with whom FERGUSON, Circuit Judge, joins, and with whom CANBY, Circuit Judge, joins in Part II, dissenting:

I respectfully dissent. In my view the challenged regulation is not authorized by Congress and the provision for warrantless searches offends the Constitution.

I

The regulation, 50 C.F.R. § 216.24 (f), establishes an indefinite policy of stationing federal observers aboard tuna boats for enforcement as well as research purposes. Because Congress expressly restricted the use of observers to the two-year period following passage of the Act and limited the function of such officials to research and scientific observation, this regulation goes far beyond the design of the statute it purports to implement.

Regulations promulgated pursuant to an enabling statute will be upheld if they are reasonably related to the purposes of the enabling legislation, Mourning v. Family Publication Service, Inc., 411 U.S. 356, 369 , 93 S.Ct. 1652, 1660 , 36 L.Ed.2d 318 (1973), but such regulations will not be sustained when they are contrary to congressional design. “The rulemaking power granted to an administrative agency charged with the administration of a federal statute is not the power to make law. Rather, it is ‘the power to adopt regulations to carry into effect the will of Congress as expressed by the statute.’ ” Ernst & Ernst v. Hochfelder, 425 U.S. 185, 213-14 , 96 S.Ct. 1375, 1391 , 47 L.Ed.2d 668 (1976) (quoting Manhattan General Equipment Co. v. Commissioner, 297 U.S. 129, 134 , 56 S.Ct. 397, 400 , 80 L.Ed. 528 (1936)). Thus, “our primary task when testing the statutory authority of a challenged regulation must always be to determine the intent of Congress.” State of California v. Block, 663 F.2d 855, 860 (9th Cir.1981).

In this case, the language of the statute and its legislative history both indicate that Congress intended to restrict the use of on-board observers to the two-year period following passage of the Act.

16 U.S.C. § 1381 provided:

*769 The period of research referred to in § 1381(d) covered “the full twenty-four calendar month period following October 21, 1972,” after which the results of such research were to be reported to Congress. 16 U.S.C. § 1381 (a). Funding for the observer program was also limited to the two-year period provided in the statute. The statutory objective was to use the observers as part of “a program of research and development for the purpose of devising improved fishing methods and gear so as to reduce to the maximum extent practicable the incidental taking of marine mammals in connection with commercial fishing.” 16 U.S.C. § 1381 (a). Congress clearly expressed its intent to use the observers only as part of a short term research program. The majority, however, sanctions the agency’s administrative decision to transform one part of a limited research program into an ongoing regulatory policy of indefinite duration.

The legislative history of the observer program underscores the two-year limitation as part of the Act’s congressional design. Section 1381 of the Act originated as a Senate amendment. The Senate report indicates that Congress intended the observer research and development program to terminate two years after passage of the Act. The majority is simply incorrect when it suggests that the observer program was merely a model after which a regulatory observer policy could be patterned. “The committee has authorized a $2 million, 2-year program to devise new methods of netting and tuna boat operating procedures which will reduce the killing of marine mammals. The committee has provided a 2-year period because it is believed that science can come up with new systems within that time.” S.Rep. No. 863, 92nd Cong., 2d Sess. 9-10 (1972). At the end of the two-year period, the best available fishing methods, if feasible, were to be mandated on commercial fishing vessels, S.Rep., supra at 21. The research program, including its $2 million appropriation and federal observer component, was restricted to a two-year period in clear and explicit terms. Neither the statutory language nor the legislative history of the observer program hint that the agency retained any discretion to extend the use of on-board observers beyond the explicit two-year period.

