marine mammal survey – Page 2 – NOAA Teacher at Sea Blog

August 1, 2007April 1, 2021

Methea Sapp-Cassanego, August 1, 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 1, 2007

Weather Data from Bridge
Visibility: 7nm lowering to less then 1 in fog
Wind Direction: Southerly
Wind Speed: 3-8 knt increasing to 8-13
Swell height: 3-5 feet

The flexible Jacob’s ladder rolled up for easy storage.

Science and Technology Log

Fog has kept our sightings to a minimum over the past two days. In fact we’ve had only two sighting since my last log on July 27^th. Yet despite today’s weather forecast, the fog horn has been silenced and everyone is outside enjoying the sunshine and stretching their eyes. It is a wonder to see color other then a shade of grey! The change in weather has also brought new sightings including 3 humpback whales, a pod of harbor porpoises, 4 right whales, a minke whale and a dozen or so pilot whales (spotted by your’s truly). These sightings kept the observers busy as well as those involved in the launching of the zodiac (aka little grey boat) and the Tucker trawl. The morning sighting of the right whales prompted a Tucker trawl sampling in order to examine the copepod densities in the surrounding areas.

Dr. Richard Pace assists with deployment of the zodiac.

The trawl did yield a higher density of copepods then all of our previous trawls which where carried out in the absence of right whale sightings, however compared to their prior experiences most of the researchers thought that the copepod densities were still on the sparse side. The sighting of pilot whales brought the first launching of the zodiac boat. The goal for this expedition is two fold: 1. To attain tissue samples from some of the pods larger whales so that genetic analysis and subsequent pedigrees may be chronicled and; 2. Acquire photographic images of individual dorsal fins in an effort to establish a method of identifying individuals based on their unique dorsal fin features. Such features may include nicks, scratches, unusual scars and or color patterns. Deployment of the zodiac requires numerous experienced hands and a wherewithal for safety. First the boat is loaded with all the supplies (photography equipment, biopsy tips and crossbows, and tissue specimen jars) that will be needed for the sampling and documentation of the pilot whales. Then the crane on the back deck is used to hoist the zodiac up and over the side of the DELAWARE II. Chief scientist, Dr. Richard Pace then climbs on board the zodiac while the crane slowly lowers the boat into the water. Dr. Pace keeps the zodiac in position while a special flexible hanging ladder called a Jacob’s ladder is unrolled down the side of the DELAWARE II. All other persons enter the zodiac from the DELAWARE’s back deck via the Jacob’s ladder.

Once deployed, the researchers make final adjustments before pursuing the pilot whales.

After the little grey boat is loaded it sets off in the direction of the whales as indicated by the observers on the fly bridge, who have all the while been communicating the whales’ position to the captain of the DELAWARE who then makes sure that the ship stays relatively close to the pod. As one can imagine three-way communication between the fly bridge, the wheel house and the zodiac is critical for not only tracking the swiftly moving whales but also for the safety of all involved. Today was my day to be on the fly bridge as all of this was going on but if the weather holds and we keep seeing pilot whales then I too may get to ride on the zodiac.

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.

July 23, 2007April 1, 2021

Methea Sapp-Cassanego, July 23, 2007

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

Deployment of the Tucker Trawl enables researchers to sample zooplankton at various depths. The cod ends of each of the three nets have been tied with white rope and are visible in the right-hand photo graph. — Deployment of the Tucker Trawl enables researchers to sample zooplankton at various depths.

Mission: Marine Mammal Survey
Geographical Area: New England
Date: July 23, 2007

Weather Data from Bridge
Visibility: less then 0.5 nm
Wind Direction: West – Southwest
Wind Speed: 5-10 mph
Swell height: 3-5 feet

Science and Technology Log

Although the weather is not especially nice today, at least we have a new project to work on. Today is Tucker Trawl Day! The trawl consists of a trio of long finely meshed nets which are mounted one above the other on a heavy metal frame. The frame is then tethered to a wire cable which runs up to a crane. Also mounted on the frame is a flow meter, which is used to measure the amount of water that has passed through the net, and a Seabird mini-logger sensor which records time, depth and temperature. Deployment of any piece of equipment requires careful coordination between numerous members of the ships crew and scientists, as the boats position, and speed must be carefully controlled. Meanwhile the crane operator and those physically preparing the nets will oversee proper operation of the nets and its sensors along with the depth and speed of its ascent and descent.

The cod ends of each of the three nets have been tied with white rope and are visible in the right-hand photo graph.

