JUSTICE BLACKMUN delivered the opinion of the Court.
Once again, a little fish has caused a commotion. See Hughes v. Oklahoma, 441 U.S. 322 (1979); TVA v. Hill, 437 U.S. 153 (1978); Cappaert v. United States, 426 U.S. 128 (1976). The fish in this case is the golden shiner, a species of minnow commonly used as live bait in sport fishing.
Appellee Robert J. Taylor (hereafter Taylor or appellee) operates a bait business in Maine. Despite a Maine statute prohibiting the importation of live baitfish,
Taylor moved to dismiss the indictment on the ground that Maine's import ban unconstitutionally burdens interstate commerce and therefore may not form the basis for a federal prosecution under the Lacey Act. Maine, pursuant to 28 U. S. C. § 2403(b), intervened to defend the validity of its statute, arguing that the ban legitimately protects the State's fisheries from parasites and nonnative species that might be included in shipments of live baitfish. The District Court found the statute constitutional and denied the motion to dismiss. United States v. Taylor, 585 F.Supp. 393 (Me. 1984). Taylor then entered a conditional plea of guilty pursuant to Federal Rule of Criminal Procedure 11(a)(2), reserving the right to appeal the District Court's ruling on the constitutional question. The Court of Appeals for the First Circuit reversed, agreeing with Taylor that the underlying state statute impermissibly restricts interstate trade. United States v. Taylor, 752 F.2d 757 (1985). Maine appealed. We set the case for plenary review and postponed consideration of Taylor's challenges to our appellate jurisdiction. 474 U.S. 943 (1985).
Maine invokes our jurisdiction under 28 U. S. C. § 1254(2), which authorizes an appeal as of right to this Court "by a party relying on a State statute held by a court of appeals to be invalid as repugnant to the Constitution, treaties or laws of the United States." Appellee, however, contends that this provision applies only to civil cases, and that, in any event, Maine lacks standing to appeal the reversal of a federal conviction. These contentions both relate to the unusual procedural posture of the case: an appeal by a State from the reversal of a federal conviction based on a violation of state law. We consider them in turn.
First, despite its procedural peculiarities, this case fits squarely within the plain terms of § 1254(2): Maine relies on a state statute that the Court of Appeals held to be unconstitutional.
The Commerce Clause of the Constitution grants Congress the power "[t]o regulate Commerce with foreign Nations, and among the several States, and with the Indian Tribes." Art. I, § 8, cl. 3. "Although the Clause thus speaks in terms of powers bestowed upon Congress, the Court long has recognized that it also limits the power of the States to erect barriers against interstate trade." Lewis v. BT Investment Managers, Inc., 447 U.S. 27, 35 (1980). Maine's statute restricts interstate trade in the most direct manner possible, blocking all inward shipments of live baitfish at the State's border. Still, as both the District Court and the Court of
In determining whether a State has overstepped its role in regulating interstate commerce, this Court has distinguished between state statutes that burden interstate transactions only incidentally, and those that affirmatively discriminate against such transactions. While statutes in the first group violate the Commerce Clause only if the burdens they impose on interstate trade are "clearly excessive in relation to the putative local benefits," Pike v. Bruce Church, Inc., 397 U.S. 137, 142 (1970), statutes in the second group are subject to more demanding scrutiny. The Court explained in Hughes v. Oklahoma, 441 U. S., at 336, that once a state law is shown to discriminate against interstate commerce "either on its face or in practical effect," the burden falls on the State to demonstrate both that the statute "serves a legitimate local purpose," and that this purpose could not be served as well by available nondiscriminatory means. See also, e. g., Sporhase v. Nebraska ex rel. Douglas, 458 U.S. 941, 957 (1982); Hunt v. Washington State Apple Advertising Comm'n, 432 U.S. 333, 353 (1977); Dean Milk Co. v. Madison, 340 U.S. 349, 354 (1951).
