Happy holiday season! This month, we decided to highlight a shy little odontocete, the harbor porpoise (Phocoena phocoena). They are not known for grand displays in the water, but we wanted to do them justice this month because we believe they do not get enough love! These shy little guys face various human threats, so keep reading to find out more about harbor porpoises!
Is it a Dolphin?
No, harbor porpoises are not dolphins at all! In fact, they are in a different family altogether- Phocoenidae. They might look the same at first glance, but major physical differences exist between the two families. Instead of having a prominent forehead and snout, harbor porpoises have a blunt and rounded head. And instead of having spade-shaped teeth like dolphins, their teeth have a more spatulated shape. Lastly, a major difference is that harbor porpoises have short and immobile necks, giving them a stumpier look than their dolphin counterparts.
Find me in the harbor
Much like their name suggests, harbor porpoises are typically found in shallow coastal waters, no deeper than 152.4 meters. They are not typically known to hang out in groups of more than ten individuals. There have been aggregations of about 200 at one time, though!
They typically eat small schooling fish, but they love squid and octopus whenever they get the opportunity. Because of their high metabolic rate and because they typically live in cooler waters, they have to replenish their energy by eating about 10% of their body weight daily!
Unlike other porpoises and dolphins, you will not see them bow-riding; they try to avoid human interaction as much as they can. But living in shallow waters poses a huge problem, considering coastal waters are teeming with anthropogenic activity.
Threats to porpoises’ survival
Human interaction is the leading threat to harbor porpoises. Fishing entanglement is one of their major threats. Feeding on commercially important schooling fish gets them in the hot zone where they can get caught up in gillnets, trawls, and herring weirs. In the late ’90s, as many as 3,000 harbor porpoises drowned annually due to commercial fishing gear in the Gulf of Maine!
As they are close to the coast, noise pollution also poses a threat to these quiet creatures. In a study by Halpern et al, in 2019, they found that 59% of the world’s oceans showed an increase in fishing, land-based pollution shipping, and climate change. It looks like the threats are not disappearing for our small friends.
What can we do to preserve them?
The infographic below is from the NOAA website. Like most marine mammals, you want to keep your distance because human presence induces stress in marine mammals. If an animal is in distress (sick, entangled, injured, etc.) DO NOT TOUCH IT! According to your region, call the appropriate number and let the officials handle it. You can see the list of numbers here. Lastly, if you see anyone violating these rules or causing harm to any marine animal, please do not hesitate to contact the hotline number below.
Thanks for reading! For more infomations click the links below:
Did you like learning about the harbor porpoise? Find out more about its cousin the vaquita:
Vaquita, the most endangered cetacean in the world
Naomi Mathew is a PhD student at University of Louisiana at Lafayette. She works on bioacoustics in marine mammals from the Gulf of Mexico. She is the co-founder of Whale Scientists. You can read more about her here
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Naomi Mathewhttps://whalescientists.com/author/naomimathew/
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Naomi Mathewhttps://whalescientists.com/author/naomimathew/
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Naomi Mathewhttps://whalescientists.com/author/naomimathew/
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Naomi Mathewhttps://whalescientists.com/author/naomimathew/
