Figure 1: A North Atlantic right whale bearing scars on its skin due to excessive entanglement.
Source Credit: New York Times (LINK)
North Atlantic right whales were considered by humans as the “right” whale to hunt, hence its name. The species carried all the right characteristics to make them accessible to mankind. They were often found near shores. They swam slowly. When killed, they would float above water. They were the perfect prey. The whales were bound for destruction from the moment they were discovered.
Humans have continually threatened the survival of the species throughout the last century. Excessive whaling of the North Atlantic right whales led the global population count to as low as below 100 in the 1920s. When the practice of whaling was made illegal in 1932, there appeared to be a shimmer of hope for the endangered species. Although it had partially recovered in number since then, the population never reached its historic peak of 21,000. But now, the marine mammals face a new challenge: shrinking.
Scientists monitored the whales for the past 40 years in the form of aerial photographs that reveal their size. The photos spoke for themselves: large scars and gashes running along the bodies of the creatures. Sadly, a recent study published in Current Biology incorporating this data shows alarming changes in the age to length ratio in the whales.
The report reveals that since 1981, the right whales in the North Atlantic have shrunk by an average of 7 percent, or approximately one meter. This may seem insignificant on paper, but the issue is more properly illustrated case by case; here were mature five year old and even ten year old whales that were the proper size of two year old juveniles. The dramatic decline in size of whales is largely rooted in their entanglement in fishing equipment.
Whales can get tangled up in fishing gear as they swim in the ocean. With thousands of tons of such equipment resting in right whale migration routes and feeding areas, this event happens pretty frequently. It is estimated that 85% of all right whales have been entangled in fishing equipment at least once in their lifetime. These entanglements have the potential to seriously harm the whales by causing fatal infections, starvation, and drowning. But the effects can also be more long term.
Entangled whales tend to carry the fishing gear for several years, which is causing the species to diminish in size. The gear can get as heavy as 4,000 pounds. Dragging such a weight around requires a lot of energy–energy that should be going into biological functions like growth.
Gear entanglement also affects the reproduction of whales in a serious manner, and could prevent the revitalization of the species. Pregnant females entangled in fishing equipment give birth to smaller calves with lower survival rates. With just 366 known individuals of the North Atlantic right whale, inefficient means of reproduction could spell extinction for the gentle giants.
Now that the problem has been identified, there must be work done to resolve it and save the North Atlantic right whales. A popular proposal among environmentalists is the reduction of ropes in fishing equipment worldwide. While the goal may seem a bit far-fetched, research is already underway, with some even testing methods of fishing that are completely rope-free. Though the protection of the critically endangered whales will certainly prove to be a difficult fight, it may be humanity’s only way to right its past wrongs against the beautiful creatures.
Q&A:
Sally: How might the change in size harm the right whales? I understand the harm during entanglement, but I am curious about the aftermath.
There is evidence to suggest that whale calves that are too small have low rates of survival. As hinted to in the article, this issue continues to worsen as undersized mother whales tend to give birth to more undersized offspring.
Wooseok: Is entanglement an issue that only / mainly affects the right whales? Or does it also have critical effects on other types of whales too?
Entanglement is a huge issue beyond the scope of just whales. It negatively impacts all forms of marine life, perhaps the most well known example being sea turtles.
Hannah: What role do right whales play in the aquatic ecosystem? Aside from the ethical problems, are there any practical reasons why the right whales must be protected?
North Atlantic right whales play a vital role in their ecosystems. As their main prey is krill and plankton, a couple of small organisms that make up the foundation of aquatic ecosystems, it is critical that the whales exist to maintain balance in each trophic level of marine life.
John: Were there actions taken to develop fishing equipment in such a way that it doesn’t get entangled with the right whales? If so, what are they?
Environmentalists are looking into alternative fishing equipment that are less prone to entanglement. Removing netting material is one way this has been done. Greater investment into ropeless fishing technologies could be the key to protecting the right whales.
Works Cited
Fisheries, NOAA. “North Atlantic Right Whale.” NOAA, www.fisheries.noaa.gov/species/north-atlantic-right-whale.
Roth, Annie. “On the Verge of Extinction, These Whales Are Also Shrinking.” The New York Times, The New York Times, 3 June 2021, www.nytimes.com/2021/06/03/science/shrinking-whales.html.
Zuckoff, Eve. “Endangered Right Whales Are Shrinking. Scientists Blame Commercial Fishing Gear.” NPR, NPR, 3 June 2021, www.npr.org/2021/06/03/1002612132/endangered-right-whales-are-shrinking-scientists-blame-commercial-fishing-gear.
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