In this installment of our Ask a Scientist Q&A series Dr. Greg Stone, CI's Chief Ocean Scientist, answered questions about marine mammals and the state of the ocean from the CI community. Due to the tremendous response – over 75 questions from around the world – some questions were omitted or consolidated. Thank you for your support and understanding.
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GENERAL QUESTIONS ABOUT MARINE MAMMALS
How do marine mammals demonstrate their memory? What experiences or information do they tend to recall?
- Tracy from the United States
Hi Tracy, thank you for your question! This is a very interesting topic, and research has taken place with both seals and dolphins on problem-solving and short-term memory. Some examples of demonstrated memory and the experiences these animals can recall would be how they forage for food, predator avoidance, and how they are able to distinguish individuals through vocalization.
If massive marine life declines, will this affect the oceans' ability to absorb carbon dioxide, thus adding to global warming?
- Joseph from the United States
Hi Joseph, thank you for your question! The role of the oceans in the global carbon cycle is without doubt very significant; they represent the largest long-term carbon sink, and they store and redistribute CO2. Of all biological (or "green") carbon that is captured worldwide, over 30 percent is captured by marine organisms and, thus. is termed "blue" carbon. Over 90 percent of the earth's CO2 is stored and cycled through the oceans.
Large organisms such as whales are responsible for exporting carbon to the deep sea from the surface of the water – especially the ocean's vegetated habitats like mangroves, seagrasses and saltmarshes. Such habitats cover less than 0.5 percent of the seabed, yet these "blue" carbon sinks are responsible for 50-70 percent of all carbon stored in the ocean sediments. Loss of blue carbon sinks creates a real threat.
Here at CI, our marine climate change scientists are studying the importance of mitigating the effects of climate change as well as finding key adaptation strategies to reduce the impacts of climate change on the world's oceans.
I've been reading a lot about the Phoenix Islands Marine Protected Area, but it seems mostly focused on fishes and corals. Has anyone done any kind of research on marine mammals in this region?
- Jake from the United States
Hi Jake, thanks for your question! During September 2009, I led a team of 15 people from such organizations as the New England Aquarium, National Geographic, the US Fish and Wildlife Service and Conservation International on an expedition to the Phoenix Islands. The aim was to conduct a study of the reefs and to document the marine life there, which included the presence of marine mammals. Here is a link to our dispatches from the field, which were sent via satellite phone:
Expedition: Phoenix Islands Protected Area
Can ocean mammals such as whales, dolphins, etc., live – at least temporarily – in fresh water (lakes, rivers)? Which ones do and do not? Thanks
- Fernando from Costa Rica
Hi Fernando, thank you for your question! Marine mammals are able to live in freshwater, at least temporarily, although over time they would become exhausted due to the lack of buoyancy provided by freshwater and a lack of food availability. Marine mammals can also have issues with their eyes and skin after prolonged exposure to freshwater. There are freshwater marine mammals, such as river dolphins, that can be found in rivers and estuaries.
What effect will krill depletion in the southern oceans have on whales and other marine mammals?
- David from the United States
Hi David, thank you for your question! As you know, climate change is a big issue these days and is having serious impacts on the marine environment. As water temperatures are rising, the ecosystem is being affected in a number of ways. In reference to krill, these shrimp-like organisms depend on sea ice to survive. In areas of the Southern Ocean around Antarctica, there is a pattern forming between the rise in water temperature and lower survival rates of South Atlantic right whale calves; it is believed this is due to a drop in the availability of krill. This has also been seen in fur seals and blue whales.
What is the biggest threat to marine life at the moment, and what can be done to stop it?
- Michelle from Australia
Hi Michelle, thank you for your question! Ocean ecosystems must respond simultaneously to multiple threats – unsustainable fishing, global climate change, habitat destruction, invasive species and pollution – that together magnify the effects of individual threats.
Overall, there are two major barriers to re-establishing a prosperous ocean. Firstly, a lack of global consensus on the status of ocean health makes it difficult to rally the global public and decision-makers around collective actions to improve it. Secondly, fragmented ocean governance restricts comprehensive ocean management, weakens enforcement of regulations and favors short-term interests over long-term ecosystem needs and human well-being.
Here at CI, we have an ambitious plan to restore and maintain a prosperous ocean through a number of global solutions which we hope will spur a revolution in marine governance and management. The result will transform ocean health and benefit the people who depend on marine resources for their livelihoods and well-being.
First, we need a globally accepted benchmark of ocean health that inspires government, corporate and civil society actions and measures the effectiveness of marine conservation efforts. Second, we need solutions that influence fisheries policy and markets to reverse deteriorating ocean health worldwide. Third, we need to pioneer new models, such as oceanscapes and seascapes, for managing and recovering ocean health at scale.
Here are some links to further information:
In a natural life span, how many miles does the average whale swim? How far can a calf swim before s/he's weaned?
- Cara from the United States
Is it possible that there are marine animals bigger than the blue whale and unknown to modern science?
- Charles from the United States
How strongly does the disruption of life cycles at the ocean floor affect larger marine life further up the food chain?
- Jonathan from the United States
Dear Dr. Stone, My grade 3 class wants to know: Where did whales come from? Why do they look different? How do they sleep?
- Allen from Canada
What is the current picture of the social life of blue whales in the oceans?
- Harri from Finland
Can you recommend any books or other publications dealing with marine mammals within the East African region?
- Martin from Kenya
I live near a river delta area. Scientific reports show that Irrawaddy dolphins are found in the area; however, I never meet anyone who has seen them. How do I spot Irrawaddy dolphins? Do I have to use a kayak/canoe rather than motorboat?
