## Facts

- David Hayashi was a part-time commercial fisherman in Hawaii who sold some of his catch.
- On January 24, 1991, Hayashi and his son were fishing for ahi (tuna) off Waianae, Hawaii, when four porpoises began eating fish off their lines.
- To scare the porpoises away from the lines, Hayashi used a rifle and fired two shots into the water behind the porpoises, intending the impact on the water to frighten them away.
- None of the shots struck any porpoise, and the stipulated record contained no evidence of physical injury to the animals.
- A Hawaii state enforcement officer reported that occupants of Hayashi’s vessel had fired at dolphins/porpoises to the National Marine Fisheries Service (NMFS).
- NMFS agents interviewed Hayashi and his son in February 1991 and obtained written statements.
- The United States charged Hayashi by information with knowingly taking a marine mammal in violation of the Marine Mammal Protection Act (MMPA), 16 U.S.C. § 1372(a)(2)(A).
- The case was tried on stipulated facts before a magistrate judge (with the parties’ consent); the magistrate judge found Hayashi guilty.
- The district court affirmed the conviction on appeal.
- Hayashi appealed to the Ninth Circuit, arguing that firing warning shots to deter porpoises from his lines was not a “take” by “harassment” under the MMPA and that the evidence was insufficient (and also raising an as-applied vagueness argument).

## Issues

1. Whether the MMPA and its implementing regulations make it a crime to take reasonable steps to deter porpoises from eating fish or bait off a fisherman’s line when the animals are not struck or directly injured.
2. Whether the stipulated record contained sufficient evidence that Hayashi’s conduct constituted a “take” by “harassment” under the MMPA.

## Decision

- The Ninth Circuit reversed Hayashi’s conviction.
- The court held that the MMPA and implementing regulations did not criminalize reasonable deterrence efforts aimed at preventing porpoises from taking fish or bait off a line, absent proof meeting the regulatory standard for harassment.
- Interpreting the statute and regulations together, the court concluded that criminal “harassment” requires a direct and significant disruption of normal marine mammal behavior (for example, migration, feeding, breeding, nursing, or sheltering).
- On the stipulated facts—two shots fired into the water behind the porpoises, no contact with the animals, and no evidence of a qualifying behavioral disruption—the evidence was insufficient to establish a criminal “take.”
- Because the case was resolved on statutory interpretation and insufficiency of the evidence, the court did not decide Hayashi’s as-applied vagueness challenge.

## Legal Principles

- Under the MMPA, a prohibited “take” includes attempts to “harass,” but criminal liability for harassment depends on the meaning supplied by the implementing regulations.
- For criminal “take” by harassment under the regulations applied in Hayashi, the government must prove a direct and significant disruption of normal marine mammal behavior, not merely that a person acted to scare an animal away.
- Reasonable deterrent actions taken to protect fish or bait on a line, without striking the animal and without evidence of the required level of behavioral disruption, do not alone establish a criminal “take.”
- When a conviction rests on stipulated facts, appellate review focuses on whether those facts, viewed in light of the governing statutory and regulatory definitions, are sufficient to prove each element beyond a reasonable doubt.
- Courts may avoid constitutional questions, including as-applied vagueness claims, when the case can be decided on narrower statutory or evidentiary grounds.

## Conclusion

United States v. Hayashi held that the MMPA’s criminal ban on “taking” marine mammals did not reach a fisherman’s reasonable warning shots fired into the water behind porpoises to keep them from eating fish off his line, where the record showed no contact with the animals and no evidence of a direct and significant disruption of normal marine mammal behavior; the Ninth Circuit therefore reversed the conviction for insufficient evidence and did not reach the as-applied vagueness challenge.


United States v. Hayashi, 22 F.3d 859 (1993)