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ORDER DENYING PLAINTIFFS’ MOTION FOR SUMMARY JUDGMENT AND GRANTING DEFENDANTS’ CROSS-MOTION FOR SUMMARY JUDGMENT ELIZABETH D. LAPORTE, United States Magistrate Judge. In this civil action for declaratory and injunctive relief, Plaintiffs Center for Biological Diversity and Greenpeace (collectively, “Plaintiffs”) allege that Defendants Jane Lubehenco, Administrator of the National Oceanic and Atmospheric Administration (“NOAA”), Gary Locke, the United States Secretary of Commerce, and the National Marine Fisheries Service (“NMFS”) violated the Endangered Species Act (“ESA”), 16 U.S.C. §§ 1531, et seq., in failing to list the ribbon seal as threatened or endangered. See Compl. ¶ 1; see also Administrative Record (“AR”) 13 (Endangered and Threatened Wildlife; Notice of 12-Month Finding on a Petition to List the Ribbon Seal as a Threatened or Endangered Species, 73 Fed. Reg. 79822). The parties filed cross-motions for summary judgment, which were fully briefed. In addition, the State of Alaska filed two amicus briefs in support of Defendants. The Court held a hearing on September 2, 2010. For the reasons stated at the hearing and in this Order, the Court denies Plaintiffs’ Motion for Summary Judgment and grants Defendants’ Cross-Motion for Summary Judgment. RIBBON SEAL The ribbon seal primarily inhabits Russia’s Sea of Okhotsk and the Bering and Chukchi Seas off of western Alaska. See AR 13 at 79823. The species is strongly associated with the sea ice during its whelping, mating and molting periods from mid-March through June. See id. Most of the rest of the year is spent at sea, and the ribbon seal is rarely seen on land. See id. Ribbon seals can live twenty to thirty years, and females give birth to one pup every year after four to five years of age. See id.; AR 11 at 11. The pup is nursed for three to four weeks and then abandoned to fend for itself. See AR 13 at 79823. Once the sea ice melts with the onset of sub-Arctic summer in June, ribbon seals spread throughout their range. See AR 11 at 10. Sea ice is essential to ribbon seal survival. AR 11 at 20-23. However, the sea ice habitat has been shrinking. AR 890 at 4 (showing declines in sea ice in the Bering and Okhotsk Seas during March through June). For example, there is evidence that for the period from 1979 through 2006, the sea ice extent in the Okhotsk Sea declined by 9.3% per decade. AR 890 at 4. One estimate states that the summer sea ice habitat in the Bering and Okhotsk Seas is projected to decline by 40% by mid-century. AR 319 at 4. Loss of Arctic sea ice (distinct from the sea ice in the Bering Sea and Okhotsk Sea) could increase shipping through the area, and therefore through some parts of the ribbon seals’ habitat. AR 11 at 84, 92. Expansion of commercial fishing could impact ribbon seals through bycatch and through competition for prey. AR 11 at 92. Because ribbon seals rely on the sea ice for breeding, whelping, nursing and molting, declines in sea ice could impact ribbon seals. AR 255 at 21-22; AR 854 at 1. Declining sea ice areas could also lead to declining birth rates if females cannot find quality ice on which to give birth. AR 11 at 27. Survival of weaned pups can be affected if they do not have sufficient ice to haul out while they are learning to swim. AR 145 at 6. Dr. Rey, a ribbon seal expert, has explained how losses of sea ice have already probably resulted in high pup mortality. AR 8 at 3 (“The case of the ribbon seal is most urgent ... Pups remain on or near the ice during a 4-week molting period, when they begin to feed. However, during 2006 and 2007, little sea ice remained beyond mid-May, depriving the pups of their habitat and requiring a high-energy demand for aquatic life. It is highly unlikely that the pups could meet this demand, probably resulting in high mortality during the following summer.”). Sea ice loss can also affect adults that need the ice to molt. AR 11 at 26-27. PROCEDURAL HISTORY In December 2007, NMFS received a petition to list the ribbon seal under the ESA. See AR 1. NMFS conducted an initial review to determine whether the petition presented “substantial scientific information indicating that the petition may be warranted.” 16 U.S.C. § 1533(b)(3)(A). NMFS issued a positive ninety-day finding and initiated a Status Review of the ribbon seal. AR 3 at 2. Alaska participated in the public comment period during which it provided information about the role that the state plays in monitoring and protecting the health of the ribbon seal and the state’s long term interest in maintaining a healthy seal population. See Alaska Amicus Brief at 2. Alaska has been actively involved in ribbon seal research and management since at least 1970, and provided NMFS with over sixty studies, reports, correspondence, or other writings by state-funded personnel. Alaska’s Amicus brief at 11. In conducting its Status Review, NMFS assembled a Biological Review Team (“BRT”) of eight expert scientists, including a climate expert from the Office of Oceanic and Atmospheric Research. See AR 521a. The Status Review was published on December 19, 2008. AR 11. The BRT concluded that ribbon seals were not in current danger of extinction throughout all or a significant portion of their range, and that the population was “likely to decline gradually for the foreseeable future [to 2050], primarily from slight but chronic impacts on reproduction and survival caused by reduced frequency of years with sea ice of suitable extent, quality and duration of persistence,” but that “despite the expectation of a gradual decline, ribbon seals are not likely to become an endangered species within the foreseeable future throughout all or a significant portion of their range.” AR 11 at 86. NMFS considered the Status Review along with other information, and recommended adopting the BRT team’s conclusions and recommendations. AR 12 at 1-3. On December 30, 2008, NMFS published the twelvemonth finding that listing the ribbon seal was not warranted. AR 13. STATUS REPORT AND TWELVEMONTH FINDING The BRT was composed of scientists with expertise in the biology and ecology of ribbon seals and in fisheries from NMFS’s Alaska Fisheries Science Center, and a climate expert from NOAA’s Pacific Marine Environment Lab..AR 13 at 79823. The BRT had two tasks: to determine whether the ribbon seal qualified as one or more species under the ESA and, if so, to conduct an extinction risk assessment to determine whether the species is endangered or threatened. Id. NMFS evaluated the extinction risk based on the five factors set forth in the ESA. 16 U.S.C. § 1533(a)(1)(A)-(E). Preliminarily, with respect to demographic factors, NMFS found that “with a population likely comprising at least 200,000 individuals, ribbon seals are not currently at risk from the demographic issues of low abundance commonly associated with ESA listing decisions.... ” AR 13 at 79824. Researchers developed a provisional population estimate of 49,000 ribbon seals in the eastern and central Bering Sea, and using “restrictive assumptions,” the number was scaled to produce total Bering Sea estimates ranging from 98,000 to 190,000. Id. Similar scalings based on a rangewide distribution produced estimates in the Bering Sea, Sea of Okhotsk and the total range of 115,000, 100,000 and 215,000 respectively. Id. NMFS found that: The current population trend is unknown, but the recent estimate of 49,000 ribbon