Visit Your Local PBS Station PBS Home PBS Home Programs A-Z TV Schedules Watch Video Donate Shop PBS Search PBS
Voyage of the Odyssey Voice from the Sea
What is the Voyage of the Odyssey Track the Voyage Interactive Ocean Class from the Sea Patrick Stewart
> Odyssey Logs -
Search by Region
- Atlantic Ocean
- Mediterranean Sea
- Mauritius
- Sri Lanka
- Maldives
- The Seychelles
- Indian Ocean
- Australia
- Papua New Guinea
- Kiribati
- Pacific Passage
- Galapagos Islands
> Odyssey Logs - Search by Topic
> Odyssey Video
> Current Location - Map
> A Day in the Life
> Meet the Crew
site map  
A Blainsville Beaked Whale
A male Blainville's beaked whale (Mesoplodon densirostris). In adult males, two tusk-like teeth erupt from the mid-lower jaw.
Photo - Courtesy of and Copyright 2005 - Diane Claridge - BMMS

August 11, 2005
The Bahamas Marine Mammal Survey
Real Audio Report -   28k


Log Transcript

This is Genevieve Johnson speaking to you from the Odyssey as we leave the Bahamas and sail toward the continental United States for the first time since leaving San Diego almost five and a half years ago.

Over the past two weeks, the Ocean Alliance in conjunction with SCRIPPS Institution of Oceanography and with the support of the Bahamas Marine Mammal Survey (BMMS) conducted a survey along the eastern and southern coasts of Abaco Island. The crew was searching for sperm whales and two elusive species of beaked whale. Blainville's beaked whale (Mesoplodon densirostris) and Cuvier's beaked whale (Ziphiius cavirostris).

For fifteen years, Diane Claridge, a research scientist from the Bahamas has recorded numerous cetacean sightings including beaked whales off Abaco Island. She began the BMMS in 1991 in an effort to document what species of cetaceans existed in the area and in the wider Caribbean region.

Diane Claridge - Bahamas Marine Mammal Survey:

    "We did a pilot study in '91 and then with funding from Earthwatch began working in the winter months - going out doing vessel surveys, figuring out which species are here and where they are found and estimating abundance for resident species."

Genevieve Johnson:

Earthwatch is a non-profit organization that engages people world wide in scientific field research and education to promote the understanding and action necessary for a sustainable environment. Eight volunteers from around the world come and stay with Diane and help the scientific team for ten days at a time. This is a great opportunity to get first hand experience with marine mammals.

To date, Diane and her research team have documented the presence of twenty-three species of marine mammal, which in addition to cetaceans includes the hooded seal and the manatee. Some species appear to be resident year round, others are seasonal, but many questions remain answered.

Photo of Diane Claridge
Diane Claridge of the Bahamas Marine Mammal Survey.
Photo - Chris Johnson

Diane Claridge:

    "The long term goals are to figure out which species are here and their seasonal occurrence and then determine which areas they are found in, their habitat requirements and if there is some areas that are more important to them than others and try to work towards conservation initiatives that would protect those areas. Then for resident species like the bottlenose dolphins, we are able to estimate abundance and monitor population changes over time."

Genevieve Johnson:

There are some species Diane and her team see regularly, resulting in a greater understanding of the ecology of these species. This is particularly true for bottlenose dolphins.

Diane Claridge:

    "With the bottlenose dolphins, which is the species we see most often because we are a shore based project so we are limited in how much time we can spend far from shore, so we have the most detailed results from that work and we are happy to announce that they seem to be a healthy population of animals, they are living long as adults with really high survival rates. We have done some contaminant studies; they have really low contaminant levels, probably lower than most people. There is high genetic diversity, all the symptoms of a healthy population, which is unique for bottlenose dolphins because they are a coastal species and the impacts from human activities are pretty high generally."

Genevieve Johnson:

Taking a break from working further offshore on the Odyssey, the crew spent a day out on the water with Diane looking for whales and dolphins closer to shore from her zodiac. We found two groups of bottlenose dolphins the team recognized as resident populations. The second group was feeding only a few hundred meters in front of Diane's research station. The pod seemed indifferent to our presence and we spent three incredible hours observing and photographing them. A particularly curious calf took an interest in the boat swimming back and forth only a few feet off the bow.

Bottlenose Calf
A resident bottlenose dolphin calf, approaches the zodiac.
Photo - Chris Johnson

Sperm whales frequent the deep water farther offshore. However, it is another species of toothed whale, the beaked whale, that Diane has a particular interest in, and a strong desire to learn more about.

Beaked whales are the least known of all cetaceans. There are currently about 20 known species belonging to the family Ziphiidae. Beaked whales are small to medium sized, deep diving toothed whales that feed primarily on squid in deep water. They are exceptionally elusive, rarely seen animals, meaning that until recently much of what we learned came mainly from stranded specimens.

