Endangered and Threatened Wildlife and Plants: Threatened Status for Southern Distinct Population Segment of North American Green Sturgeon, 17757-17766 [06-3326]

Agencies

• DEPARTMENT OF COMMERCE
• National Oceanic and Atmospheric Administration

[Federal Register Volume 71, Number 67 (Friday, April 7, 2006)]
[Unknown Section]
[Pages 17757-17766]
From the Federal Register Online via the Government Printing Office [www.gpo.gov]
[FR Doc No: 06-3326]


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DEPARTMENT OF COMMERCE

National Oceanic and Atmospheric Administration

50 CFR Part 223

[Docket No. 050323081-6079-02; I.D. 031505C]
RIN 0648-AT02


Endangered and Threatened Wildlife and Plants: Threatened Status 
for Southern Distinct Population Segment of North American Green 
Sturgeon

AGENCY: National Marine Fisheries Service (NMFS), National Oceanic and 
Atmospheric Administration (NOAA), Commerce.

ACTION: Final rule.

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SUMMARY: Following completion of a comprehensive Endangered Species Act 
(ESA) Status Review and Update for the North American green sturgeon 
(Acipenser medirostris; hereafter, ``green sturgeon''), we, NOAA's 
National Marine Fisheries Service (NMFS), published a Proposed Rule to 
list the Southern distinct population segment (DPS) of green sturgeon 
as threatened on April 6, 2005. After considering public comments on 
the Proposed Rule, we are issuing a Final Rule to list the Southern DPS 
as a threatened species. NMFS is currently considering issuance of 
protective regulations that may be necessary and advisable to provide 
for the conservation of the species. With this document we are also 
soliciting information that may be relevant to our analysis of 
protective regulations and to the designation of critical habitat for 
the Southern DPS of green sturgeon. Details of our analyses, their 
outcome, and a request for public comment on our proposals will be 
published in subsequent Federal Register notices.

DATES: This final rule is effective June 6, 2006. Replies to the 
request for information regarding a subsequent ESA section 4(d) Rule 
and critical habitat designation must be received by July 5, 2006.

ADDRESSES: You may submit information by any of the following methods:
     E-Mail: GreenSturgeon.Information@noaa.gov.
     Webform at the Federal Rulemaking Portal: 
www.regulations.gov. Follow the instructions at that site for 
submitting comments.
     Fax: 1-562-980-4027, Attention: Melissa Neuman.
     Mail: Submit written information to Chief, Protected 
Resources Division, Southwest Region, National Marine Fisheries 
Service, 501 West Ocean Blvd., Suite 4200, Long Beach, CA 90802 4213.
    Reference materials regarding this determination can be obtained 
via the Internet at: https://www.nmfs.noaa.gov or by submitting a 
request to the Assistant Regional Administrator, Protected Resources 
Division, Southwest Region, NMFS, 501 West Ocean Blvd., Suite 4200, 
Long Beach, CA 90802-4213.

FOR FURTHER INFORMATION CONTACT: Melissa Neuman, NMFS, Southwest Region 
(562) 980-4115 or Lisa Manning, NMFS, Office of Protected Resources 
(301) 713-1401.

SUPPLEMENTARY INFORMATION:

Background

    On June 12, 2001, we received a petition from the Environmental 
Protection and Information Center (EPIC), Center for Biological 
Diversity, and WaterKeepers Northern California requesting that we list 
the green sturgeon as threatened or endangered under the ESA and that 
critical habitat be designated for the species concurrently with any 
listing determination. On December 14, 2001, we provided notice of our 
90-day finding that the petition presented substantial scientific 
information indicating that the petitioned action may be warranted and 
requested information to assist with a Status Review to determine if 
green sturgeon warranted listing under the ESA (66 FR 64793). To assist 
in the Status Review, we formed a Biological Review Team (BRT) 
comprised of scientists from our Northwest and Southwest Fisheries 
Science Centers and from the United States Geological Survey (USGS). We 
also requested technical information and comments from state and tribal 
co-managers in California, Oregon, and Washington, as well as from 
scientists and individuals having research or management expertise 
pertaining to green sturgeon from California and the Pacific Northwest. 
The BRT considered the best available scientific and commercial 
information, including information presented in the petition and in 
response to our request for information concerning the status of and 
efforts being made to protect the species (66 FR 64793; December 14, 
2001). After completion of the Status Review (Adams et al., 2002), we 
determined on January 23, 2003 (68 FR 4433), that green sturgeon is 
comprised of two DPSs that qualify as species under the ESA: (1) a 
northern DPS consisting of populations in coastal watersheds northward 
of and including the Eel River (``Northern DPS''); and (2) a southern 
DPS consisting of coastal and Central Valley populations south of the 
Eel River, with the only known spawning population in the Sacramento 
River (``Southern DPS''). After consideration of a variety of 
information to assess risk factors, including abundance, fishing 
impacts, and habitat modification, destruction, and loss, we determined 
that neither DPS warranted listing as threatened or endangered (68 FR 
4433). Uncertainties in the structure and status of both DPSs led us to 
add them to the Species of Concern List (formerly the candidate species 
list; 69 FR 19975; April 15, 2004).
    On April 7, 2003, EPIC (and others) challenged our ``not 
warranted'' finding for green sturgeon. The U.S. District Court for the 
Northern District of California issued an order on March 2, 2004, which 
set aside our ``not warranted'' finding and remanded the matter to us 
for redetermination of whether green sturgeon is in danger of 
extinction throughout all or a significant portion of its range, or is 
likely to become so within the foreseeable future, because the Court 
was not satisfied with our examination of whether purported lost 
spawning habitat constituted a significant portion of either DPS' 
range. We reestablished the BRT and asked the BRT to consider recent 
scientific and commercial information available regarding the 
biological status of green sturgeon and to assist us in assessing the 
viability of the species throughout all or a significant portion of its 
range. We published a notice on June 18, 2004, soliciting new 
information beyond that considered in the previous Status Review and 
listing determination (69 FR 34135). Following the close of this public 
comment period on August 17, 2004, we convened the BRT to draft an 
updated Status Review and distribute the updated Status Review to co-
managers (i.e., States of Washington, Oregon and California, Yurok and 
Hoopa Tribes, U.S. Fish and Wildlife Service (FWS), and the California 
Bay-Delta Program) for their review and comment. This updated Status 
Review was finalized on February 22, 2005.
    In a Federal Register notice published on April 6, 2005 (70 FR 
17386), we reaffirmed our earlier determination that the northern green 
sturgeon DPS does not warrant an ESA listing, but that this

[[Page 17758]]

DPS should remain on the Species of Concern List due to remaining 
uncertainty in the status of, and threats faced by, the Northern DPS. 
We, however, revised our previous ``not warranted'' finding for the 
Southern DPS and proposed to list it as threatened under the ESA based 
on: (1) New information showing that the majority of spawning adults 
are concentrated into one spawning river (i.e., Sacramento River), thus 
increasing the risk of extirpation due to catastrophic events; (2) 
information that threats have remained severe since the first Status 
Review and have not been adequately addressed by conservation measures 
currently in place; (3) new information showing evidence of lost 
spawning habitat in the upper Sacramento and Feather Rivers; and (4) 
fishery-independent data exhibiting a negative trend in juvenile green 
sturgeon abundance. We also solicited comments and new or additional 
information regarding the status of, and critical habitat for, the 
Southern DPS to help develop a final listing determination and possible 
designation of critical habitat and ESA Section 4(d) regulations in 
subsequent rule-making.

