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July 22, 2024July 24, 2024

Nick Lee: The Data, July 15, 2024

NOAA Teacher at Sea
Nick Lee
Aboard NOAA Ship Oscar Dyson
June 29 – July 20, 2024

Mission: Pollock Acoustic-Trawl Survey

Geographic Area of Cruise: Eastern Bering Sea

Date: July 15, 2024

Weather Data from the Bridge:

Latitude: 59° 51.9 N

Longitude: 173° 53.5 W

Wind Speed: 11 knots

Air Temperature: 6.1° Celsius (42.9° Fahrenheit)

Science and Technology Log:

On my cruise, scientists take acoustic measurements along the length of each transect. To ensure that they are accurately estimating the abundance of pollock, they take steps to separate out any backscatter that they believe didn’t come from pollock.

Scientists then apply algorithms to the data in order to estimate pollock abundance over the entire survey area. First, they break up the transect into 0.5 nautical mile (NM) sections and record the average backscatter for that section. Specifically, scientists are interested in the areal density – the amount of backscatter per square nautical mile (NM²).

This data can be challenging to interpret, so one way the scientists represent it visually is with a stick plot over the survey area:

Stick plot showing acoustic backscatter from the 2022 pollock survey. This is a simple map of the Bering Sea, where the land of Alaska appears in gray and the water is white with some bathymetric lines. The transect lines run straight, at a slight angle on this rotated map, across the waters. Yellow bars of different sizes stick up off the transect lines at an angle. — *Acoustic backscatter from the 2022 pollock survey.*

In this graphic, the transect lines are shown in black, and the density of acoustic backscatter for each 0.5 NM section is represented with a yellow stick. The longer the stick, the greater the density of backscatter at that location.

Scientists then use this data to perform calculations on the entire survey area, including the space in between transects. For each 0.5 NM section of transect, the acoustic density is extrapolated halfway to the next transect on either side.

Diagram showing transect lines, and how acoustic density is applied across the survey area. Three gray vertical lines, evenly spaced, are each labeled "transect line;" dotted lines mark the distance halfway between each transect line. A smaller portion of the middle transect line is colored red instead of gray. It's labeled with a parallel double-sided arrow marking out "0.5 nautical mile." A red box the height of that red section stretches as far to the left and right as the next dotted halfway line; one side is labeled "half distance to next transect." — In this diagram, the red line represents a 0.5 NM section of transect for which acoustic density is calculated. This acoustic density is then applied to the entire pink rectangle, which extends halfway to the next to the transect on either side.

By doing this process for every 0.5 NM section of transect studied, scientists are able to calculate values of acoustic density for the entire survey area.

Map of current survey area with transect lines and boxes showing the area over which transect data is extrapolated. — *Map of current survey area and transect lines (black), with boxes (purple) indicating the area over which data from each transect is extrapolated.*

Getting from acoustic density to pollock abundance takes another set of calculations, this time making use of trawl data. The pollock caught in each trawl can vary drastically in terms of size – some trawls are mostly juveniles, some trawls are mostly adults, and some are an even mix of both. For a given location, scientists use data from the nearest geographic trawl to estimate the distribution of fish in that area.

Distribution of pollock centered around 20-30 cm. This is a bar chart. The x-axis displays length in centimeters (0 to 80 cm) and the y-axis displays proportion of the catch (0 to 0.125). The majority of the bars are black, but a minor portion are colored partially red, indicating proportions of identified male pollock, or blue, indicating proportions of identified of female pollock. — *In some trawls, the most fish were within 20-30 cm in length (above) while in others, most fish were over 40 cm in length (below).*

Distribution of pollock centered around 40-50 cm. This is a bar chart. The x-axis displays length in centimeters (0 to 80 cm) and the y-axis displays proportion of the catch (0 to 0.125). The majority of the bars are black, but a minor portion are colored partially red, indicating proportions of identified male pollock, or blue, indicating proportions of identified of female pollock.

Having trawl data is necessary to convert the acoustic data into fish abundance because small and large pollock do not reflect backscatter equally. Scientists have studied this, and they have created a relationship for the different backscatter reflected by different length pollock. Using the distribution of pollock in the nearest trawl, scientists are able to proportionally allocate the observed backscatter to pollock of different lengths.

