New Dawn for the Dusky Shark

Earlier this month, ocean conservation nonprofit Oceana sued the administration for its failure to address and protect the dusky shark. 

Dusky sharks are found throughout world waters, including off of Cape Cod. Considered to be highly migratory, these sharks can live upwards of 40 years but do not reach sexual maturity until they’re about 20, making them ‘slow growth’ sharks. This is where the problem lies.

Beginning in the 1970s dusky sharks were a popular target for commercial and recreational fishing. It’s estimated that through a combination of overfishing, bycatch, and the shark fin trade, that the population of dusky sharks in the Atlantic has declined by 65 percent. Because these sharks don’t reach sexual maturity until 20 and have a gestation time of 18 months, they’re highly susceptible to overfishing and are unable to easily rebuild their population.

In 2000 the National Marine Fisheries Service outlawed fishermen from targeting the shark, but did not take bycatch into consideration. As outlined in the lawsuit, Oceana stipulated that the federal government has “failed to establish measures necessary to end overfishing and rebuild the dusky shark population to a healthy level” and failed “to ensure that bycatch does not exceed the annual catch limit it set for dusky sharks and failed to demonstrate how the measures it did include will be sufficient to rebuild the dusky shark population and end overfishing.”


At the moment, the shark remains a species of concern under the Fisheries Service and although the ban was placed on targeting these animals, longlinge fishing is often ensnaring these sharks. As reported by Oceana, in 2010 more than 4,000 dusky sharks were captured and discarded off of longlines.

Longlines are a problem of their own. Looking at dusky sharks specifically, it is estimated that “more than 80 percent of immature dusky sharks and more than 40 percent of adults caught on bottom longlines die by the time they are hauled to the fishing vessel.” Beyond that, the Fisheries Service estimates that 10-42 percent of sharks caught by bottom longlines that are alive at the time they are released die afterward, and a similar study found that “as 97 percent of sharks die, either on the vessel or post-release, after spending more than three hours hooked on a line.

As estimated by Oceana, more than 75,000 dusky sharks have been caught through bycatch since fishing was prohibited in 2000. Alternatively, even if overfishing were to stop today it would take the population 100 years at least to recover.

In reality, this lawsuit speaks for the larger shark and migratory fish populations. Our current means of fishing are unsustainable and do not leave time for populations to recover. As to how the administration will respond to this remains a mixed bag. Previously Donald Trump has said the following when it comes to sharks:

However, on May 9 the administration added the daggernose shark, striped smooth-hound shark, spiny angel shark, and Argentine angel shark to the Endangered Species List, although simultaneously calling into question the status of our national marine monuments.

Featured photo and article photo both by Richard Ling, Creative Commons. 

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