Biology and Life History of Green Sturgeon

    A thorough account of green sturgeon biology and life history may 
be found in the previous determination (68 FR 4433; January 23, 2003), 
in the Status Review and Update (Adams et al., 2002, 2005), and in the 
Proposed Rule to list the Southern DPS of green sturgeon as threatened 
under the ESA (70 FR 17386; April 6, 2005).

Statutory Framework for ESA Listing Determinations

    Section 4 of the ESA (16 U.S.C. 1533) and implementing regulations 
(50 CFR part 424) set forth the procedures for adding species to the 
Federal list of threatened and endangered species. Section 4 requires 
that listing determinations be based solely on the best scientific and 
commercial data available, without consideration of possible economic 
or other impacts of such determinations, after having conducted a 
status review of the species and considering conservation efforts being 
made to protect the species. After assessing a species's level of 
extinction risk and identifying factors that have led to its decline, 
we then assess existing efforts being made to protect the species to 
determine if those measures ameliorate the risks faced by the species. 
In judging the efficacy of existing protective efforts, we rely on the 
joint NMFS-FWS ``Policy for Evaluation of Conservation Efforts When 
Making Listing Decisions'' (``PECE;'' 68 FR 15100; March 28, 2003).

Summary of Comments Received

    A public hearing was held on July 6, 2005, and the public comment 
period closed on July 27, 2005. We received 32 comments by fax, 
standard mail and e-mail. Thirteen of the commenters urged us to 
withdraw its proposal to list the Southern DPS as threatened. Ten of 
the commenters urged us to list the Southern DPS as endangered, not 
threatened, under the ESA, to revise our previous ``not warranted'' 
finding for the Northern DPS, and to invoke ESA Section 9 take 
prohibitions and designate critical habitat for listed entities 
immediately. One commenter expressed mixed views of our proposal to 
list the Southern DPS as threatened. Eight commenters provided no 
opinion on our listing determinations, but requested that we exempt 
certain captive populations of green sturgeon from threatened status 
and forthcoming ESA protections.
    Comment 1: Several commenters felt that we did not have enough 
information to proceed with a listing and thus our proposal was 
arbitrary and capricious.
    Response: The ESA requires that listing decisions be based solely 
on the best scientific and commercial data available and, therefore, 
does not specify a minimum level of proof required to proceed. The 
question as to whether there is sufficient information is an issue 
addressed as part of the listing decision, and the BRT makes scientific 
recommendations to NMFS through its Status Review and Updates that 
inform the listing decision. In our December 14, 2001, 90-day finding 
(66 FR 64793), we solicited information from the state and tribal co-
managers, as well as from scientists and individuals with research or 
management expertise pertaining to green sturgeon from California and 
the Pacific Northwest, to assist with the green sturgeon Status Review. 
We also solicited any new information from the public since the 2001 
solicitation (69 FR 34135; June 18, 2004) to assist us in updating our 
Status Review. On January 27, 2005, we distributed the Status Review 
Update to our co-managers for review. All of the information obtained 
during these solicitations was considered and used in developing our 
proposed and final listing determinations.
    The BRT reiterated its recommendation that the Southern green 
sturgeon DPS is likely to become an endangered species within the 
foreseeable future throughout all or a significant portion of its 
range. This recommendation was made after considering the best 
available information on the loss of historical habitat, the 
concentration of the spawning population into a single location, the 
trend in the salvage data, and the cumulative risk from a number of 
different threats in the Sacramento River and Delta system.
    We concluded that the blockage of green sturgeon by dams from their 
original spawning grounds substantially increased extinction risk. 
Green sturgeon historically spawned in higher-elevation, diverse 
habitats in multiple rivers within the range of the Southern DPS. 
Construction of dams and associated impoundments, which have altered 
temperature and hydrologic regimes and simplified instream habitats 
compared to their natural spawning grounds, are believed to have 
substantially decreased spawning success.
    The concentration of spawning into a single remaining habitat 
greatly increases the potential for catastrophic extinction of green 
sturgeon within the Southern DPS, even if green sturgeon populations 
were sustainable in this habitat in the long-term. The possibility of 
extirpation due to a catastrophic event was dramatically demonstrated 
by the 1991 Cantara herbicide spill. Nineteen thousand gallons of the 
herbicide metam sodium were released from a derailed train compartment 
into the Sacramento River killing nearly all aquatic life within a 45-
mile segment of the river (https://www.cantaratrustees.org/spill.htm).
    The green sturgeon salvage data imply a substantial decline in 
population numbers (see response to Comment 3 below). We remain 
concerned about the cumulative amount of risk to green sturgeon from a 
number of threats in the Sacramento River and Delta system. These 
threats were reviewed in the green sturgeon Status Review and Update. 
We are also concerned about how these different threats interact in 
their influence on green sturgeon. A number of ecological indicators, 
such as the recent collapse of the pelagic food web in the Delta, 
suggest that there are serious problems within the ecosystem upon which 
green sturgeon depend for an important portion of their life cycle. 
Recent unpublished reports, public presentations, and press releases by 
the California Department of Fish and Game (CDFG) indicate that many of 
the Delta's fish species have declined to the lowest levels ever 
recorded (https://science.calwater.ca.gov/pdf/workshops/IEP_POD_
2005WorkSynthesis-draft_111405.pdf)

[[Page 17759]]