The District Court and the Court of Appeals both reasoned correctly that, since Maine's import ban discriminates on its face against interstate trade, it should be subject to the strict requirements of Hughes v. Oklahoma, notwithstanding Maine's argument that those requirements were waived by the Lacey Act Amendments of 1981. It is well established that Congress may authorize the States to engage in regulation that the Commerce Clause would otherwise forbid. See, e. g., Southern Pacific Co. v. Arizona ex rel. Sullivan, 325 U.S. 761, 769 (1945). But because of the important role
Before this Court, Maine concedes that the Lacey Act Amendments do not exempt state wildlife legislation from scrutiny under the Commerce Clause. See Reply Brief for Appellant 3, n. 2. The State insists, however, that the Amendments should lower the intensity of the scrutiny that would otherwise be applied. We do not agree. An unambiguous indication of congressional intent is required before a federal statute will be read to authorize otherwise invalid state legislation, regardless of whether the purported authorization takes the form of a flat exemption from Commerce Clause scrutiny or the less direct form of a reduction in the level of scrutiny. Absent "a clear expression of approval by Congress," any relaxation in the restrictions on state power otherwise imposed by the Commerce Clause unacceptably increases "the risk that unrepresented interests will be adversely affected by restraints on commerce." South-Central Timber, supra, at 92.
In this case, there simply is no unambiguous statement of any congressional intent whatsoever "to alter the limits of state power otherwise imposed by the Commerce Clause," United States v. Public Utilities Comm'n of California, 345 U.S. 295, 304 (1953). In arguing to the contrary, Maine relies almost exclusively on the following findings in the Senate Report on the Lacey Act Amendments:
Maine reads this passage, particularly the last sentence, to direct federal courts to treat state wildlife laws more leniently. We find this interpretation not only less than obvious but positively strained; by far the more natural reading of the last sentence is that it refers only to the availability of federal investigative and prosecutorial resources to enforce valid state wildlife laws. The passage certainly does not make "unmistakably clear" that Congress intended in 1981 to alter in any way the level of Commerce Clause scrutiny applied to those laws. Maine's ban on the importation of live baitfish thus is constitutional only if it satisfies the requirements ordinarily applied under Hughes v. Oklahoma to local regulation that discriminates against interstate trade: the statute must serve a legitimate local purpose, and the purpose must be one that cannot be served as well by available nondiscriminatory means.
The District Court found after an evidentiary hearing that both parts of the Hughes test were satisfied, but the Court of Appeals disagreed. We conclude that the Court of Appeals erred in setting aside the findings of the District Court. To explain why, we need to discuss the proceedings below in some detail.
The evidentiary hearing on which the District Court based its conclusions was one before a Magistrate. Three scientific experts testified for the prosecution and one for the defense. The prosecution experts testified that live baitfish imported
The prosecution experts further testified that there was no satisfactory way to inspect shipments of live baitfish for parasites or commingled species.
Appellee's expert denied that any scientific justification supported Maine's total ban on the importation of baitfish. Id., at 241. He testified that none of the three parasites discussed by the prosecution witnesses posed any significant threat to fish in the wild, id., at 206-212, 228-232, and that sampling techniques had not been developed for baitfish precisely because there was no need for them. Id., at 265-266. He further testified that professional baitfish farmers raise their fish in ponds that have been freshly drained to ensure that no other species is inadvertently collected. Id., at 239-240.
Weighing all the testimony, the Magistrate concluded that both prongs of the Hughes test were satisfied, and accordingly that appellee's motion to dismiss the indictment should be denied. Appellee filed objections, but the District Court, after an independent review of the evidence, reached the same conclusions. First, the court found that Maine "clearly has a legitimate and substantial purpose in prohibiting the importation of live bait fish," because "substantial uncertainties" surrounded the effects that baitfish parasites would have on the State's unique population of wild fish, and the consequences of introducing nonnative species were similarly
Although the Court of Appeals did not expressly set aside the District Court's finding of a legitimate local purpose, it noted that several factors "cast doubt" on that finding. 752 F. 2d, at 762. First, Maine was apparently the only State to bar all importation of live baitfish. See id., at 761. Second, Maine accepted interstate shipments of other freshwater fish, subject to an inspection requirement. Third, "an aura
Despite these indications of protectionist intent, the Court of Appeals rested its invalidation of Maine's import ban on a different basis, concluding that Maine had not demonstrated that any legitimate local purpose served by the ban could not be promoted equally well without discriminating so heavily against interstate commerce. Specifically, the court found it "difficult to reconcile" Maine's claim that it could not rely on sampling and inspection with the State's reliance on similar procedures in the case of other freshwater fish. Id., at 762.