Weather conditions and small boats often restrict Diane's team to inshore waters reducing the opportunity for encounters with these whales. However, through her dedication and the longevity of her program, Diane contributes much to what is known about the population ecology of beaked whales, particularly Blainville's beaked whale.

Diane Claridge:

    "In this part of the Bahamas there is primarily two species of beaked whales, only two that we have confirmed sightings of at sea, although we have had a third species strand and found remains of them so we know they are around, they are just extremely cryptic. Then of those two species, there is one, the Blainville's or dense beaked whale that is here regularly enough that we are able to use photo identification techniques to learn about their population ecology. We don't have that many encounters because they are difficult animals to find and you need really calm water. We don't believe there is very high abundance of them, we have estimated annual abundance within our study area and it's low. We know that females as adults spend more time in our study area than males do, so the males tend to have larger ranges and roam more which isn't surprising. We have found some difference in habitat use between the younger, sub-adult animals, or immature animals and the adults. The adults seem to be occupying the primary habitat and the most productive areas."

Genevieve Johnson:

In recent years, military operations employing mid-frequency, long-range tactical sonar have caused beaked whale to strand around the world.

A multi-species stranding of 17 cetaceans including the Cuvier's and Blainville's beaked whales occurred along Diane's study sight along Abaco Island on March 15 - 16, 2000.

I asked Diane whether she noticed any significant change in her sightings data following the mass stranding?

Diane Claridge:

    "There definitely was an impact as a result of that one naval exercise here. The larger of the two beaked whales, the Cuvier's beaked whales essentially disappeared from our study area for almost two years. We are now seeing them again, but we didn't see any for 22 months after the exercises."

Genevieve Johnson:

So little is known of beaked whales that scientists like Diane are working to learn more in order to understand how noise in the ocean affects them.

Chris Johnson and Meagan Dunphy-Daly both graduated from Oberlin College
BMMS researcher Meagan Dunphy-Daly shows photo-identification images from their digital catalog to Chris Johnson of the Odyssey.
Photo - Genevieve Johnson

Diane Claridge:

    "We have actually had some resights of individuals that we had seen prior, we are seeing them again and that was the species that was most represented in the stranding - the majority of animals that stranded were Cuvier's beaked whales."

Genevieve Johnson:

Current legislation protecting marine mammals in the Bahamas is minimal and difficult to enforce. Although the marine habitat appears comparatively healthy, Diane is concerned.

Diane Claridge:

    "There is not a high abundance of any one species here as far as we have learned. There is an interesting high diversity of marine mammal species here, particularly the toothed whales, but there doesn't seem to be a lot of any one species. For that reason alone, you would want to proceed with caution in presenting any changes in the marine environment that could cause problems for them. There are plans for big changes, there is a huge area north of the Abacos that has been leased out for oil and gas exploration, and they will find oil there, whether or not it is economically feasible for them to extract oil is yet to be determined. Then like everywhere in the world there is increased shipping traffic and the noise associated with the vessels.

    There will be more naval maneuvers in the area too which is of concern, but they are not supposed to do that particular exercise in this particular place in peace time ever again. But certainly, yes there are naval exercises and in certain areas in the Bahamas that is a concern too."

Genevieve Johnson:

Diane's field research schedule is hectic and year round. Yet, unlike many researchers the crew has met during the Voyage, Diane believes in the value of sharing her work by conducting local educational workshops and camps for kids.

Diane Claridge with loca students
Diane shares the research experience through a hands-on environmental education program with local students from Abaco.
Photo - Courtesy of Diane Claridge of the BMMS

Diane Claridge:

    "Some of our outreach work that we do here is mostly focused on Abaco Island and primarily here in Sandy Point. We run an environmental camp and have about 30 children participate in a multi-week program where they get hands on experience. They are in the field and its not just focused on marine mammals, although that is always the highlight for them is to get out on the water and see dolphins. But we take them kayaking and bird watching and really just exploring their own backyard in a way that they have never done before."

Genevieve Johnson:

As the crew bid Diane and her team farewell, we were left with a feeling of hope for the future of marine mammals in the Bahamas. By taking the time to incorporate 'Earthwatch' volunteers from around the globe in her research, and sharing the wonders of these animals with children in her local community, Diane's unique approach inspires an obvious sense of pride and responsibility toward the marine environment.

Links:

Odyssey log written by Genevieve Johnson.

Note - Stay tuned for the next Odyssey log as we sail up the east coast of the United States. The Voyage of the Odyssey will be finishing in Boston, MA on August 17th. We will post the location and time of our arrival - so if you are in the Boston area, come and watch the crew bring Odyssey home!

<< Back

 
 
> Home > Voice from the Sea > What is the Voyage? > Track the Voyage > Interactive Ocean > Class from the Sea > Patrick Stewart > Help with Plugins? > Site Map