    Toxins, invasive species, and water project operations, all 
identified as threats to the Southern DPS of green sturgeon, may be 
acting in concert or individually to lower pelagic productivity in the 
Delta. In addition, CDFG estimates that the population of legal-sized 
(117 to 183cm total length (TL)) white sturgeon has experienced a six-
fold decline since 1998 (M. Gingras, CDFG, pers. comm.).
    We considered both the BRT's conclusions, information received via 
the review process and solicitations for information, and conservation 
efforts currently being made to protect the Southern DPS (see Response 
to Comment 8 below) in reaching our listing decision. The best 
available scientific and commercial information was sufficient to 
conclude that the Southern DPS is likely to become endangered within 
the foreseeable future.
    Comment 2: Several commenters felt that the rationale we used for 
determining whether Southern DPS spawning habitat has been lost over 
time was flawed because a surrogate species was used to determine 
habitat suitability and because lost habitat was not quantified.
    Response: Chinook habitat modeling, the only such habitat 
assessment currently available to describe loss of riverine habitat in 
the Central Valley, is appropriate for use in determining habitat 
availability trends for green sturgeon for several reasons. Both green 
sturgeon and spring-run Chinook are anadromous species that evolved in 
the pre-dam Central Valley environment where they had access to higher 
elevation, cooler water habitats. Both species are affected by the 
limited amount of cool water spawning and rearing habitat. Cool water 
habitat can best be approximated by mean annual discharge or the amount 
of high elevation habitat (Lindley et al., 2004). It is generally 
accepted that green sturgeon (FWS, 1994) and spring-run Chinook (Moyle, 
2002) historically used spawning grounds in the area above Shasta Dam. 
White sturgeon were observed in the Pitt River to the vicinity of Lake 
Britton (FWS, 2005) above Shasta Dam, and presumably green sturgeon 
occurred at these elevations as well. Green sturgeon and Chinook 
spawning temperature tolerances are similar. Green sturgeon spawn in 
water temperatures ranging from 8[deg] to 14[deg] C (FERC, 2004a), 
although eggs have been artificially incubated at temperatures as high 
as 15.8[deg] C (Deng, 2000). Chinook temperature spawning tolerances 
are in the range of 5.6[deg] to 12.8[deg] C (FERC, 2004b). The 
similarities in spawning temperature ranges suggest that spawning in 
the pre-dam period may have occurred at similar water temperatures and, 
therefore, at similar discharges and elevations. The similarity of 
spawning requirements for these two species allows for the use of a 
surrogate species for habitat analysis. In summary, Chinook habitat 
modeling has shown that pre-dam, diverse, natural, higher-elevation 
spawning and rearing habitats were replaced with a smaller, 
concentrated, simpler spawning habitat. The BRT concluded that a 
similar replacement has occurred for green sturgeon as well and 
considered this habitat replacement to greatly increase extinction risk 
for green sturgeon. A direct green sturgeon habitat analysis is 
preferable to using a surrogate, and that analysis is currently 
underway at the Southwest Fisheries Science Center, but results are 
currently not available.
    The BRT discussed the possibility of quantifying lost spawning 
habitat in terms of the number of linear miles of river habitat lost 
due to dam construction in the Sacramento and Feather Rivers. It was 
decided that this type of quantification should wait until the green 
sturgeon habitat analysis is complete so that this information can be 
used to inform decisions made in subsequent rule-making.
    Comment 3: Several commenters stated that habitat availability 
should not be compared before and after construction of dams in the 
Central Valley because their construction occurred too long ago. 
Instead, it was suggested that the evaluation of habitat loss be based 
on more recent times.
    Response: We disagree with the commenters' views that we have 
inappropriately evaluated habitat loss over time for the Southern DPS. 
ESA section 7(a)(2) implementing regulations define environmental 
baseline as including the effects of past and present Federal, state, 
or private actions and other human activities which have led to the 
current status of the species and its habitat (50 CFR 402.02). We have 
adopted this definition here to examine changes in freshwater habitat 
availability for green sturgeon from a time when very few Federal, 
state, or private activities curtailed habitat within the boundaries of 
the Southern DPS to a time when many actions have irreparably altered 
habitat. This definition includes no temporal limit when considering 
changes in habitat availability to inform ESA decisions. In addition, 
in previous listing decisions for salmon and steelhead, we have used 
pre- and post-dam construction information in considering habitat loss 
and declines in abundance.
    Comment 4: Several commenters questioned whether we used new data 
to inform the revision of our previous ``not warranted'' finding to a 
threatened listing for the Southern DPS.
    Response: We did use new information, collected since the 
publication of the first Status Review in 2002, to revise the previous 
``not warranted'' finding for the Southern DPS. Several recent sources 
of data (Hancock, 2002; CDFG, 2003) have suggested that riparian 
habitat in the Central Valley continues to decline in quantity and 
quality and that the threats causing these declines are steadily 
getting worse over time rather than better. The Chinook Habitat 
Assessment (Lindley et al., 2004) used as a surrogate to infer loss of 
green sturgeon habitat was not available at the time of the 2002 Status 
Review. Tagging studies conducted throughout the range of green 
sturgeon have provided new information on movement patterns and use of 
freshwater, estuarine, and marine habitats by juveniles and adults (S. 
Lindley, SWFSC and M. Moser, NWFSC, pers. comm.). These studies suggest 
that green sturgeon return to spawning rivers on a more frequent basis 
(2-3 years) than previously thought (S. Lindley, SWFSC, pers. comm.). 
Thus, the proportion of a given individual's time spent in freshwater 
spawning habitat may be larger than previously thought, highlighting 
the importance of freshwater habitat quality and quantity to overall 
population viability.
    Additional sightings and observation of behaviors of green and 
white sturgeon have been reported in the Sacramento, Feather, and San 
Joaquin rivers, including sturgeon remains being identified in middens 
in the San Joaquin River (southernmost documented location to date; 
Gobalet et al., 2004). Much of these data are from personal 
communications (Beamesderfer et al., 2004) and as such are not 
comprehensive, but they are useful for establishing presence and for 
informing our conclusions regarding habitat use. This new information 
has led us to conclude that: (1) the Sacramento River is the only 
spawning population remaining in the Southern DPS; (2) the Feather 
River likely supported a spawning population in the past, but does not 
currently; and (3) the San Joaquin River may have supported a spawning 
population in the past based on recent (2003) white sturgeon spawning 
and past presence in the system.

[[Page 17760]]

