The North Atlantic right whale (Eubalaena glacialis) is a baleen whale, one of three right whale species belonging to the genus Eubalaena
Conservation status for North Atlantic right whale : Critically endangered
Entanglement in fishing gear is a deadly threat to these critically endangered animals.
Scientists estimate that before commercial whaling scaled up in the 18th and 19th centuries, there may have been as many as 10,000 North Atlantic right whales.
Today, fewer than 360 individuals remain. Almost 90% of them have been entangled at least once.
When whales become entangled in fishing gear, they use extra energy dragging it as they swim.
If the rope is caught around their mouths, they may struggle to feed and slowly starve.
Ropes wrapped around whales’ bodies, flippers or tails can cut into the animals’ skin and become deeply embedded in their flesh.
This can cause infections, chronic emaciation and damage to whales’ blubber, muscle, bone and baleen – the bristly structures in their mouths that they use to filter prey from the water.
North Atlantic right whales are legally protected, both internationally and in U.S. waters, including policies that seek to reduce deaths or serious injuries resulting from entanglements.
However, even when entanglement does not kill a whale, it can affect individuals’ ability to reproduce, which is critically important for a species with such low numbers.
North Atlantic right whales historically started breeding by around 9 years of age and gave birth to a single calf every three to four years thereafter for several decades.
Today, however, many females have yet to reproduce at all.
Moreover, those that have successfully produced calves now don’t produce another calf for more than seven years on average.
Research has shown that poor health and physical condition are making it harder for these females to even start breeding.
Since the early 1980s, North Atlantic right whales have literally shrunk: Adults have shorter bodies than they did several decades ago.
This trend is associated with entanglements in fishing gear.
As is true for all mammals, decreasing female body size reduces the likelihood of reproducing. Smaller whales have fewer calves.
New study found that female right whales who have experienced even a minor entanglement before reaching sexual maturity may not ever start to breed.
Even females who have previously reproduced are less likely to breed again following an entanglement event.
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