seals in the eastern and central Bering Sea is consistent enough with historical estimates to suggest that no major or catastrophic change has occurred in recent decades. The species is thought to occupy its entire historically observed range. There are no portions of their range in which ribbon seals have been reported to have disappeared, nor are they known to be demographically at risk in any portion of their range. Id. Plaintiffs state that the population estimates are overly optimistic because there is not much data, so it is equally likely that the population is declining. Further, the Status Review states that “no current and reliable abundance estimates have been published.” AR 11 at 37. The Status Review also states: “the great uncertainty about ribbon seal population trends restricts the overall confidence in assessing the species’ long term risks.” AR 11 at 44. NMFS concluded that: “overall, it appears that ribbon seals have had generally good conditions in the central Bering Sea during the past several decades.” AR 11 at 30 (citing Quackenbush and Citta (2008)). But the Quackenbush and Citta study was limited in its ability to detect population change because of low sample size. AR 328 at 27-28 (finding a trend to older classes of ribbon seals, which might be indicative of declining population). Another Quackenbush study (AR 329) revealed that the majority of subsistence hunters offering an opinion had not observed a decline in ribbon seal populations since they began hunting (although there was little information about ribbon seals because they are rarely encountered). AR 11 at 38-39. With respect to the first factor, present or threatened destruction, modification or curtailment of habitat or range, NMFS addressed the issue of sea ice coverage in the ribbon seal’s range. The BRT’s climate change expert, Dr. Overland, and his colleague, Dr. Stabeno, prepared a paper on climate change impacts to the ribbon seal. AR 445. The result of that analysis was the recognition by NMFS scientists of a distinction in climate science between summer ice in the Arctic and spring ice in the Bering Sea: “decoupling of the climate system between summer ice extent in the Arctic basin and spring ice extent in the Bering Sea, and thus the climate impact on the habitats for the ribbon and other ice-associated seals of the Bering Sea.” AR 11 at 49. The twelve-month finding states: Unlike the Arctic Ocean, where sea ice is present year round, the ice in the Bering Sea and Sea of Okhotsk is seasonal in nature. The main thermodynamic physical influence at high latitudes is the cold and darkness that occurs in winter. Therefore, despite the recent dramatic reductions in Arctic Ocean ice extent during summer, the sea ice in the northern Bering Sea and Sea of Okhotsk is expected to continue forming annually in winter for the foreseeable future. Id. Moreover, “[t]he result is that the seasonal formation of sea ice in the northern Bering Sea and Sea of Okhotsk is substantially decoupled from the summer ice extent in the Arctic Ocean, and is expected to continue annually through the foreseeable future, along with typical, large interannual variations in extent and duration of persistence.” Id. This definition regarding the de-coupling of the two ice areas is supported by three sets of data. First, the Overland and Stabeno paper reviewed climate data for Nome, Alaska indicating that the average high temperature was -3 degrees C, and concluded that even assuming a warming of 3 degrees C by 2050, “it is likely that melting of sea ice will not begin until May for either present or future global warming conditions.” AR 445 at 2. Second, NMFS scientists examined sea ice conditions in the Bering Sea in 2008, which presented near record-high sea ice in the Bering Sea, with the melt not occurring until June, which is a clearer case of decoupling. AR 445 at 2-3; AR 11 at 50. Third, NMFS’s scientists performed new modeling by Dr. Overland using the same model to his earlier paper with Wang in 2007. AR 319. That modeling showed that “while there is some decrease in sea ice area in April out to 2050 ... it is nearly impossible to create a sea ice free Bering Sea in April.” AR 445 at 5 (predicting “large interannual variability” in May, which is “not unlike the climatological record”). This result contrasts with projections of summer ice in the Arctic Ocean, where climate models indicate a 50% sea ice loss or more by 2050. AR 445 at 5. The new modeling concluded that “sea ice cover will remain a major ecological factor for the northern Bering Sea and the Sea of Okhotsk during late winter through spring.” AR 11 at 55. However, the data indicated that there may be “more frequent years of low or minimal ice extent, particularly in May-June. Id. The Status Review team observed that the seasonal formation of sea ice in the northern Bering Sea and the Sea of Okhotsk is substantially de-coupled from the summer ice formation in the Arctic Ocean. AR 11 at 63. Therefore, the review team analyzed models dealing with the former, not the latter, areas. AR 11 at 63 (analysis indicates that “the late March to early May period in which the peak of reproduction occurs will continue to have substantial ice for the foreseeable future.”). The de-coupling of the Bering-Okhotsk sea ice regime from the Arctic regime means that: “ribbon seals ... are anticipated to experience little or no direct effects from the further retreat of summer sea ice in the Arctic polar basin, as they are primarily a pelagic, sub-Arctic species during the summer months.” AR 11 at 67. Instead, “if ribbon seal habitat within the current range is reduced by climate change, it is plausible that the population will adjust by shifting its range to include new habitat made suitable by, for example, a northward shift of the typical spring ice edge.” AR 11 at 46-47. Plaintiffs argue that de-coupling does not change the fact that both summer sea ice in the Arctic and winter sea ice in the Bering and Okhotsk Seas are disappearing. AR 889, 890, 891, 905. NMFS responds that the characterization of the latter ice as “disappearing” is overstated because there is evidence that the sea ice will remain within the parameters to which the ribbon seal is adapted. AR 11 at 95. Further, “while there may be more frequent years in which sea ice coverage is reduced, the late March to early May period in which the peak of ribbon seal reproduction occurs will continue to have substantial ice for the foreseeable future.” AR 13 at 79825. NMFS noted that there had been no study to verify whether vital rates of reproduction or survival have been affected by interannual variations in ice extent and breeding. Id. Survival of the young could be affected because the ice will not extend as far south as it has typically in the past, but “lacking relevant data, the most conservative approach is to assume that the population has been at equilibrium with respect to conditions in the past and that a change such as more frequent breeding farther from preferred foraging habitats will have some impact in vital rates.” Id. (concluding that slight increase in warmer years will have “some impact on reproductive rates”). The Status Review team, however, found a lack of relevant data regarding impacts on seal reproduction. AR 11 at 63-64 (finding that the analogy to harp seals is inapt because they have characteristics such as grouping and being tied to specific places, that