NOAA Shark Survey Shows East Coast Populations Improving

Lisa Natanson, a research fish biologist with the National Oceanic and Atmospheric Administration (NOAA), has been fascinated by sharks since she was seven years old. Growing up in the San Francisco Bay Area, she says the marine environment plays an important role in residents’ lives.

“I just was interested in sharks from a young age and never lost interest,” says Natanson in an interview with R&D Magazine.

The Bay Area is known for its great white shark population. According to the San Francisco Chronicle, scientists have estimated the Bay Area population to number around 2,400, a staggering figure when estimates in the 1990s ranged from 200 to 400.

These days, Natanson’s focus is on shark populations along the east coast. For 29 years, NOAA has surveyed shark populations in order to monitor health and abundance in the Atlantic Ocean. This year, 2,835 sharks were captured, the most in the survey’s history and a good indicator of healthy shark populations. Seventy-seven percent of those sharks were tagged and released. Researchers record the length, sex and location of each animal caught.



In 2012’s survey, 1,831 sharks were caught.

Natanson’s been involved in the survey since its inception, only missing one survey. They are conducted every two or three years. In 1996, she started leading them.

“(It) never gets old,’ she says of seeing sharks. “They’re really neat…It’s hard to describe, they’re just beautiful.”

In ideal conditions, sharks are captured in waters from Fort Pierce, Fla., to Delaware. But the survey’s breadth is contingent on weather conditions. This year’s survey ended in North Carolina. “We got hit by the Tropical Storm Anna off North Carolina” and were grounded for a week, Natanson says.

This year’s survey was conducted from the 100-ft charter fishing vessel Eagle Eye II between April 4 and May 22. According to Natanson, spring timing is crucial because shark populations are more concentrated. In the summer, they travel as far north as Canada.

“We’re working 24 hrs (and) we’re not in very often,” she says, noting the researchers spend between one to three weeks at sea on each leg.

Thirteen species were captured, including great white, sandbar, Atlantic sharpnose, dusky, tiger, blacktip, scalloped hammerhead, silky, sand tiger, bull, great hammerhead, nurse and spinner sharks.

The largest captured was a 12.5-ft tiger shark off North Carolina’s coast.

Normally, the survey doesn’t yield great whites or bulls, Natanson says. However, this year the team caught an unprecedented six bull sharks.

“Way back when, we didn’t used to get blacktips, and now we’re seeing a lot of blacktips,” she adds. On the east coast, blacktips are threatened by fishing. Additionally, the species has a slow maturation process, between 12 and 18 years. However, regulations are in place to protect the species. Their presence is the 2015 survey is an indicator conservation efforts are working, according to Natanson.

Bottom longline fishing methods are used for capture, with depths ranging from 30 to 240 ft. The lines are outfitted with around 300 hooks, according to Natanson.

Though some sharks do perish during the process, the researchers use those specimens to study growth, reproduction and food habits. “On this survey, reproductive information was obtained from 170 sharks, backbones were removed for age and growth work from 109 sharks and stomachs were examined in 82 sharks,” according to the NOAA.

Though involved in the field for a number of decades, Natanson doesn’t point to one shark species as her favorite. “The favorite one is the one I’m working on at the time,” she says.