Graph showing that as pollock length increases, acoustic backscatter also increases. The x-axis shows pollock length in centimeters (0 to 80) and the y-axis shows acoustic size in "(TS, dB re 1 m2)", ranging from -50 to -30. A blue line curves gently from the lower right corner ("small fish, weak backscatter") to the upper right corner ("large fish, strong backscatter.") — *As pollock length increases, backscatter also increases.*
(Equation from Lauffenburger et al., 2023. Mining previous acoustic surveys to improve walleye pollock (Gadus chalcogrammus) target strength estimates, ICES Journal of Marine Science, Volume 80, Issue 6, August 2023, Pages 1683–1696, https://doi.org/10.1093/icesjms/fsad094)

As an example, let’s simplify the two locations sampled in the graphs above. Suppose the first location had only 20 cm pollock, the second had only 40 cm pollock, and equal backscatter was observed at both sites. Scientists know that, all else being equal, 20 cm pollock produce less backscatter than 40 cm pollock. This means that in order to reflect the same backscatter, there must be a greater number of 20 cm pollock than 40 cm pollock.

By repeating a similar process for each geographic location, scientists are able to estimate the number of pollock in the entire survey area!

Personal Log

The sailing and many of the operations of NOAA Ship Oscar Dyson are done by NOAA Corps officers. I hadn’t heard of the NOAA Corps before sailing, but I’ve since learned that they play an important role in facilitating NOAA research.

To learn more about the experience of NOAA Corps officers, I interviewed Ensign Savi Morales.

Ensign Savi Morales working with John Swenson, a member of the deck crew. Engisn Morales wears the blue every day uniform of the NOAA Corps and stands at a bank of navigational computers on the bridge. Both men gaze down at a display screen. — *Ensign Savi Morales (left) on the bridge collaborating with John Swenson, a member of the deck crew.*

Why did you decide to become a NOAA Corps officer?

I’ve always wanted to support the protection of the environment and mitigating climate change. After college, I was trying to figure out where I would contribute the most. I really loved being out on the water, and I had sailed plenty but I wanted to find a way to combine my interests in an environment I contribute the most. The NOAA Corps felt like it was a combination of those things.

I also loved the idea of working with the crew, engineering department, and science. I really enjoy that mixture of groups we have aboard Dyson, which makes every trip’s dynamic different. There’s also a lot of hands-on experience on the bridge deck making our 12 days packed with projects I work on. The NOAA Corps embraces a diverse skill set in order to think and act like a Swiss army knife and be a jack of all trades.

What are your responsibilities on board the ship?

My responsibilities are two 4-hour bridge watches as a Junior Officer of the Deck as I work towards becoming a fully qualified Officer of the Deck. In between my watches I work on tasks related to my responsibilities as the Dyson’s damage control officer, assistant navigation officer, and assistant public affairs officer. I track the sea service hours for our augmenting and personal crew, which they can use to upgrade their license. I maintain flags, and I do monthly safety rounds, inspecting fire extinguishers and fire stations.

What do you enjoy the most about your work?

I enjoy meeting the characters that come to the Dyson, definitely an eclectic but fun group. I also enjoy how much they’ve thrown me into the mix and had me figure things out. It’s a little bit of a trial by fire, but I learn really quick and I’d rather learn by doing.

What part of your job with NOAA did you least expect to be doing?

Checking fire extinguishers, there’s about 100 on board and they all need to be checked monthly. It takes about 3-4 hours.

Here in the Bering Sea you hear about the big, massive waves, but it’s not always like that. The Aleutian Islands are gorgeous with lots of wildlife. I don’t think I’ve seen this many bald eagles, orcas, or puffins in my entire life. They always brighten my day.

What advice do you have for a young person interested in a career in the NOAA Corps?

NOAA Corps requires you to have a four-year college degree in order to apply. Other than that, I’d say find opportunities to go out on the water. There’s high school scholarships, there’s college scholarships. You can also volunteer if you have time. I volunteered at the UC Davis Bodega marine lab. I visited once a week just to hang out with the scientists, with the crew to see if this is what I liked. Be curious and experience things for yourself!

