Tag Archives: right whale

Upcalls and gunshots are music to scientists’ ears


By Sarah Paquette

First published in the MLA Newsletter, February, 2012

Much of a North Atlantic right whales’ life is a mystery. Scientists have identified waters off the coasts of Florida and Georgia as winter calving grounds for right whales, but were not sure where the non-pregnant whales went during the winter months. In December 2008, NOAA’s Northeast Fisheries Science Center conducted an aerial survey and sighted over 44 right whales in the Central Gulf of Maine near the Outer Falls region over a ten-day period. The sighting intrigued Jacqueline Bort, a Master’s student at the Collage of the Atlantic, so she decided to study the whales’ use of the habitat for her thesis.

“There were two parts to the project,” explained Bort, now the marine mammal and sea turtle research technician at Virginia Aquarium Stranding Response. “I was looking at seasonal and daily patterns of use of the area and the type of calls the whales used.” Bort, with funding from the Department of Marine Resources (DMR), was looking for two types of calls: up calls and gunshots, both of which are associated with Surface Active Groups (SAG), a mating behavior. “Up calls are contact calls,” said Erin Summers, marine resource scientist at the DMR, who has also been listening to whales in the Gulf of Maine. “Everyone in the population uses this call. It’s like asking, “Where are you” or saying “Here I am.” It’s very common. Gunshots are mating sounds commonly used during SAG.”

A Marine Autonomous Recording Unit ready to go. Photo by Erin Summers.

Bort recorded whale calls using a Marine Autonomous Recording unit (MARU), or pop-up buoy, designed by Cornell University. Inside each buoy, there is a hydrophone connected to a hard drive that records sounds. The buoy is anchored to the ocean floor and can stay there for three to six months, passively recording sounds the entire time. When it is time to retrieve the buoy, a signal is sent to it, telling the buoy to sever its tie. The buoy then pops to the surface. Once the hard drive is removed from the buoy, the recordings are downloaded and digitized.

“There are two ways to use the data,” explained Bort. “You can use automatic detectors [to look for specific calls or whale species], or you can hand browse through each day.” Bort found high call rates between October and February, with a high number of gunshot calls in October, November and December. “Gunshots began to drop off in December and all calls dropped off at the end of February. Then they pick up again in August and September,” she said.

Based on right whales’ gestation period of 13 months, scientists believe whales are mating between October and December. The following December or January, pregnant females give birth to calves off the coasts of Florida and Georgia. Bort’s recordings suggest that non-pregnant whales spend their winters in the Central Gulf of Maine and use the area as a breeding ground. “The next step is to go out and identify the whales to see which individuals are using the habitat and determine if the population includes an age class that is reproductive,” said Bort. “We can also observe the behavior of the whales in the area and collect fecal samples for hormonal information.” If reproductive whales are found in the Central Gulf of Maine, SAGs are observed and hormone levels indicate sexually active whales, the habitat might be confirmed as a breeding ground for North Atlantic right whales.

Dropping a Marine Autonomous Recording Unit over the side can be a tricky proposition as times. Erin Summers photo.

“Right now we are still putting together the puzzle,” said Bort. “I would like to continue to monitor the area to see if it is being used as continuously as we think. There has been some variability in populations in the past.” Bort plans to submit an article about her findings for publication. “It’s up to the federal government as to what to do about protection of the area. But I think it will affect shipping lanes more than fisheries,” she said.

Sound comes in to play even to protect the whales themselves. Cornell University’s Ornithology Lab has a new method to alert ships of right whales in their paths. The Right Whale Listening Network set auto detection buoys in shipping lanes off the north Atlantic coast in January 2008 where they are continuously recording sounds under water. When the software in the buoy detects a right whale call, it sends a cell or satellite phone call to an analyst in the Ornithology lab. The analyst checks the recording to verify that it is a right whale call and then sends out an alert to ships in the area that a right whale has been detected. With 24-hour surveillance, the lab hopes to reduce the number of whales involved in ship strikes, one of the biggest threats to this endangered species.

“Acoustics are being used more often. It’s good for places that are hard to reach by boat or plane in bad weather,” said Summers, who has been working with DMR and COA on various acoustic projects. For more than four years, the DMR has worked with COA students to monitor whales around Mount Desert Island. “Whales show up there every year; there is a high population every summer,” explained Summers. The recorded sounds are compared with boat surveys from the same area to gain better understanding of how many whales use the habitat.“

DMR has also deployed buoys in state waters to look for the presence and absence of whales during the fall. There are no surveys, boat or aerial, documenting the presence or absence of whales in these areas,” said Summers. She said the recordings are done on a weekly basis during the peak of the fishing season to listen for humpback, fin and right whales. “Acoustics is the most cost effective way to monitor the whales and it has one hundred percent coverage of the area. The only downside to acoustics is that it doesn’t pick up any non-vocalizing whales,” she said.
It will most likely be years before there are any conclusive answers about right whales’ use of the central Gulf of Maine. If it is found to be a breeding ground for the endangered animals, the area will likely be protected. “NMFS is looking to update critical habitat for right whales. Right now, they use feeding data and the amount of copepods found in an area [as determining factors]. This might change if [Outer Falls region of the central Gulf of Maine] is found to be breeding ground,” Summers said.

