NOAA scientists, a student, and a teacher participating in the NOAA Teacher At Sea Program kicked off a series of surveys supporting the Atlantic Marine Assessment Program for Protected Species.
“I feel really lucky to have been involved with this program for the last 15 years. This fantastic time series has helped us provide accurate and precise abundance and trends for many of our region’s protected species, interpret their status, and provide data needed for ocean developers and other ocean users,” said Debi Palka, the program’s principal investigator and chief scientist for the shipboard surveys. “Under the Marine Mammal Protection Act and the Endangered Species Act, our mission is to recover protected marine species while allowing economic growth, recreational opportunities, and offshore marine development in our region. Our program meets those needs. Very few science organizations are able to do this kind of long-term data collection throughout the U.S. Atlantic Ocean.”
The team conducted marine mammal, sea turtle, seabird, and ecosystem surveys aboard a NOAA vessel and plane between January 6 and February 21. Their surveys ran from Massachusetts to North Carolina, inshore to the Exclusive Economic Zone. This winter survey is particularly important because there’s limited winter data on these species, especially in offshore waters.
From the Sea
The shipboard survey aboard NOAA Ship Pisces was an ecosystem survey focused on multiple species. It collected trophic-level data on marine mammals, sea turtles, seabirds, large fish, marine plankton, and oceanographic conditions. This work was split among four teams:
- Seabird team
- “Big-eye” sighting team for cetaceans
- Passive acoustics team
- Oceanography team.
The shipboard survey ran two sets of zigzag tracks. In total, they surveyed during parts of 23 days, for about 200 hours, covering about 2,000 nautical miles.
Seabirds
The seabird team used the traditional strip transect data collection method with unaided eyes—no binoculars or other means of magnification. They observed 9,691 individual birds, including 28 species in 10 families/subfamilies, and 11 species-groups of unidentified ducks, auks, murres, puffins, gulls, and terns.
The most common birds they saw were Dovekies and Bonaparte’s gulls. Some of the most notable, rare birds were non-breeding great shearwaters, sargasso shearwaters, and two lost landbirds, yellow-rumped warblers. They also saw a single massive feeding flock of birds consisting of more than 5,000 individuals.
The “big eye” team followed the traditional transect data collection methods using unaided eyes and 25x150 powered binoculars to detect marine mammals, sea turtles, and large fish that come to the surface. They observed:
- 117 whales: blue whales, goose-beaked whales, otherwise known as Cuvier’s beaked whales, Sowerby’s beaked whales, fin whales, minke whales, North Atlantic right whales, humpback whales, sperm whales, and some unidentified whales
- 2,034 dolphins: bottlenose dolphins, common dolphins, pilot whales (either short-finned or long-finned), Risso’s dolphins, striped dolphins, and some unidentified dolphins
- 35 large fish: basking sharks and ocean sunfish
“We were surprised to see humpback whales everywhere we surveyed—from less than 1 mile off the coasts of New Jersey and Virginia, to warm Gulf Stream waters off North Carolina, and to waters deeper than 3,000 meters off Maryland,” said Palka.
The team was able to get fairly close to a couple groups of right whales off the mouth of the Chesapeake Bay. They photographed the callosity patterns on their heads for later identification.
Passive Acoustics
The passive acoustics team used a towed hydrophone array to detect and record marine mammal vocalizations in waters deeper than 100 meters. While towing the array behind the vessel, they had roughly 360 detections. They detected at least 11 species, including:
- A singing humpback whale
- Sperm whales
- Two species of beaked whales
- Pilot whales
- Risso’s dolphins, striped, common, and bottlenose dolphins
- Potentially a group of rough-toothed dolphins.
While humpback whale song is not uncommon to hear, it was a big surprise for our acoustics team. “The equipment we used filters out low frequency sounds. Most of the humpback whale song is low frequency so hearing notes above the filter in our recordings is special,” said Annamaria DeAngelis, research biologist and acoustician.
Listen for a series of “whoops” and “wooo” vocalizations at 03:00, 08:25, 19:00, 24:15, and 34:00 seconds.
