FACT OF THE WEEK: Whales play a crucial role in the carbon cycle

MORE ON THIS: In a previous Fact of the Week, we learned how plankton helps the oceans ‘biological pump’, a process that supports the global carbon cycle by removing carbon from the air and storing it in the deep sea. This week, we’re going to talk about the largest living creatures in the ocean, whales, and their role in the carbon cycle. Their movements, deaths, and even feces all contribute to the ‘whale pump’ which works with the biological pump to promote carbon storage.

Movement: When whales swim from deep waters to the surface, they move nutrients up with them. Bringing nutrients to the surface increases the food source for phytoplankton, which play the first part in carbon uptake.

 

Death: When dead whales sink to the ocean floor, they take with them all the carbon that has built up in their body over their lifetime. As the largest marine mammals, that’s a lot of carbon, similar to the huge amounts of carbon stored in old trees.

Feces: When whales swim to the surface, they poo, releasing large fecal plumes which are extremely nutrient-rich and widely consumed by plankton. As one of the larger whale species, sperm whale poop alone might remove hundreds of thousands of tons of carbon from the atmosphere by promoting plankton growth.

Before population declines due to industrial whaling, it is estimated that large baleen whales used to remove millions of tons more carbon than they do today. Scientists suggest that restoring whale populations could greatly increase ocean carbon storage again and may be just as effective as reforestation projects and ocean iron fertilization.

By Kaitlin Yehle

 

FURTHER READING:

  1. Whales Keep Carbon out of the Atmosphere.
  2. The Impact of Whaling on the Ocean Carbon Cycle: Why Bigger Was Better.
  3. Whales as marine ecosystem engineers. Frontiers in Ecology and the Environment. Roman J, Estes JA, Morissette L, Smith C, Costa D, McCarthy J, Nation JB, Nicol S, Pershing A and Smetacek V. 2014. 12(7): 377-385.

 

Exciting matches in South Pacific catalog

We have been busy in the research department adding humpback whales from the 2016 Hervey Bay field season into our South Pacific humpback whale catalog. Along with adding some new animals, we have already made two matches, which is quite a feat considering that each new photo has to be checked against over 6000 others.

The two matched whales were each sighted with a calf during this field season, meaning we can confidently know that they are females. Both females have a long sighting history going back to 1993. Although we don’t know their exact ages, this sighting span means that both animals are at least 23 years old. As we continue to process the 2016 field data, we’re looking forward to making additional matches like these two in order to help us learn more about the South Pacific humpback whales.

Marine Biologist & Mai Tai Maker: My Life as a PWF Marine Naturalist

I can’t count the number of times a guest on our boat will come up to me, enthusiastically gushing “You have the most amazing job!” or “Wow, what an office!” It’s true — I do have a great job and the best view at PacWhale. As ECO team members, we encounter incredible marine wildlife on a daily basis, and we are doing meaningful conservation and education work. But there’s a lot more to being a Marine Naturalist than meets the eye.

For starters … who serves up crumbly apple danishes and yummy banana bread slices for breakfast? The naturalists do! Who makes sure everyone is properly caffeinated, sun-screened, and snorkeling gear-equipped? We do! Who makes sure all questions are answered and reasonable requests fulfilled so our wonderful guests can have the best day of their vacation? Why, the naturalists of course!

We wear a lot of hats out there on the water, and I’m not just talking about our cute PWF whale-tail caps. We’re lifeguards, waiters, educators, snorkel instructors, nautical knot experts, onboard researchers, whale spotters, wildlife interpreters, reef tour guides, sunscreen applicators, keiki teachers, fish experts, fundraisers, deck hands, boat scrubbers, gear washers, freedivers, boat mechanics, bilge pumpers, and ultimately — advocates of ocean love and environmental stewardship.

It’s a lot of work, we never stop moving, and we love what we do. The ocean is our thing. It’s what wakes us up in the morning and gets us excited about work every day. Every time a little kid gasps with wonder at a sea turtle, or an excited first-time visitor asks me about a fish they’ve never seen before, or anyone laughs at my whale jokes, another wave of gratitude washes over me. These little things make me stop and ask myself “Do I actually get to do this for a living?

And how exactly does one become a Marine Naturalist? Stay tuned for my next post and also check out this page for more info on PacWhale’s vessel crew.

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FACT OF THE WEEK – Plankton, the unsung hero of the ocean

Zooplankton caught in the leeward waters of Maui. Specimens shown under the microscope.

 

 

 

 

 

 

 

 

 

Here in Maui we witness one of the greatest migrations in the world—that of the humpback whale. However, what our human eyes can’t see is another one of the world’s largest mass migrations happening every dawn and dusk in waters around the world.  Microscopic zooplankton move vertically through the water column to seek prey and avoid predators. This is called diel vertical migration (DVM).

Under the cover of darkness each night, zooplankton migrate to the surface of the ocean to feed on phytoplankton (“plant” plankton). In the darkness, predators can’t see them as well which makes feeding safer. Once the sun rises, the zooplankton retreat deeper into sea to avoid being seen by hungry fish. Because zooplankton are so small, this journey is as difficult for them as it would be for a person to swim through an ocean of molasses.

Here in Hawaii and throughout the tropics, plankton is much less abundant. This is why our water is so crystal clear and why whales must migrate up to Alaska’s plankton-rich water to feed. However, there are still small amounts of plankton in these waters, and the cycles of DVM affect it each day and night.

DVM is very important to a healthy ocean. After zooplankton fill up on carbon-rich phytoplankton and migrate deeper into the water column, they excrete that same carbon. This helps a process called the “biological pump” that captures carbon dioxide from the air and moves it into the deep sea where some provides nutrients for other organisms, and some becomes part of the sandy bottom.  If the biological pump didn’t exist, almost twice as much carbon dioxide would be in our atmosphere. DVM is a small variable in this large process that keeps our planet healthy.

 

For further information, see the links below.

By Simona Clausnitzer