Did you know?

NOAA Corps is one of the country’s eight uniformed services, and its officers operate NOAA ships and aircraft around the country. After completing basic training at the US Coast Guard Academy, NOAA officers assist in fisheries research, seafloor mapping, monitoring atmospheric conditions, and may respond to natural disasters and extreme weather. Learn more at the NOAA Corps website here!

July 8, 2014August 21, 2021

Mary Murrian: My First Days in Dutch Harbor, July 6, 2014

NOAA Teacher at Sea

Mary Murrian

Aboard NOAA Ship Oscar Dyson

July 4 – 22, 2014

Mission: Annual Walleye Pollock Survey

Geographical Area of Cruise: Bering Sea North of Dutch Harbor

Date: Sunday, July 6th, 2014

Weather Data from the Bridge:

Wind Speed: 6 kts

Air Temperature: 8.6 degrees Celsius

Weather conditions: Hazy

Barometric Pressure: 1009.9

Latitude: 5923.6198 N

Longitude: 17030.6395 W

Science and Technology Log

Part One of the Survey Trawl: Getting Ready to Fish

This is a picture of a pollock from our first trawl.

Today is my second day aboard the Oscar Dyson. We are anxiously waiting for the echosounder (more information on echosounder follows) to send us a visual indication that a large abundance of fish is ready to be caught. The point of the survey is to measure the abundance of Walleye Pollock throughout specific regions in the Bering Sea and manage the fisheries that harvest these fish for commercial use to process and sell across the world. The Walleye Pollock are one of the largest populations of fish. It is important to manage their populations due to over-fishing could cause a substantial decrease the species. This would be detrimental to our ecosystem. The food web [interconnecting food chains; i.e. Sun, plants or producers (algae), primary consumers, animals that eat plants (zooplankton), secondary consumers, animals that eat other animals (pollock), and decomposers, plants or animals that break down dead matter (bacteria)] could be altered and would cause a negative effect on other producers and consumers that depend on the pollock for food or maintain their population.

The main food source for young pollock is copepods, a very small marine animal (it looks like a grain of rice with handle bars). They also eat zooplankton (animals in the plankton), crustaceans, and other bottom dwelling sea life. On the weird side of the species, adult pollock are known to eat smaller pollock. That’s right, they eat each other, otherwise known as cannibalism. Pollock is one of the main food sources for young fur seal pups and other marine life in Alaskan waters. Without the pollock, the food web would be greatly altered and not in a positive way.

How do we track the pollock?

Tracking begins in the acoustics lab. Acoustics is the branch of science concerned with the properties of sound. The acoustics lab on board the Oscar Dyson, is the main work room where scientists can monitor life in the ocean using an echosounder which measures how many fish there are with sound to track the walleye pollock’s location in the ocean. They also use the ships’s GPS (Global Positioning System), a navigation system, to track the location of the NOAA vessel and trawl path.

What is sonar and how does it work?

Sonar (sound ranging & navigation; it’s a product of World War II) allows scientists to “see” things in the ocean using sound by measuring the amount of sound bouncing off of objects in the water. On this survey, sonar images are displayed as colors on several computer monitors, which are used to see when fish are present and their abundance. Strong echoes show up as red, and weak echoes are shown as white. The greater the amount of sound reported by the sonar as red signals, the greater the amount of fish.

Echo Sonar Screen Showing the patterns of echos from the ocean.

How does it work? There is a piece of equipment attached to the bottom of the ship called the echosounder. It sends pings (sound pulses) to the bottom of the ocean and measures how much sound bounces back to track possible fish locations. The echo from the ocean floor shows up as a very strong red signal. When echoes appear before the sound hits the ocean floor, this represents the ping colliding with an object in the water such as a fish.