Back in the dry lab several other hands are at work preparing the sampling jars, labels and documentation for the incoming specimens.It does not take long before everyone is in place and the net is lowered. The trawl will be lowered to the seafloor at which point a devise called a messenger will be snapped on to the wire cable. The messenger is a heavy brass cylinder (about the size of a small fist), which runs down the cable and hits a special releasing lever near the trawl’s metal frame. Release of this lever closes the bottom net and opens the middle net. Deployment of a second messenger then closes the middle net and opens the top net. Control of the opening and closing of the three individual nets allows researchers to take samples at specific depths. After several minutes the Tucker Trawl begins its ascent. It should be noted that the Tucker is not used to sample fish; therefore, we are not expecting to capture any vertebrates. The speed of the trawl is fairly slow so that fish have plenty of time to get out of the net’s way. What we are hoping to capture are Copepods. These tiny lipid-filled zooplankton are the primary food source for the endangered right whale. (For more information regarding copepods and right whales please read my log from July 21^st 2007). Once the trawl is on deck we use a low-pressure saltwater hose to rinse the nets. We work our way from the mouth of the net downward so that every organism is rinsed into the narrow end of the net which is called the cod end.

Kate Swails, Biologist in the Office of Protected Resources rinses the Tucker Trawl contents from a sieve into formalin filled jars. — Kate Swails, Biologist, rinses the Tucker Trawl contents from a sieve into formalin filled jars.

Then the cod end is carefully untied and its contents rinsed into a fine mesh sieve. The gauge of the mesh sieve is large enough to flush phytoplankton out of the sample while retaining zooplankton.The sieves are then shuttled to the dry lab where the contents are raised with seawater and formalin. Later these same jars will be shipped to a lab in Poland where the samples contents will be sorted, identified and counted. All copepods in the sample will also be tallied in accordance to one of six life stages. Aside from physically enabling us to put masses of copepods in jars the results of the Tucker Trawl are also compared to the results from the conductivity/temperature/depth sensor (CTD) and video plankton recorder (VPR). (Please see my log dated July 21^st for further explanation and photos). Furthermore Tucker Trawls are also used to help indicate the likelihood that whales are in the area; empty trawls mean no whale food and few if any whales. Naturally, packed trawls signify ripe feeding grounds which may be worth staying on to survey.

The samples will eventually be shipped to Poland for full analysis.

This soft-ball sized deep sea sponge was unintentionally caught in the Tucker Trawl.

July 21, 2007April 1, 2021

Methea Sapp-Cassanego, July 21, 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 21, 2007

Weather Data from Bridge
Visibility: 7nm
Wind Direction: West-northwest
Wind Speed: 5-10 mph
Swell height: 6 to 8 feet

Peter Duley stands with the vertical profiling package, which is the property of Dr. Mark Baumgartner, Woods Hole Oceanographic Institution.

Science and Technology Log

Yesterday and today were spent traveling down 3 transect lines. Each transect line is a total of 18 miles long and sits 5 miles apart from its neighboring transect. The 3 transects are further divided into stations so that each transect contains 6 stations which are evenly spaced by three miles. The boats captain and crew ensure that the boat is correctly positioned according to the transects and stations. Upon arrival at a given station the bridge radios the dry lab and preparations begin in order to launch an instrument called a vertical profiling package. The vertical profiling system on board the DELAWARE II is the property of Dr. Mark Baumgartner of the Woods Hole Oceanographic Institution and is operated by Melissa Patrician, Oceanographic Technician at Woods Hole Oceanographic Institution.

This trio of instruments is bolted to the inner rim of a round aluminum cage that helps protect the sensitive instruments and allows multiple instruments to be lowered in one convenient package. Three instruments are on this particular cage: One is a conductivity, temperature, depth (CTD) sensor which also happens to measure phytoplankton concentrations via a fluorometer. The second implement is an optical plankton counter (OPC). This instrument functions by projecting a beam of light against a sensor plate. When particles (marine snow, copepods, krill, or other types of plankton) pass in front of the sensor plate they block the beam of light and are thus recorded by a remote computer. The computer software then enables the scientist to sort these light-interrupting events by particle size. The third instrument is a video plankton recorder (VPR), which may take as many as 30,000 photo frames per sample. The resulting images help to give researchers a visual confirmation as to the various life forms inhabiting the water column.

After each instrument has been checked and is in sync with its perspective computer the vertical profiling package is lowered from the deck via a motorized cable. The instruments are lowered to within a meter of the seafloor and then are immediately lifted back to the surface. During the down-and-back journey all points of data collected by the 3 instruments are loaded onto three computers for later analysis.

Researchers hope that by sampling the water column they can gain a better understanding of the biotic and abiotic factors that affect copepods and their distributions. Copepods are of particular interest as they are a primary food source for a multitude of marine animals from fish fry to whales.