In addition to its unauthorized extension of the operative period for the observer program, the regulation also expands the function of the government observers beyond the research component contemplated by Congress by enlisting them as inspection and enforcement officials. When Congress created the two-year observer program, it expressly stated that the observer presence was a research tool aimed at “the development of improved fishing methods and gear as authorized by this section.” 16 U.S.C. § 1381 (d). The regulation, however, extends the duration of the observer presence indefinitely and transforms the observers from mere researchers into enforcement officers who collect information for use against the fishermen in civil and criminal actions. To label them now merely “observers” is an understatement. They are now federal inspectors who maintain constant surveillance to ensure that fishermen comply with federal law. The majority is correct to say this is probably the most efficient way to guarantee that the fishermen fish by the rules, but it is not what Congress provided. The observer program was not developed in a spirit of expediency. If Congress contemplated the use of live-in observers for enforcement purposes, it could have expressly provided for such a function in the observer statute or at least granted the Secretary the discretion to create additional functions for the observers.

Instead, Congress specifically addressed the methods of enforcing the statutory scheme in § 1377 of the Act, which allows warrantless searches of vessels only if there is “reasonable cause to believe” that a vessel or crew member is violating the Act or its regulations. 16 U.S.C. § 1377 (d). 1 *770 Hence, the very structure of the Act itself — indeed its own language — indicates that Congress did not envision warrantless searches by on-board observers as an enforcement mechanism. The majority, however, seizes on that part of the language of § 1377 which suggests that the enforcement measures it authorizes are “in addition to any other authority conferred by law.” 16 U.S.C. § 1377 (d). The majority asserts that this language indicates that Congress vested the Secretary with the power to create additional enforcement measures even in contravention of the express statutory limitations of § 1377. Under the majority’s reading of the statute, the Secretary, apparently without limitation, may abrogate the explicit search and seizure restrictions of § 1377 and effectively render most of that section a nullity. Beyond the fact that neither the plain language of the statute nor its legislative history substantiates such an interpretation, the majority’s reading defies basic principles of statutory construction because “acceptance of that meaning would lead to absurd results ... or would thwart the obvious purpose of the statute.” Trans Alaska Pipeline Rate Cases, 436 U.S. 631, 643 , 98 S.Ct. 2053, 2061 , 56 L.Ed.2d 591 (1978) (quoting Commissioner v. Brown, 380 U.S. 563, 571 , 85 S.Ct. 1162, 1166 , 14 L.Ed.2d 75 (1965)). This self-emasculating interpretation of § 1377 is contrary to the presumption against reading a statute in a manner which renders it ineffective. F.T.C. v. Manager, Retail Credit Co., 515 F.2d 988, 995 (D.C.Cir.1975). The majority’s reading of § 1377 exaggerates the language of a single phrase to eviscerate the statute’s internal enforcement scheme, a scheme that was designed to enforce the Act without disregarding the privacy concerns of those who would be subject to it.

The majority suggests that subsequent congressional inaction infers approval of the way observers are used under the regulation. Such inaction is not a helpful indicator of congressional intent when the statutory language itself suggests a contrary interpretation. S.E.C. v. Sloan, 436 U.S. 103, 117 , 98 S.Ct. 1702, 1711 , 56 L.Ed.2d 148 (1978). When Congress has squarely faced the propriety of a regulatory measure, congressional non-action may be evidence of congressional approval. Bob Jones University v. United States, -U.S. -, 103 S.Ct. 2017, 2033 , 76 L.Ed.2d 157 (1983). Absent such direct consideration, however, “[n]on-action by Congress is not often a useful guide...” Bob Jones University, supra, at 2033 .

The majority attempts to bolster its finding of congressional approval by noting that Congress has amended the Act without disturbing the Secretary’s use of on-board observers. This argument is unpersuasive because the on-board observer program was not specifically addressed in subsequent legislative action. Indeed, the Supreme Court recently rejected such an argument in Aaron v. S.E.C., 446 U.S. 680 , 100 S.Ct. 1945 , 64 L.Ed.2d 611 (1980). There, the Court refused to adopt an agency’s statutory interpretation which was premised on congressional *771 failure to disturb that interpretation in subsequent legislative amendments to the authorizing act. “[S]ince the legislative consideration of those statutes was addressed principally to matters other than that at issue here, it is our view that the failure of Congress to overturn the Commission’s interpretation falls far short of providing a basis to support a construction of § 10(b) so clearly at odds with its plain meaning and legislative history.” Id. at 694, n. 11, 100 S.Ct. at 1954, n. 11 .

