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.

 

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

FACT OF THE WEEK: False Killer Whales Call Hawaii Home

MORE ON THIS: False killer whales, while a globally distributed species, have a special tie to Maui and the four-island region. Recent research has found that a very small group of this odontocete, or toothed whale species,  calls Hawaiian waters home, making them genetically different from offshore groups. This makes this population especially interesting because false killer whales are generally thought to prefer deep ocean environments far from any land.

Genetic tests were completed on samples collected from groups of false killer whales around the main Hawaiian islands and locations throughout the North Pacific. Researchers found samples collected from individual whales close to the Islands were most genetically unique when compared to samples from whales in the Pacific Ocean, Panama and Mexico. The uniqueness of the samples indicates there are two separate populations; an inshore population and an offshore population.

Their acrobatic displays and tendencies to bow ride make false killer whales hard to miss if you are lucky enough to see one. Hawaii insular population numbers are predicted to be as low as 123 individuals, with only 46 capable of breeding. There is good news though. The insular false killer whale population was classified as an Endangered Species in 2012, meaning this population now has extra protection. Keep your eyes open. If you’re lucky you will see one of Hawaii’s very own false killer whales.

FURTHER READING:

  1. Protecting Hawaii’s False Killer Whale. Pacific Whale Foundation. Accessed October 8, 2015
  2. Baird, R. (2009). A review of false killer whales in Hawaiian waters: biology, status, and risk factors. US Marine Mammal Commission: 1-40.
  3. Chivers et al. (2009). Genetic Variation and Evidence for population structure in eastern North Pacific false killer whales. Canadian Journal of Zoology, 85: 783-94.

Written by Chelsea Brown

FACT OF THE WEEK: Hairy Humpback Whales

FACT OF THE WEEK: Humpback whales have hair!

MORE ON THIS: You probably know that whales and dolphins are marine mammals. Marine mammals, like terrestrial or land mammals, must have a certain set of characteristics to be called mammals – these include giving birth to live young and having hairs on their bodies. But where are the hairs on whales?

In fact, you have probably seen the hairs on humpback whales and not known what they were. The bumps on the rostrum, or head, and the pectoral fins of a humpback whale are, in fact, hair follicles. Called “tubercles,” these fist-sized bumps contain one hair follicle each, connected to a set of sensitive nerves. Why do humpback whales have these sensitive whiskers? There are multiple speculative theories in scientific literature, but no consensus.

Some think that tubercles serve as a sensory organ for the whale. It is thought that the single hair in each tubercle is used to detect temperature change in the water, the speed of the whale, and may even help to detect the presence of prey in the whale’s “blind spots.” Along with the idea that these tubercles serve a sensory purpose, comes an idea that tubercles assist with the hydrodynamics of the animal. It has been shown that these bumps increase lift and decrease drag in the water. Humpbacks are assumed to be one of the most acrobatic whales for their size. These tubercles may be a contributing factor for their agility.

Whale tubercles have inspired design ideas behind wind turbines, airplane wings and propellers. An energy company called WhalePower is applying tubercle-inspired bumps to numerous types of wind turbines and fans including industrial ceiling fans and computer fans to improve their efficiency, safety, and cost-effectiveness. These hairy humpback whales have inspired a new type of “greener” energy technology.

FURTHER READING:

  1. Forestell, P. H. and Kaufman, G. D. 2008. Humpbacks of Hawaiʻi: The Long Journey Back. Hawaii, USA. 216 pages.
  2. “Whalepower.” N.D. The Science.
  3. Canter, N. 2008. Humpback whales inspire new wind turbine technology.

Written by Stephanie Stack

FACT OF THE WEEK: Bio-Fluorescent Coral Flaunts Underwater Light Show

MORE ON THIS: It is easy to see the beauty of coral reefs when snorkeling or diving during the day, but have you ever seen the colors of coral at night?

Coral reefs are known to put on a light show known as bio-fluorescence.  A family of proteins provides this fluorescence by absorbing one color and emitting another.  Each protein provides a different color; the most common is the green fluorescent protein known as GFP.  When the wavelengths of color are absorbed then re-emitted, some of the energy is lost.  This changes the wavelength, which determines the color.

Species of coral known to give off this fluorescence are found in Hawai‘i and can be seen on night dives with special dive lights.  If you’re interested in seeing this phenomenon, you can contact your local dive shop to ask about night diving to see fluorescent coral or, if you’d like to stay dry, you can visit the Maui Ocean Center which has some of this coral on exhibit.

