Endangered and Threatened Wildlife and Plants: Proposed Threatened Status for Southern Distinct Population Segment of North American Green Sturgeon, 17386-17401 [05-6611]

Agencies

• DEPARTMENT OF COMMERCE
• National Oceanic and Atmospheric Administration

[Federal Register Volume 70, Number 65 (Wednesday, April 6, 2005)]
[Proposed Rules]
[Pages 17386-17401]
From the Federal Register Online via the Government Printing Office [www.gpo.gov]
[FR Doc No: 05-6611]


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DEPARTMENT OF COMMERCE

National Oceanic and Atmospheric Administration

50 CFR Part 223

[Docket No. 050323081-5081-01; I.D. 031505C]
RIN 0648-AT02


Endangered and Threatened Wildlife and Plants: Proposed 
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: Proposed rule; request for comments.

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SUMMARY: We, the NMFS, have completed an update of an Endangered 
Species Act (ESA) status review for the North American green sturgeon 
(Acipenser medirostris; hereafter ``green sturgeon''). After reviewing 
new and updated information on the status of green sturgeon and 
considering whether green sturgeon is in danger of extinction 
throughout all or a significant portion of its range, or is likely to 
become endangered within the foreseeable future throughout all or a 
significant portion of its range, we confirm our earlier determination 
that the species is comprised of two distinct population segments 
(DPSs) that qualify as species under the ESA, the Northern and Southern 
DPSs. We reaffirm our earlier determination that the Northern DPS does 
not warrant listing as threatened or endangered at this time, and we 
will maintain the DPS on the Species of Concern List due to remaining 
uncertainties about its status and threats. We revise our previous 
``not warranted'' finding for the Southern DPS and propose to list it 
as threatened. This revision is based on: 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; threats that have remained severe since the 
last status review and have not been adequately addressed by 
conservation measures currently in place; fishery-independent data 
exhibiting a negative trend in juvenile green sturgeon abundance; and 
new information showing evidence of lost spawning habitat in the upper 
Sacramento and Feather Rivers. We will reevaluate the status of the 
Northern DPS in 5 years. If the proposed listing is finalized, a 
recovery plan will be prepared and implemented for the Southern DPS. 
Protective regulations under ESA section 4(d) and critical habitat will 
be proposed in a subsequent Federal Register notice.

DATES: Comments on this proposal must be received by July 5, 2005. A 
public hearing will be held promptly if any person so requests by May 
23, 2005. Notice of the location and time of any such hearing will be 
published in the Federal Register not less than 15 days before the 
hearing is held.

ADDRESSES: You may submit comments by any of the following methods:
     E-Mail: GreenSturgeon.Comments@noaa.gov
     Federal e-Rulemaking Portal: https://www.regulations.gov. 
Follow the instructions for submitting comments.
     Mail: Submit written comments to Chief, Protected 
Resources Division, Southwest Region, National Marine Fisheries 
Service, 501 West Ocean Blvd., Suite 4200, Long Beach, CA, 90802-4213.
    The updated green sturgeon status review and other 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, or the Assistant Regional Administrator, Protected 
Resources Division, Northwest Region, NMFS, 1201 NE Lloyd Avenue, Suite 
1100, Portland, OR 97232.

FOR FURTHER INFORMATION CONTACT: Melissa Neuman, NMFS, Southwest Region 
(562) 980-4115; Scott Rumsey, NMFS, Northwest Region (503) 872-2791; 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 Information Center, Center

[[Page 17387]]

 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 determination 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). The BRT presented its findings in a 
final status review report for North American green sturgeon (Adams et 
al., 2002). Under the ESA, a listing determination may address a 
species, subspecies, or a DPS of any vertebrate species which 
interbreeds when mature (16 U.S.C. 1532(16)). On February 7, 1996, the 
U.S. Fish and Wildlife Service (FWS) and NMFS adopted a policy 
describing what constitutes a DPS of a taxonomic species (61 FR 4722). 
The joint DPS policy identified two elements that must be considered 
when making DPS determinations: (1) The discreteness of the population 
segment in relation to the remainder of the species (or subspecies) to 
which it belongs; and (2) the significance of the population segment to 
the remainder of the species (or subspecies) to which it belongs. After 
conducting the status review, we determined 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 population in the Sacramento River 
(``Southern DPS'').
    The BRT considered the following information in order to assess 
risk factors for each green sturgeon DPS: (1) abundance trends from 
fisheries data; (2) the effects of fishing bycatch; (3) the possible 
loss of spawning habitat in rivers where spawning is reported to have 
occurred historically, but apparently no longer does; (4) concentration 
of spawning in the Klamath and Sacramento River systems; (5) lack of 
adequate population abundance data; (6) potentially lethal water 
temperatures and adverse effects of contaminants; (7) entrainment 
(defined here as loss of green sturgeon due to water diversion) by 
water projects; and (8) adverse effects of non-native species. Based on 
the 2002 risk assessment, we determined on January 23, 2003, 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). Along with the finding, we 
announced that we would reevaluate the status of green sturgeon in 5 
years.
    On April 7, 2003, the Environmental Protection Information Center 
(and other Plaintiffs) 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 endangered 
within the foreseeable future throughout all or a significant portion 
of its range. The U.S. District Court's March 2004 remand was issued 
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 in the early summer of 2004 
and added a new member from USGS who possessed considerable knowledge 
of green sturgeon. The BRT was asked 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 information from the 
public to assist us in updating our status review and making a new 
listing determination (69 FR 34135).
    In addition to the information solicited during the first status 
review, we solicited any new information beyond that considered in the 
2002 green sturgeon status review or the January 2003 1-year ``not 
warranted'' finding on the following topics for the Northern and 
Southern DPSs of green sturgeon: (1) new genetic, morphological, 
physiological, or ecological information relevant to DPS 
identification; (2) current or historic information documenting the 
geographic extent (e.g., area, river mile distance) and magnitude 
(e.g., abundance of spawning females, reproductive output) of spawning 
in particular river systems (e.g., Fraser River, Umpqua River, South 
Fork Trinity River, Eel River, Feather River, and San Joaquin River); 
(3) information documenting the current geographic extent and magnitude 
of spawning in areas other than where it is known to presently occur 
(i.e., areas other than the Sacramento River, Klamath River and Rogue 
River); (4) the legitimacy of references used to support information 
regarding current or historic spawning in the systems mentioned above 
in (2) and (3), particularly citations by Houston (1988) for the Fraser 
River; Lauman et al. (1972) and the Oregon Department of Fish and 
Wildlife (ODFW) (2002) for the Umpqua River; Moyle et al. (1992) and 
references therein for the South Fork Trinity River; Puckett (1976), 
Moyle et al. (1992) and references therein for the Eel River; Wang 
(1986) and FWS (1995) for the Feather River; and Moyle et al. (1992) 
and references therein for the San Joaquin River; (5) historic, current 
or future factors that may be responsible for the reported loss of 
spawning habitat and associated spawning populations; and (6) fishery-
dependent and -independent abundance data for analysis of population 
trends.
    The public comment period closed on August 17, 2004. The BRT 
convened to draft an updated status review in November 2004.
    On January 27, 2005, we distributed the updated status review to 
co-managers (i.e., States of Washington, Oregon and California, Yurok 
and Hoopa Tribes, FWS, and the California Bay-Delta Program) for 
review. The final updated status review for green sturgeon was 
completed by the BRT on February 22, 2005, and submitted to NMFS 
Regional Offices for further consideration prior to the publication of 
this notice.

