Beth Lancaster – NOAA Teacher at Sea Blog

April 13, 2008April 2, 2021

Beth Lancaster, April 13, 2008

NOAA Teacher at Sea
Beth Lancaster
Onboard NOAA Ship McArthur II
April 6 – 14, 2008

Mission: Examine the spatial and temporal relationships between zooplankton, top predators, and oceanographic processes
Geographical area of cruise: Cordell Bank Nat’l Marine Sanctuary & Farallones Escarpment, CA
Date: April 13, 2008

reported surface sea water temperatures for the California coast from satellite data. The region of sampling is indicated by the box. — Reported surface sea water temps for the CA coast from satellite data. The region of sampling is indicated by the box.

Weather Data from the Bridge

April 11, 2008
Wind – Northwest 4-17 knots
Swell Waves – 3-8 Feet
Surface Sea Water Temperature – 9.3-11.9^oC

April 12, 2008
Wind – Light Swell Waves –1 to less than 1 foot
Surface Sea Water Temp – 9.2-12.5^oC

Science & Technology Log April 13, 2008

At the onset of this cruise, ocean winds and swells kept scientists on alert for the next rock of the boat or wave crashing over the side, and into the fantail work area. These winds play an important role in delivering nutrient rich cold waters to the Cordell Bank and the Gulf of Farallones marine areas – this process is referred to as upwelling. Conditions on Thursday April 11 marked a noticeable change in the weather for this research cruise. Winds hit a low of 4 knots and swells of three feet were reported from the bridge for the majority of the day. On April 12 it was hard to believe that we were conducting research out on the ocean. Conditions were magnificent. Winds were light and swells were less than one foot. This change in conditions is termed a period of “relaxation.”

The term relaxation refers to a period when winds decrease, allowing for conditions that promote a boost in primary productivity. These conditions include decreased turbulence and the presence of sun and nutrients. The nutrients are readily available from the upwelling and phytoplankton are retained in the well-lit surface waters due to the decrease in wind mixing and the resulting stratification (layering) of the surface waters – thus, providing the optimal conditions for photosynthesis to take place. Figure one shows surface water temperatures from April 12, 2008. There was a visible change over the course of the research cruise in surface temperatures with the decrease in winds and swells indicating conditions suitable for primary productivity.

Left to Right: Beth Lancaster, Rachel Fontana (Grad Student, UC Davis), and Caymin Ackerman (Lab Assistant, PRBO) enjoy the sun and calm waters while waiting for a sample to return off the McARTHUR II.

Continuous samples of plankton were taken during the day-time throughout the course of the research cruise. My observations suggest that samples collected early in the trip revealed little macroscopic (visible to the eye) plankton, while samples collected later in the trip during the relaxation event are more diverse and robust. Samples will be examined following the research cruise to draw conclusions based upon quantitative data. Night-time operations included targeted sampling for krill to look at species composition, overall abundance, age and sex. Krill feed on phytoplankton, and will at times appear green after feeding. The optimal conditions for phytoplankton growth during a period of relaxation will result in a feast for krill that migrate up the water column at night to feed. A large portion of many resident and migratory bird and mammal diets consists of krill, indicating their importance to this marine ecosystem.

Weather conditions over the last few days also provided great visibility for mammal and bird observers. Nevertheless, there were still very few sightings of birds and mammals during this time period. One sighting of importance was of a short-tailed albatross, an endangered species that is an infrequent visitor to the California Current ecosystem. The short-tailed albatross population is estimated at 2000, and is currently recovering from feather harvesting in the late nineteenth century and loss of breeding grounds to a natural disaster. For more information on the short-tailed albatross visit here.

Putting it all together…..

All of the sampling done over the course of this cruise will allow scientists to look at the dynamics of the food chain during the early springtime. This is just a small piece of a larger puzzle. The same sampling protocol has been utilized at different times of year in the same research area since the projects beginning in 2004. This will allow researchers to look at the entire ecosystem, its health, and the interdependence of species to drive management decisions.

Personal Log

As the trip comes to an end I’m grateful to both the scientists and crew members onboard the McARTHUR II. I now have a better understanding of physical oceanography, and the Cordell Bank and Farallones Escarpment ecosystem which I am looking forward to sharing with students for years to come. The McArthur crew has been kind enough to answer every one of my many questions, made me feel welcome, and given me an idea of what life is like at sea. Thank you! This was truly an experience I will remember and look forward to sharing with others.

