diversions, various water storage projects, channelization, and additional lake and in-stream alterations Radant et al. 1987, p. 13; UDWR and UDNR 1997, p. 11; Andersen et al. 2007, p. 8. Many of these modifications and water depletions remain today, and continue to hinder the quantity and quality of June sucker rearing and spawning habitat, which in turn impacts species resiliency.
In 1849, settlers founded Fort Utah along the Provo River and began modifying the waters of Utah Lake and its main tributaries USBR 1989, p. 3.
In 1872, a low dam was placed across the lake outflow to the Jordan River, changing the function of Utah Lake into a storage reservoir CUWCD 2004, p. 2.
By the early 1900s, a pumping plant was constructed at the outflow to allow the lake to be lowered below the outlet elevation; this structure has since been modified and enlarged Andersen et al.
2007, p. 5. The present capacity of the pumping plant is 1,050 cubic feet per second cfs 29.7 cubic meters per second cms, and it can lower the lake level 810 ft 2.43.0 m below the compromise elevation of 4,489 ft 1,368
m Andersen et al. 2007, p. 5. The compromise elevation is a managed lake elevation target that the responsible water authorities have agreed not to exceed through the active storage of water. This compromise elevation was intended to balance the threat of flooding among lands adjacent to Utah Lake and those downstream along the Jordan River CUWCD 2004, p. 7.
As a storage reservoir, the surface elevation of Utah Lake fluctuates widely. Prior to the influence of water development projects, annual fluctuations averaged 2.1 ft 0.6 m per year. For approximately 50 years, under the influence of water development projects, water levels fluctuated an average of 3.5 ft 1.0 m annually prior to the completion of the Central Utah Project. The Central Utah Project was the largest water resources development program in Utah, distributing portions of Utahs share of Colorado River water.
After its completion, annual lake fluctuations averaged 2.5 ft 0.8 m Hickman and Thurin 2007, p. 20.
Fluctuation in surface elevation of Utah Lake particularly while the Central Utah Project was under construction is
PO 00000

Frm 00009

Fmt 4701

Sfmt 4700

199

one of the possible factors that contributed to the marked degradation of shoreline habitat and aquatic vegetation in the lake and to a decline in June sucker refugial habitat from predators Hickman and Thurin 2007, p.
23.
The long history of water management in the Provo River, including river alterations, dredging, and channelization efforts, has modified the historical braided and complex delta into a single trapezoidal channel Radant et al. 1987, p. 15; Olsen et al.
2002, p. 11. The current channel lacks vegetative cover, habitat complexity, and the food sources necessary to sustain larval fishes rearing in the lower Provo River Stamp et al. 2008, p. 20.
Additionally, the lower 2 mi 3.2 km of the Provo River experience a backwater effect, where the velocity stalls under low-flow scenarios and a high seasonal lake level causes the water to back up from the lake into the Provo River Stamp et al. 2008, p. 20. The slack water substantially reduces the number of larvae drifting into the lake. As a result of their poorly developed swimming abilities, the larvae either starve or are consumed by predators in this lower stretch of river Ellsworth et al. 2010, p. 9. Because of the extensive modification of the lower Provo River, in the past, most June sucker larvae have not survived longer than 20 days after hatching Ellsworth et al. 2010, pp.
910. The upcoming PRDRP is designed to increase survival of larvae by providing additional rearing habitat along the Provo River PRDRP 2017, entire.
Similar to the Provo River, Hobble Creek and other tributaries of significance Spanish Fork River and American Fork River have been extensively modified by human activities. The hydrological regimes are altered by multiple dams and diversions, and the stream channels have been straightened and dredged into incised trapezoidal canals Stamp et al.
2002, p. 5. These alterations resulted in the streams becoming isolated from their historical floodplains and having modified flow velocities and pool-riffle sequences Stamp et al. 2002, p. 6.
Until recent restoration efforts were implemented, the Hobble Creek channel had almost no gradient and ended without a defined connection to the lake interface in Provo Bay due to diversion structures and dredging. In the past, the channel was blocked by debris that created barriers to fish migration, preventing adult June suckers from accessing the main stem of Hobble Creek.

E:FRFM04JAR2.SGM

04JAR2