- Asti from Indonesia
Dear Dr. Greg Stone, I would like to know: Among the whale species nowadays, which one is the most antique?
- Daniel from Peru
Which mammals live in the Indian Ocean? Apart from that, I would like to know about corals. How can we identify corals and sea weeds, and what kind of corals are living in the Indian Ocean?
- Anuradha from Sri Lanka
What marine mammals are the most critically endangered right now, and what would be the potential impact (if known) if they disappear?
- Laura from the United States
How long can dolphins and whales swim underwater without taking air from the surface again? I teach English at schools, and some children wondered about that, but I couldn't give them an answer.
- Patricia from Argentina
Where can I get a chart with all of the basic information on cetaceans? I'd like to help in teaching people about sea life, and I need basic info.
- Marcos from Costa Rica
What kind of barnacles grow on whales? And do the barnacles hurt the whales?
- Eddie from the United States
Hi, I was wondering about sea mammals and how endangered they are. Are there real numbers? Thanks for your time.
- Carlos from Peru
Hello Dr. Stone, Is it true that some marine mammals have or carry Omega-3 and that they are hunted because of it, besides being hunted for their meat/flesh? Isn't it possible to get Omega-3 in an artificial way?
- Manuel from Paraguay
My seven-year-old has three questions. How many teeth does a great white shark have? Is it true that we know more about space than our own oceans? Could you tell me more about the Pacific barreleye?
- Sara from Canada
How close are scientists to understanding the sonar language of whales and dolphins, and when could these scientists expect to be able to actively communicate with them?
- Marcia from the United States
I live in Brasilia, capital of Brazil. What are the statistics and numbers reflecting the real situation of marine life today? A big hug and congratulations on your beautiful and important work and its contribution to the planet.
- Luciana from Brazil
How does a walrus eat with those huge tusks? Don't they block the food?
- Ben from the United States
I have read in an article about sea otter numbers declining fast due to the sudden predation of whales (because the whales' other prey has declined due to us). Is that still a very big problem, or has the situation improved?
- Simona from Denmark
Since marine mammals, for the most part, travel all over, how can any country make a determination about how they are to be treated or affected, as no country can actually own them?
- Valerie from the United States
Any answers to why marine mammals beach themselves?
- Anca from the United States
What sources do you highly recommend to edify my two home schooled children regarding requisite global management?
- Gregory from the United States
Why isn't there more being done to protect the seals? From climate change to hunting, there isn't much being done ?
- Kelly from the United States
I heard while watching the move "The Cove" that dolphins are self-aware. Is this true for whales? How is it measured?
- Robert from the United States
Hello, I read a rumor some time ago that whales know when they are about to die, and hours before their death, they dive deep down to abysses and die, forming a cemetery, much like elephants do. I wanted to make sure it's true – or not. Thank You.
- Paola from Mexico
When Nudibranchs acquire new tools for survival via the consumption of other Nudibranchs, is there a period of digestion that is toxic and life-threatening to the predator?
- Si from the United Kingdom
Is anything being done to address the problem of collisions between whales and ships? I understand that the only reason shipping lanes are in known whale migration areas is financial. What is being considered to discourage this?
- Kevin from the United States
1. Are there certain cetaceans that have healthy readings of contaminants & if so, where are they located? 2. Have ocean temperatures affected migration & increased mortality? 3. Can we use satellites to arrest unlawful cetacean capturers?
- Andrew from Canada
In this millennium, have there been (and where, at what date) new discoveries of late-surviving archaeocetes?
- Rhys from Australia
EDUCATION RELATED QUESTIONS
Danica from the United States, Ally from the United States, Michelle from Australia and Trisha from the United States presented questions related to educational and career opportunities.
TOURISM RELATED QUESTIONS
Katie from the United Kingdom, A. Fry from the United States, Debby from the United States and Michelle from Australia presented questions regarding tourism and marine mammals.
'THE COVE' DOLPHIN HARVEST AND WHALING RELATED QUESTIONS
Mike from the United States, John from the United States, Connie from the United States, Maryanne from the United States, Gordon from the United States, Jordan from Canada and Victor from Thailand had questions about whaling and dolphin harvest with some references to the movie "The Cove".
QUESTIONS ABOUT SLEEPING HABITS OF MARINE MAMMALS
Blue from the United States, Robert from the United States and Craig from the United States provided excellent questions about the sleeping habits of marine mammals.
DUGONG AND MANATEE QUESTIONS
Joshi from India and Suzy from the United Kingdom asked questions about conservation efforts form manatees and dugongs.
OIL SPILL RELATED QUESTIONS
Jen from the United States, Colleen from the United States, Shelley from the United States, Alma from Mexico, Suzanne from the United States, Susan from the United States and A. Robbins from the United States inquired about the Gulf oil spill and the impacts this will have on ocean health and biodiversity.
WASTE AND PLASTICS RELATED QUESTIONS
Can't you get the "Prototype This" team at the Discovery Channel to invent a plastic-eating robot, that derives power from consuming plastic, to clean up our beaches and possibly our oceans of plastic debris?
- Robert from the United States
What, if any, is the impact of plastics in the oceans on the health of cetaceans, etc.?
- Dave from the United States
What can factories do to throw away their waste in a way that the ocean is not polluted?
- Lorena from Bolivia
Are there any plans to clean up the plastic accumulation in the Pacific Ocean?
- Doris from the United States
STATUS OF THE WORLD'S OCEANS
Nelson from East Timor and William from the United States asked about the current global state of our oceans and marine biodiversity.
Best fishes, everyone!
– Dr. Greg Stone
Chief Ocean Scientist