Hello to all,
The North Atlantic holds about 15,000 to 16,000 humpback whales (Megaptera Novenglae) and its population is gradually increasing. Before the hunt we had about 150,000 individuals, so only 10% of its original population.
The "Samaná Marine Mammal Sanctuary is the most important breeding and birthing area for humpback whales in the North Atlantic.
Since last year the population is protected and no longer at the stage of extinction. This does not prevent some countries from continuing to hunt them.
About 6000 individuals have been recorded with a name, a photo and a number for the last 40 years. The identification method is based on the caudals (tail) of these whales when they dive. Each one of them has different marks or spots and shows real fingerprints. The researchers' goal is to create a family tree for each whale. I knew that this population had white pectorals (fins) on both sides, unlike the one located in the South Pacific. It is true that my swim in French Polynesia (Rangiroa, summer 2009) with one of them reminded me this detail.
The most famous in Republican waters is the female SALT, which was first photographed in 1975. She is often found during the winter season in the Samanà sanctuary where she comes to breed as well as in the Gulf of Maine in the United States (east coast of Boston) to feed in summer. She gave birth to 10 pups at a rate of one every 2 to 3 years.
This birthing cycle is usual if the female is healthy and resistant.
We are often asked why whales do not feed in warm waters, for example here in the Caribbean? According to the answers given by many scientists, the abundance of fish and their diversity is present, but the volume is not concentrated enough in a specific place. In the north, the cold waters favor areas that are conducive to this volume and the whales know them perfectly. The density is more important in the north but not enough in the warm waters. It is the same in the southern hemisphere. This explains why whales need to make migrations of several thousand kilometers. A humpback whale has been observed from Samaná to Norway, which implies a swim of 7000 km! So the whales do not feed in the waters of Samaná but reproduce, meet and give birth here.
This year has been rich in births. No less than 17 newborns confirmed thanks to the photos taken by the researchers on board the boats. Last year we counted only 3! Why such births this year? Nobody really knows.
Another characteristic fact is that the female feeds her calf every day, and he ingests 200 liters of milk daily and grows 50 kg per day. His mother loses about 25% of her weight, that is to say about 10 tons (knowing that she can do 40 tons). The two will stay together one year, the time to show him the way to and from Samaná and the north.
On the other hand, less duels of males for the conquest of the female, the biologist Kim Beddall has already seen 20 males around a female. This year 2 to 3 males around a female and quite quiet. Is this a low year for breeding, and why?
It is interesting to see that the mother rarely shows her tail before diving in the presence of her pup. The pup cannot stay underwater for a long time (on average 3-4 minutes at an age of about 4 weeks) and the mother does not dive deeply. This is the reason why it was difficult to photograph its caudal but only its dorsal on each side and the same process for the newborn. Sometimes, a male accompanies the two and plays a role of companion or protection.
Once we observed an aggressive behavior towards the mother. However this male is not the father of the cub and we do not know exactly his role?
Concerning the groups of humpback whales, there are several solitary groups. Rarely large groups as I can see in Canada or elsewhere. We can distinguish
mostly isolated pairs, like a female and a male, 2 males or a mother and her calf, or 3 whales like the mother, her calf and the male escort. But never a pair of females! Everything has been proven by the biopsy and the identification of the caudals. These pairs can be distant in the whole bay of Samaná and one can navigate for a long time between 2 observations.
All humpback whales jump out of the water. The male, the female, the mother or the calf. I was able to photograph an adult whale and a calf doing it. One day a calf did it for 20 minutes without stopping, my best memory as a photographer and guide. The jumps vary from a full 360° body turn, the body out horizontally, a half turn 180°, or just taking the head off the surface.
These jumps are accompanied by pectoral or caudal fins hitting the surface. These are common habits for this species of baleen whales. The most beautiful too! A body of 40 tons lying out of the water does not leave anyone indifferent. I remember the noise and the mark on the surface when the body falls back. Indescribable! I let you imagine when I saw 2 humpback whales doing it at the same time, a terrible noise!
Used to rough water in Canada and elsewhere, I thought I would find calmer water in Samanà. However, January and February were very windy, with peak speeds of over 30 knots and 4-meter waves. The result: all the passengers were sick. There was not a calm day or two during the first months, always waves. Only 2 or 3 trips out of the 3 months without tourists getting sick. A hell for some, and for us too! March was very good, little wind and a beautiful sea, a real treat for customers and photographers. Also, easier to find them.
The distance of Samaná Bay from the south and north shore is about 25 km when the sanctuary starts and then widens out to sea (depth of the bay about 35 km). It looks like the St. Lawrence River (Quebec, Canada) at the level of Tadoussac when I sail in summer (but about 40 km wide). In Canada, whales are often concentrated in the same places. Food is a big part of it. Here, whales can be everywhere and you have to sail long distances to find them. Sometimes, we could observe a mother and her calf quickly, but it was rare. For this reason, our cruises vary between 3 and 4 hours. 2 cruises in the day during 3 weeks exhausted us.
When I look at the size of the females, they are bigger than the males, and their body is much wider than in Canada. The difference is very clear. This explains their long migration from Samaná to the north, the energy spent makes them weak and skinny.
I have very good memories of my experience as a translator on Kim Beddall's boat and I am honored to have worked for her. She is probably the best in the study of these marine animals in the North Atlantic and the first in the Dominican Republic (since 1985). She had lent me her camera so I was able to help her team and the other scientists with the identification.
I had the chance to work as an interpreter and photographer.
Dominican Republic - Samaná - January 2011
Julien Marchal