The scientists monitor the echosounder signal so they can convey to the ships’s bridge and commanding officer to release the nets so that they can identify the animals reflecting the sound. The net catches anything in its path such as jellyfish, star fish, crabs, snails, clams, and a variety of other fish species. Years of experience allows the NOAA scientists the ability to distinguish between the colors represented on the computer monitor and determine which markings represent pollock versus krill or other sea life. We also measure the echoes at different frequencies and can tell whether we have located fish such as pollock, or smaller aquatic life (zooplankton). The red color shown on the sonar screen is also an indicator of pollock, which form dense schools. The greater amount of red color shown on the sonar monitor, the better opportunity to we have to catch a larger sample of pollock.

The Science Team Wonderful group of people.

Once we have located the pollock and the net is ready, it is time to fish. It is not as easy as you think, although the deck hands and surveyors make it look simple. In order to survey the pollock, we have to trawl the ocean. Depending on the sonar location of the pollock, the trawl can gather fish from the bottom of floor, middle level and/or surface of the ocean covering preplanned locations or coordinates. Note: Not all the fish caught are pollock.

The preplanned survey path is called transect lines with head due north for a certain distance. When the path turns at a 90 degree angle west (called cross-transect lines) and turns around another 90 degree angle heading back south again. This is repeated numerous times over the course of each leg in order to cover a greater area of the ocean floor. In my case we are navigating the Bering Sea. My voyage, on the Oscar Dyson is actually the second leg of the survey, in which, scientists are trawling for walleye pollock. There are a total of three legs planned covering a distance of approximately 6,200nmi (nautical miles, that is).

Trawling is where we release a large net into the sea located on the stern (the back of the boat). Trawling is similar to herding sheep. The fish swim into the net as the boat continues to move forward, eventually moving to the smaller end of the net. Once the sonar screen (located on a computer monitor) shows that we have collected a large enough sample of pollock, the deck hands reel the net back on board the boat.

The crew are beginning to release the trawl net.

This is the stern of the boat where the trawl net gets released into the ocean.

We have caught the fish, now what? Stay tuned for my exciting experience in the wet lab handling the pollock and other marine wild life. It is most certainly an opportunity of a lifetime.

Personal Log

What an adventure!

I was lucky enough to spend a day exploring Dutch Harbor, Alaska before departing on the pollock survey across the Bering Sea. It took me three plane rides, several short lay-overs and and a car ride to get here, a total of 16 hours. There is a four hour time difference between Dutch Harbor and Dover, Delaware. It takes some getting used to, but definitely worth it. The sun sets shortly after 12:00 midnight and appears again around 5:00 in the morning. Going to sleep when it’s still daylight can be tricky. Thank goodness I have a curtain surrounding my bed. Speaking of the bed, it is extremely comfortable. It is one of those soft pillow top beds. Getting in and out of the top bunk can be challenging. I haven’t fallen yet.

During my tour through the small town of Dutch Harbor, I have encountered very friendly residents and fishermen from around the world. I was fortunate to see the U.S. Coast Guard ship Healy docked at the harbor. What a beautiful vessel. Dutch Harbor has one full grocery store (Safeway) just like we have in Delaware, with the exception of some of the local Alaska food products like Alaska BBQ potato chips. They have a merchant store that sells a variety of items ranging from food, souvenirs, clothing, and hardware. They have three local restaurants and a mom and pop fast food establishment. One of the restaurants is located in the only local Inn the Aleutian hotel, which also includes a gift shop. Dutch Harbor is home to several major fisheries. Dutch Harbor is rich in history and is home to the native Aleutian tribe. I took a tour of their local museum. It was filled with the history and journey of the Aleutian people. While driving through town, I got a chance to see their elementary and high school. They both looked relatively new. Dutch Harbor is also home to our nation’s first Russian Orthodox Church. Alaska is our 50th state and was purchased from Russia in 1867.

Me and the Oscar Dyson — Mary Murian in front of the Oscar Dyson

A very funny photo of me in my survival suit.

One of the coolest parts of my tour was walking around the area known as the “spit”. The “spit” is located directly behind the airport. I’m told it is called the “spit” because the land and water are spitting distance in length and width. We walked along the shoreline and discovered hundreds of small snails gathered around the rocks. We also found hermit crabs, starfish, sea anemones, jellyfish, and red algae. We saw red colored water, which is a bloom or a population explosion of tiny algae that get so thick that they change the color of the water.