It is unknown why fluorescence occurs, but there are speculations from scientists.  Some believe that it acts as a sunscreen for the coral.  Researchers also have proposed that the fluorescence creates light to allow algae to grow in deeper water; algae is the major food source of most corals.

Research is focusing on coral fluorescence for several reasons.  The first reason is due to the fragile state of coral reefs in our climate-changing world.  Some studies suggest that the intensity of the fluorescence can be a sign that the coral is under stress and may indicate that the coral is about to bleach.

Medical research is also greatly benefiting from coral fluorescence research.  The same proteins the corals use to fluoresce are being used to help monitor biological processes within diseases to further understand how they work. This is done by using the fluorescence as a marker so scientists can watch cells divide or viruses spread.

FURTHER READING:

  1. Roach, John. 2005. “Glowing Coral Proteins Aid Medical Research.” National Geographic. http://news.nationalgeographic.com/news/2005/01/0112_050112_coralproteins.html
  2. Roth,  Melissa S., Fran, Tung-Yung, Deheyen, Dimitri D. 2013. “Life History Changes in Coral Fluorescence and the Effects of Light Intensity on Larval Physiology and Settelement in Seriatopora hystrix.” Plos One. http://www.plosone.org/article/info%3Adoi%2F10.1371%2Fjournal.pone.0059476
  3. University of California – San Diego. 2013. “Fluorescent light revealed as gauge of coral health: Mysterious glow of light found to correlate with coral stress prior to bleaching.” Science Daily. www.sciencedaily.com/releases/2013/03/130312092918.htm.

Written by Sarah Mousel

FACT OF THE WEEK: Hawaii’s State Mammal is Critically Endangered

MORE ON THIS: To native Hawaiians, this furry creature may be referred to as ‘llioholoikauaua, but you personally know them as Hawaiian monk seals. These monk seals are endemic, meaning they are only found in Hawai‘i. They are one of the most endangered animals in the world, with their population of about 1,100 still declining.

These marine mammals are semiaquatic, spending most of their time at sea and some of their time on land.  “Hauling out” is a process where the seal goes onto the beaches to sleep, nurse, molt and rest. Here, a mother will nurse her pup for about 6 weeks and then the roughly 200-pound pup will have to fend for itself. An adult will grow from 6 to 7.5 feet in length and will weight between 375 to 600 pounds. They are generalist feeders, feeding on what is readily available, such as squid, eel, octopi, fish, and crustaceans.

There are many dangers that threaten the life of a monk seal. Food limitations, marine debris entanglement, falling victim to bycatch, mother-pup disturbances and illegal sealing (killing) are some of the anthropogenic, or human-caused, threats to these mammals. Disease outbreaks, predators and low genetic diversity are some of the natural threats that can harm them.  However, overfishing, littering, utilizing harmful fishery equipment, and harassing or killing seals are all very crucial things that humans can cease doing to promote population growth. Natural disturbances may not be able to be avoided, but humans can learn to live in harmony with these animals.

What we can do to help is:

  • give the seals lots of space when hauled out or in the water
  • follow fishing guidelines and restrictions
  • pick up litter
  • report stranded or entangled seals to the NOAA Fisheries Marine Mammal Hotline at 1-888-256-9840
  • report harassment to NOAA Fisheries Office of Law Enforcement at 1-888-853-1964
  • report ALL sightings of monk seals on Maui to (808) 292-2372

Many foundations around the island may also have volunteer opportunities for the public. Educating the public around hauled out seals and helping with population counts can benefit them immensely.  Even you can help the monk seal!

FURTHER READING:

  1. Hawai‘i Wildlife Watching Guide: Hawaiian Monk Seal. Pacific Whale Foundation. 2010. http://www.pacificwhale.org/sites/pacificwhale.org/files/Monk-Seal-Guide.pdf
  2. Protected Resources Division. NOAA. 2010. http://www.fpir.noaa.gov/PRD/prd_hms_population_threats.html
  3. Hawaiian Monk Seal. National Geographic. n.d. http://animals.nationalgeographic.com/animals/mammals/hawaiian-monk-seal
  4. Who’s Killing Hawaii’s Monk Seals? Huffington Post. 2013. Nathan Eagle & Sophie Cook. http://www.huffingtonpost.com/2013/12/06/killing-monk-seals_n_4399723.html

Written by Melissa Freese