Harbor Porpoise (Phocoena phocoena)

Harbor Porpoise
(Phocoena phocoena)
Photo: NOAA

Did You Know?

· Their name is derived from the Latin word for pig (porcus) and are sometimes called "puffing pigs" by fishermen.

· Harbor porpoises are most commonly found in bays, estuaries, harbors, and fjords.

· When surfacing for air, they do not splash; they roll from beak to fluke and arch the back.

Status
MMPA - Harbor porpoises, like all marine mammals, are protected under the MMPA.

Taxonomy
Kingdom: Animalia
Phylum: Chordata
Class: Mammalia
Order: Cetacea
Family: Phocoenidae
Genus: Phocoena
Species: phocoena

Species Description
Harbor porpoises have a small, robust body with a short, blunt beak. Harbor porpoise males reach average lengths just over 5 ft (1.5 m) while females are slightly larger with average lengths of 5.5 ft (1.7 m). The average adult harbor porpoise weighs between 135 and 170 lbs (61-77 kg).

Mid-way down the body sits a medium-sized triangular dorsal fin. The back of the animal is dark gray while the belly and throat are white. There is a dark gray chin patch and also intermediate shades of gray along the sides of the animal.

Harbor porpoises are non-social animals usually seen in groups of 2 to 5 animals. When surfacing for air, they do not splash; they roll from beak to fluke and arch their backs. Little information is known about their social behavior.

Females reach sexual maturity at 3-4 years and may give birth every year for several years in a row. Gestation lasts for 10-11 months and lactation lasts for 8 to 12 months. The harbor porpoise lifespan is about 24 years.

They feed on demersal and benthic species, mainly consisting of schooling fish (e.g., herring and capelin) and cephalopods.

Habitat
Harbor porpoises inhabit northern temperate and subarctic coastal and offshore waters. They are commonly found in bays, estuaries, harbors, and fjords less than 650 ft (200 m) deep.

Distribution
Harbor porpoises have a discontinuous distribution. In the North Atlantic, they range from West Greenland to Cape Hatteras, NC (but do not enter Hudson Bay), and from the Barents Sea to West Africa. In the North Pacific, they are found from Japan (34°N) north to the Chukchi Sea and from Monterey Bay, CA to the Beaufort Sea.

Population Trends
There are 10 stocks of harbor porpoises in U.S. Waters: Bering Sea, Gulf of Alaska, Gulf of Maine-Bay of Fundy, Inland WA, Monterey Bay, Morro Bay, Northern California-Southern Oregon, Oregon-Washington Coastal, San Francisco-Russian River, and Southeast Alaska. NMFS Stock Assessment Reports (SARs) include estimated population sizes for the 10 U.S. stocks and are summarized below. Population trends for all of the U.S. stocks are currently unknown.

Stock	Estimated Abundance	Reference*
Bering Sea	66,078	SAR 2006
Gulf of Alaska	41,854	SAR 2006
Gulf of Maine-Bay of Fundy	89,054	SAR 2007
Inland WA	10,682	SAR 2006
Monterey Bay	1,613	SAR 2004
Morro Bay	1,656	SAR 2004
Northern California-Southern Oregon	17,763	SAR 2002
Oregon-Washington Coastal	37,745	SAR 2006
San Francisco-Russian River	8,521	SAR 2004
Southeast Alaska	17,076	SAR 2006

* NMFS Stock Assessment Reports (SARs) for the Harbor Porpoise

Threats
The primary threat to harbor porpoises is bycatch in fishing gear, specifically in gillnets and trawls. In Canada, harbor porpoises are also incidentally taken in herring weirs.

Conservation Efforts
In 1996, NMFS convened two take reduction teams (TRT) to mitigate bycatch of harbor porpoises in gillnet fisheries, the Gulf of Maine Harbor Porpoise TRT and the Mid-Atlantic TRT. The Gulf of Maine TRT addresses gillnet fisheries in waters from Maine through Rhode Island and the Mid-Atlantic TRT addresses waters from the Connecticut/New York border through the North Carolina/South Carolina border. The teams submitted draft take reduction plans to NMFS and the agency finalized the plans in 1998.

The Harbor Porpoise Take Reduction Plan requires commercial fishermen to use pingers in gillnets in designated times and areas. There are also times and areas where gillnet fishing activities are prohibited. The HPTRT continues to meet to monitor the progress of the take reduction plans in achieving the MMPA long-term goal of reducing harbor porpoise bycatch to a zero mortality and serious injury rate.

Regulatory Overview
This species is protected under the Marine Mammal Protection Act of 1972 as amended. NMFS has classified the following U.S. stocks of harbor porpoises as "strategic" stocks: Bering Sea, Gulf of Alaska and Southeast Alaska. Harbor porpoises are considered Vulnerable on the IUCN Red List .

Key Documents
(All documents are in PDF format.)

Title	Federal Register	Date
Status Review: Gulf of Maine/Bay of Fundy stock	66 FR 53195	10/19/2001
Harbor Porpoise Take Reduction Plan	63 FR 66464	12/02/1998
Stock Assessment Reports	n/a	various

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