One of numerous amazing views in Dutch Harbor

tas 2014 day 1 and perboarding july 2-4th 089 — Starfish

Another animal in abundance in Dutch Harbor is the bald eagle. There is practically one on every light post or tall structure. Often the bald eagles are perched in small groups. Watch out: if you walk too close to a nesting mother, she will come after you. They are massive, regal animals. I never get tired of watching them.

We had to watch our step, the snails were everywhere along the shoreline of the Spit.

Russian Orthodox Church in Dutch Harbor, AK

Did You Know?

Did you know that Alaska’s United States Coast Guard vessel has the ability to break through sea ice?

This is especially helpful if you want to study northern areas, which are often ice covered, in the winter, and to assist a smaller boat if it gets trapped in the ice.

U.S. Coast Guard Ship Healy docked at the Spit.

Did you know that scientists set time to Greenwich Mean Time (GMT) which is the time in a place in England?

This reduces confusion (e.g. related to daylight savings, time zones) when the measurements are analyzed.

Key Vocabulary:

Carnivore

Primary Consumer

Secondary Consumer

Nautical Miles

Trawling

Stern

Acoustics

Decomposers

Echosounder

Meet the Scientist:

Alex De Biologist — Alex De Robertis Chief Scientist

Leg II Chief Scientist Dr. Alex De Robertis

Title: NOAA Research Fishery Biologist (10 years)

Education: UCLA Biology Undergraduate Degree

Scripps Institute Oceanography San Diego, CA PhD.

Newport, Oregon Post Doctorate work

Living Quarters:

Born in Argentina and moved to England when one-year old.

Lived in Switzerland and moved to Los Angeles,CA at the age of 13.

Currently lives in Seattle, Washington, and he has two kids aged one and five.

Job Responsibilities:

Responsible for acoustic trawl surveying at Alaska Fisheries Science Center

Was able to help with the Gulf of Mexico oil spill clean-up using the same echo sonar used on trawl surveys.

What is cool about his work:

He enjoys his work, especially the chance to travel to different geographic locations and meet new people. “You never know what you are going to encounter; there is always a surprise or curve ball, when that occurs you adjust and just go with it”.

In the near future, he would love to see or be part of the design for an autonomous ocean robot that will simplify the surveying process.

He has been interested in oceans and biology since a small boy. He remembers seeing two divers emerge from the sea and was amazed it was possible.

August 3, 2007April 1, 2021

Methea Sapp-Cassanego, August 3, 2007

NOAA Teacher at Sea
Methea Sapp-Cassanego
Onboard NOAA Ship Delaware II
July 19 – August 8, 2007

Mission: Marine Mammal Survey
Geographical Area: New England
Date: August 3, 2007

Weather Data from Bridge
Visibility: 5 in haze lowering 3 to 5 in showers
Wind Direction: Southwest
Wind Speed: 10-15 knt increasing to 20 knt.
Swell height: 3-5 feet building 4-6 feet

Pilot whales as seen from the zodiac—note the calf in the foreground. Photo courtesy of Brenda Rone. — Pilot whales as seen from the zodiac—note the calf in the foreground.

Science and Technology Log

Today was another great day for sightings. Critter counts include sperm whales, white sided dolphins, a whopping 17 minke whales, a Sei whale, offshore bottle nose dolphins, a finback whale, another pod of pilot whales and 100’s of common dolphins. At one point during my starboard observation shift, both I and my portside counterpart were calling off sightings so rapidly that the recorder was having problems keeping up with us. We both paused for a moment and pulled away from the big eyes to look around and discover that we were surrounded by literally 100’s upon 100’s of common dolphins. The sea was frothing with their activities; some doing aerobatics, others charging, some came to bow-ride of the ship, while other could be seen chasing large fish which were identified as yellow-fin tuna.

Researchers position themselves to rejoin the main ship. — Researchers position themselves to rejoin the ship.

