GU-04-01 Caribbean Humpback Whale Survey

Cruise GU0501, Legs I, II, and III
January 13 - March 17, 2005

Project:	Caribbean Humpback Whale Survey
Dates:	01/15/04 - 03/17/04
Intended Study Area:	Silver Bank, Dominican Republic
Project:	The objectives of this project were to conduct biopsy sampling of individual humpback whales for genetic and other analyses as part of the NMFS assessment of the North Atlantic humpback population entitled "More North Atlantic Humpbacks" (MONAH); conduct photo-identification of individual humpback whales for same; and to document occurrence and distribution of other cetacean species as observed.

This was the second consecutive year Gunter participated in the project taking Gunter away from its usual working areas in the Gulf of Mexico. After 6-day transit, the Gunter dropped anchor at Silver Bank, a roughly 900 square nautical miles reef, located 45 miles NE of Dominican Republic in the Caribbean. It is a well known breeding and nursing ground for humpback whales (Megaptera novaeangliae) most of which are believed to migrate from the entire north Atlantic. The high seasonal density of whales at this location is one of the reasons why Silver Bank was chosen as the site for this study. A special permit was granted by the government of the Dominican Republic to survey the waters of its sanctuary. (Editor's note - scientific information below courtesy of Phil Clapham, PHD, NOAA National Marine Mammal Lab, Seattle. All photos below courtesy of NOAA).

route to Silver Bank
The transit from Pascaguola, Mississippi took the Gunter within view of the north shore of Cuba and Great Inagua Island, Bahamas. The 65-day project was broken into 3 legs and 2 visits to San Juan, PR.

Silver Bank rises sharply from the depths of about 5500 feet to about 60 - 90 ft. The eastern side (light blue area on the chart) is fringed with coral heads which break the surface.

A member of the baleen family, Humpback whales are found in all oceans of the world. Newborns average 15-16 ft and grow to 45-55 ft when adults (females tend to be bigger). Adults weigh up to 45 tons. From their summer feeding grounds in the high latitudes (both northern and southern hemispheres), Humpback whales migrate thousands of miles to their winter calving and mating grounds in the tropics. Females reach sexual maturity at about age 5 and will calve every 2 or 3 years thereafter although annual calving is not uncommon. Humpbacks do not eat during winter months, subsisting instead on reserves of fat built up over the summer feeding season. In fact, female whales may loose up to 1/3 of their body weight during the nursing period which can last up to a year. They live to be 50 or older.


Gunter's daily small boat operations included deploying "R3" (left), "Little Grey Boat" (middle) and "BOB" (Big Orange Boat, on the right). Each scientific team consisted of a coxswain, photographer, biopsy shooter, and data recorder. The boats spent up to 10 hours a day documenting whales, weather permitting. Unlike last year, this year we were blessed with a phenomenal stretch of good weather and the boats were able to work 95% of the time. At the end of each day, another 3 to 4 hours were spent processing the data and preparing the boats and equipment for next day's operations.

Determining population size is crucial to the conservation of the particular specie in question. In the case of the Humpback whales, 2 forms of identifications are being used - photo IDs and biopsies. The whales have unique tail and fin patterns which helps the scientists identify and keep records of individual animals. With 13 years of collecting photo IDs of Humpback whales, close to 12,000 individuals in the North Atlantic have been cataloged of which, 6000 are Gulf of Maine 'residents'. It isn't uncommon to hear a scientist say that they recognize a whale they see on Silver Bank from the North Atlantic. Some whales even have names and have been tracked for over 10 years.

Scientist Brenda Rone 'shooting' on assignment

Samples for genetic analysis are obtained by shooting a small dart from a crossbow at the whale. The dart takes a small sample of skin and blubber before bouncing off into the water. Back in the laboratory, DNA extracted from the sample can often answer questions like sex, population structure, evolutionary history, paternity of offspring, social relationship and whales biology, to name a few. In the photos - a dart aimed at the whale's 'hump' and a sample ready to be packed and stored to be analyzed later on shore.

The following photos are an example of how the Photo ID works - as you can see, there are no two humpback dorsal fins or tails alike (click on photos to enlarge).

Using Photo IDs and genetic analysis, scientists were able to conclude that Humpback whales are loyal to their northern feeding grounds yet mix with other groups on their tropical breeding grounds. Whales from Gulf of Maine, Newfoundland, Labrador, Norway, Greenland and Iceland meet annually in the Caribbean where mating takes place. At the end of the season, the animals return to their respective feeding grounds with the newborns following their mothers. Mixing of the genes is believed, among other things, to contribute to the resilience of Humpback whales. Considering that at one time 95% of the population was decimated, all surveys agree that this species is making a strong comeback. "If the results of our survey continue to support this theory" says scientist Phil Clapham, "removing Humpback whales from the Endangered Species List may follow. By doing so, the resources will shift to support other species in need".

Unique to the Humpbacks whales are their long flippers and animated behavior. They are also very curios creatures. They came very close to the Gunter while on anchor and the crew and scientists were able to watch them roll and flip, slap their flippers or tails, spy hop or breach, or simply 'glide' around the ship. Their spectacular fights over females could be seen and heard miles away. Below are some photos of their unique behavior. To see more photos of the like, please go to more whale photos (All photos courtesy of NOAA. Click on photos to enlarge) - Enjoy!

Breach

ready for take off

spy hopping

Belly up

Fluking before a dive

Humpback whales share Silver Bank with a wreck of a Korean freighter called Polyxeni. The ship, displacing 200GT at the time, ran aground in May 1982. She slammed into the reef, situating itself high and partly dry - her engine room and part of the stern remained underwater. Rumor has it that she was running drugs and chased by a USCG cutter when she ran aground. She was left to rust away on the reef. By the time the first non-Dominicans boarded here, in 1983, all valuables had been stripped except for a full set of charts and bottles of hot sauce. In 2005, the wreck provides a good reference point.

Although surveying Humpback whales consumed the better part of Gunter's days, there was more to life onboard and ashore. Below is a collection of photos of shipboard activities, the people behind this operation and, a few highlights from our visits to San Juan, Puerto Rico. All photos courtesy of NOAA (Please click on photos to enlarge). Enjoy!

6 Shots of chain at the water edge.

Gunter spent the better part of the cruise 'attached' to the bottom of Silver Bank, DR

Diving with whales - LCDR Pica and ENS Perry had company while diving to

retrieve scientific gear (photo by Suzan Zaretsky)

Close encounters - LCDR Pica looking

in the eye of a Hmpback whale

(photo by ENS Perry)

Eye of the whale

(photo by ENS Perry)

Little Grey Boat is positioning itself to

take biopsy and ID photos of a whale

Our morning routine - after deploying BOB (in the water, aft of the ship) and Little Grey Boat, R3 was last to go into the water (photo by Miri Skoriak)

A beautiful sunrise or...