[[Page 17388]]

Biology and Life History of Green Sturgeon

    A thorough account of green sturgeon biology and life history may 
be found in the previous 1-year finding (68 FR 4433; January 23, 2003) 
and the updated status review (Adams et al., 2005), which are 
incorporated here by reference. The following is a summary of that 
information.

Adult Distribution and Feeding

    The green sturgeon is the most widely distributed member of the 
sturgeon family Acipenseridae. Like all sturgeon species it is 
anadromous, but it is also the most marine-oriented of the sturgeon 
species. Green sturgeon are known to range in nearshore marine waters 
from Mexico to the Bering Sea and are commonly observed in bays and 
estuaries along the western coast of North America, with particularly 
large concentrations entering the Columbia River estuary, Willapa Bay, 
and Grays Harbor during the late summer (Moyle et al., 1992). The 
reasons for these concentrations are unclear, but do not appear to be 
related to spawning or feeding (Beamesderfer, 2000).
    Little is known about adult green sturgeon feeding. Adults in the 
Sacramento-San Joaquin Delta are reported to feed on benthic 
invertebrates including shrimp, mollusks, amphipods, and even small 
fish (Moyle et al., 1992). One hundred and twenty-one green sturgeon 
stomach samples from the Columbia River gillnet fishery were empty with 
the exception of one fish, while all white sturgeon stomachs contained 
digested material (ODFW 2002).

Spawning

    Adult green sturgeon are thought to spawn every 3 to 5 years 
(Tracy, 1990), but new information suggests that spawning could occur 
as frequently as every 2 years (Lindley and Moser, pers. comm., 2004). 
Adults typically migrate into fresh water beginning in late February 
(Moyle et al., 1995); spawning occurs from March July, with peak 
activity from April June (Moyle et al., 1995). Confirmed spawning 
populations in North America are in the Rogue (Erickson et al., 2001, 
Rien et al., 2001), Klamath, and Sacramento Rivers (Moyle et al., 1992; 
CDFG, 2002). Green sturgeon females produce 60,000 - 140,000 eggs 
(Moyle et al., 1992), and they are the largest eggs (diameter 4.34mm) 
of any sturgeon species (Cech et al., 2000). Spawning occurs in deep 
turbulent river mainstems. Klamath and Rogue River populations appear 
to spawn within 100 miles (161 km) of the ocean, while the Sacramento 
spawning run may travel over 200 miles (322 km). Specific spawning 
habitat preferences are unclear, but eggs likely are broadcast over 
large cobble where they settle into the cracks (Moyle et al., 1995). 
Optimum flow and temperature requirements for spawning and incubation 
are unclear, but spawning success in most sturgeons is related to these 
factors (Dettlaff et al.,1993). Temperatures above 68 F (20[deg]C) were 
lethal to embryos in laboratory experiments (Cech et al., 2000).

Early Life History and Maturation

    Green sturgeon larvae first feed at 10 days post hatch and grow 
quickly reaching a length of 66mm and a weight of 1.8 g in 3 weeks of 
exogenous feeding. Metamorphosis to the juvenile stage is complete at 
45 days. Juveniles continue to grow rapidly, reaching 300mm in 1 year 
and over 600mm within 2 3 years for the Klamath River (Nakamoto et al., 
1995). Juveniles spend from 1 4 years in fresh and estuarine waters and 
disperse into salt water at lengths of 300-750mm. The little that is 
known regarding juvenile green sturgeon feeding habits comes from a 
study conducted in the Sacramento-San Joaquin Delta, where juveniles 
fed on opossum shrimp and amphipods (Radtke, 1966).
    Green sturgeon disperse widely in the ocean after their out-
migration from freshwater (Moyle et al., 1992). Tagged green sturgeon 
from the Sacramento and Columbia Rivers are primarily captured to the 
north in coastal and estuarine waters, with some fish tagged in the 
Columbia River being recaptured as far north as British Columbia (WDFW, 
2002a). While there is some bias associated with recovery of tagged 
fish through commercial fishing, the pattern of a northern migration is 
supported by the large concentration of green sturgeon in the Columbia 
River estuary, Willapa Bay, and Grays Harbor, which peaks in August. 
These fish tend to be immature; however, mature fish and at least one 
ripe fish have been found in the lower Columbia River (WDFW, 2002a). 
Genetic evidence suggests that Columbia River green sturgeon are a 
mixture of fish from at least the Sacramento, Klamath, and Rogue Rivers 
(Israel et al., 2002). Mature males range from 139 199cm in fork length 
(FL) and 15 to 30 years of age (VanEenennaam, 2002). Mature females 
range from 157 223cm FL and 17 to 40 years of age. Maximum ages of 
adult green sturgeon are likely to range from 60-70 years (Moyle, 
2002).