In another stand-out recording, the acoustic team may have captured the echolocation clicks of a Gervais’ beaked whale while in the Gulf Stream off Cape Hatteras, North Carolina. “There is a lot of interest in being able to reliably tell this species from True’s beaked whale. We were in their habitat for just a brief time so getting a recording was amazing—like finding a needle in a haystack,” DeAngelis said.
The acoustic team also captured audio of sperm whales using echolocation clicks to search for and find prey. DeAngelis added, “You can get a sense of the animal’s size based on the interval between clicks. A long interval typically indicates a large male, and a shorter interval indicates a female or juvenile male.” These whales change their clicking rates when they home in on prey. “When you hear the change, you’re instantly rooting for the whale’s success. If there’s a long silence after the whale homed in on prey, then it most likely consumed its prey—score 1 for the sperm whale, and 0 for the squid!”
Sperm whale clip of an individual searching and finding prey. Rapid clicking that sounds like a fluttery sound indicates that the whale is honing in on prey.
Oceanography
The oceanography team collected plankton samples using two types of bongo nets. These data help us better understand where and how much prey is available for protected species to eat. The team also deployed a CTD to measure conductivity, temperature, and depth to assess the ocean’s physical, biological, and chemical conditions. This helps us better understand things like ecosystem productivity, fish spawning, larval recruitment, and species distribution. We can then make connections between animal patterns and the ocean conditions found in the Northwest Atlantic. This helps us understand how protected species interact with their environment and interact with human activities occurring in the same waters.
The team saw a range of plankton. Salps—a gelatinous zooplankton—dominated continental shelf and shelf break samples. Samples collected off the continental shelf contained fierce looking fish that live in the ocean twilight zone, about 200–1,000 meters below the ocean’s surface. These include hatchetfish, viperfish, and bristlemouths. They also saw smaller crustaceans like krill, amphipods, and copepods. Two unusual catches were an adult lined seahorse and a snipe eel.
From the Sky
During the aerial survey, the team focused on documenting whales, dolphins, seals, sea turtles, sharks, and other marine animals to generate abundance estimates. The team conducted 32 flights over 26 days, covering about 3,000 nautical miles of tracklines aboard a NOAA Twin Otter plane. They used a combination of traditional unaided-eye methods and a new, innovative camera system that continuously photographs a strip of water directly below the plane. “We’re excited about this new camera system since we may need to use it in future aerial abundance surveys like this one,” said Palka. “We’re currently in the process of developing AI models to assist with identifying potential animals from the thousands of images we collect during a single survey.”
They observed:
- 30 whales: fin whales, minke whales, North Atlantic right whales, humpback whales, sperm whales, and some unidentified whales
- 1,540 dolphins: bottlenose dolphins, common dolphins, pilot whales (either short-finned or long-finned), Risso’s dolphins, and some unidentified dolphins
- 163 sea turtles: green turtles, Kemps Ridley’s turtles, leatherback turtles, loggerhead turtles, and unidentified turtles
- 86 large fish: basking sharks, ocean sunfish, hammerhead sharks, white sharks, manta rays, and unidentified sharks
- Hundreds of gray seals and harbor seals hauled out on various islands off Massachusetts to New York—we’re still counting!
Teamwork Makes the Dream Work
- In addition to scientists from the Northeast Fisheries Science Center, a number of individuals within and outside NOAA Fisheries also participated this year, including:
- NOAA Greater Atlantic Regional Fisheries Office
- NOAA Southeast Fisheries Science Center
- NOAA Pacific Islands Fisheries Science Center
- NOAA Alaska Fisheries Science Center
- Lily Novak, Massachusetts Maritime Academy
- Kiersten Newtoff, NOAA Teacher At Sea
- Intermittent contractors on the aerial and shipboard surveys
- “Having talented scientists from around the United States involved in our surveys means we get all the expertise needed to efficiently and successfully conduct multi-platform surveys, using a variety of data collection techniques, and targeting multiple species from all trophic levels,” said Palka. “We couldn’t have done it without all these talented people.”
- NOAA Fisheries and the U.S. Navy provided funding to conduct this year’s series of surveys.