Animals Seen April 11, 2008

Cassin’s Auklet (36), Black-legged Kittiwake (1), Western Gull (61), Herring Gull (1), Red-necked Phalarope (8), Sooty Shearwater (12), Northern Fulmar (6), Steller sea-lion (35), California Gull (6), Rhinoceros Auklet (9), Black-footed Albatross (6), and Bonaparte’s Gull (1).

Animals Seen April 12, 2008

Black-footed Albatross (11), Northern Fulmar (6), Western Gull (48), California Gull (5), Cassin’s Auklet (25), Common Loon (2), Common Murre (58), Bonaparte’s Gull (4), Sooty Shearwater (8), Dall’s Porpoise (6), Red-necked Phalarope (26), Pink-footed Shearwater (3), California Sea Lion (2), Rhinoceros Auklet (10), Humpback Whale (1), Harbor Seal (1), and Glaucous-winged Gull (2).

April 9, 2008April 2, 2021

Beth Lancaster, April 9, 2008

NOAA Teacher at Sea
Beth Lancaster
Onboard NOAA Ship McArthur II
April 6 – 14, 2008

Weather Data from the Bridge
Wind – Northwest 20 – 35 knots
Swell Waves – 4-12 feet
Sea Water Temp – 9.4 – 10.5^oC

A 24-hour forecast of sea conditions for April 7, 2008 off the West Coast of the United States. The red section indicates swells that range from 12 to 15 feet. — A 24-hour forecast of sea conditions for April 7, 2008 off the West Coast of the United States. The red section indicates swells 12 to 15 feet.

Reported sea surface temperatures from April 7, 2008 for coastal California from satellite data. The coastal wind did in fact cause an upwelling and cooling of water along the coast. The purple area indicates temperatures 8-8.5oC and the blue 8.6-10oC. — Today’s reported sea surface temperatures for coastal California from satellite data. The coastal wind did in fact cause an upwelling and cooling of water along the coast. The purple area indicates temperatures 8-8.5 degrees C.

The weather reports collected from the bridge of the McARTHUR II reported that the waters traveled over the course of the day did in fact reach 12 feet. The winds from the northwest cause an upwelling effect, which brings deep, nutrient-rich cooler waters to the continental shelf area off the coast of California. This nutrient-rich water plays a large role in the food web of the area, increasing primary productivity, which will then result in large numbers of marine mammals and birds due to the availability of prey items. This period of upwelling in the area of Cordell Bank and Gulf of the Farallones National Marine Sanctuaries marks the beginning of a productive time of year.

Science and Technology Log

Part of the mission on this cruise is to gather oceanographic processes data to look at the relationship between biotic (living) and abiotic (nonliving) factors within the study area. While many samples are being collected through observation and survey equipment outside of the ship, there is just as much being collected in the laboratory onboard the McArthur II. The ship is equipped with several pieces of equipment that report physical features and measurements throughout the day. This information is recorded for scientists onboard to utilize in their data analysis. The following is a list of equipment, and their functions being used to measure oceanic processes:

Thermosalinograph (TSG) – Surface water is pumped from the ocean through a hose to this piece of equipment which measures temperature and salinity. There is an additional probe that measures CO2. All information collected during the course of the cruise will be given to researchers to use in data analysis.

Scientific Echosounder – Sends a sound wave into the water column. If there is anything in the water column this sound wave will reflect back to the ship. The longer it takes for the reflected wave to get back to the ship the farther away the target is. Comparing three different frequencies emitted by the echosounder allow scientists to identify different types of plankton in the water column, and set sampling sites.

Navigation Software – Allows researchers to track where they have been and where they are going. Because nets and other equipment are being deployed from the ship this computer software allows scientists to view the charted underwater topography to determine placement and depth of equipment. By marking sample sites using the software, scientists can look at the relationship between the ocean’s topography and living organisms collected.

NOAA Teacher at Sea Beth Lancaster (left) and NOAA Chief scientist Dr. Lisa Etherington (right) view sampling areas using navigation software in the McARTHUR II’s dry lab. — NOAA TAS Beth Lancaster (left) and NOAA Chief scientist Dr. Lisa Etherington (right) view sampling areas using navigation software in the McARTHUR II’s dry lab.