Summary of New Information

Consideration as a ``Species'' Under the ESA

    The ESA defines species as ``any subspecies of fish or wildlife or 
plants, and any distinct population segment of any species of 
vertebrate fish or wildlife that interbreeds when mature'' 16 U.S.C. 
1532(16). This definition allows for the recognition of DPSs at levels 
below taxonomically recognized species or subspecies. On February 7, 
1996, the FWS and NMFS published a joint policy to clarify the phrase 
``distinct population segment'' for the purposes of listing, delisting 
and reclassifying species under the ESA (61 FR 4722). This policy 
identifies two criteria that must be met for a population segment to be 
considered a DPS under the ESA: (1) The discreteness of the population 
segment in relation to the remainder of the species or subspecies to 
which it belongs; and (2) the significance of the population segment to 
the species or subspecies to which it belongs.
    New genetic information in combination with the tendency of 
sturgeon to exhibit high spawning site fidelity confirms the 
conclusions drawn during the previous 1-year ``not warranted'' finding 
(68 FR 4433; January 29, 2003) that the northern and southern 
populations of green sturgeon are ``discrete'' and ``significant'' as 
defined in the DPS policy. (For a complete discussion of the 
discreteness and significance of the U.S. population of green sturgeon 
see 68 FR at 4437).

Genetic Information

    Updated analyses of green sturgeon genetic structure were made 
available from University of California - Davis (J. Israel and B. May, 
pers. comm., 2004). These results incorporated a greater number of 
samples including new adult samples from the Umpqua River, new juvenile 
samples from the Sacramento River, and an increase in microsatellite 
DNA loci to nine over the six reported in the previous status review 
and discussed in Israel et. al. (2004). Green sturgeon samples 
demonstrate a strong division between a grouping of the Rogue, Klamath, 
and Umpqua Rivers versus a grouping of the Sacramento and Columbia 
Rivers and San Pablo Bay samples. The northern group included mixed 
stock green sturgeon samples from the Umpqua River as well as single 
stock samples from the Rogue and Klamath Rivers and the southern group 
included mixed stock samples from the Columbia River, samples from San 
Pablo Bay that may be either mixed or single stock, and single stock 
samples from the Sacramento River.

[[Page 17389]]

Oceanic Distribution and Behavior

    New oceanic distribution and behavior information came from pop-off 
archival tags (7 fish), Oregon trawl logbook analysis, and acoustic 
tags (168 fish). These data indicated that green sturgeon generally 
make northward migrations, to points as far north as northwest 
Vancouver Island, Canada, upon returning to the ocean. During oceanic 
migrations, archival tagged fish occupied depths of 40-70 m and 
remained exclusively inside the 110 m contour. These results are 
confirmed by Oregon trawl logbook records (Erickson and Hightower, 
2004). Fish marked in spawning areas (Rogue and Klamath Rivers and San 
Pablo Bay) and in mixed stock areas (Columbia River and Willapa Bay) 
with acoustic tags in 2002, 2003, and 2004 sustained migrations of 100 
km per day. Several fish tagged in 2002 returned to the Rogue River in 
2004, suggesting a minimal spawning periodicity of 2 years if it is 
assumed that these fish were ripe and returning to the River to spawn 
(S. Lindley and M. Moser, pers. comm., 2004).

Freshwater Distribution Information

    We requested new historic and/or current information for particular 
river systems where historic and current spawning status is uncertain 
(e.g., Fraser River, Umpqua River, South Fork Trinity River, Eel River, 
Feather River, and San Joaquin River; 69 FR 34135). New information was 
received for the Chehalis, Umpqua, Rogue, and Eel Rivers within the 
Northern DPS and the Sacramento, Feather, and San Joaquin Rivers within 
the Southern DPS.

Northern DPS

    Washington Department of Fish and Wildlife (WDFW) investigated the 
Chehalis River as potential green sturgeon habitat, and while it 
appears to possess suitable habitat features for green and white 
sturgeon spawning, there has not been evidence of spawning occurring in 
this basin (WDFW, 2004). Data summarized from catch record cards 
suggest that a few green sturgeon were caught in sport fisheries as far 
upriver as 60 kilometers during July 2002, March 2003, and December 
2003, but these may be misidentifications of white sturgeon, which are 
much more common within the basin. Sport anglers have reported small 
green sturgeon in Grays Harbor; however, these fish were most likely of 
a post-migratory size and therefore were not fish rearing in the 
estuary. Green and white sturgeon eggs and larvae have not been 
observed in the Chehalis River or Grays Harbor.
    There are two confirmed records of green sturgeon captured above 
tidal influence in the Umpqua River (T. Rien, pers. comm., 2004). In 
July 2000, two juvenile green sturgeon (each approximately 10-cm long) 
were regurgitated from two smallmouth bass caught at river kilometer 
(rkm) 134 on the Umpqua River. The ODFW interviewed the local angling 
guide, and the one available regurgitated fish was positively 
identified as a green sturgeon. The other regurgitated sturgeon was not 
available to examine. In April 1979, a 1.8 m green sturgeon was caught 
at rkm 164 on the Umpqua River. A picture of the fish was published in 
the Roseburg News Review (May 3, 1979) and it was visually identified 
as a green sturgeon by ODFW. ODFW has sampled the Umpqua River in 2002, 
2003, and 2004 using gill nets, beach seines, snorkeling, and 
underwater video, and their sampling efforts did not capture any green 
sturgeon above tidal influence in the Umpqua River.
    A putative green juvenile sturgeon was captured at Big Butte Creek 
(rkm 254) near Lost Creek Dam on the Rogue River (R. Reisenbichler, 
pers. comm., 2004). This is unusual because it is very high in the 
system and above two major dams with fish ladders (Savage Rapids and 
Gold Ray) and several smaller dams.
    Adult green sturgeon were sighted on the mainstem Eel River near 
Fort Seward, California (rkm 101) during snorkel surveys in 1995 and 
1996 (S. Downie, pers. comm., 2004). Three sturgeon were sighted each 
year at a place locally known as ``The Sturgeon Hole.'' Two juvenile 
green sturgeon were captured in the Eel River estuary in 1994 by trawl 
(S. Cannata, pers. comm., 2004). The first one was 282mm FL and the 
second was 510mm. This is in addition to the previously reported 
capture of 26 juvenile green sturgeon near Fort Seward in 1967 and 1968 
(Pluckett, 1976).