Because the plain language of § 1381 and its legislative history demonstrate that the on-board observer program was limited to research duties during the two-year period following passage of the Act, the Secretary’s regulation adopting an indefinite policy of on-board observers for enforcement purposes as well as research is unauthorized.

II

The absence of statutory authorization, however, is only one basis for finding this regulation invalid. The regulation also offends the Constitution because it empowers federal inspectors to conduct searches in violation of the fourth amendment.

The majority, in its discussion of the regulation’s fourth amendment impact, sidesteps and fails to confront the threshold question of whether the intrusiveness of stationing government observers on private fishing vessels for extended periods constitutes a search. The majority suggests that the observer policy may not constitute a search within the meaning of the fourth amendment because the government officials confine their observations to the open deck or open sea. This understates the actual operation of the observers. They are more than mere passive onlookers; they are uninvited government inspectors who live with the crew for weeks at sea, watching all aspects of fishing operations, conducting research and collecting data and information that may be used against the tuna fishermen in civil and criminal proceedings. This is not “a brief detention where officials come on board, visit public areas of the vessel, and inspect documents.” United States v. Villamonte-Marquez, - U.S. -, 103 S.Ct. 2573, 2581 , 77 L.Ed.2d 22 (1983). This regulation places live-in government inspectors on private vessels for surveillance purposes over a period of months and results in the type of governmental invasion that is well within the protection of the fourth amendment. Despite the majority’s ambivalence on this issue, the use of government inspectors under the regulation is a search within the meaning of the fourth amendment. As such, it is presumptively unconstitutional in the absence of a warrant, and “[t]he burden is on the government to prove that the departure from the warrant requirement was justified.” United States v. Martin, 693 F.2d 77, 78 (9th Cir.1982) (per curiam); Coolidge v. New Hampshire, 403 U.S. 443, 455 , 91 S.Ct. 2022, 2032 , 29 L.Ed.2d 564 (1971).

The majority decides, however, that even if this use of observers constitutes a search, it is reasonable because it falls within the pervasively regulated industry exception to the warrant requirement. The majority suggests that because the tuna fishing industry has been subject to government regulation, the acceptance of federal observers must be part of the regulatory burden that goes with the benefit of tuna fishing. The majority ventures into uncharted territory, however, because the Supreme Court has admonished that the regulated industry exception is a narrow one, one that neither the Supreme Court nor this court has ever embraced in the absence of explicit statutory authorization for the warrantless search scheme it purports to justify. Moreover, the regulated industry exception has never been used to justify warrantless surveillance schemes such as the one in this case. Until now, the exception has only applied to warrantless inspections of particular businesses on a periodic basis. The majority breaks new ground by applying the exception to warrantless surveillance schemes conducted for days and months at a time.

In regulated industry cases, warrantless searches are still presumptively unreasonable and the government retains the burden *772 of justifying its disregard for the warrant requirement. Marshall v. Barlow’s Inc., 436 U.S. 307, 312-13 , 98 S.Ct. 1816, 1820-21 , 56 L.Ed.2d 305 (1978). “The businessman, like the occupant of a residence, has a constitutional right to go about his business free from unreasonable official entries upon his private commercial property.” Id., at 312 , 98 S.Ct. at 1820 (quoting See v. Seattle, 387 U.S. 541, 543 , 87 S.Ct. 1737, 1739 , 18 L.Ed.2d 943 (1967)). In this case, the government has failed to meet its burden of justifying the warrantless intrusions which the challenged regulation authorizes.