In a repeat from several days ago the pilot whale sighting prompted another launch of the zodiac…only this time I got to climb down the Jacob’s ladder and go for a zodiac ride which brought me as close to pilot whale as I could ever hope to be. We were able to procure 5 tissue samples for further genetic study along with an untold number of dorsal fin photographs. (Please see log from August 1^st for further explanation of these genetic studies and photos.) My job on the zodiac was to fill out the photography data sheets which record the GPS headings, frame numbers, animal position within pod, approximate size of animal, special markings on the animal, if an attempt to biopsy the whale was made, if the shot resulted in a hit or miss….etc. I was madly recording all this information as cameras were shooting and crossbows were firing and the whole experience whizzed past me. I hope I didn’t forget to record anything!

An ill-fated Northern yellow warbler rests on the deck of the DELAWARE II — An ill-fated Northern yellow warbler rests on the deck of thevDELAWARE II

Aside from all the sightings (some of which have become rather common place), and my zodiac ride I really have nothing left to report for the day….except of course that the day flew by. In fact every day passes in a blink…even the foggy ones. I suppose that’s what happens when each day is filled with something new to see and do. Before I sign off for the day I’ll leave you with two more species profiles. One of which may surprise you!

Yellow warbler (Dendroica petechia)

There are approximately 40 subspecies of this widely distributed little bird. This bird, in particular, was most likely from the subspecies aestiva thus making it a ‘Northern’ yellow warbler.

As a true bird-lover I’ve been taking notice and taking note of every new bird I’ve seen while out at sea, and naturally all of the birds I’ve seen lately from black-backed gulls to shearwaters are suppose to be out here in the open ocean searching for fish and bobbing around in the waves while resting. The yellow warbler however is not suppose to be here….and in fact being at sea means certain death for the delicate songbird as its food source is almost non-existent out here and it is ill-equipped to handle a lack of freshwater. The warbler pictured above probably hitched a ride with us following our 24 hour port call in Yarmouth, Nova Scotia. Sad to say that this warbler did in fact perish at sea despite my offerings of fresh water and bread crumbs (I was all out of their primary food which are insects!) A second warbler and a grosbeak did however find the boat as we were coming back into harbor so we hope they were more fortunate then the first stowaway.

Identification: The yellow warbler is fairly large compared to other warblers and has an exceedingly short set of tail feathers. Both sexes have a yellowish green head and back with yellow underbellies. Females tend to be a bit duller in color while males typically have brown streaks on the cheek and breast. Distribution: The Northern Warbler breeds from Alaska to Newfoundland and Southern Labrador, south to South Carolina and into Northern Georgia, and as far west as the Pacific Coast. It is also found periodically in the American Southwest. Migration: Winters in the Bahamas, Northern Mexico, Peru and the Brazilian Amazon. Diet and Habitat: In its northern and eastern distribution the warblers live in damp habitats surrounding swamps, bogs, marshes, ponds and stream or river banks. They will also feed and nest in woodland areas, meadows, and overgrown pasture lands. In the west and southwest the bird is restricted mainly to riparian habitats. Unfortunately riparian habitat is rapidly decreasing in the Southwest as are the population of yellow warblers within this region. The warbler feeds primarily on insects, but will occasionally eat berries. Listen to its song here.

Common Dolphin

Until recently both the short-beaked and long-beaked common dolphins were considered to be one species. Although much of the recent research and literature still does not differentiate between short-beaked and long-beaked, they are technically two different species. For the purposes of our survey we also did not distinguish between the two as they are nearly identical in physical appearance.

Short Beaked Common Dolphin and Long-beaked Common Dolphin

Identification: Very distinctive crisscross patterning on the sides; yellow/tan patches on the side, dark gray over the topside and pale underside. Light grey patch along the peduncle of the tail.

Max length and weight: 330 pounds and 9 feet. Males are just slightly larger then females

Diet and Feeding: Fish and squid

Migration: No organized or seasonal migration

Distribution: Widely distributed throughout the Atlantic, Pacific, and Indian Oceans as well as the Black and Mediterranean Seas. Special Note: Common Dolphins are especially active and are commonly seen doing aerobatics and bow riding. They are also extremely vocal; to such a degree that their high pitched whistles and clicks may be heard above water.