Southern DPS

    Recent habitat evaluations conducted in the upper Sacramento and 
Feather Rivers for salmonid recovery planning suggest that significant 
potential green sturgeon spawning habitat was made inaccessible or 
altered by dams (historical habitat characteristics, temperature, and 
geology summarized in Lindley et al., 2004). This spawning habitat may 
have extended up into the three major branches of the Sacramento River, 
the Little Sacramento River, the Pit River system, and the McCloud 
River.
    Green and white sturgeon adults have been observed periodically in 
small numbers in the Feather River (Beamesderfer et al., 2004). There 
are at least two confirmed records of adult green sturgeon in 2004. 
There are no records of larval or juvenile sturgeon of either species, 
even prior to the 1960's when Oroville Dam was built. There are reports 
that green sturgeon may reproduce in the Feather River during high flow 
years (CDFG, 2002), but these are not specific and are unconfirmed.
    Small fisheries for sturgeon occur in spring on the San Joaquin 
River between Mossdale and the Merced River (Kohlhorst, 1976). Though 
sturgeon are known to migrate into the San Joaquin River, no efforts 
have been made to document sturgeon reproduction (FWS, 1995). In 
addition, data are not regularly collected at diversions on the San 
Joaquin River, and when sturgeon have been collected, species 
differentiation rarely occurred. Information exists through interviews 
with biologists, wardens, and anglers regarding the presence and 
potential spawning of white sturgeon on the San Joaquin River (FWS, 
1995). Two juvenile white sturgeon caught at Woodbridge on the 
Mokelumne River (rkm 63) in 2003 are the first confirmation of white 
sturgeon reproduction in the San Joaquin River system (Beamesderfer et 
al., 2004). Though no green sturgeon have ever been documented in the 
San Joaquin River upstream of the Delta or in the Stanislaus, Tuolumne, 
and Merced Rivers (CDFG, 2002; Beamesderfer et al., 2004), the San 
Joaquin River and its tributaries have been heavily modified in ways 
that reduce suitability for sturgeon since the 1940s, so the lack of 
contemporary information cannot be considered evidence of historical 
green sturgeon absence. Moreover, species with a similar dependence on 
historic deep cool waters of the San Joaquin for spawning (i.e., 
spring-run Chinook salmon; Yoshiyama et al., 2001; and white sturgeon, 
FWS, 1995) are either extirpated or nearly so on the San Joaquin River, 
indicating that a once self-sustaining green sturgeon population on the 
San Joaquin River may have been possible.

Catch Information

    The coastwide bycatch of green sturgeon continues to be reduced 
over time as noted in the previous status review (Adams et al., 2002). 
Based on updated and corrected bycatch numbers, green sturgeon take has 
been reduced from a high of 9,065 in 1986 to 862 in 2001, the last year 
in the previous status review, to 512 in 2003. The greatest reductions 
in bycatch (direct and indirect) were for the commercial fisheries in 
the Northern

[[Page 17390]]

 DPS, specifically the Columbia River, Willapa Bay, and Grays Harbor. 
This reduction has occurred due to regulatory changes summarized in 
Adams et al. (2002), Appendix 1 Table 2. Yurok and Hoopa tribal green 
sturgeon fisheries have remained constant, with relatively constant 
effort, and together account for 59 percent of the coastwide green 
sturgeon catch in 2003.

Historic Spawning Status

    Information presented in the first status review (Adams et al., 
2002) and new information presented here regarding the historic and 
current spawning status of green sturgeon were analyzed.

Conclusions from New Information

    In earlier technical memos and Federal Register publications (66 FR 
64793, December 14, 2001; 68 FR 4433, January 23, 2003), we reported 
the loss of green sturgeon spawning habitat in the Umpqua, Fraser, 
South Fork Trinity, Eel (Northern DPS), Upper Sacramento, Feather, and 
possibly San Joaquin Rivers (Southern DPS) based on information 
presented in the petition. These claims prompted us to report that 
green sturgeon experienced a significant reduction in spawning area. 
New analysis of existing information and the submission of new 
information to us in August 2004 (69 FR 34135) leads us to revise these 
earlier judgments in the following ways.

Northern DPS

    There is no evidence of historic or current spawning in the Fraser 
or Chehalis Rivers (D. Lane, pers. comm., 2004; WDFW, 2004). Based on 
the lack of data, we cannot conclude that there has been a loss of 
spawning habitat over time in these systems.
    Known historic and current spawning, based primarily on the 
presence of juvenile green sturgeon, occurs in the Umpqua, Rogue, 
Klamath and Trinity Rivers, and, therefore, we conclude that 
populations have not been extirpated from these systems (T. Rein, pers. 
comm., 2004; Erickson et al., 2002; Moyle, 2002; Sheiff et al., 2001). 
We are uncertain as to whether spawning habitat has been lost in the 
Umpqua River. A significant reduction in spawning habitat is not likely 
to have occurred in the Rogue River because there are no impassable 
barriers along green sturgeon migration routes. Although the Klamath 
River has undergone human alteration, data suggest that the geographic 
extent of spawning in the system has not been reduced over time. A 
paucity of data for the Trinity River limits our ability to comment on 
the magnitude of loss of spawning habitat in this system.
    There is evidence to suggest that green sturgeon spawned in the 
South Fork Trinity River and continue to spawn there to some degree, 
based on the presence of adults in freshwater areas above tidal 
influence (CDFG, 1978; Moyle et al., 1992). We suspect that spawning 
habitat still exists in this system, but have no evidence to comment on 
whether spawning habitat has been reduced over time.
    The Eel River is the only system in the Northern DPS where the 
status of spawning since historic times is believed to have changed. 
Spawning is known to have occurred in the past based on the presence of 
juveniles (Plunkett, 1976), but recently, only adults have been present 
in the River (S. Downie, pers. comm., 2004) and one juvenile, whose 
natal stream origin is uncertain, was collected in the estuary. Despite 
Moyle et al.'s (2002) claim that green sturgeon have been extirpated 
from the Eel River, we determined that our ability to make a conclusion 
regarding extirpation is limited by: (1) low sampling effort in recent 
times (see Status of Green Sturgeon DPSs: Northern DPS); and (2) our 
inability to determine how much spawning habitat or reproductive 
potential may have been lost.

