Environmental statutes that prohibit the storage or discharge of wastes without a permit have been deemed public welfare offenses. (People v. Matthews (1992) 7 Cal. App. 4th 1052, 1057-1058 [9 Cal. Rptr. 2d 348].) Here, section 1600 of the Fish and Game Code expressly indicates that the Legislature's intent in enacting section 1603 was to provide for the protection and conservation of fish and wildlife resources, a goal that the Legislature declared to be "of the utmost public interest." Accordingly, illegal alteration of a streambed has the appearance of a public welfare offense. The language of Fish and Game Code section 1603 also supports an alternative understanding of the pertinent mens rea. Section 1603 lacks any reference to a specific intent, and thus the offense in question is plausibly interpreted as a general intent crime. (People v. Daniels, supra, 14 Cal. 3d at pp. 860-861.) However, we do not need to resolve whether the offense at issue is a public welfare offense or general intent crime. On either alternative, knowledge that one's conduct is unlawful is not an element of the offense, and thus ignorance of the notification requirements of section 1603 is not a defense. (1 Witkin & Epstein, Cal. Criminal Law, supra, 218-219, pp. 251-254.)