Under the pervasively regulated industry exception, a warrant may not be required “when Congress has reasonably determined that warrantless searches are necessary to further a regulatory scheme and the federal regulatory presence is sufficiently comprehensive and defined that the owner of commercial property cannot help but be aware that his property will be subject to periodic inspections undertaken for specific purposes.” Donovan v. Dewey, 452 U.S. 594, 600 , 101 S.Ct. 2534, 2539 , 69 L.Ed.2d 262 (1981). While planting government observers on fishing vessels for the duration of the expeditions may offer the most efficient method of policing the Act, enthusiasm for this enforcement technique should not obscure the essential constitutional requirement that the warrantless quality of such a procedure must be vital to the regulatory scheme. The government has not proffered any convincing explanation why waiver of the warrant requirement is essential to the enforcement of the Act or to the effective implementation of the observer program.

In Donovan v. Dewey, 452 U.S. 594 , 101 S.Ct. 2534 , 69 L.Ed.2d 262 (1981), the Supreme Court upheld a warrantless search scheme under the Federal Mine Safety and Health Act of 1977, 30 U.S.C. § 813 (a) (1976). The statute allowed federal mine inspectors to make unannounced inspections of underground mines four times a year and surface mines twice a year. The Court noted that a warrant requirement could frustrate such an inspection scheme because unannounced inspections were needed to effectuate the scheme’s objective of deterring hazardous mine conditions. Id. at 603 , 101 S.Ct. at 2540 . In United States v. Kaiyo Maru No. 53, 699 F.2d 989 (9th Cir.1983), this court upheld a warrantless search scheme designed to enforce the Fishery Conservation and Management Act. 16 U.S.C. § 1861 (b). The court concluded that dispensing with the warrant requirement for Coast Guard inspections of fishing boats in the Fishery Conservation Zone was necessary due to the logistical barriers of obtaining a warrant for ships at sea. Id. at 995 .

A comparable element of necessity is missing in this case. The regulation authorizes boarding by federal observers at the time of departure and provides for notification of the observer presence several days before the expedition begins. After they are aboard, the observers make their observations and inspections throughout the duration of the fishing trip. Nothing in this procedure indicates that a warrant requirement would frustrate the objectives of the regulatory search scheme. Research and observation activities under the regulatory procedure can be conducted in the same manner whether or not a warrant is obtained. Although a warrant requirement in this case might be an administrative annoyance, the inconvenience it poses is an insufficient basis to “vitiate the general constitutional requirement that for a search to be reasonable a warrant must be obtained.” Marshall, 436 U.S. at 324 , 98 S.Ct. at 1827 . Moreover, a warrant requirement pursuant to a regulatory search scheme need not be based on evidence of specific violations or actions on particular boats. A warrant requirement in this context would be designed to ensure governmental compliance with reasonable legislative and regulatory standards for the frequency and scope of the search operation'. Id. at 320 , 98 S.Ct. at 1824; Camara v. Municipal Court, 387 U.S. 523, 538 , 87 S.Ct. 1727, 1735-36 , 18 L.Ed.2d 930 (1967). Such a requirement preserves the historic function of checking the potential for arbitrary government conduct without frustrating the legitimate objectives of the Marine Mammal Protection Act. This *773 balance is especially important as virtually all guidelines regarding the conduct of the observer operation emanate from internal agency policies instead of statutory or regulatory guidelines with force of law.

As the reasonableness of a regulatory search scheme “depends on the specific enforcement needs and privacy guarantees of each statute,” Kaiyo Mara No. 53, 699 F.2d at 995 , and as the burden of demonstrating the need to by-pass the warrant requirement rests with the government, the absence of any persuasive proof that warrant-less searches are necessary calls for adherence to the general rule instead of the exception. A warrant is required for this regulatory search scheme.

Ill

Because 50 C.F.R. § 216.24 (f) exceeds congressional authorization and establishes a search scheme in violation of the fourth amendment of the Constitution, I dissent.

. Execution of process; arrest; search; seizure (d) Any person authorized by the Secretary to enforce this subchapter may execute any *770 warrant or process issued by any officer or court of competent jurisdiction for the enforcement of this subchapter. Such person so authorized may, in addition to any other authority conferred by law—

16 U.S.C. 1377(d).