Southern DPS

    Known historic and current spawning, based on the presence of 
juvenile green sturgeon, occurs in the Sacramento River (Adams et al., 
2002). We have indirect evidence, based on habitat assessments of 
Chinook salmon, that the geographic extent of spawning has been reduced 
due to impassable barriers (the Keswick and Shasta dams) in the upper 
Sacramento River. We have not been able to quantify the reduction of 
habitat to date, and are uncertain how reduction in spawning habitat 
has affected the population's viability.
    Spawning is suspected to have occurred in the Feather River due to 
the presence of adults in the system (CDFG, 2002). Although there is no 
evidence of spawning in the past or now, the continued presence of 
adults in the system suggests that green sturgeon are trying to migrate 
into presumed spawning areas now blocked by the Oroville Dam. 
Therefore, we conclude that spawning habitat may have been lost in the 
Feather River, but we were not able to determine how much habitat or 
reproductive potential was lost.
    There is no evidence of historic or current spawning in the San 
Joaquin River (Beamesderfer, 2004; Adams et al., 2002; CDFG, 2002). 
While we cannot make any conclusions regarding loss of spawning habitat 
over time in the San Joaquin River, indirect evidence from a variety of 
sources (Moyle, 2002; Lindley et al., 2004; L. Hess, pers. comm., 2004) 
suggests that both adult and juvenile green sturgeon may have been 
present in this system in the past. If spawning did occur in the San 
Joaquin River in the past, there may have been a reduction in spawning 
habitat again due to reasons mentioned above for the Sacramento and 
Feather Rivers.

Summary of Factors Affecting the Species

    Section 4 of the ESA (16 U.S.C. 1533) and regulations promulgated 
to implement the listing provisions of the ESA (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. A species may be determined to be 
endangered or threatened due to one or more of the five factors 
described in section 4(a)(1) of the ESA. We must determine if either 
DPS of green sturgeon 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 human-made 
factors affecting its continued existence.

Species-wide Factors

    Ocean and estuarine bycatch of green sturgeon in the white sturgeon 
and salmonid fisheries was considered a species-wide factor for decline 
since its impact could not be apportioned to one DPS or the other. 
Current total catch of green sturgeon has been reduced to 6 percent of 
its 1986 high value of 9,065 fish; this does not, however, necessarily 
represent a reduction in green sturgeon abundance. 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). Yurok and Hoopa tribal catch has 
remained relatively constant during the entire time series. The 
reduction in catch through protective

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 management measures represents a reduction in risk to the Northern 
DPS. 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.
    A summary of DPS-specific factors for decline is presented below 
(Tables 1 and 2). These factors were only considered for those river 
systems with known or suspected historical or current spawning 
activity.

Northern DPS Factors

    The potential factors for decline in the Northern DPS are reduced 
flows, changed flow regimes, increased temperatures, and reduced oxygen 
concentrations, principally in the Klamath-Trinity and Eel River 
systems (Table 1). The impact of these factors is uncertain. This DPS 
also has the only major in-river fishery for green sturgeon (Yurok and 
Hoopa tribal fisheries in the Klamath-Trinity River system), the 
effects of which are uncertain, but catch data show no obvious signs of 
decline. As mentioned in the previous section, species-wide reduction 
in bycatch fishing mortality through protective management measures 
reduces the threat of overfishing in the Northern DPS. No risks due to 
disease, predation, or inadequacy of existing regulatory mechanisms 
were identified. The Northern DPS has two known major spawning 
populations (e.g., the Klamath-Trinity River system and the Rogue 
River) that are not close to one another geographically, thus spreading 
risks of extinction over more than one spawning area. Spawning also 
appears to occur infrequently in the Umpqua River. This gives the 
Northern DPS some additional protection.

Southern DPS Factors

    The principal factor for decline for this DPS comes from the 
reduction of green sturgeon spawning area to a limited area of the 
Sacramento River (Table 2). 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 on the Feather River are similar to those faced in the 
Sacramento River (NMFS, 2004). The BRT concluded that a viable spawning 
population of green sturgeon no longer exists in the Feather River and 
was likely lost due to the habitat blockage as a result of Oroville Dam 
and from thermal barriers associated with the Thermalito Afterbay 
Facility (Table 2). Any observations of adult green sturgeon likely 
represent individuals that were stranded as a result of these barriers.
    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 agricultural, 
municipal, and industrial water diversions in the Sacramento River and 
Delta to green sturgeon are largely unknown as juvenile sturgeon are 
often not identified, and current California Department of Fish and 
Game (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 (Table 2 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 (Table 
2). This association of year class strength with outflow is also found 
in other anadromous fishes inhabiting the Estuary, such as striped 
bass, Chinook salmon, American shad, and longfin smelt (Stevens and 
Miller, 1983). Mean April-May flow rates of 566 cubic meters per second 
appear to be the minimum required for the production of good year class 
strength based on approximately 20 years of sturgeon salvage data at 
the Skinner Fish Facility (CDFG, 2002). According to this criterion, 
low flow rates occurred slightly more than 50 percent of the time 
during the years spanning 1968-1987 (CDFG, 2002). The FWS (1995) used 
water year types, based on an index developed for the Sacramento Basin 
(California Department of Water Resources, 2004), to suggest that low 
flow conditions occurred 53 percent of the time during the years 
spanning 1944-2004. It is postulated that low flow rates could dampen 
survival by hampering the dispersal of larvae to areas of greater food 
availability, hampering the dispersal of larvae to all available 
habitat, delaying the transportation of larvae downstream of water 
diversions in the Delta, or decreasing nutrient supply to the nursery, 
thus stifling productivity (CDFG, 1992). There are no current 
indications that flow rates will increase over time.
    High temperatures no longer seem to be the problem that they once 
were with the installation of the Shasta Dam temperature control device 
in 1997, although Shasta Dam has a limited storage capacity and cold 
water reserves could be depleted in long droughts (Table 2). 
Temperatures at RBDD have not been higher than 16[deg] C since 1995 
(California Data Exchange Center) and are within the green sturgeon egg 
and larvae optimum for growth and survival of 15[deg] to 19[deg] C 
(Mayfield and Cech, 2004). However, green sturgeon reproduction before 
1995 may well have been adversely affected by temperature and these 
earlier high temperatures may have caused population reductions that 
would still affect the overall population size and age-structure (Table 
2). Water temperatures on Feather River downstream of the Thermalito 
Afterbay outlet are considerably higher than temperatures in the low-
flow channel (FWS, 1995). It is likely that high water temperatures 
(greater than 17.2[deg] C) may deleteriously affect sturgeon egg and 
larval development, especially for late-spawning fish in drier water 
years (FWS, 1995). CDFG (2002) also indicated water temperatures may be 
inadequate for spawning and egg incubation in the Feather River during 
many years as the result of releases of warmed water from Thermalito 
Afterbay. CDFG believed this may be one reason neither green nor white 
sturgeon are found in the river in low-flow years. It is not expected 
that water temperatures will become more favorable in the near future 
(CDFG, 2002) and thus elevated water temperature continues to be a 
threat.
    Sturgeon have high vulnerability to fisheries, and the trophy 
status of large white sturgeon makes these fishes a high priority for 
enforcement to protect against poaching (Table 2; CDFG, 2002). Green 
sturgeon are caught incidentally in these white sturgeon fisheries.
    Non-native species are an ongoing problem in the Sacramento-San 
Joaquin River and Delta systems (Table 2; CDFG, 2002). One risk for 
green sturgeon associated with the introduction of non-native species 
involves the replacement of relatively uncontaminated food items with 
those that may be contaminated. For example, the non-native overbite 
clam, Potamocorbula amurensis, introduced in 1988, has become the most 
common food of white sturgeon and was found in the only green

