The Marine Mammal Protection Act and Why It Matters…

While we all want to connect with nature, sometimes it’s best left alone or observed from a distance.


It’s summer and that means more people in the water and potentially, encountering marine life. If you’re out on a boat and spot some dolphins, it may be tempting to motor over toward them and even slip in the water.

But did you know that’s actually illegal?

In the United States, marine mammals are protected under the Marine Mammal Protection Act, which was signed into law in 1972 by President Nixon with strong bipartisan support. The act protects the animals from harm and having their natural behaviors, such as feeding, nursing, resting or mating, disrupted by humans. The act also ensures the maintenance of healthy populations and that any depleted populations are rebuilt.

Studies have shown that tourist boats and swimmers are stressful to dolphins. “This has a negative impact, not only on individual animals, but on the population as a whole and long term it could be devastating,” said biologist Dr. Per Berggren in an article. Avoiding humans causes the dolphins to waste precious energy that should be spent on mating, socializing or feeding. While we all want to connect with nature, sometimes it’s best left alone or observed from a distance.

So, we’ve put a few points together to sum up the MMPA and what it does, as well as how we are able to work in the water with wild dolphins as scientists


1. What animals does the MMPA protect?

The MMPA protects all marine mammals, which includes: dolphins, manatees, polar bears, seals, sea lions, sea otters, walruses and whales. In total, it protects 125 marine mammal species.

2. What does the MMPA do?

The MMPA prohibits feeding, hunting, harassing, capturing, or killing any marine mammal or attempting to do so. These activities are referred to as a “take.” It also prohibits the import, transport, export, purchase or sale of marine mammals and their parts or products,” according to NOAA.

This is partly why you should NOT feed manatees lettuce or freshwater. Not only is it not good for them, it’s against the law. Manatees are protected under both the MMPA and the Endangered Species Act. According to the Florida Fish and Wildlife Conservation Commission, “anyone convicted of violating state law faces maximum fines of $500 and/or imprisonment of up to 60 days. Conviction for violating federal protection laws is punishable by fines up to $100,000 and/or one year in prison.”

3. Are there exceptions to these prohibitions?

Yes, there are exceptions.

Under the Marine Mammal Authorization Program, commercial fishing vessels are allowed to accidentally kill or injure marine mammals — referred to as incidental take — during commercial fishing operations, by obtaining an annual authorization permit from NOAA Fisheries. The fishing operations are classified into categories based on the number of marine mammal deaths or injuries that they cause.

Fisheries Categories:

Category I designates fisheries with frequent deaths and serious injuries incidental to commercial fishing.

Category II designates fisheries with occasional deaths and serious injuries.

Category III designates fisheries with a remote likelihood or no known deaths or serious injuries.

For example, the Mid-Atlantic gillnet fishery— a Category I fishery— has an estimated 3,950 vessels or persons. The marine mammal species unintentionally killed or injured in this fishery includes the bottlenose dolphin, common dolphin, gray seal, harbor porpoise, harbor seal, humpback whale, and minke whale.

Authorizations can also be made for the unintentional “take” of marine mammals during certain activities not related to commercial fishing, including military and sonar training exercises, oil and gas development, and construction projects. As you can see, many of the authorizations for non-commercial fishing activity deal with underwater noise.

Scientists and commericial photographers/filmmakers working with marine mammals must apply for permits as well, for what is called “permitted directed take.” Directed take means the activity is intentional and targeted for a marine mammal, such as a filmmaker approaching a feeding dolphin for footage in an educational documentary, or a scientist tagging a whale to study their movement patterns. For a scientific permit, the application must include details such as the specific people working on the project, a description of the study and why it’s necessary, and the nature of the take, among other things.

So, to study dolphins in the U.S. as biologists (and also in the Bahamas, which we’ll get to below), we have to apply for special permits. Our Florida work is to examine where and when the dolphins use the Florida coastline, as well as establish a catalog of individuals for photo-identification. The nature of the study does not require us entering the water with the animals, and therefore our permit does not include that authorization. We can, however, approach them to take photographs and record environmental data, like water depth, location and habitat type.

In case you’re wondering about the Bahamas….

The Bahamas has its own Marine Mammal Protection Act, as do other countries. In order to conduct our scientific projects there, we must apply for an annual permit with the Department of Marine Resources. In this case, we apply to work in the water because of the nature of our long-term study to observe underwater behavior and vocalizations (among other things).

Many people travel to the Bahamas to swim with the famous curious spotted dolphins. Anyone running commercial trips to observe or interact with the dolphins must apply for a permit or license under the act. And as with the U.S. MMPA, harassment of marine mammals is not allowed, along with feeding, hunting, or killing.

A researcher with the WDP works in the water with dolphins under permit to collect data. Photo by Bethany Augliere.

4. What are the guidelines if you do spot a whale or dolphin in the wild?

The MMPA protects animals from harassment, which includes being pursued. When viewing dolphins in the wild, remain 50 years away (about half the length of a football field). This is also true for porpoises, seals and sea lions.

For large whales, remain 100 yards from large whales. Certain states have laws that are even more specific. For instance, Federal law requires vessels to remain 100 yards away from humpback whales in Hawaii and Alaska waters, 200 yards from killer whales in Washington State inland waters, and 500 yards away from North Atlantic right whales throughout U.S. waters.

Check out this list from NOAA for more viewing guidelines.

5. So does the MMPA work?

Yes! According to a study, marine mammals in the U.S. are doing better than anywhere else in the world. Before the MMPA was passed, millions of dolphins died in tuna nets. After the law was passed, that number dropped to about 20,000 deaths per year. (Yes, dolphins still die in tuna nets, just not as many).

In Florida, manatees have rebounded to about 6,300 individuals, up from an estimated 1,300 in 1991. Other populations have also increased, including harbor and gray seals, California sea lions, blue whales and gray whales.

4. What can people do if they see a marine mammal violation?

To report marine mammal violations, such as people feeding, attempting to feed, or harassing marine mammals in the wild, please contact the NOAA Fisheries Enforcement Hotline: 1-800-853-1964. You also may call the closest Office of Law Enforcement to report a possible violation. Information may be left anonymously.

For more information about the MMPA, go to NOAA Fisheries.