References

Collins Wild Guide: Whales and Dolphins. Harper Collins Publishers, New York, New York, 2006.

July 27, 2007April 1, 2021

Methea Sapp-Cassanego, July 27, 2007

NOAA Teacher at Sea
Methea Sapp-Cassanego
Onboard NOAA Ship Delaware II
July 19 – August 8, 2007

Mission: Marine Mammal Survey
Geographical Area: New England
Date: July 27, 2007

Weather Data from Bridge
Visibility: 7nm lowering to less then 2 in patchy fog
Wind Direction: Westerly
Wind Speed: 8-13 knots with gusts of 20
Swell height: 2-4 feet

From left to right; Melissa Warden, Kate Swails, and Methea Sapp staff their observatory stations on the flying bridge of the DELAWARE II — From left to right; Melissa Warden, Kate Swails, and Methea Sapp staff their observatory stations on the flying bridge

Science and Technology Log

Today marks one of the most active sighting days yet! The species list for today included the following; common Atlantic dolphin, fin whale, sei whale, sperm whale, humpback whale, white sided dolphin, minke whale, offshore bottlenose dolphin and pilot whale. The methodology for logging each sighting is fairly straight forward yet detail orientated. There are nine of us scientists on board and we have been organized into shifts which begin at 7:00am and end at 18:00. In the absence of fog three of us are stationed on the fly bridge at any given time; one person uses big eyes on the starboard side, the second person serves as the sightings recorder and the third person uses the big eyes on the port side. Every thirty minutes we rotate stations with the port side station retiring from their shift, and a new person taking up watch on the starboard side.

Data is recorded in two electronic touch pad tablets called Pingles. The first pingle is used to record effort and as such is updated each time a rotation is made. Other points of effort which are also recorded are weather conditions, beaufort scale (or degree of wave action), sun angle, glare, swell height, swell angle, etc. The second pingle is used to record the sightings. When an observer calls out “sighting” the recorder will log the following information (as iterated by the observer):

Animal identification
Cue (or what the observer saw first ie. a splash, or the animal itself)
Behavior (swimming, milling, aerobatics etc)
Bearing relative to the ship
Swim direction relative to the ship
Distance from the horizon
Best head count followed by estimations of highest and lowest probable numbers

Flukes of two different humpbacks; Notice the variations in white and black patterning. Such patterns are used by researchers to identify and track individual humpbacks.

On a day like today the recorder is certainly in the hot seat trying to log the sightings of two people! Based on today’s sighting list I’ve chosen two species to profile for you, the humpback whale and sperm whale.

Species Profile for Sightings of July 25^th 2007

Humpback Whale, Megaptera novaeangliae Identification: Stocky body, black topside with white or mottled underside, flippers are exceedingly long and marked with white as is the fluke. Flukes are often visible when animal begins dive. (see photo below) Max length and weight: 56 ft and 40 tons Diet and Feeding: Krill and small schooling fish. Up to 20 individuals may cooperatively hunt and feed via bubble net fishing. Humpbacks are a baleen whale Migration: Extensive migration between Antarctic feeding grounds to breeding grounds off the coast of Columbia. Round trip = 11,000 miles Distribution: Ranges from the poles to the tropic. Have made a good post-whaling recovery and are one of the best studied of all cetaceans. Record breaker for the longest flippers: Averages 15 feet but may be as long as 18 feet; humpback flippers are the longest of any whale species.

Sperm Whale, Physeter catodon Identification: Huge square shaped head; no dorsal fin; blow is often angled forward; body is dark and wrinkled Max length and weight: 36 ft and 24 tons (female), 59 ft and 57 tons (male) Such sexual dimorphism is rare among whales. Diet and Feeding: Mostly squid and some octopi, sharks and other fish. Sperm whales are a toothed whale as opposed to a baleen whale. Migration: Is not wide spread in females and young whales although adult males will travel long distances. Distribution: Sperm whales are found in population clusters from the tropics to the extreme southern and northern latitudes. They are most common offshore in deep water. Record breaker: The sperm whale holds three records in the cetacean world; One being that it is the largest of the tooth whales. This whale also holds the record for diving depth and longest dive. One particularly large male sperm whale has been recorded diving to 6,500 feet and on a separate dive stayed down for 52 min. Famous Sperm Whale: Moby Dick; the great white whale from Herman Melville’s 1851 classic Moby Dick.