[[Page 17392]]

sturgeon examined thus far (CDFG, 2002). The overbite clam is known to 
bioaccumulate selenium, a toxic metal (CDFG, 2002; Linville et al., 
2004). Green sturgeon may also experience predation by introduced 
species including striped bass.
    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 striped bass larvae (Bailey, 
1994). 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, 
the BRT concluded that some degree of risk from contaminants probably 
also occurs for green sturgeon (Table 2).
    The previous status review (Adams et al., 2002) summarized juvenile 
entrainment and change in annual mean number over time. Juvenile 
entrainment is considered a type of threat imposed by water diversion 
(Table 2).

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Status of Green Sturgeon DPS

Northern DPS

    The Fraser River in Canada currently has a catch and release 
fishery for sturgeon, but the number of green sturgeon captured is 
extremely small. A tagging study in 1992-1993 tagged 2300 sturgeon and 
only one was a green sturgeon (D. Lane, pers. comm., 2004). Green 
sturgeon occur off the West Coast of Vancouver Island where they are 
taken in the trawl fishery. These fish are thought to be from spawning 
areas in the United States, and this idea is supported by the recent 
acoustic and pop-off archival tagging. WDFW has investigated the 
possibility of green sturgeon spawning in the Chehalis River as it 
appears to provide suitable habitat features to support spawning. 
However, no evidence of spawning in this system has occurred to date. 
Currently, there is limited fishing in Grays Harbor, but no evidence of 
spawning has been found (WDFW, 2004).
    Spawning does appear to take place in the Umpqua River, but is 
probably rare. Juvenile green sturgeon were identified in the system in 
2000. Spawning in the Umpqua River apparently is not common since 
substantial sampling efforts in 2002, 2003, and 2004 failed to find any 
evidence of green sturgeon spawning.
    The presence of green sturgeon spawning in the Rogue River has been 
only recently discovered. The river is less manipulated and habitat 
seems to be of better quality than in other green sturgeon spawning 
rivers. Blockages to migration of anadromous fish are likely to be 
upriver of the historical extent of green sturgeon spawning habitat 
and, therefore, do not seem to be limiting; habitat seems to be roughly 
what it was historically. Other anadromous salmonid fishes are 
generally doing well in the Rogue River (Weitkamp et al., 1995; Busby 
et al., 1996; and Myers et al., 1998).
    The Klamath River has the largest green sturgeon spawning 
population. Spawning still occurs upstream to the historical limit of 
its habitat range (Ishi Pishi Falls). Out-migrant juvenile green 
sturgeon are captured each year in screw traps at Big Bar (Schieff et 
al., 2001). The BRT expressed concerns over recent fish kills in the 
Klamath River, but reached no conclusions regarding whether or not the 
temperature regime in the system played a part in this mortality event. 
The Yurok tribal fishery comprises the majority of green sturgeon catch 
coastwide. There is no new information regarding abundance trends since 
the last status review (Adams et al., 2002). As discussed in the 
previous status review, the trends in numbers and size are difficult to 
interpret, but do not appear to indicate population decline.
    There are few available data regarding the status of green sturgeon 
in the Trinity River system. The Hoopa Tribe has a small in-river 
fishery which takes fewer than 30 adult green sturgeon each year. 
Juvenile out-migrant green sturgeon are captured in most years in small 
numbers at Willow Creek (Schieff et al., 2001). Due to the continued 
presence of juveniles within the system, the BRT was not convinced that 
green sturgeon were extirpated from the South Fork Trinity River by the 
1964 flood as suggested by Moyle (2002).
    The Eel River is the southern-most known spawning area in the 
Northern DPS. Moyle et al. (1992) suggested that green sturgeon were 
extirpated from the Eel River following the 1964 flood. The 1955 and 
1964 floods delivered large amounts of sediment into the Eel River. 
These historical flood events, combined with land use practices, have 
resulted in persisting high sediment levels. Some portion of the deep 
holes that green sturgeon use during spawning were filled in by the 
1955 and 1964 flood events, but the extent of sturgeon habitat loss is 
unknown. The BRT was not convinced that green sturgeon have been 
extirpated from the Eel River. Sightings of adults in both 1995 and 
1996 and of juveniles in the estuary in 1994 suggest that a green 
sturgeon population persists in the Eel River, although severely 
reduced from historical levels. Sampling was limited with adult surveys 
conducted only in 1995 and 1996 and estuarine surveys conducted only in 
1993 and 1994.
    The evaluation of extinction risk over a ``significant portion of 
its range'' is difficult for this DPS because of the lack of historical 
data about green sturgeon spawning areas. As explained above, in 
earlier technical memos and Federal Register publications (66 FR 64793, 
December 14, 2001; 68 FR 4433, January 23, 2003) we had discussed the 
possibility that spawning habitat in the Fraser, Umqua, South Fork 
Trinity, and Eel Rivers had beenseverely reduced. However, after 
reviewing both existing and new information, we have revised those 
earlier judgments and now conclude that the Eel River is the only 
system in the Northern DPS where the status of spawning since historic 
times is believed to have changed. All BRT members felt that the 
historic spawning area of the DPS had been larger than the current 
spawning area, but with no historical data describing spawning areas, 
there was a range of thought about how much larger.
    The BRT was unable to come to firm consensus on what should be 
considered ``a significant portion'' for this DPS, however, they 
generally agreed that ``a significant portion'' of the DPS's range 
would include either the Klamath or Rogue Rivers, and that the South 
Fork Trinity and Eel Rivers do not represent a significant portion of 
the DPS's range. The BRT's opinion regarding ``significant portion of 
its range'' is supported by drawing analogies from salmonid habitat use 
and estimated abundance in the Klamath, Rogue, South Fork Trinity and 
Eel Rivers (Lindley et al., 2004). Salmonid spawning habitat is more 
extensive and estimated population abundance is higher in the Klamath 
and Rogue Rivers than in the South Fork Trinity and Eel Rivers, and we 
expect that green sturgeon habitat requirements and population size are 
correlated with those of salmonids, both historically and today. Also, 
the geology of the Eel River, in particular, is more erosive and prone 
to sedimentation events, suggesting that spawning habitat in the Eel 
River is of poorer quality than that in the Klamath and Rogue Rivers. 
Finally, evidence suggests that the Klamath and Rogue Rivers played a 
more important role in historic Yurok and Hoopa tribal sturgeon 
fisheries than the Eel and South Fork Trinity Rivers (FWS, 1981), again 
supporting the BRT's conclusion that neither the Eel nor South Fork 
Trinity Rivers constitute a significant portion of the Northern DPS' 
range.