Personal Log

I have been onboard the McARTHUR II for four days, and have enjoyed every minute of helping out with the research project. Scientists have been so patient and willing to answer all of my questions. The crewmembers onboard the McARTHUR II are very friendly and helpful. I now have a much better understanding of the marine physical environment than I did upon my arrival! I am enjoying living at sea, even the small bunks! The ship is actually very large you would never know there were more than twenty people onboard!

Animals Seen Today

Black-footed Albatross, Pteropod, Pigeon Guillemot, Copepods, Brandt’s Cormorant, Ctenophore, Sooty Shearwater, Krill, Northern Fulmar, Microscopic Plankton, Black-legged Kittiwake, California Gull, Western Gull, Common Murre, Cassin’s Auklet, Rhinoceros, Auklet, and Bonaparte’s Gull.

April 7, 2008April 2, 2021

Beth Lancaster, April 7, 2008

NOAA Teacher at Sea
Beth Lancaster
Onboard NOAA Ship McArthur II
April 6 – 14, 2008

Beth Lancaster (right) preserves a plankton sample collected using a hoop net. — NOAA Teacher at Sea Beth Lancaster bottles a surface water sample that will be tested for the presence of nutrients.

Science and Technology Log

Today was the first full daytime operations. We began shortly after 7:00 a.m., and covered a 90 kilometer transect throughout the course of the day ending at 6:00 p.m. At each sampling point along the transect a series of measurements and observations were made to look at relationships between the physical ocean environment, and abundance of living organisms that are observed and collected to gain a better understanding of the physical and biological features of the area, and how they interact. The daytime crew was divided into two groups: the marine mammal and bird observers, and a second group that was responsible for collecting water and plankton samples as well as other various physical measurements of the water. I worked with the second group, and will share what sampling I assisted with.

At each sampling point we used the CTD, which is a piece of equipment that has several probes on it, to collect a vertical sample of the water column. When the CTD is deployed into the water it is sent down 200 meters below the surface and collects water conductivity (used to calculate salinity), temperature, depth, and turbidity. There is also a fluorometer attached to the CTD that measures the fluorescence of chlorophyll-a, which approximates the abundance of phytoplankton. The CTD collects all this data, and can then be downloaded onto a computer. Surface water samples were also collected at each sampling point, and will be tested for the presence of nutrients which would also have a direct impact on the abundance of organisms in the area.

To gather information on the living organisms present at each site, a hoop net was used to collect samples of plankton. The net was sent down approximately 50 meters, and collected all of the tiny living organisms (zooplankton) on a screen as the net was pulled through the water column. When the hoop net was brought back onboard, the cod end of the net (where the sample is collected) was transferred to a sample bottle, and preserved for further investigations in the laboratory. In addition to the living organisms collected in the hoop net, marine mammal and bird observations are being made from the flying bridge of the ship. That would be the highest point on the boat, and not the location for people who are afraid of heights. Due to rough sea conditions (10-12 foot swells), sightings were few and far between today. Springtime within Cordell Bank National Marine Sanctuary is a time where strong winds cause upwelling of deeper waters towards the surface near the coast. This upwelled water is colder and has higher nutrient concentrations.

Sample of krill caught in the daytime with a hoop net.

This influx in nutrients means the ecosystem becomes very productive. Given this high influx of nutrients, prey items for birds and mammals are readily available. The food of choice for a lot of these organisms is krill (a shrimplike zooplankton.) We did collect some krill in the hoop net during the day, but the abundance of krill in shallower water is much greater in the evening, when krill migrate from deep depths towards the surface. The night crew is collecting krill using a tucker trawl, which has three separate nets that are opened and closed at different depths. Krill play a vital role in the ecosystem scientists are currently studying. They provide nourishment for resident and migratory birds as well as marine mammals. There is sufficient nutrient availability for primary producers which are then food for primary consumers such as krill, and therefore food availability for secondary consumers such as fish and tertiary consumers such as whales and dolphins.

Throughout the week the same measurements will be taken at different sights along the continental shelf and continental slope in the region of Cordell Bank National Marine Sanctuary and the Farallones Escarpment (within Gulf of the Farallones National Marine Sanctuary). This information will allow scientists to better understand the dynamic relationship between zooplankton, top predators, and oceanographic processes. Data gathered will also be used in conservation planning of the marine sanctuaries.

Some Animal Sightings
Black-footed Albatross, Ancient Murrelet, Northern Fulmar, Laysan Albatross, and Pacific White-sided Dolphin.