    Comment 5: A few commenters felt that the importance of the Feather 
River as historical green sturgeon habitat was overstated, as was the 
possibility that the Thermalito Afterbay has caused a thermal barrier 
to fish passage and successful spawning and subsequent recruitments.
    Response: We reiterate our conclusion that the Feather River once 
supported a green sturgeon spawning population, and the loss of this 
population resulted in a substantial increase in extinction risk for 
the Southern DPS, regardless of the size of the population. The 
conclusion that there had been a Feather River population was based on 
sightings of individual green sturgeon, statements by experts, and use 
of the habitat by surrogate species. A number of experts have expressed 
the opinion that the Feather River once supported a viable green 
sturgeon population. CDFG (2002) stated ``the most likely loss of 
spawning habitat is in the Feather River, as Oroville Dam blocks access 
to potential spawning habitat'', and CDFG shows the Feather River as 
green sturgeon habitat on its online distribution map (https://
www.calfish.org). Moyle (2002) stated, ``In the Sacramento drainage 
capture of larval green sturgeon in salmon outmigrant traps indicates 
that the lower Feather River may be a principal spawning area.'' 
Finally, the conclusion that the Feather River contained a green 
sturgeon population is also supported by habitat use patterns of 
surrogate species: (1) the historic presence of white sturgeon in the 
Feather River (Painter, 1977); and (2) the Chinook habitat analysis, 
which suggests that Chinook used the North, Middle, and South forks of 
the Feather River as well as the Yuba River (Lindley et al., 2004) as 
spawning habitat.
    Although adult green sturgeon occurrence in the Feather River and 
its tributary, Bear River, has been documented from the past (USFWS, 
1995; Moyle, 2002) to the present (Beamesderfer et al., 2004; CDWR, 
2005), larval and juvenile green sturgeon have not been collected 
during recent efforts (2000-2001 and 2003). These efforts included 
attempts to collect larval and juvenile sturgeon during early spring 
through summer using rotary screw traps, artificial substrates, and 
larval nets deployed at multiple locations (Schaffter and Kohlhorst, 
2001; A. Seesholtz, 2003, 2005). These results support our conclusion 
that an effective population of spawning green sturgeon does not exist 
in the Feather River at the present time.
    The BRT's concern about the Thermalito Afterbay creating a thermal 
barrier was based on a comment that warm water releases from the 
Afterbay may increase temperatures to levels that are undesirable for 
green sturgeon spawning and incubation especially during low flow years 
(CDFG, 2002). Given that other data suggest that high water 
temperatures have posed a threat to successful green sturgeon spawning 
and recruitment in the Feather River (FWS, 1995) and historically in 
the Sacramento River (prior to installation of the Shasta Dam 
temperature control device in 1997), we do not believe we have 
overstated its importance.
    Comment 6: One commenter stated that a large portion of the green 
sturgeon population is at sea at any given time and that the marine-
inhabiting portion of the green sturgeon population would serve as a 
buffer against extinction.
    Response: We do not believe that green sturgeon are significantly 
buffered against extinction by the marine portion of their populations. 
Green sturgeon have the most extensive marine distribution of all 
sturgeon. The buffering argument is that only a small fraction of the 
total population is in freshwater at any given time, and the marine 
portion provides a sanctuary against extinction risk. While this is 
true of a one-time catastrophic event, other persistent risk factors 
will continue to have impacts on green sturgeon spawning and 
recruitment success, the most important factors for determining 
population viability. While there may be a relatively large number of 
green sturgeon in the ocean compared to freshwater at any given point 
in time, it is the freshwater component of an individual's life history 
that determines whether that individual will spawn successfully and 
produce offspring that survive to maturity. In addition, green 
sturgeon, as with most other fish species, are most vulnerable and 
likely experience their highest natural mortality rates during the 
portion of their lives spent in freshwater as larvae and juveniles 
(Houde, 1987). Thus, additional risks faced during the freshwater 
portion of green sturgeon's life history are likely most critical in 
determining long-term viability of the Southern DPS. In addition, it 
appears that green sturgeon may return to spawn on a shorter cycle than 
previously thought. Green sturgeon have been found to return to spawn 
on a 2- or 3-year cycle (S. Lindley, NMFS, per. comm.). Also, subadult 
green sturgeon have been observed in spawning areas (S. Lindley, NMFS, 
per. comm.). The cumulative risk experienced by the Southern DPS while 
in freshwater habitat is likely higher than previously thought because 
the proportion of time that any individuals spends in the marine 
environment may be much smaller than previously thought.
    Comment 7: Many commenters believed that we overstated the 
importance and utility of salvage data to ascertain trends in green 
sturgeon numbers.
    Response: Our proposed determination that the Southern DPS of green 
sturgeon face extinction in the foreseeable future was based on 
multiple lines of data and was not solely dependent on the salvage 
data. The BRT reconsidered the salvage data in greater depth and 
concluded that the numbers of green sturgeon were higher in the salvage 
facilities data prior to 1986 compared to after. However, it appears 
that expansions were larger in this period as many commentators 
suggested. The State facility numbers provided the longest time series, 
thus the BRT focused on these data for the analysis. The BRT concluded 
that not only were the estimated numbers of green sturgeon 14 times 
higher in the pre-1986 period than after, but the number of actual 
green sturgeon observed was 3 1/2 times higher in the pre-1986 period. 
There is further support for high juvenile sturgeon abundance during 
the 1974-75 period from the white sturgeon trammel net sampling. The 
green sturgeon to white sturgeon ratio of fish less than 102 cm was 
1.661 in 1974. This is more than twice the next highest year and six 
times higher than the average. Independent evidence from two different 
sampling sources is strong justification for assuming that the 1974-75 
period was one of high juvenile green sturgeon abundance, and this type 
of recruitment success has not been observed since.
    The BRT also found support for the many comments suggesting that 
salvage estimate expansions were higher in the pre-1986 period. A 
General Linear Model analysis of the green sturgeon estimates compared 
to observed fish in the pre-1986 period showed that one observed fish 
was converted to 48 estimated fish (coefficient = 47.9, F = 303 with 16 
df, p=0.001). The same analysis for the period from 1986 to 2001 showed 
that one observed fish was converted into 9.7 estimated fish 
(coefficient = 9.7, F = 12.4 with df =14, p =0.003). Therefore, we 
acknowledge that expansion rates were higher prior to 1986. However, 
even after accounting for the higher expansion rates, there were more 
green sturgeon present in salvage operations prior to 1986. Other 
caveats about the use of the salvage data are reviewed in the Status 
Review and Update.

[[Page 17761]]