What do whales see?


By Sarah Paquette

First published in the MLA Newsletter, November, 2011

The MLA continues its series of articles on endangered whales and the laws in place to protect them. New whale rules to reduce the risk of entangling endangered whales in vertical lines will go into effect in 2014. The fifth part of this series investigates how right whales’ vision could affect the gear fishermen use.

Whales apparently can see just one color clearly underwater. Photo courtesy of NOAA.

Before comparing a whale and human eye, it is important to understand the basic parts and functions of the eye. “Think of the eye like a camera,” explained Dr. Jeffery Fasick, assistant professor of biological sciences at Kean University in New Jersey who has researched marine mammal eyes. “You have a lens in front for focusing and a film in the back for recording.” The colors we see are determined by our eye’s sensitivity to certain wavelengths of light. Photoreceptors called cones allow us to see in bright light, while rods help us see in less light. The human eye contains three types of cones: red, blue, and green-sensitive. The combination of these allows us to see one million hues and colors during the day. We only have one type of rod, though, which is why we can only see in black and white at night.

“Whales only have one cone, which is sensitive to green light, so they see in black and white in light and dark,” Fasick said. They have one cone and one rod, both of which are sensitive to light in the blue/green range of the color spectrum. “They match their cones and rods to the color of the water. To them, everything is bright,” explained Fasick. This means that anything that looks blue or green to the human eye is invisible in the water to whales. The one color that whales can see as a dark shape in their bright, watery environment is red. Copepods, the main food source for right whales, are red, allowing whales to see a group of them as a dark mass.

“Sight is the best way to get the most information in a short period of time,” said Fasick. “Their eyes bulge out to focus on the mouth to see copepods go in.”

It may be that underwater whales see very little clearly. New England Aquarium photo.

Dr. Scott Kraus, vice president of research at the New England Aquarium in Boston wanted to know  what would happen if fishing gear came in different colors, vertical lines in particular. Kraus wanted to find out if different colors would contrast with the color of the water, allowing whales to see a potential threat. To investigate, Kraus used different colored PVC pipes and placed them in front of whales. This research is still underway, so no conclusions have been made yet. However, Fasick points out that there is very little known about the optics of the eye, so color may not be the only player in the search to understand what whales see.

“We (scientists) know almost nothing about the optics of the eye,” Fasick said. “We know they have a shallow eye cup, which makes us believe a whale’s focal point is only a few meters in the distance. So even if whales can pick out red vertical lines, they would have to be close to them for the gear to be in focus.” Fasick also pointed out that we don’t know how smart right whales are. “What you have is a large, slow moving whale with poor vision. They might see gear as a foreign object, but they don’t know how to react to it,” he said.

In order to learn more about right whales’ eyes, Fasick said researchers need an eye to study. “We had a good eye from a stranded calf, but it still wasn’t great,” he said. There aren’t many right whale strandings and even when there are, the tissues in the eye aren’t fresh, explained Fasick. The best option, according to Fasick, is to study bowhead whale eyes. “[They] are a good source of tissue and are kissing cousins of the right whales,” he said.

In depth studies on other marine mammals’ eyesight have revealed interesting findings. Bottlenose dolphins were found to have acute, focused vision both in and out of water. “Bottlenose dolphins are able to focus straight ahead and to their side,” said Fasick. Eyesight appears to be important to dolphins for locating food, but they also rely on echolocation, something right whales lack.

“We are just starting to embark on the senses,” Fasick said. There is still much to be learned about right whales, but Kraus and Fasick have made great strides towards better understanding what whales see. And if Kraus’ research finds that right whales can see red rope well enough to swim around it, fishermen may start seeing some colorful changes to their gear.

Ocean Soul: A Magical Day with a Right Whale


By MLA Staff

This week’s video looks at Southern Right Whales. National Geographic photographer Brian Skerry talks about his close encounter with these whales while photographing them for a story. It can be dangerous to be this close to such a large animal, but the images and story from Skerry are remarkable.

 

First posted on YouTube, October 31, 2011 by NationalGeographic