Sorry, no photos of the sperm whale sighting

References

Collins Wild Guide: Whales and Dolphins. HarperCollins Publishers, New York, New York. 2006.

July 24, 2007April 1, 2021

Methea Sapp-Cassanego, July 24, 2007

NOAA Teacher at Sea
Methea Sapp-Cassanego
Onboard NOAA Ship Delaware II
July 19 – August 8, 2007

Mission: Marine Mammal Survey
Geographical Area: New England
Date: July 24, 2007

Weather Data from Bridge
Visibility: less then 0.5 nm
Wind Direction: Easterly
Wind Speed: 5-10 mph increasing to 20
Swell height: 3 to 5 feet

A photograph of a C. finmarchicus C5 with a large oil sac, taken with a VPR (Video Plankton Recorder).

Science and Technology Log

Dense fog has given us little to see or do but listen to the fog horn for the past two days. Therefore today’s entry will be less of an activities report and more of an informative piece that will hopefully elucidate just one of the many ecological relationships which we aim to study…once the fog lifts of course.

Got Copepods?

Mammalian foraging strategies are as diverse as mammal themselves, from coordinated packs of prowling wolves to a solitary grazing rhinoceros. Yet regardless of the critter, the energy (or calories) spent pursuing a meal must be less then the energy gained from eating the meal. This simple equation of energy expenditures to energy gains must be kept in the positive for proper growth, development, and reproduction. All of this may seem fairly intuitive and straight forward until you stop to consider the right whale Eubalaena glacialis. This whale is one of the largest predatory animals on the planet measuring up to 17 meters and weighing 40-50 tons, yet feeds almost exclusively on a small ephemeral looking copepod which measures 1-2 mm long.

The copepod preferred by right whales is called Calanus finmarchicus but is often referred to simply as Calanus. Calanus, like most copepods feed on phytoplankton, transition through a number of growth stages, and aggregate in large concentrations of up to ~ 4,000 copepods per cubic liter of water. As far as right whale feeding goes the copepod of choice is most calorically valuable during stage 5 of its life cycle. By this stage (C5) the copepod has sequestered a significant amount of lipid (specifically wax esters) in a part of its body called an oil sack.

Right whales feed on copepods by either skimming the waters surface or diving; sometimes reaching feeding depths of 175 meters. Regardless of depth, the whale pushes its open mouth through the water and then shuts it while forcing the big gulp through its baleen plates which boarder the upper mandible. All filter feeding whales possess baleen, although the baleen of right whales is very fine and hair-like in texture, therefore enabling it to filter out the miniscule copepods. In contrast, a humpback’s baleen is thick and bristle-like and more adept to filtering larger krill and small fish.

In order to maintain proper growth a right whale must consume copious amounts of copepods. Melissa Patrician, an Oceanographic Technician for Woods Hole Oceanographic Institute, reports that scientists estimate that a right whale consumes on average of 2-4,000 pounds (wet weight) of copepods per day. This is the equivalent weight of 1 Volkswagen beetle and calorically equal to 3,000 Big Macs. In general right whales can be found feeding in four main locations within the North Atlantic. These feeding grounds are centered around the Bay of Fundy, Roseway Basin, Cap Cod Bay, and the Great South Channel which runs E. of Nantucket.

Understanding the intricacies of copepod life and right whale feeding are just part of a greater body of knowledge which is aimed at saving the right whale from extinction. Researchers estimate that only 390 right whales are left following the extensive whaling practices of the 19^th century. Scientists from multiple disciplines including but not limited to, pathologists, reproductive endocrinologists, geneticists, veterinarians, behavioral ecologists, and toxicologists are all working to protect the species from disease, entanglement, ship-strike and to better understand recent declines in reproductive success.

This diving sequence depicts right whale foraging for nutrient rich Calanus finmarchicus. — This diving sequence depicts a right whale foraging for nutrient rich Calanus finmarchicus.