Following the reversal of appellee's conviction, Maine and the United States petitioned for rehearing on the ground that the Court of Appeals had improperly disregarded the District Court's findings of fact. The court denied the petitions, concluding that, since the unavailability of a less discriminatory alternative "was a mixed finding of law and fact," a reviewing court "was free to examine carefully the factual record and to draw its own conclusions." Id., at 765.
Although the proffered justification for any local discrimination against interstate commerce must be subjected to "the strictest scrutiny," Hughes v. Oklahoma, 441 U. S., at 337, the empirical component of that scrutiny, like any other form of factfinding, " `is the basic responsibility of district courts,
More importantly, we agree with the District Court that the "abstract possibility," id., at 398, of developing acceptable testing procedures, particularly when there is no assurance as to their effectiveness, does not make those procedures an "[a]vailabl[e] . . . nondiscriminatory alternativ[e]," Hunt, 432 U. S., at 353, for purpose of the Commerce Clause. A State must make reasonable efforts to avoid restraining the free flow of commerce across its borders, but it is not required to develop new and unproven means of protection at an uncertain cost. Appellee, of course, is free to work on his own or in conjunction with other bait dealers to develop scientifically acceptable sampling and inspection procedures for golden shiners; if and when such procedures are developed, Maine no longer may be able to justify its import ban. The State need not join in those efforts, however, and it need not pretend they already have succeeded.
Although the Court of Appeals did not expressly overturn the District Court's finding that Maine's import ban serves a legitimate local purpose, appellee argues as an alternative ground for affirmance that this finding should be rejected. After reviewing the expert testimony presented to the Magistrate, however, we cannot say that the District Court clearly erred in finding that substantial scientific uncertainty surrounds the effect that baitfish parasites and nonnative species could have on Maine's fisheries. Moreover, we agree with the District Court that Maine has a legitimate interest in guarding against imperfectly understood environmental risks, despite the possibility that they may ultimately prove to be negligible. "[T]he constitutional principles underlying the commerce clause cannot be read as requiring the State of Maine to sit idly by and wait until potentially irreversible environmental damage has occurred or until the scientific community agrees on what disease organisms are or are not dangerous before it acts to avoid such consequences." 585 F. Supp., at 397.
Nor do we think that much doubt is cast on the legitimacy of Maine's purposes by what the Court of Appeals took to be signs of protectionist intent. Shielding in-state industries from out-of-state competition is almost never a legitimate local purpose, and state laws that amount to "simple economic protectionism" consequently have been subject to a "virtually per se rule of invalidity." Philadelphia v. New Jersey, 437 U.S. 617, 624 (1978); accord, e. g., Minnesota v. Clover Leaf Creamery Co., 449 U.S. 456, 471 (1981).
We fully agree with the Magistrate that "[t]hese three sentences do not convert the Maine statute into an economic protectionism
The other evidence of protectionism identified by the Court of Appeals is no more persuasive. The fact that Maine allows importation of salmonids, for which standardized sampling and inspection procedures are available, hardly demonstrates that Maine has no legitimate interest in prohibiting the importation of baitfish, for which such procedures have not yet been devised. Nor is this demonstrated by the fact that other States may not have enacted similar bans, especially
The Commerce Clause significantly limits the ability of States and localities to regulate or otherwise burden the flow of interstate commerce, but it does not elevate free trade above all other values. As long as a State does not needlessly obstruct interstate trade or attempt to "place itself in a position of economic isolation," Baldwin v. G. A. F. Seelig, Inc., 294 U.S. 511, 527 (1935), it retains broad regulatory authority to protect the health and safety of its citizens and the integrity of its natural resources. The evidence in this case amply supports the District Court's findings that Maine's ban on the importation of live baitfish serves legitimate local purposes that could not adequately be served by available nondiscriminatory alternatives. This is not a case of arbitrary discrimination against interstate commerce; the
It is so ordered.