Conclusion-Northern DPS

    Based on the input provided by the BRT, we conclude that the 
Northern DPS of green sturgeon is not in danger of extinction, nor 
likely to become endangered in the foreseeable future, in all or a 
significant portion of its range. While a significant portion of the 
DPS' range would include either the Klamath or the Rogue Rivers, 
neither of these populations is regarded as being at risk of 
extirpation now or in the foreseeable future. The BRT was not convinced 
that green sturgeon were extirpated from the South Fork Trinity or Eel 
Rivers, even though it is likely that the Eel River population, in 
particular, has suffered a severe reduction since historic times. 
Reference data from salmonid habitat assessments and tribal fisheries 
data suggest that even though green sturgeon populations in the Eel and 
South Fork Trinity Rivers are likely low, these rivers do not represent 
a significant portion of the DPS' range. The majority of the BRT felt 
that the presence of two

[[Page 17396]]

well-separated and significant spawning populations in the Klamath and 
Rogue Rivers, and the effective reduction in green sturgeon catch due 
to implemented regulatory mechanisms, confer a low level of risk to the 
DPS. A minority felt that overall paucity of data generates such 
uncertainty in green sturgeon status that the DPS' level of extinction 
risk may be higher than available data appear to indicate. The BRT 
expressed concern regarding the lack of data and monitoring efforts to 
adequately monitor the status of, and manage potential threats to, 
green sturgeon populations in this DPS. The BRT recommended that the 
Northern DPS be placed on the Species of Concern List, that their 
status be reviewed in at least 5 years, and that population status 
monitoring be implemented immediately.

Southern DPS

    The BRT concluded that the Sacramento River contains the only known 
green sturgeon spawning population in this DPS. There are no updated 
population trends data since the last status review. The BRT concluded 
that there was almost certainly a substantial loss of spawning habitat 
behind Keswick and Shasta dams (FWS, 1995b, historical habitat data 
summarized in Lindley et al., 2004 for salmonids). Green sturgeon 
currently occur up to the impassible barrier at Keswick Dam (FWS, 
1995b). It is unlikely that green sturgeon reproduced in their current 
spawning area under the historical temperature regime that occurred 
before the construction of Shasta and Keswick dams. At present, water 
temperatures in the current spawning area are lower than they were 
historically due to releases from Shasta Dam. Prior to dam 
construction, green sturgeon would have had to migrate farther up the 
mainstem than they do now in order to encounter water temperatures cool 
enough to trigger spawning. The BRT considered it possible that the 
additional habitat behind Shasta Dam in the Pit, McCloud, and Little 
Sacramento systems would have supported separate populations or at 
least a single, larger Sacramento River population less vulnerable to 
catastrophes than one confined to a single mainstem, but the BRT was 
unable to be specific due to the paucity of historical information. The 
BRT expressed concern about the habitat limitation and potential 
threats that green sturgeon faced in the Sacramento River and again 
expressed particular concern about the high numbers of juveniles 
entrained prior to 1986.
    Juvenile entrainment data provide an indication of how abundance 
has changed over time (1968-present). For the State facility (John 
Skinner Fish Facility; 1968-2001), the estimated average number of 
green sturgeon taken per year prior to 1986 was 732; from 1986 on, the 
average number was 47. For the Federal facility (Tracy Fish Collection 
Facility; 1980-2001), the average number prior to 1986 was 889; from 
1986 on, the average was 32. The significant reduction in numbers is 
consistent across the State and Federal facilities and is also 
consistent with significant reductions in estimated white sturgeon take 
within the same time periods (NMFS, 2005). In addition, evidence 
indicates export levels at both facilities have increased 
substantially, particularly at the State facility since the 1970s and 
1980s (as exhibited by yearly acre-feet exported from Federal and State 
facilities, NMFS, 2005). Though there are many assumptions associated 
with fish salvage estimates at these facilities (i.e., estimates are 
expanded catches from brief sampling periods; CDFG, 2002), this 
information may be the best available data in determining the 
population trends of the Southern DPS.
    The BRT concluded that an effective population of spawning green 
sturgeon does not exist in the Feather River. Although there is no 
evidence of spawning in the Feather River either in the past or now, 
the continued presence of adults in the system suggests that green 
sturgeon are trying to migrate ito presumed spawning areas now blocked 
by Oroville Dam, suggesting in turn that spawning habitat on the Fraser 
River may bave been lost. A substantial amount of habitat in the 
Feather River was lost with the construction of Oroville Dam 
(constructed in 1961) and from thermal barriers at the Thermalito 
Afterbay facility (CDFG, 2002). FWS (1995b) stated that ``Evidence also 
suggests that [white] sturgeon reproduction occurs in both the Feather 
and Bear rivers.'' Again, the BRT assumed that a similar suggestion 
could be made for green sturgeon in the face of the paucity of data. 
Sturgeon (including some documented green sturgeon) still regularly 
occur in the Bear and Yuba Rivers (CDFG, 2002; Beamesderfer et al., 
2004) and, therefore, must migrate through the Feather River. Threats 
to green sturgeon are similar to those faced in the Sacramento River.
    Though the BRT concluded that there was not sufficient information 
to establish whether the San Joaquin River system once supported a 
viable green sturgeon population, we see no reason to exclude the San 
Joaquin River system as a possibly occupied watershed in the past based 
on similar conclusions reached for Chinook salmon habitat assessments 
in the Sacramento and Feather Rivers. While some authors indicate that 
there is no evidence of green sturgeon occurrence or spawning in the 
San Joaquin River (Beamesderfer et al., 2004; Adams et al., 2002; CDFG, 
2002), sampling effort has been extremely limited. Thus, no evidence of 
presence does not necessarily mean that green sturgeon do not occur in 
this system. Moyle (2002) suggested that green sturgeon reproduction 
may have taken place in the San Joaquin River because numerous juvenile 
green sturgeon have been captured at Santa Clara Shoal and Brannan 
Island Recreational Area in the Delta. Both adult and juvenile green 
sturgeon salvage recoveries at the Federal facility, located closest to 
the San Joaquin River, also provide some evidence that the San Joaquin 
River system may at least be occupied by green sturgeon during parts of 
the year. The potential threats faced by green sturgeon if they do 
occur or occurred in the past in the San Joaquin system would be 
similar in nature to those faced in the Sacramento River, but would 
likely be more extreme because there are a greater number of impassable 
barriers in this system, many of which lack fish passage structures, 
and flow rates are lower in the San Joaquin than those in the 
Sacramento.