    Comment 8: Several commenters stated that we did not consider or 
that we inappropriately discounted other data sources that would have 
been valuable for determining trends in abundance.
    Response: The BRT reviewed other data sources suggested by the 
commenters and determined that they had been considered previously and 
in some cases were deemed not useful, usually due to the lack of green 
sturgeon occurring in the data series. The CDFG San Pablo Bay sturgeon 
trammel net sampling, the Klamath Tribal Catch time series, and the 
Glenn-Colusa Irrigation District (GCID) screw trap data were all 
analyzed in the original Status Review, and detailed discussions of 
these data sets may be found there (Adams et al., 2002). Briefly, the 
CDFG San Pablo Bay trammel net sampling provided the only non-harvest 
based population estimates of abundance over time from 1954-2001. The 
data exhibited no significant trend over time, and it suffers from a 
number of biases: (1) The data depend on tag recoveries from the sport 
fishery and, therefore, reflect varying levels of effort; (2) sampling 
prior to 1990 was irregular; and (3) the estimates for green sturgeon 
are calculated incidentally based on tag returns from white sturgeon 
and assume that the temporal, spatial and gear vulnerabilities of both 
species are equal. The GCID sampling began in 1987, underwent a gear 
change in 1991, and has occurred each year since that time except for 
1998. The total number of juvenile green sturgeon has fluctuated by 
over an order of magnitude between some years, but no clear temporal 
trends could be discerned despite a steady decline in numbers since 
1997. We hope these data will be a useful indicator of green sturgeon 
juvenile abundance trends in the future as the temporal coverage of the 
sampling increases. The Klamath Tribal Catch time series refers to the 
Northern DPS and therefore will not be addressed here.
    Examination of other data sets was conducted in preparation for the 
original Status Review, but the BRT concluded that: (1) the spatial/
temporal scale of sampling or the gear type was not appropriate for 
ascertaining trends in the Southern DPS abundance; and/or (2) too few 
green sturgeon were captured during the time series to make conclusions 
about trends over time. For example, after 21 years (1980-2001) of 
conducting the San Francisco Bay otter trawl survey (CDFG, 2002), only 
61 green sturgeon were collected from four locations between 1980 and 
2001. However, in earlier sampling during an 11-month period between 
September 1963 and August 1964, 28 green sturgeon were captured with 
similar gear while 138 were captured with gill nets (CDFG, 2002), again 
indicating higher previous abundances. The UC Davis Suisun Marsh otter 
trawl sampling data set was also considered in preparation for the 
original Status Review, but was not found useful since fewer than 12 
individuals were taken in 25 years of sampling (P. Moyle, UC Davis, 
per. comm.). The gear is suitable for taking small sturgeon, but few 
were found in the sampling area during the entire course of the 
sampling, and, thus, an analysis of trends could not be conducted. 
Indian midden data were not found useful for establishing historical 
range during preparation of the original Status Review (Gobalet et al., 
2004) since midden data did not record sturgeon presence throughout the 
area of known historical occurrence. Further investigation (K. Gobalet, 
CSU Bakersfield, per. comm.) reveals that sturgeon bones were found at 
Lake Tulare, in the San Joaquin Valley system, the southernmost 
location recorded for sturgeon presence. Unfortunately, investigators 
are not able to distinguish between green and white sturgeon bones.
    Two data sets had not been considered previously. The Chipps Island 
midwater trawl program only captured 15 green sturgeon in over 33,000 
trawls conducted from 1976 to 2004 (P. Cadrett, USFWS, per. comm.). The 
BRT's conclusion was that this information was not useful in 
determining green sturgeon status or trends. The striped bass summer 
townet survey, designed to collect 38 mm larvae, only collected a 
``handful of sturgeon'' during the time series beginning in 1959 (P. 
Coulston, CDFG, per. comm.). The BRT did not find this ancillary catch 
information to be reliable for determining green sturgeon status or 
trends.
    Comment 9: Several commenters felt that recent state, local and 
Federal conservation efforts will help ensure the long-term viability 
of the Southern DPS to the point that a listing is not necessary.
    Response: To consider that a formalized conservation effort 
contributes to forming a basis for not listing a species, we must find 
that the conservation effort is sufficiently certain to be implemented 
and effective so as to have contributed to the elimination or adequate 
reduction of one or more threats to the species identified through the 
ESA section 4(a)(1) analysis (pursuant to PECE, 68 FR 15100). In the 
proposed listing determination, we noted promising efforts to improve 
the quality of habitat and reduce threats to species that exhibit some 
degree of spatial and/or temporal overlap in spawning requirements with 
the Southern DPS in the Central Valley. However, NMFS does not believe 
that these efforts will reduce the risks to the Southern DPS enough to 
negate a threatened listing for the Southern DPS. When considering 
protective efforts, we need to weigh the certainty of their 
implementation and effectiveness against the threats causing risk to 
the Southern DPS. The actions proposed or being carried out by the 
California Bay-Delta Program (CALFED), the Central Valley Project 
Improvement Act (CVPIA), and CDFG include: (1) improving flow 
conditions in the Central Valley; (2) installing additional fish 
screens and improving fish passage; and (3) implementing stricter 
fishing regulations. These actions represent important contributions to 
addressing limiting factors for the Southern DPS; however, at this time 
these efforts alone do not substantially ameliorate risks to the 
Southern DPS such that protections afforded under the ESA are no longer 
necessary. As noted in the proposed listing determination (70 FR 17386; 
April 6, 2005) and summarized above, we feel that continued and 
additional conservation efforts are necessary beyond those addressed by 
commenters.
    Comment 10: Several commenters opposed our proposal to list the 
Southern DPS as threatened and believed that an endangered listing was 
warranted. They disagreed that the habitat restoration efforts 
associated with CALFED, the CVPIA, and newly proposed CDFG fishing 
regulations provide sufficient certainty of implementation and 
effectiveness (pursuant to PECE) to conclude that the Southern DPS 
should be listed as threatened rather than endangered.
    Response: We believe that the Southern DPS is likely to become 
endangered in the foreseeable future throughout all or a significant 
portion of its range, but is not currently in danger of extinction for 
the following reasons. There is evidence that the Southern DPS 
continues to spawn in the Sacramento River and that spawning habitat of 
suitable quality still exists there. The best available data suggest 
that Southern DPS adults and juveniles have been present consistently 
within the Sacramento River system over a relatively long time period, 
despite the suggestion of decreasing abundance over the last decade. 
Thus, the continued presence of a viable green sturgeon population in 
the Sacramento River supports our conclusion that the Southern DPS is 
not at imminent risk of

[[Page 17762]]

extinction, but that risk of extinction in the foreseeable future is 
possible over the longer-term if the threats to the species are not 
ameliorated.
    While we are encouraged by the recent proposals by: (1) CALFED and 
the CVPIA to specifically include green sturgeon monitoring and 
research activities in their habitat improvement and planning efforts 
in the Central Valley; and by (2) CDFG's proposal to implement more 
protective sturgeon fishing regulations and a directed monitoring 
program for green sturgeon, we agree that these measures do not provide 
sufficient certainty of implementation and effectiveness to negate a 
threatened listing (pursuant to the PECE Policy), as explained above . 
We do believe, however, that the proposals toimplement additional 
conservation measures over the short- and long-term offer additional 
assurance that extinction of the Southern DPS is unlikely to occur 
imminently.
    Comment 11: Several commenters supported the exclusion of captive-
bred green sturgeon from the Southern DPS and thought that take, 
transport, delivery, shipment and sale of captive-bred green sturgeon 
and the progeny thereof for domestic and international commerce should 
be allowed. The commenters thought that maintenance of a non-listed, 
captive-bred population of green sturgeon, originating from broodstock 
taken from the Klamath and Sacramento Rivers would: (1) further 
research goals and inform future management decisions; (2) take 
pressure off over-exploited wild stocks of beluga sturgeon through 
production of alternative sources of caviar; and (3) serve as a 
safeguard population for the Sacramento River in the event that the 
wild population experiences additional declines and requires 
supplementation through enhancement.
    Response: While the ESA authorizes the listing, delisting, or 
reclassification of a species, subspecies, or DPS of a vertebrate 
species, it does not authorize the exclusion of a subset or portion of 
a listed species, subspecies, or DPS from a listing decision. In 2001, 
the U.S. District Court in Eugene, Oregon (Alsea Valley Alliance v. 
Evans, 161 F. Supp. 2d 1154 (D. Or. 2001)) (Alsea), ruled that once we 
had delineated a DPS (for Oregon Coast coho), the ESA did not allow 
listing only a subset (that which excluded 10 hatchery stocks) of that 
DPS. We have reviewed no data to suggest that captive-bred green 
sturgeon are more than moderately diverged from local, native 
populations in the Klamath and Sacramento River.
    We believe that many of the benefits derived from captive-bred 
populations of green sturgeon, outlined by the commenters above, are 
valid and important to the overall conservation and recovery of the 
Southern DPS. In an effort to ensure that the native populations are 
not adversely affected, we will consider carefully the exemptions 
requested as we develop an ESA section 4(d) Rule in subsequent rule-
making.