are different from ribbon seals). Subadults, which molt earlier than adults and are not constrained by habitat requirements for breeding, “may be the least sensitive to the availability and quality of sea ice.” Id. Adult ribbon seals, which are the last to molt, might be expected to be the most affected by the warmer years, but NMFS could not quantify the impacts or the extent to which ribbon seals may adapt by shifting locations for molting. Id. NMFS concluded that: “the anticipated slight increase in frequency of years with low ice extent in May and June is likely to have some impact on survival rates.” Id. NMFS found some mitigating factors, including that ribbon seals “may be less constrained to a specific geographic area or region of the ice pack once breeding is complete, around the time of the adult molt.” AR 13 at 79826. Also, the models used by NMFS to determine the existence of sea ice may show no sea ice where in fact there is sufficient sea ice for the ribbon seal. Id. Also, the age of maturation for females has been low and pregnancy rates have been high in the recent past, implying that foraging conditions have been more favorable than previously. Id. Further, the Status Review team found other factors indicating that ribbon seals are particularly resilient in the face of climate change. For example, there is data that some seal species may be able to breed earlier in the year in gradual response to environmental conditions. AR 11 at 65 (citing AR 241). Further, there is data showing the ribbon seals are highly mobile and thus more likely to move with the ice. AR 11 at 65-66 (citing AR 115). The Status Review identified factors going to the ribbon seal’s resilience, stating that the seal’s evolution “includes at least one period when the conditions were in many respects similar to consensus model projections for high northern latitudes in the late 21st century.” AR 11 at 95. Thus, the review team concluded that the seal retained the “genetic plasticity to adapt to ... climatic extremes.” Id. NMFS concluded that: “the net impacts will be slight but chronic and likely to cause a gradual decline in the ribbon seal population, but such decline is of insufficient magnitude to place it in danger of extinction throughout all or a significant portion of its range, now or within the foreseeable future.” AR 13 at 79826. NMFS contrasted the ribbon seal with the recent decision to list the polar bear as threatened. AR 13 at 79826. NMFS addressed ocean acidification, which is a result of increased carbon dioxide in the atmosphere, stating that it “may impact ribbon seal survival and recruitment through disruption of trophic regimes that are dependent on calcifying organisms,” but that the “nature and timing of such impacts are ... extremely uncertain.” Id. Finally, NMFS noted that changes in ribbon seal prey, “anticipated in response to habitat changes resulting from ocean warming, and loss of sea ice, have the potential for negative impacts, but these impacts are not well understood.” Id. With respect to the second factor, NMFS looked at over-utilization for commercial, subsistence, recreational, scientific or educational purposes and determined that these were “currently at very low levels and [are] not projected to increase to significant threat levels in the foreseeable future.” AR 13 at 79826-79827. NMFS noted that even though Russian commercial harvest quotas are quite high (approximately 18,000 annually), “the actual takes are low because of poor economic viability.” Id. at 79827. Subsistence harvest levels are historically low, but could increase if sea ice conditions force ribbon seals closer to land occupied by Alaskan Native communities. Id. Third, NMFS looked at disease, parasites and predation, none of which are a significant threat to the ribbon seal. AR 13 at 79827. A variety of pathogens and diseases were found among ribbon seals, but the population impact was unknown, although there could be an increase if the habitat is shifted. Id. Ribbon seals are not known to be the primary prey of any predators. Id. Fourth, NMFS examined the inadequacy of existing regulatory measures and found that: There is little evidence that the inadequacy of existing regulatory mechanisms currently poses a threat to ribbon seals throughout all or a significant portion of their range. However, there are no known regulatory mechanisms that effectively address global reductions in sea ice habitat at this time. Also, it is unclear what regulatory mechanisms are in place to ensure that potential commercial harvests in Russia are conducted in a sustainable fashion. AR 13 at 79827. Fifth, NMFS also examined other natural or manmade factors affecting the species’ continued existence. AR 13 at 79827. Although there are some pollutants in the habitat, there was no “conspicuous evidence of toxicity or other significant impacts to the species.” Id. Oil and gas exploration and development activities could affect the ribbon seal, but would probably be low because the ribbon seal is highly dispersed during the year when they are not breeding, whelping and molting. Id. The threat posed by oil spills would increase if development and shipping activities increase across the ribbon seal range. Id. NMFS noted that bycatch is not a particularly significant threat. Id. Shipping traffic could increase with the decrease of Arctic sea ice, which could have an impact on ribbon seals. Id. NMFS also addressed conservation efforts, and stated that it was not aware of any conservation efforts. AR 13 at 79828. Nor is the ribbon seal subject to any special protections or designations by foreign nations. Id. NMFS concluded that: (1) Ribbon seals are not in current danger of extinction throughout all or a significant portion of their range; (2) the abundance of the ribbon seal population is likely to decline gradually for the foreseeable future, primarily from slight but chronic impacts on reproduction and survival caused by reduced frequency of years with sea ice of suitable extent, quality, and duration of persistence; (3) despite the expectation of a gradual decline, ribbon seals are not likely to become an endangered species within the foreseeable future throughout all or a significant portion of their range. AR 13 at 79828. Nevertheless, NMFS added the ribbon seal to the Species of Concern list, which will “(1) increase public awareness about the species; (2) further identify data deficiencies and uncertainties in the species’ status and the threats it faces; (3) and stimulate cooperative research efforts to obtain the information necessary to evaluate the species’ status and threats.” Id. LEGAL STANDARD The Court reviews challenges under the ESA to ensure that the agency has not acted in a manner that is: “arbitrary, capricious, an abuse of discretion, or otherwise not in accordance with law.” 5 U.S.C. § 706; see also River Runners for Wilderness v. Martin, 593 F.3d 1064, 1067 (9th Cir.2010) (stating that the plaintiffs in that case had not satisfied the “high threshold” for setting aside agency action); Trout Unlimited v. Lohn, 559 F.3d 946, 955 (9th Cir.2009) (“In applying this standard, we defer to the informed exercise of agency discretion, especially where that discretion is exercised in an area where the agency has special ‘technical expertise.’ ”); Okanogan Highlands Alliance v. Williams, 236 F.3d 468, 471 (9th Cir.2000). Further: Normally, an agency rule would be arbitrary and capricious if the agency has relied on factors which Congress has not intended it to consider, entirely failed to consider an important aspect of the problem, offered an explanation for its decision that runs counter to the evidence before the agency, or is so implausible that it could not be ascribed to a difference in view or the product of agency expertise. Motor Vehicle Manufacturers Association of the United States, Inc. v. State Farm Mutual Automobile Ins. Co., 463 U.S. 29, 43, 103 S.Ct. 2856, 77 L.Ed.2d 443 (1983). The Court’s role is to: consider whether the [agency’s] decision was based on a consideration of the relevant factors and whether there has been a clear error of judgment, [citation omitted]. Although this inquiry into the facts is to be searching and careful, the ultimate standard of review is a narrow one. The court is not empowered to substitute its judgment for that of the agency. The final inquiry is whether the Secretary’s action followed the necessary procedural requirements. Citizens to Preserve Overton Park, Inc. v. Volpe, 401 U.S. 402, 416, 91 S.Ct. 814, 28 L.Ed.2d 136 (1971). Further, “[i]n recognition of the agency’s technical expertise the court usually defers to the agency’s analysis, particularly within its area of competence.” Arizona Cattle Growers’Association v. Salazar, 606 F.3d 1160, 1163 (9th Cir.2010) (citing Earth Island Inst. v. Hogarth, 494 F.3d 757, 766 (9th Cir.2007); Nat’l Ass’n of Home Builders v. Norton, 340 F.3d 835, 843-44 (9th Cir.2003)); see also Trout Unlimited, 559 F.3d at 959 (“It is not our role to ask whether we would have given more or less weight to different evidence, were we the agency. Assessing a species’ likelihood of extinction involves a great deal of predictive judgment. Such judgments are entitled to particularly deferential review.”). “However, the court need not defer to the agency when the agency’s decision is without substantial basis in fact, and there must be a rational connection between the facts found and the determinations made.” Id. (citing Earth Island, 494 F.3d at 766); see also Brower v. Evans, 257 F.3d 1058, 1065 (9th Cir.2001) (“The deference accorded an agency’s scientific or technical expertise is not unlimited. The presumption of agency expertise can be rebutted when its decisions, while relying on scientific expertise, are not reasoned.”) (internal citation omitted). FRAMEWORK OF THE ENDANGERED SPECIES ACT Congress enacted the ESA in 1973 “to provide a means whereby the ecosystems upon which endangered species and threatened species depend may be conserved.” 16 U.S.C. § 1531(b). The ESA’s “primary purpose ... is to prevent animal and plant species endangerment and extinction caused by man’s influence on ecosystems, and to return the species to the point where they are viable components of their ecosystems.” H.R.Rep. No. 95-1625, at 5 (1978), reprinted in 1978 U.S.C.C.A.N. 9453, 9455. The ESA requires NMFS to engage in certain analyses that are at issue in this case. First, NMFS must decide whether a population of fish or wildlife constitutes a “species” or a “distinct population segment” within the meaning of the ESA. The ESA defines “species” to include “any subspecies of fish or wildlife or plants, and any distinct population segment of any species of vertebrate fish or wildlife which interbreeds when mature.” 16 U.S.C. § 1532(16) (emphasis added). “The ability to designate and list [distinct population segments] allows the [agency] to provide different levels of protection to different populations of the same species.” Nat’l Ass’n of Home Builders v. Norton, 340 F.3d 835, 842 (9th Cir.2003). The ESA does not define the term “distinct population segment.” Second, after deciding whether a population of fish or wildlife constitutes a “species” or a “distinct population segment,” NMFS must decide whether to “list” the species or distinct population segment. A species or distinct population segment may be listed as either “endangered” or “threatened.” 16 U.S.C. § 1533(a)(1). An “endangered” species “is in danger of extinction throughout all or a significant portion of its range.” Id. § 1532(6). A “threatened” species “is likely to become an endangered species within the foreseeable future.” Id. § 1532(20). A species may be considered “threatened” or “endangered” because of: (A) the present or threatened destruction, modification, or curtailment of its habitat or range; (B) overutilization for commercial, recreational, scientific, or educational purposes; (C) disease or predation; (D) the inadequacy of existing regulatory mechanisms; or (E) other natural or manmade factors affecting its continued existence. Id. § 1533(a)(1)(A)-(E). The ultimate listing determinations must be based “solely on ... the best scientific and commercial data available after conducting a review of the status of the species.” Id. § 1533(b)(1)(A). The identification of a downward trend in habitat by itself is not sufficient to establish that a species should be listed under the ESA. See Defenders of Wildlife v. Norton, 258 F.3d 1136, 1143 (9th Cir.2001) (stating that it “does not make sense to assume that the loss of a predetermined percentage of habitat or range would necessarily qualify a species for listing.”). Plaintiffs argue that the best available scientific and commercial data standard gives “the benefit of the doubt” to the species. See Center for Biological Diversity v. Lohn, 296 F.Supp.2d 1223, 1239 (W.D.Wash.2003). However, as the Court in Trout Unlimited v. Lohn, 645 F.Supp.2d 929, 947 (D.Or.2007) observed: “Although an agency must still use the best available science to make that [listing] determination, Conner [v. Burford, 848 F.2d 1441 (9th Cir.1988) ] cannot be read to require an agency to ‘give the benefit of the doubt to the species’ under Section 4 if the data is uncertain or inconclusive. Such a reading would require listing a species as threatened if there is any possibility of it becoming endangered in the foreseeable future. This would result in all or nearly all species being listed as threatened.” See also Alaska Amicus brief Ex. A (EPIC v. NMFS, C-02-5401 EDL at 15-16 (Mar. 2, 2004)). DISCUSSION Plaintiffs argue that the twelve-month finding was arbitrary and capricious because: (1) NMFS failed to engage in a rational analysis of whether any distinct population segment (“DPS”) of the ribbon seal may warrant listing or whether the species is threatened or endangered in a “significant portion of its range;” and (2) NMFS relied on an irrational time frame for the “foreseeable future.” Plaintiffs also argue that NMFS erred by not utilizing the best available science in making its twelve-month finding. 1. “Significant portion of its range” A species is endangered if it is “in danger of extinction throughout all or a significant portion of its range," and is threatened if it is “likely to become an endangered species within the foreseeable future throughout all or a significant portion of its range.” See 16 U.S.C. § 1532(6), (20) (emphasis added). This definition marked a “significant shift” away from prior statutory language, which considered a species to be endangered only when it was threatened with worldwide extinction. H.R.Rep. No. 93-412 at 10 (1973). Although the agency has wide discretion in determining what constitutes a significant portion of the range, the agency must consider and explain whether a species is endangered or threatened throughout a significant portion of its range if “there are major geographical areas in which it is no longer viable but once was.” See Defenders of Wildlife v. Norton, 258 F.3d 1136, 1145 (9th Cir.2001) (“where, as here, it is on the record apparent that the area in which the lizard is expected to survive is much smaller than its historical range, the Secretary must at least explain her conclusion that the area in which the species can no longer live is not a ‘significant portion of its range.’ ”). This task includes consideration of lost historical range. See Tucson Herpetological Society v. Salazar, 566 F.3d 870, 876 (9th Cir.2009). As noted above, in the twelve-month finding at issue here, NMFS concluded that ribbon seals was not in current danger of extinction throughout all or a significant portion of their range, and that despite the expectation of a gradual decline in the abundance of ribbon seals, they are not likely to become an endangered species within the foreseeable future throughout all or a significant portion of their range. See AR 13 at 79828. Plaintiffs argue that NMFS used a definition of “significant portion of its range” that the Ninth Circuit rejected in Defenders of Wildlife. In that case, the Fish & Wildlife Service (“FWS”) determined that the flat-tailed horned lizard did not warrant listing as a threatened species. The court found that the Secretary failed to address the “significant portion of range” at all in the notice. In the Secretary’s briefing, she interpreted the significant portion of range language to mean that: a species is eligible for protection under the ESA if it ‘faces threats in enough key portions of its range that the entire species is in danger of extinction, or will be within the foreseeable future.’ Defenders of Wildlife, 258 F.3d at 1141 (“She therefore assumes that a species is in danger of extinction in ‘a significant portion of its range’ only if it is in danger of extinction everywhere.”). The court determined that this was a redundant and unacceptable reading of the statute: If, however, the effect of extinction throughout “a significant portion of its range” is the threat of extinction everywhere, then the threat of extinction throughout “a significant portion of its range” is equivalent to the threat of extinction throughout all its range. Because the statute already defines “endangered species” as those that are “in danger of extinction throughout all ... of [their] range,” the Secretary’s interpretation of “a significant portion of its range” has the effect of rendering the phrase superfluous. Defenders of Wildlife, 258 F.3d at 1141-42. Here, in the Status Review, the BRT stated that: However, in assessing extinction risk, the BRT considered whether any of the threats set forth below posed a risk to the species throughout all or a significant portion of its range, as a species must be declared to be endangered or threatened even if it is at risk in only a portion of its range, when that portion is important to the species’ continued viability. AR 11 at 26. Plaintiffs equate the portion of the range being important to viability of the species as a whole to the improper requirement that the portion place the entire species in danger of extinction. Plaintiffs argue that the failure to use a proper construction of “significant portion of range” was not harmless because Defendants failed, for example, to separately consider the ribbon seal’s risk of extinction in the Sea of Okhotsk. Defendants respond that the definition in Defenders of Wildlife was deficient because it rendered the significant portion of the range language superfluous, whereas here the Status Review states only that the portion of a range would be significant if it was important to the species’ viability, as opposed to determinative of viability. Further, Defendants note that the Ninth Circuit has stated that the “significant portion of its range” language is “inherently ambiguous.” Defenders of Wildlife, 258 F.3d at 1141. Thus, Defendants argue that it was entirely proper for them to imbue the term “significant” with a biological basis. See AR 743.b. Whatever the merits of this dispute in the abstract, the result here is the same. Defenders of Wildlife teaches that if the area in which a species is expected to survive is smaller than its historical range, the agency must explain why the area in which the species cannot live is not a significant portion of the range. Here, NMFS did so, stating in its twelve-month finding that: The species is thought to occupy its entire historically observed range. There are no portions of their range in which ribbon seals have been reported to have disappeared, nor are they known to be demographically at risk in any portion of their range. AR 13 at 79824. Thus, even using the accepted definition from Defenders of Wildlife, NMFS has found that there are no “major geographical areas in which [the ribbon seal] is not longer viable but once was.” Plaintiffs argue that using an improper definition was not harmless error because NMFS failed to consider whether the ribbon seal was at risk of extinction in the separate area of the Sea of Okhotsk, which lies exclusively in Russian waters. The Sea of Okhotsk provides habitat for about half of the ribbon seal population. AR 13 at 79824. Plaintiffs argue that there is only one sentence in the Status Review about sea ice in the Sea of Okhotsk: “As this region is dominated by cold air masses for much of the winter and spring, we would expect the present seasonal cycle of first year sea ice to continue to dominate the future habitat of the Sea of Okhotsk, similar to the Bering Sea.” AR 11 at 55. Plaintiffs argue that in making this statement, NMFS improperly ignored two published studies that Plaintiffs believe show large-scale past and future declines in sea ice in the Sea of Okhotsk. The first study, from Meier in 2007, reported that sea ice extent in the Sea of Okhotsk declined by 9.3% per decade during 1979-2006, and that the declines were significant during the months when ribbon seals use the sea ice. AR 890 at 4, Table 2. Although Plaintiffs argue that NMFS failed to consider the Meier study, Defendants point out that it was included in the administrative record, which indicates that it was considered by NMFS. See Thompson v. U.S. Dep’t of Labor, 885 F.2d 551, 555 (9th Cir.1989) (stating that: “The ‘whole’ administrative record, therefore, consists of all documents and materials directly or indirectly considered by agency decision-makers and includes evidence contrary to the agency’s position.”). Further, Defendants point to the new analysis of sea ice trends in the Sea of Okhotsk conducted around the same time as the Meier study by NMFS climate scientist Wang, who reached a different conclusion. The Wang study stated that: “Reduced sea ice areas are seen over three out of four (except the Sea of Okhotsk) sub-Arctic seas in recent decades, particularly after 2000 based on combined in situ and satellite observations.” AR 410 at 1 (Wang study (2007) (emphasis added)). Even though the Wang study was addressing primarily atmospheric forcing, it also addressed sea ice. AR 410 at 15 (stating that “negative sea ice anomalies since the late 1990’s are apparent for all but the Sea of Okhotsk.”). Plaintiffs argue that the Wang study itself states that sea ice analysis is unreliable. Although the study says that “caution must be used in interpreting sea ice data,” that statement supports the