Conclusion-Southern DPS

    The majority of the BRT concluded that the Southern DPS is likely 
to become endangered in the foreseeable future throughout all of its 
range. The BRT felt that the blockage of green sturgeon spawning from 
what were historic spawning areas above Shasta Dam (although it is 
unclear whether these were separate populations) and the accompanying 
decrease in spawning area with the loss of a potential spawning area in 
the Feather River make green sturgeon in the Southern DPS likely to 
become endangered within the foreseeable future. We believe that the 
loss of potential spawning habitat in the San Joaquin River system also 
may have contributed to the overall decline of the Southern DPS. The 
majority of the BRT also felt that the concentration of spawning adults 
in the Sacramento River places this DPS at even greater risk of 
extinction. No BRT members felt that the DPS was at imminent risk of 
extinction.

[[Page 17397]]

Efforts Being Made to Protect Green Sturgeon

    Section 4(b)(1)(A) of the ESA requires the Secretary of Commerce to 
make listing determinations solely on the basis of the best scientific 
and commercial data available after taking into account efforts being 
made to protect a species. Therefore, in making its listing 
determinations, we first assess a DPS's level of extinction risk and 
identify 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 DPS.
    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). 
PECE 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 policy 
articulates several criteria for evaluating the certainty of 
implementation and effectiveness of protective efforts to aid in 
determining whether a species should be listed as threatened or 
endangered. Evaluations of the certainty an effort will be implemented 
include whether: the necessary resources (e.g., funding and staffing) 
are available; the requisite agreements have been formalized such that 
the necessary authority and regulatory mechanisms are in place; there 
is a schedule for completion and evaluation of the stated objectives; 
and (for voluntary efforts) the necessary incentives are in place to 
ensure adequate participation. 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.
    PECE also notes several important caveats. Satisfaction of the 
above mentioned criteria for implementation and effectiveness 
establishes a given protective effort as a candidate for consideration, 
but does not mean that an effort will ultimately change the risk 
assessment. The policy stresses that just as listing determinations 
must be based on the viability of the species at the time of review, so 
they must be based on the state of protective efforts at the time of 
the listing determination. PECE does not provide explicit guidance on 
how protective efforts affecting only a portion of a species' range may 
affect a listing determination, other than to say that such efforts 
will be evaluated in the context of other efforts being made and the 
species' overall viability. There are circumstances where threats are 
so imminent, widespread, and/or complex that it may be impossible for 
any agreement or plan to include sufficient efforts to result in a 
determination that listing is not warranted.
    Conservation measures that may apply to listed species include 
conservation measures 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 in Oregon and Washington have 
considerably reduced the catch of green sturgeon. There are no targeted 
commercial fisheries on green sturgeon, and recreational fishing 
remains negligible. Commercial by-catch of green sturgeon occurs 
predominantly during the early fall salmon and white sturgeon fisheries 
in the lower Columbia River, when the green sturgeon have migrated into 
the estuary and lower river mainstem. Fisheries are timed to avoid 
coinciding with peak periods of green sturgeon presence. Since 2002, 
Oregon and Washington have adopted daily landing limits for sturgeon 
during fall Columbia River commercial salmon seasons. This management 
action has resulted in a significant decrease in green sturgeon catch 
due to the higher value (price per pound) of white sturgeon on the 
commercial market. Harvesters now typically release all green sturgeon 
(alive) to fill their weekly or daily landing limit with the more 
valuable white sturgeon. Additionally, this management approach has 
allowed the commercial fishery to access its allocation of white 
sturgeon prior to periods of peak green sturgeon presence and without 
any fisheries targeting sturgeon, further minimizing green sturgeon by-
catch.
    Protective efforts on the Klamath and Trinity Rivers began with 
take limits and maximum size ranges through the late 1970s, and between 
1978 and 1993 seasonal limits were imposed to prohibit the take of 
sturgeon in the Klamath River upstream of and including the Trinity 
River. All sturgeon fishing has been prohibited in the Klamath-Trinity 
system since 1993. Sturgeon fishing also has been prohibited since 1993 
in all waters of the Eel River from the mouth to rkm 153 including all 
waters of the South Fork Eel River downstream of Benbow Dam (CDFG, 
2002). Sturgeon fishing in rivers and bays in Del Norte and Humboldt 
Counties, including the Smith River, Humboldt and Arcata Bays, and all 
tidal waters, has been prohibited since 1993. General angling 
regulations apply to sturgeon angling from Mendocino County south (one 
fish per day between 117 and 183cm TL).
    Both white and green sturgeon are protected by the same fishing 
regulations in the Sacramento-San Joaquin system. No commercial take is 
permitted and angling take is restricted to one fish per day between 
117 and 183cm TL. An additional 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). Active sturgeon enforcement is often employed in areas where 
sturgeon are concentrated and particularly vulnerable to the fishery.
    There is no commercial fishery for green sturgeon in Canada, 
although the species is taken as by-catch in white sturgeon and salmon 
fisheries.

Habitat Protection Efforts

    In the United States, the Central Valley Project Improvement Act 
(CVPIA) is a Federal act directing the Secretary of the Interior to 
amend previous authorizations of California's Central Valley Project to 
include fish and wildlife protection, restoration, and mitigation as 
project purposes having equal priority with irrigation and domestic 
use, and fish and wildlife enhancement as a project purpose equal to 
power generation. As a result o