Status of the Southern DPS of Green Sturgeon

    We have reviewed the petition, the reports of the BRT (NMFS, 2002, 
2004), co-manager comments, public comments, and other available 
published and unpublished information, and we have consulted with 
species experts and other individuals familiar with green sturgeon. We 
conclude that the Southern DPS is likely to become endangered in the 
foreseeable future throughout all of its range because: (1) the 
Sacramento River contains the only known green sturgeon spawning 
population in this DPS, and the concentration of spawning adults in one 
river places this DPS at risk; (2) there was a substantial loss of 
spawning habitat in the upper Sacramento and Feather Rivers (FWS, 
1995b, historical habitat data summarized in Lindley et al., 2004 for 
salmonids) for reasons cited in the first Status Review, Update, and 
the Proposed Rule (see those documents for a full discussion) and the 
loss of this spawning habitat contributed to the overall decline of the 
Southern DPS; (3) recent studies (since 2002) have indicated that the 
Sacramento River and Delta System face mounting threats with regard to 
maintenance of habitat quality and quantity and the Southern DPS is 
directly dependent upon this ecosystem for its long-term viability; and 
(4) fishery-independent data collected at the State and Federal salvage 
facilities indicate a decrease in observed numbers of juvenile green 
sturgeon collected from 1968 to 2001.
    We conclude that the Southern DPS of green sturgeon is not 
presently in danger of extinction throughout all or a significant 
portion of its range. The continued persistence of green sturgeon 
adults and juveniles in the Sacramento River indicates that this 
population is viable and is not at imminent risk of extinction. We 
believe that spawning habitat has been lost in the Sacramento and 
Feather Rivers, and possibly in the San Joaquin River, but due to a 
paucity of data, we are unable to determine the geographic extent and 
demographic consequences of this loss.

Summary of Factors Affecting the Southern DPS of Green Sturgeon

    Section 4(a)(1) of the ESA and NMFS's implementing regulations (50 
CFR part 424) state that we must determine whether a species is 
endangered or threatened because of any one or a combination of the 
following factors: (1) the present or threatened destruction, 
modification, or curtailment of its habitat or range; (2) 
overutilization for commercial, recreational, scientific, or 
educational purposes; (3) disease or predation; (4) inadequacy of 
existing regulatory mechanisms; or (5) other natural or man-made 
factors affecting its continued existence. We have previously detailed 
the impacts of various factors contributing to the decline of the 
Southern DPS in our Proposed Rule (70 FR 17386, April 6, 2005), as well 
as in the Status Review and Update (e.g., Adams et al., 2002, 2005). 
The primary factors responsible for the decline of the Southern DPS are 
the destruction, modification or curtailment of habitat and inadequacy 
of existing regulatory mechanisms. The following discussion briefly 
summarizes findings regarding threats to the Southern DPS.

The Present or Threatened Destruction, Modification, or Curtailment of 
its Habitat or Range

    The principal factor for decline of the Southern DPS is the 
reduction of the spawning area to a limited area of the Sacramento 
River. Keswick Dam provides an impassible barrier blocking green 
sturgeon access to what were likely historic spawning grounds upstream 
(FWS, 1995). A substantial amount of habitat in the Feather River above 
Oroville Dam also was lost, and threats to green sturgeon in the 
Feather River are similar to those faced by green sturgeon in the 
Sacramento River (NMFS, 2004). The BRT concluded that an effective 
population of spawning green sturgeon (i.e., a population that is 
contributing offspring to the next generation) no longer exists in the 
Feather River and was likely lost due to habitat blockage caused by the 
construction of Oroville Dam and from thermal barriers associated with 
the Thermalito Afterbay Facility.
    Potential adult migration barriers to green sturgeon include the 
Red Bluff Diversion Dam (RBDD), Sacramento Deep Water Ship Channel 
locks, Fremont Weir, Sutter Bypass, and the Delta Cross Channel Gates 
on the Sacramento River, and Shanghai Bench and Sunset Pumps on the 
Feather River. The threat of screened and unscreened

[[Page 17763]]

agricultural, municipal, and industrial water diversions in the 
Sacramento River and Delta to green sturgeon is largely unknown as 
juvenile sturgeon are often not identified and current CDFG and NMFS 
screen criteria do not address sturgeon. Based on the temporal 
occurrence of juvenile green sturgeon and the high density of water 
diversion structures along rearing and migration routes, we find the 
potential threat of these diversions to be serious and in need of study 
(NMFS, 2005).
    CDFG (1992) and FWS (1995) found a strong correlation between mean 
daily freshwater outflow (April to July) and white sturgeon year class 
strength in the Sacramento-San Joaquin Estuary (these studies primarily 
involve the more abundant white sturgeon; however, the threats to green 
sturgeon are thought to be similar), indicating that insufficient flow 
rates are likely to pose a significant threat to green sturgeon.
    High water temperatures may pose a problem on the Feather River 
downstream of the Thermalito Afterbay outlet (FWS, 1995), and it is not 
expected that water temperatures in the system will become more 
favorable in the near future (CDFG, 2002). Elevated water temperature 
is likely no longer a problem in the Sacramento River with the 
installation of the Shasta Dam temperature control device in 1997. 
However, the possible long-term adverse affects on the overall 
population size and age-structure from elevated water temperature and 
the limited storage capacity and cold water reserves of the Shasta Dam 
in the past are still cause for concern.
    Contamination of the Sacramento River increased substantially in 
the mid-1970s when application of rice pesticides increased (FWS, 
1995). Estimated toxic concentrations for the Sacramento River during 
1970-1988 may have deleteriously affected the larvae of another 
anadromous species (e.g., striped bass) that occupies similar habitat 
as green sturgeon larvae (Bailey, 1994), and a recent report indicates 
that toxins may be at least partially responsible for the pelagic 
organism decline in the Delta. (https://science.calwater.ca.gov/pdf/
workshops/IEP_POD_2005WorkSynthesis-draft_111405.pdf)White sturgeon 
may also accumulate PCBs and selenium (White et al., 1989). While green 
sturgeon spend more time in the marine environment than white sturgeon 
and, therefore, may have less exposure, we conclude that some degree of 
risk from contaminants probably occurs for green sturgeon.

