Shelley Gordon: The Serengeti of the Sea, July 26, 2019


NOAA Teacher at Sea

Shelley Gordon

Aboard R/V Fulmar

July 19-26, 2019

Mission:  Applied California Current Ecosystem Studies Survey (ACCESS)

Geographic Area of Cruise:  Pacific Ocean, Northern and Central California Coast

Date:  July 26, 2019

My NOAA Teacher at Sea experience wrapped up yesterday with our 7th, and final, day of the cruise.  Our last day was another observation-only day where we travelled along two transects (lines 5 and 7) and recorded what could be seen from above the water.  I want to wrap up my experience by sharing some information about this observation technique and what I’ve learned about some of the living things we were able to observe on this trip. 

The Serengeti ecosystem in Eastern Africa is well known for its diversity of life and massive annual migrations.  On the wall of R/V Fulmar there is a large map of the three National Marine Sanctuaries (Cordell Bank, Greater Farallones, and Monterey Bay) off the coast of central California with the words “the Serengeti of the Sea” written at the bottom.  Like the Serengeti, the marine ecosystem in this area of the world supports a high diversity of life and intricate food webs.  Many of the species that thrive in these waters migrate from great distances, far greater than the well documented wildebeest migrations in Africa. 

A map of the protected areas off the central California coast.
Image from farallones.noaa.gov

The three National Marine Sanctuaries and adjacent state and federal parks protect a total of 10,676 square miles of habitat, helping to create a thriving ecosystem.  One thing that became clear to me on this cruise is that this is a massive amount of space!  To collect observation data, scientists sit on the flying bridge (or upper deck) and systematically record what they can see as the boat moves at a constant speed of ~10 knots along the transect.  Depending on the weather (we had days that were pretty foggy and other days that were overcast, but pretty clear), you can see several kilometers in any direction.  To complete an offshore observation line, it takes about 2.5 hours.  So, it is a full day to complete 2 observation lines, especially when you include the travel time to and from each line.  During that time, there are times when you can see very little other than wind-blown whitecaps on the surface of the water.  There are other times when there is a frenzy of activity.

(From left to right) Dani Lipski, Dru Delvin, Rachel Pound, Jaime Jahncke, Kirsten Lindquist, and Jan Roletto recording observation data from the flying bridge.

There are four roles is the observation data collection.  Sitting on the starboard side of the boat, Kirsten Lindquist’s job is to identify and describe all of the birds she observes within 200 meters of the side of the boat.  Some examples of “calls” she made include: “Common Murre, 3, zone 2, water” or “Western Gull, 1, zone 1, flying, 270°.”  To explain, she calls out the name of the bird, the number that she sees in the group, the relative distance they are from the boat (zone 1 or zone 2), and what they are doing (sitting on the water, flying, feeding, etc…).  This data is all recorded in the computer by Jaime Jahncke.  Dru Devlin and Jan Roletto (one on each side of the boat) are responsible for observing other things on the surface, including animals, boats, fishing gear, trash, kelp, etc…  An example of a call they relay to Jaime to record is:  “First cue blow, by eye, bearing 270°, reticle 5, observer 9, side 1, traveling, humpback whale, 2, 3, 2.”  There is a lot going on in this data, but it basically explains the observer has seen a group of humpback whales in the distance off the front of the boat (bearing 0°).  The group is swimming along the surface and the size of the group is between 2-3 individuals.  The observers use reticle markings, fine lines in the eyepiece of binoculars, to estimate how far the object is from the boat (reticle 14 is at the boat, reticle 0 is on the horizon).  Using the bearing and reticle numbers, the computer then can use the GPS location of the boat to estimate where that animal was at the time of the recorded observation.  Using all of this data collected over the course of time, scientists are able to put together a picture of where animals, birds, and other objects are frequently seen within the sanctuaries.  This can also help them identify changes in animal numbers or behavior, and/or the need for a change in management strategies.

An example of a map showing humpback whale observation data on ACCESS in 2018.
Image: Point Blue/ONMS/ACCESS

One of the seabird species we saw relatively frequently were Sooty Shearwaters.  These birds are interesting to me because the migrate to the sanctuaries from their breeding grounds in New Zealand, an amazing 6500 miles away!  What’s even more impressive is that their migration is not just from New Zealand to California; they actually complete a circular migration route, first traveling up the western Pacific toward Japan and the Artic, and then they drop down to the pacific coast of North America before returning to their breeding grounds in New Zealand.  We also observed Pink-Footed Shearwaters, which nest off the coast of Chile. 

Sooty Shearwaters taking off from the surface of the water.  Photo:  Dru Devlin

When we were out on the offshore transects beyond the continental shelf break, we were frequently able to observe Black-Footed Albatrosses.  These large seabirds are well known for their long migrations as well.  The population we observed in the sanctuaries nest in the Hawaiian Islands and visit the California coast to feed.  From dissecting Albatross boluses (regurgitated food) with students at Roosevelt, I had previously learned that their diet consists of a lot of squid.  Since squid are actively feeding at night, albatross also do a lot of their hunting at night.  I was curious how they could find their prey and I learned that they have an incredible sense of smell that they can use to detect food.  They are known to follow ships and feed on refuse in the wake, and this seemed to be apparent because when we were collecting samples at stations beyond the shelf break we were often joined by multiple albatrosses.  At one station, I counted 19 Black-Footed Albatrosses floating in a group near the boat.

Two Black-Footed Albatrosses near the boat. Photo: Dru Devlin
A Black-Footed Albatross in flight.
Photo: Dru Devlin

I was also very interested to learn about the way that albatrosses and other large seabirds (including shearwaters) conserve energy during their long flights.  Dynamic soaring allows them to gain energy from the wind above the ocean waves without flapping their wings.  We often observed these birds flapping their wings a few times and then soaring very close to the surface of the water before flapping again.  Apparently, in favorable wind conditions, these birds can us this method to fly great distances without flapping their wings at all, thus conserving energy.

Three humpback whales surfacing. Photo: Dru Devlin

Another animal that I was on the constant lookout for were whales.  These gigantic mammals have always captured my imagination.  On this cruise we were lucky enough to see quite a few humpback whales.  These large baleen whales are known for their acrobatic displays, occasionally launching their body out of the water in an action called breaching.  I was able to observe a few whales breaching, and also several instances of whales rolling on the surface of the water slapping their long flippers or tail at the surface.  One of the highlights was seeing humpbacks lunge feeding at the surface.  Lunge feeding is when the whale opens its mouth widely, engulfing a large amount to water and prey.  The whale then pushes the water out of its throat pouch, leaving the prey behind to consume.  One of the favorite foods of humpback whales is krill.  Using the Tucker trawl net at very deep depths, we were able to collect some large krill samples that will be analyzed back at the lab. 

There are several other species of whales that can be present in the sanctuaries at different times throughout the year, including blue whales, gray whales, fin whales, and minke whales, but we did not positively identify any of those species on this trip.  The scientists on board were specifically surprised that we did not see any blue whales, as they usually observe a few on cruises at this time of year.

Gallery

Here are a few other images of animals that we saw and were able to capture in the camera lens.

Did You Know?

Scientists can use robots to explore the undersea environment?  From October 3rd-11th, scientists from the Greater Farallones and Cordell Bank National Marine Sanctuaries will be partnering with the Ocean Exploration Trust to learn more about life beneath the waves.  Working aboard the Exploration Vessel (E/V) Nautilius, the team will use remotely operated vehicles (ROVs) to explore deep-sea coral reef and sponge habitats.  And, we will be able to follow along live

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