study’s statements that data from before 1978 may have been sparse and that the introduction of satellite data may have caused spikes— not that all data is unreliable. AR 410 at 15 (“[Data] is more reliable after 1979 with blending in the satellite observations.”). Further, Plaintiffs have not shown that Defendants ignored the Meier study or improperly relied on the Wang study in reaching its decision. See Ecology Center v. Castaneda, 574 F.3d 652, 659 (9th Cir.2009) (“Though a party may cite studies that support a conclusion different from the one the Forest Service reached, it is not our role to weigh competing scientific analyses.”). Plaintiffs also argue that Defendants failed to consider a second study projecting significant continuing declines in sea ice in the Sea of Okhotsk through 2100. See AR 319 (Overland and Wang 2007 study). The Overland and Wang study projected in 2007 that the extent of summer sea ice in the Okhotsk Sea will decline by 40% by 2050, and will continue to decline through 2100, and that winter sea ice may also decline by 40%. AR 319 at 1, 6. The Status Review, however, explains that: ‘We have used the same procedure as in Overland and Wang (2007) for summer and winter ice extents to assess the confidence for using IPCC climate models (Meehl et al. 2007a) to project April and May first-year sea ice extents for the eastern Bering Sea.” AR 11 at 53. Thus, the Overland and Wang 2007 study was coauthored by the same climate scientist (Overland) who participated on the BRT, and the modeling in the Status Review was based on the original 2007 study that he co-authored. AR 11 at 53-55. Although Plaintiffs take issue with the fact that the BRT did not conduct this analysis for the Okhotsk Sea, the Status Review also states that: “As this region is dominated by cold air masses for much of the winter and spring, we would expect the present seasonal cycle of first year sea ice to continue to dominate the future habitat of the Sea of Okhotsk, similar to the Bering Sea.” AR 11 at 55. Plaintiffs have not shown that NMFS failed to consider the ice in the Sea of Okhotsk. Both the Wang study and the Overland and Wang 2007 study were included in the administrative record, and NMFS concluded that the Sea of Okhotsk was not a separate portion of the ribbon seal range. Further, Defendants point to numerous citations in the administrative record regarding data that Defendants considered regarding the seal in the Okhotsk Sea. See AR 138 (food habits of seals, including the ribbon seal), 187 (same), 212 (noting reduction of sealing in Okhotsk Sea), 324 (listing details of ribbon seals including life span, exploitation, census data, food), 347 (discussing variability of sea ice in Okhotsk Sea), 394 (report of migration of seals, including ribbon seals). In addition, NMFS engaged in personal communications with Russian scientists regarding the ribbon seal. AR 11 at 68-70, 79-80. In sum, Plaintiffs’ arguments that NMFS did not properly analyze the “significant portion of its range” are not persuasive. The twelve-month finding states that the seals occupy their entire historically observed range, and there is no evidence to the contrary. 2. Distinct population segments 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 which interbreeds when mature.” 16 U.S.C. § 1532(16). A Distinct Population Segment (“DPS”) can be designated if it is both “discrete” and “significant.” See Policy Regarding the Recognition of Distinct Vertebrate Population Segments Under the Endangered Species Act, 61 Fed. Reg. 4722 (Feb. 7, 1996). A population segment is discrete if: 1. It is markedly separated from other populations of the same taxon as a consequence of physical, physiological, ecological, or behavioral factors. Quantitative measures of genetic or morphological discontinuity may provide evidence of this separation; 2. It is delimited by international governmental boundaries within which differences in control of exploitation, management of habitat, conservation status, or regulatory mechanisms exist that are significant in light of section 4(a)(1)(D) of the Act. 61 Fed. Reg. 4722, 4725. If a population segment is discrete under one or both of the above conditions, the agency must examine the biological and ecological significance of the population segment. Id. In making this examination, the agency shall: consider available scientific evidence of the discrete population segment’s importance to the taxon to which it belongs. This consideration may include, but is not limited to, the following: 1. Persistence of the discrete population segment in an ecological setting unusual or unique for the taxon, 2. Evidence that loss of the discrete population segment would result in a significant gap in the range of a taxon, 3. Evidence that the discrete population segment represents the only surviving natural occurrence of a taxon that may be more abundant elsewhere as an introduced population outside its historic range, or 4. Evidence that the discrete population segment differs markedly from other populations of the species in its genetic characteristics. 61 Fed. Reg. 4722, 4725. “Any one of the factors is sufficient to support a listing determination if the factor causes the species to be in danger of extinction or likely to become an endangered species in the foreseeable future throughout all or a significant portion of its range.” Defenders of Wildlife v. Salazar, 729 F.Supp.2d 1207, 1214 (D.Mont.2010). Listing decisions must be made “solely on the basis of the best scientific and commercial data available,” and without reference to possible economic or other impacts of such a determination. 16 U.S.C. § 1533(b)(1)(A); 50 C.F.R. § 424.11(b); 50 C.F.R. § 424.13. Further, if a population segment is discrete and significant, its evaluation for endangered or threatened status will be based on the ESA’s definitions of those terms and a review of the factors enumerated in section 4(a). It may be appropriate to assign different classifications to different DPSs of the same vertebrate tax-on. See 61 FR 4722, 4725. Here, in the twelve-month finding, NMFS concluded that under the DPS policy: Although there are two main breeding areas for ribbon seals, one in the Sea of Okhotsk and one in the Bering Sea, there is currently no evidence of discrete populations on which to base a separation into DPSs. Therefore, the entire global population was considered to comprise the species for the purpose of assessing extinction risk. AR 13 at 79824. The Status Review concluded that: “In summary, no compelling evidence has been presented for demographically significant population structure within the ribbon seal breeding distribution.” AR 11 at 25. The BRT recommended that a high priority be placed on obtaining an inventory of relevant samples to conduct a genetic analysis. Id. Plaintiffs argue that these brief references to whether a DPS exists show that NMFS improperly failed to analyze both the discreteness and significance prongs of the policy. Specifically, Plaintiffs focus on the lack of analysis of whether discreteness exists based on different management regimes across international borders, and argue that there are differing management regimes for Russian ribbon seals in the Sea of Okhotsk and Alaskan ribbon seals in the Bering Sea that would satisfy that prong. See Nat’l Ass’n of Home Builders v. Norton, 340 F.3d 835, 842 (9th Cir.2003) (“Although the use of international borders ‘may introduce an artificial and non-biological element’ into the discreteness standard, ‘it appears to be reasonable for national legislation ... to recognize units delimited by international boundaries when these coincide with differences in the management, status, or exploitation of a species.’ ”) (citing 61 Fed. Reg. at 4723). The Status Review reveals that Russia has previously had a significant commercial hunt of ribbon seals. For example, for the period from 1957-1968, the commercial harvest had total catches ranging between 11,300 and 27,100 ribbon seals per year. AR 11 at 53. Beginning in 1969, quotas were introduced in Russia, with limits set at 7,000 ribbon seals per year in the Okhotsk Sea and 3,000 in the Bering Sea. Id. at 54. In the early 1980’s, the quotas were further reduced to 3,500 ribbon seals per year, but sources suggest that the regulations were not actually followed. Id. Commercial harvest was 5,000 to 6,000 ribbon seals per year in the Okhotsk Sea from 1969-1992, and even higher in 1982-1989, ranging from 9,000 to 15,000 per year. Id. Commercial harvest remained high during the 1990’s in the Okhotsk Sea. Id. Beginning in 1991, commercial sealing became less economically viable. Id. at 55. In the early 2000’s, Russia increased their quotas on ribbon seals in Russian waters, allowing total catches between 16,700 and 21,000 per year during 2002-2005. Id. The actual harvest levels, however, were a fraction of those amounts, and current harvest rates remain low in the tens to few hundreds of ribbon seals per year. Id. The Status Review acknowledged that: “The recent high quotas for ribbon seals in Russian waters represent a potential risk.” Id. By contrast, commercial hunting of marine mammals in U.S. territorial waters is prohibited by the Marine Mammal Protection Act. Id. A. Waiver Defendants argue that Plaintiffs have waived any claim that NMFS should have designated a Russian DPS. Specifically, Defendants argue that a twelve-month finding is to be made on the petitioned action (16 U.S.C. § 1533(b)(3)(B)(i)), and that the petition in this case did not request that NMFS designate any DPS for the ribbon seal. AR 1 at 11 (petition stating that: “the distribution of the ribbon seal is apparently continuous from the Okhotsk Sea to the Bering Sea,” and that “there is no genetic evidence available to split these groups.”). Further, Defendants point to the ninety-day finding, in which NMFS requested that the public submit information relevant to whether “any populations of ice seal species may qualify as distinct population segments” (AR 3 at 2-3), and Plaintiffs did not provide any information on that issue. The cases cited by Defendants for their waiver argument, however, do not address the ESA petitioning process. See, e.g., United States v. L.A. Tucker Truck Lines, Inc., 344 U.S. 33, 37, 73 S.Ct. 67, 97 L.Ed. 54 (1952); Muckleshoot Indian Tribe v. FERC, 993 F.2d 1428, 1433 (9th Cir.1993). Further, the Ninth Circuit has stated: In general, we will not invoke the waiver rule in our review of a notice-and-comment proceeding if an agency has had an opportunity to consider the issue. This is true even if the issue was considered sua sponte by the agency or was raised by someone other than the petitioning party. Portland General Elec. Co. v. BPA, 501 F.3d 1009, 1024, n. 13 (9th Cir.2007) (“BPA sought broad public participation and invited comments in these proceedings. If we required each participant in a notice-and-comment proceeding to raise every issue or be barred from seeking judicial review of the agency’s action, we would be sanctioning the unnecessary multiplication of comments and proceedings before the administrative agency. That would serve neither the agency nor the parties.”). Here, Plaintiffs stated in the petition that there was some evidence of two distinct ribbon seal populations (in the Okhotsk Sea and the Bering Sea), but that there was also evidence to the contrary. AR 1 at 11. The petition stated that additional research on ribbon seal stock structure was needed. Id. The petition also included several recommendations for further research, including one to identify populations and subpopulations of ribbon seals. AR 1 at 79. Although Defendants argue that a reference to populations is not enough to trigger a DPS analysis, Plaintiffs raised the issue of the absence of and need for population data for ribbon seals in their petition. Thus, Portland General Electric supports the conclusion that there was no waiver. B. Merits The parties focus on the second prong of the discreteness analysis, that is: (2) It is delimited by international governmental boundaries within which differences in control of exploitation, management of habitat, conservation status, or regulatory mechanisms exist that are significant in light of section 4(a)(1)(D) of the Act. 61 Fed. Reg. 4722, 4725. Plaintiffs argue that there is ample evidence that this prong is satisfied, as management of species by Russia and the United States differs greatly. The Status Review states: Commercial hunting of marine mammals is prohibited in U.S. territorial waters by the MMPA and is not considered a threat to the species in this part of its range. However, the recent high commercial quotas set by Russia for ribbon seals are a potential risk. Regulations which govern commercial harvest of ice seals in Russia are over 20 years old and are artifacts from the former Soviet Union. Therefore, it is unclear what mechanisms are currently in place in Russia to ensure that potential commercial harvests remain within sustainable levels. AR 11 at 79 (citation to authorities omitted). Plaintiffs argue that given the significant differences in management of the species, NMFS should have considered whether those differences warranted having a separate DPS for the ribbon seal. Defendants argue, however, that even if there are regulatory differences between Russia and the United States, those differences must be “significant in light of section 4(a)(1)(D)” of the ESA, and in this case they are not. Section 4(a)(1)(D) refers to the inadequacy of existing regulatory mechanisms as a factor to be considered in listing determinations. NMFS states that it considered the current status of the Russian harvest of the ribbon seal and determined that even though quotas are high, the actual harvest is low, so there is no real threat to the seal. AR 11 at 80, AR 13 at 6. The entirety of NMFS’s analysis in the twelve-month finding about regulatory mechanisms is: There is little evidence that the inadequacy of existing regulatory mechanisms currently poses a threat to ribbon seals throughout all or a significant portion of their range. However, there are no known regulatory mechanisms that effectively address global reductions in sea ice habitat at this time. Also, it is unclear what regulatory mechanisms are in place to ensure that potential commercial harvests in Russia are conducted in a sustainable fashion. 