Overutilization for Commercial, Recreational, Scientific or Educational 
Purposes

    While this factor was not considered the primary factor causing the 
decline of the Southern DPS, it is believed that past and present 
commercial and recreational fishing is likely to pose a threat to the 
Southern DPS. Ocean and estuarine bycatch of green sturgeon in the 
Oregon and Washington white sturgeon and salmonid fisheries (which may 
take some Southern DPS fish) has been reduced to 6 percent of its 1986 
high value of 9,065 fish. The recent reduction is due to newly imposed 
fishing regulations in Oregon and Washington. Commercial fisheries 
targeting sturgeon have not been allowed in the Columbia River or 
Willapa Bay since 2001, and recreational fishing remains negligible 
(WDFW, 2004). CDFG (2002) estimated an average fishing mortality of 2.2 
percent for green sturgeon based on tag return data in the Sacramento-
San Joaquin Estuary. The impact of this fishing mortality rate is 
unknown. Potential new regulatory measures being considered by the 
State of California (M. Gingras, CDFG, pers. comm.) may confer reduced 
risk to the Southern green sturgeon DPS because regulatory measures 
recently implemented within the Northern DPS (see Proposed Rule, 70 FR 
17386, April 6, 2005) seem to have had a positive effect on that DPS. 
However, we remain concerned about the risks associated with fishing 
pressure and poaching within the Southern DPS.
    CDFG has stated that sturgeon are highly vulnerable to fisheries, 
and the trophy status of large white sturgeon makes sturgeon a high 
priority for enforcement to protect against poaching (CDFG, 2002). In 
fact, a number of sturgeon poaching operations have been discovered in 
recent years (e.g., https://www.dfg.ca.gov/news/news04/04040.html), and 
we expect poaching pressure to remain high because of the increasing 
demand for caviar, coupled with the decline of other sturgeon species 
around the world, primarily the beluga sturgeon. So while we are 
uncertain how poaching may affect the Southern DPS, we believe that it 
does pose a real risk and that future efforts by the agencies should be 
made to estimate annual mortality rates due to poaching.

Disease or Predation

    Although a number of viral and bacterial infections have been 
reported in hatcheries (https://aquanic.org/publicat/usda_rac/efs/srac/
7200fs.pdf), and habitat conditions such as low water flows and high 
temperatures can exacerbate susceptibility to infectious diseases, we 
do not believe there is sufficient information to suggest that disease 
has played an important role in the decline of the Southern DPS. Non-
native species are an ongoing problem in the Sacramento-San Joaquin 
River and Delta systems through introductions and modification of 
habitat (CDFG, 2002). However, at present we are not able to estimate 
mortality rates imposed by non-native predators (i.e. striped bass) on 
green sturgeon. We do know that striped bass may affect the population 
viability of Chinook salmon (Lindley and Mohr, 2003) and may impose 
significant predation rates on other anadromous species (Blackwell and 
Juanes, 1998). Therefore, we maintain that, while predation risk 
imposed by striped bass on the Southern DPS is uncertain, it likely 
exists, and additional studies are needed to determine the importance 
of this threat to the long-term survival of the Southern DPS.

The Inadequacy of Existing Regulatory Mechanisms

    We reviewed existing regulatory mechanisms in the Proposed Rule as 
part of our evaluation of efforts being made to protect green sturgeon 
(70 FR 17386; April 6, 2005). We noted several Federal, State, and 
local regulatory programs that have been implemented to help reduce 
historical risks to green sturgeon. In particular, changes in 
regulations governing fisheries in Washington and Oregon have 
potentially reduced the risks for the Southern DPS, though regulations 
in California have not changed since the previous Status Review and 
Update. In addition, although there have been efforts to improve 
habitat conditions across the range of the Southern DPS, less has been 
accomplished through regulatory mechanisms to reduce threats posed by 
blocked passage to spawning habitat and water diversions. Thus, we 
conclude that inadequacy of existing regulatory mechanisms has 
contributed significantly to the decline of the Southern DPS and to the 
severity of threats that the Southern DPS currently faces.

Other Natural or Manmade Factors Affecting Its Continued Existence

    This factor was not considered a primary factor in the decline of 
the Southern DPS. Non-native species are an ongoing problem in the 
Sacramento-San Joaquin River and Delta systems (CDFG, 2002). One risk 
for green sturgeon associated with the introduction of non-native 
species

[[Page 17764]]

involves the replacement of relatively uncontaminated food items with 
those that may be contaminated (70 FR 17386; April 6, 2005).
    The previous Status Review (Adams et al., 2002) summarized juvenile 
entrainment data and change in annual mean number over time. Juvenile 
entrainment is considered a type of threat imposed by water diversions, 
but the degree to which it is affecting the continued existence of the 
Southern DPS remains uncertain.

Efforts Being Made to Protect the Southern DPS of Green Sturgeon

    The PECE policy (68 FR 15100; March 28, 2003) provides direction 
for the consideration of protective efforts identified in conservation 
agreements, conservation plans, management plans, or similar documents 
(developed by Federal agencies, State and local governments, Tribal 
governments, businesses, organizations, and individuals) that have not 
yet been implemented, or have been implemented but have not yet 
demonstrated effectiveness. The evaluation of the certainty of an 
effort's effectiveness is made on the basis of whether the effort or 
plan: establishes specific conservation objectives; identifies the 
necessary steps to reduce threats or factors for decline; includes 
quantifiable performance measures for the monitoring of compliance and 
effectiveness; incorporates the principles of adaptive management; and 
is likely to improve the species' viability at the time of the listing 
determination.
    Conservation measures that may apply to listed species include 
those implemented by tribes, states, foreign nations, local 
governments, and private organizations. Also, Federal, tribal, state, 
and foreign nations' recovery actions (16 U.S.C. 1533(f)), Federal 
consultation requirements (16 U.S.C. 1536), and prohibitions on taking 
(16 U.S.C. 1538) constitute conservation measures. In addition, 
recognition through Federal government or state listing promotes public 
awareness and conservation actions by Federal, state, tribal 
governments, foreign nations, private organizations, and individuals.

Fishing Regulations

    Recent management strategies affecting the Northern and Southern 
DPS are outlined in the Proposed Rule (70 FR 17386; April 6, 2005). 
Here we summarize fishery management efforts that affect only the 
Southern DPS. Recent implementation of sturgeon fishing restrictions in 
Oregon and Washington and protective efforts put in place on the 
Klamath, Trinity, and Eel Rivers in the 1970s, 1980s, and 1990s may 
offer protection to the Southern DPS.
    General CDFG angling regulations apply to sturgeon angling from 
Mendocino County south (one fish per day between 117 and 183 cm TL). 
Both white and green sturgeon are protected by the same fishing 
regulations in the Sacramento-San Joaquin system and a closure in 
central San Francisco Bay occurs between January 1 and March 15, 
coinciding with the herring spawning season to protect sturgeon feeding 
on herring eggs (CDFG, 2002). No commercial take is permitted. Active 
sturgeon enforcement is often employed in areas where sturgeon are 
concentrated and particularly vulnerable to the fishery.
    Recently, CDFG recognized that ``extant California fishing 
regulations permit a greater degree of risk to green sturgeon than is 
necessary to allow the popular sturgeon fishery'' (CDFG, 2005). Through 
outreach efforts, it has found strong support for more protective 
sturgeon fishing regulations among the sturgeon fishing community. The 
Fish and Game Commission (Commission) passed an Emergency Regulation 
proposed by CDFG on March 3, 2006, that outlines the following new 
regulations for the recreational sturgeon fishery in California: (1) a 
zero bag limit for green sturgeon throughout California; and (2) a 117-
142 cm fork length (FL) slot limit for white sturgeon throughout 
California. This Emergency Regulation was prompted by the most recent 
(2005) abundance estimate for white sturgeon (117-183 cm FL) in San 
Pablo Bay exhibiting approximately an order of magnitude decline from 
the estimate made in 1998. In addition, the Commission was concerned 
because: (1) other sources of data suggested a large decline in 
abundance of white sturgeon (117-183 cm FL); (2) substantial gaps in 
the existing data regarding abundance of white sturgeon outside the 
117-183 cm FL range; (3) there is substantial and effective fishing 
pressure; and (4) there is interest by the public to implement more 
protective regulations for sturgeon in California. Currently, the CDFG 
and the Commission are working together towards implementing a long-
term set of regulations for the recreational sturgeon fishery that 
would be put in place by 2007.