JUSTICE STEVENS, dissenting.
There is something fishy about this case. Maine is the only State in the Union that blatantly discriminates against out-of-state baitfish by flatly prohibiting their importation. Although golden shiners are already present and thriving in Maine (and, perhaps not coincidentally, the subject of a flourishing domestic industry), Maine excludes golden shiners grown and harvested (and, perhaps not coincidentally, sold) in other States. This kind of stark discrimination against out-of-state articles of commerce requires rigorous justification by the discriminating State. "When discrimination against commerce of the type we have found is demonstrated, the burden falls on the State to justify it both in terms of the local benefits flowing from the statute and the unavailability of nondiscriminatory alternatives adequate to preserve the local interests at stake." Hunt v. Washington State Apple Advertising Comm'n, 432 U.S. 333, 353 (1977).
Like the District Court, the Court concludes that uncertainty about possible ecological effects from the possible presence of parasites and nonnative species in shipments of out-of-state shiners suffices to carry the State's burden of proving a legitimate public purpose. Ante, at 142-143, 148. The Court similarly concludes that the State has no obligation to develop feasible inspection procedures that would make a total ban unnecessary. Ante, at 147. It seems clear, however, that the presumption should run the other way. Since the State engages in obvious discrimination against out-of-state commerce, it should be put to its proof. Ambiguity about dangers and alternatives should actually defeat, rather than sustain, the discriminatory measure.
Significantly, the Court of Appeals, which is more familiar with Maine's natural resources and with its legislation than we are, was concerned by the uniqueness of Maine's ban. That court felt, as I do, that Maine's unquestionable natural splendor notwithstanding, the State has not carried its substantial burden of proving why it cannot meet its environmental concerns in the same manner as other States with the same interest in the health of their fish and ecology. Cf. ante, at 151, n. 22 (describing less restrictive procedures in other States).
I respectfully dissent.
"Cases in the courts of appeals may be reviewed by the Supreme Court by the following methods:
"(1) By writ of certiorari granted upon the petition of any party to any civil or criminal case, before or after rendition of judgment or decree;
"(2) By appeal by a party relying on a State statute held by a court of appeals to be invalid as repugnant to the Constitution, treaties or laws of the United States, but such appeal shall preclude review by writ of certiorari at the instance of such appellant, and the review on appeal shall be restricted to the Federal questions presented;
"(3) By certification at any time by a court of appeals of any question of law in any civil or criminal case as to which instructions are desired, and upon such certification the Supreme Court may give binding instructions or require the entire record to be sent up for decision of the entire matter in controversy."
"Any case in a circuit court of appeals where is drawn in question the validity of a statute of any State, on the ground of its being repugnant to the Constitution, treaties, or laws of the United States, and the decision is against its validity, may, at the election of the party relying on such State statute, be taken to the Supreme Court for review on writ of error or appeal; but in that event a review on certiorari shall not be allowed at the instance of such party, and the review on such writ of error or appeal shall be restricted to an examination and decision of the Federal questions presented in the case." Act of Feb. 13, 1925, § 1, 43 Stat. 939.
Until then, appeals were allowed as of right from decisions of the courts of appeals only in civil cases involving more than $1,000, and not arising under the diversity, admiralty, patent, or revenue jurisdiction of the federal courts. See Act of Mar. 3, 1891, § 6, 26 Stat. 828.
The relevant portion of the 1925 Act was added on the floor of the Senate, and the debates surrounding the amendment contain no suggestion that it was intended to apply only in civil cases. See 66 Cong. Rec. 2753-2754, 2757, 2919-2925 (1925).
"In any action, suit, or proceeding in a court of the United States to which a State or any agency, officer, or employee thereof is not a party, wherein the constitutionality of any statute of that State affecting the public interest is drawn in question, the court shall certify such fact to the attorney general of the State, and shall permit the State to intervene for presentation of evidence, if evidence is otherwise admissible in the case, and for argument on the question of constitutionality. The State shall, subject to the applicable provisions of law, have all the rights of a party and be subject to all liabilities of a party as to court costs to the extent necessary for a proper presentation of the facts and law relating to the question of constitutionality."