73 Fed. Reg. at 79827. Thus, NMFS argues that, given the current and expected rate of Russian harvest, there was no difference in regulatory mechanisms that were significant to the ribbon seal, and any threats to the ribbon seal are only potential, whereas the DPS policy focuses on actual threats. See AR 95 at 5 (“We base our listing decisions on the status of the species at that time, not on some time in the future.”). The agency did not act arbitrarily or capriciously in concluding that although Russia has a different regulatory mechanism in place regarding commercial harvest of the ribbon seal, the actual threat to the ribbon seal is low and there is no evidence that existing regulatory mechanisms are significant in light of § 1533(a)(1)(D). Plaintiffs argue that another difference between Russia and the United States is significant, although it points in the opposite direction: Russia has signed on to the Kyoto Protocol on greenhouse gases whereas the United States has not. However, it is not apparent that greenhouse gases stop at borders between nations, and Plaintiffs fail to explain how Russia’s agreement to some controls on greenhouse gases means that its ribbon seal population faces a reduced risk compared to those in American waters. Plaintiffs also contend that there is precedent for dividing the Russian and United States breeding populations of a species under the ESA. Specifically, the Alaskan breeding population of the Stellar’s eider is listed as threatened under the ESA, while the Russian population is not. See Endangered and Threatened Wildlife and Plants; Threatened Status for the Alaska Breeding Population of the Stellar’s Eider, 62 Fed. Reg. 31748 (June 11, 1997). However, the fact that FWS listed a distinct population segment in a case involving another species does not mandate a particular result in this case. Defendants have adequately considered whether the international differences warranted a finding of discreteness under the second prong of the NMFS policy. 3. Foreseeable future NMFS was required to determine if the ribbon seal was a threatened species, which is defined as: “any species which is likely to become an endangered species within the foreseeable future throughout all or a significant portion of its range.” 16 U.S.C. § 1532(20). There is no statutory definition of “foreseeable future,” and the “definition of ‘foreseeable future’ may vary depending on the particular species .... ” See Western Watersheds Project v. Foss, 2005 WL 2002473, at *14, *16 (D.Idaho Aug. 19, 2005). Here, NMFS determined the foreseeable future to be to the year 2050 because past and current emissions of greenhouse gases have already largely set the course for changes in the atmosphere and climate until that time, and because of enormous uncertainty about future social and political decisions on emissions that will dominate projection of conditions father into the future. Beyond the year 2050, projections of climate scenarios are too heavily dependant on socio economic assumptions and are therefore too divergent for reliable use in assessing threats to ribbon seals. AR 13 at 79823; see also AR 409 at 12 (study entitled Climate of the Arctic Marine Environment); AR 276 at 3 (“By mid-century (2046-2065), the choice of scenario becomes important” and “By late century (2090-2099), differences between scenarios are large”). NMFS stated in the twelve-month finding that the foreseeable future determination used in this case was the same as used in the FWS’s decision to list the polar bear. Id. Plaintiffs argue that NMFS violated the ESA by limiting the foreseeable future to 2050 and by not considering impacts to the end of the century because NMFS: (1) irrationally dismissed universally-accepted Intergovernmental Panel on Climate Change (IPCC) climate scenarios as too variable to be foreseeable; (2) illegally relied on uncertain future regulatory measures to conjure a false appearance of uncertainty; (3) disregarded the fact that all climate scenarios are worse for the ribbon seal after 2050; (4) ignored the frequent prior use of time-frames of 100 years or more to determine species status; (5) instituted a standard by which ribbon seals will be doomed to extinction before ESA protections can kick in; and (6) arbitrarily ignored ocean acidification impacts beyond 2050 that NMFS itself has foreseen. See Pls.’ Mot. at 16; Pls.’ Reply at 14. Defendants argue that 2050 is the proper cutoff date for the foreseeable future because the chief potential threat to ribbon seals is global climate change, and because of the general scientific consensus that climate projections past mid-century rapidly deteriorate in reliability. See AR 11 at 40; AR 85 at 15 (polar bear listing decision); 75 Fed. Reg. 6438, 6456-57, 6462-63 (Feb. 9, 2010) (not listing the American pika based on climate change considerations). A. Deference under Skidmore or Chevron Defendants argue that they are entitled to deference under Chevron v. Natural Res. Def. Council, 467 U.S. 837, 104 S.Ct. 2778, 81 L.Ed.2d 694 (1984) and/or Skidmore v. Swift & Co., 323 U.S. 134, 140, 65 S.Ct. 161, 89 L.Ed. 124 (1944) for their interpretation of “foreseeable future” in this case. Judicial review of an agency’s interpretation of a statute is governed by the two-part formula announced in Chevron. A court reviewing an administrative interpretation of a statute must first ask “whether Congress has directly spoken to the precise question at issue.” Chevron, 467 U.S. at 842, 104 S.Ct. 2778. If the statute is unambiguous, then the court “must give effect to the unambiguously expressed intent of Congress” regardless of the agency’s view. Id. at 843, 104 S.Ct. 2778. However, if the statute is silent or ambiguous with respect to the specific issue, then a court must defer to the agency’s interpretation unless that interpretation is unreasonable. Id. at 843-44, 104 S.Ct. 2778; United States v. Mead Corp., 533 U.S. 218, 229, 121 S.Ct. 2164, 150 L.Ed.2d 292 (2001). Under Chevron: [i]f Congress has explicitly left a gap for an agency to fill, there is an express delegation of authority to the agency to elucidate a specific provision of the statute by regulation. Such legislative regulations are given controlling weight unless they are arbitrary, capricious or manifestly contrary to the statute. Chevron, 467 U.S. at 844, 104 S.Ct. 2778. Here, Defendants argue that Congress left an “explicit gap” for an agency-promulgated regulation that NMFS filled when it interpreted “foreseeable future” in this case, especially since the term was subject to public notice and comment. However, the definition of foreseeable future as ending in 2050 in the context of climate regulations and the Bering and Okhotsk Seas at issue in this suit is not the kind of “legislative regulation” addressed by Chevron because its application is limited to this case. “If Chevron deference is inapplicable because Congress has not delegated interpretative authority to the agency, the agency’s views still ‘constitute a body of experience and informed judgment to which courts and litigants may properly resort for guidance.’ ” Skidmore, 823 U.S. at 140, 65 S.Ct. 161. “Levels of deference given to agency statutory interpretations vary with the circumstances, and as the level of deference that a court is required to give increases, so too does the tolerable marginal difference between a court and an agency’s interpretations.” Hawaii ex rel. Atty. Gen. v. Fed. Emergency Mgmt. Agency, 294 F.3d 1152, 1158 (9th Cir.2002). The precise degree of deference warranted depends on the statute and agency action at issue. Mead, 533 U.S. at 227-31, 121 S.Ct. 2164. Factors affecting the level of deference given to an agency’s interpretation include “the degree of the agency’s care, its consistency, formality, and relative expertness, and the persuasiveness of the agency’s position.” Id. at 228, 121 S.Ct. 2164 (citations and footnotes omitted). The cases upon which Defen