Q&A+with+Conservation+International

Q&A with Conservation International

Question 1: Can ocean mammals such as whales, dolphins, etc., live – at least temporarily – in fresh water (lakes, rivers)? Which ones do and do not?

Answer from Conservation International: 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.

My imput: I found this topic very interesting since saltwater has a higher density than freshwater, marine animals that have normal habitats in saltwater have to swim harder to stay afloat. I never knew that fresh water could cause issues with animals' skin if they have prolonged exposure. I never thought there were fresh water river dolphins!

Question 2: What effect will krill depletion in the southern oceans have on whales and other marine mammals?

Answer from Conservation International: 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.

My imput: This situation, if placed on a scatter plot, could be called a negative relationship. By this I mean as the temperature increases the amount of krill decreases due to their home being ice. It is interesting how everything on the earth is connected and when one environment is affected, another is also threatened.

Question 3: If massive marine life declines, will this affect the oceans' ability to absorb carbon dioxide, thus adding to global warming?

Answer from Conservation International: 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.

My imput: It is amazing that 90 percent of the earth's Co2 (carbon dioxide) is cycled by the ocean! I never would have thought that animals such as whales were the ones to transport Co2 to the ocean floor.