Habitat Protection Efforts

    A summary of protective habitat efforts is provided in our response 
to Comment 10 above. For a more detailed description, see the Proposed 
Rule (70 FR 17386; April 6, 2005). We review our consideration of how 
these efforts will affect the Southern DPS in our response to Comment 9 
above, and a more detailed examination is provided in the Proposed Rule 
(70 FR 17386; April 6, 2005). Our main conclusions are that: (1) green 
sturgeon focused research will be used to enhance our understanding of 
the risk factors affecting recovery, thereby improving our ability to 
develop effective management measures; however, at present they do not 
directly help to alleviate threats that this species faces in the wild; 
and (2) all ongoing fish screen and passage studies are designed 
primarily to meet the minimum qualifications outlined by the NMFS and 
CDFG fish screen criteria, and though these improvements will likely 
benefit salmonids, there is no evidence showing that these measures 
will decrease the likelihood of green sturgeon mortality.
    As evaluated pursuant to PECE, the above described protective 
efforts do not as yet, individually or collectively, provide sufficient 
certainty of implementation and effectiveness to counter the conclusion 
that the Southern DPS is likely to become an endangered species in the 
foreseeable future throughout its range.

Final Listing Determination

    Based on our evaluation of the best available scientific 
information and the ongoing state and Federal conservation efforts, the 
Southern DPS is likely to become endangered in the foreseeable future 
throughout all of its range and should be listed as threatened. This 
threatened determination is based on the reduction of potential 
spawning habitat, the severe threats to the single remaining spawning 
population, the inability to alleviate these threats with the 
conservation measures currently in place, and the decrease in observed 
numbers of juvenile green sturgeon collected in the past two decades 
compared to those collected historically.

Take Prohibitions and Protective Regulations

    Section 9 of the ESA prohibits the take of endangered species. The 
term ``take'' means to harass, harm, pursue, hunt, shoot, wound, kill, 
trap, capture, or collect, or to attempt to engage in any such conduct 
(16 U.S.C. 1532(19)). In the case of threatened species, ESA section 
4(d) leaves it to the Secretary's discretion whether to, and to what 
extent to, extend the section 9(a) ``take'' prohibitions to the 
species, and authorizes the NMFS to issue regulations it considers 
necessary and advisable for the conservation of the species. Thus, we 
have flexibility under section 4(d) to tailor protective

[[Page 17765]]

regulations, taking into account the effectiveness of available 
conservation measures. The 4(d) protective regulations may prohibit, 
with respect to threatened species, some or all of the acts which 
section 9(a) of the ESA prohibits with respect to endangered species. 
These 9(a) prohibitions and 4(d) regulations apply to all individuals, 
organizations, and agencies subject to U.S. jurisdiction. We will 
evaluate protective regulations pursuant to section 4(d) for the 
Southern green sturgeon DPS and issue proposed regulations in 
forthcoming rules that will be published in the Federal Register.

Other Protective Measures

    Section 7(a)(2) of the ESA requires Federal agencies to confer with 
us on actions likely to jeopardize the continued existence of species 
proposed for listing or result in the destruction or adverse 
modification of proposed critical habitat. If a Federal action is 
likely to adversely affect a listed species or destroy or adversely 
modify its critical habitat, the responsible Federal agency must 
initiate formal consultation. Examples of Federal actions that may 
affect the Southern green sturgeon DPS include: water diversion for 
human use; point and non-point source discharge of persistent 
contaminants; contaminated waste disposal; water quality standards; and 
fishery management practices.
    Sections 10(a)(1)(A) and (B) of the ESA provide us with authority 
to grant exceptions to the ESA's Section 9 ''take'' prohibitions. 
Section 10(a)(1)(A) scientific research and enhancement permits may be 
issued to entities (Federal and non-Federal) for scientific purposes or 
to enhance the propagation or survival of a listed species. The type of 
activities potentially requiring a section 10(a)(1)(A) research/
enhancement permit include scientific research that targets green 
sturgeon.
    Section 10(a)(1)(B) incidental take permits may be issued to non-
Federal entities performing activities that may incidentally take 
listed species, as long as the taking is incidental to, and not the 
purpose of, the carrying out of an otherwise lawful activity.

Service Policies on Endangered and Threatened Fish and Wildlife

    In December 2004, the Office of Management and Budget (OMB) issued 
a Final Information Quality Bulletin for Peer Review establishing 
minimum peer review standards, a transparent process for public 
disclosure of peer review planning, and opportunities for public 
participation. The OMB Bulletin, implemented under the Information 
Quality Act (Public Law 106-554), is intended to enhance the quality 
and credibility of the Federal government's scientific information, and 
applies to influential scientific information disseminated on or after 
June 16, 2005.
    Pursuant to our 1994 policy on peer review (59 FR 34270; July 1, 
1994), we have solicited the expert opinions of at least three 
appropriate and independent specialists regarding pertinent scientific 
or commercial data and assumptions relating to the taxonomy, population 
models, and supportive biological and ecological information for 
species under consideration for listing. We conclude that these expert 
reviews satisfy the requirements for ``adequate [prior] peer review'' 
contained in the Bulletin (sec. II.2.).

Critical Habitat

    Critical habitat is defined in section 3 of the ESA as: (i) the 
specific areas within the geographical area occupied by the species, at 
the time it is listed in accordance with the ESA, on which are found 
those physical or biological features (I) essential to the conservation 
of the species and (II) which may require special management 
considerations or protection; and (ii) specific areas outside the 
geographical area occupied by the species at the time it is listed upon 
a determination that such areas are essential for the conservation of 
the species (16 U.S.C. 1532(5)(A). Section 4(b) of the ESA states that 
designation of critical habitat should occur at the same time as the 
final ruling, unless the Secretary deems that critical habitat is not 
then determinable, in which case the time to critical habitat 
designation may be extended by 1 year. In a previous Federal Register 
notice (66 FR 64793; December 14, 2001) we requested specific 
information on critical habitat; however, because no substantial 
information was received, we are again seeking public input and 
information to assist in gathering and analyzing the best available 
scientific data to support a critical habitat designation.
    The Secretary has determined that critical habitat designation for 
the Southern DPS is not yet determinable. We will continue to meet with 
co-managers and other stakeholders to review information that will be 
used in the overall designation process. We will then initiate 
rulemaking with the publication in the Federal Register of a proposed 
designation of critical habitat, followed by a period for public 
comment and the opportunity for public hearings.