Feb 7th to Feb 14 2009 on the Silver Bank 80 miles off Domincan Republic Print
Written by Andrew Stevenson   

The Silver Bank is located 80 miles north of the Dominican Republic and approximately the same distance from the Turks and Caicos Islands and is one of the most important breeding and calving zones of the North Atlantic humpback whales. Research indicates that the Silver Bank contains the largest population of humpbacks in the North Atlantic Ocean, if not the world. During 1993, YONAH a research group took 1,752 different biopsies during a six-week period within a six-mile circumference. Conservative estimates believe up to five thousand humpbacks pass through the Silver Bank each winter season.

Domincan Republic's Silver Bank Sanctuary, established on October 14, 1986, was enlarged and renamed the "Sanctuary for the Marine Mammals of the Dominican Republic". The jurisdiction of the sanctuary now encompasses Samana Bay and the Northern and Eastern coastline of the Dominican Republic, a frequently traveled area of the North Atlantic Humpback Whale on their way to various breeding and calving locations in the Antilles. These breeding and calving grounds include the waters of the Dominican Republic (primarily Silver Bank, Navidad Bank and Samana Bay), Mona Passage (Puerto Rico), Virgin Bank and Anguilla Bank.

Most of the 'Bermuda' whales that we have identified on their breeding grounds in the Caribbean have been previously matched down on the Silver Bank. The first wave of whales to arrive on the Silver Bank in December after their summer feeding up north are the pregnant females.They are also the last to leave. The first whales to leave are the females without calves followed by the males and then the females with calves.The whales leave the Silver Bank for their long migration up to their feeding grounds in Canada about the first week to middle of March.  This corresponds roughly with a ten day to two-week travel time with the first wave of migrating whales arriving here in Bermuda about the last week of March. 

While the North Atlantic humpback whale spends spring, summer and autumn in the high latitude feeding areas of the Gulf of Maine, Gulf of St. Lawrence, Newfoundland/Labrador, Greenland and Iceland, as winter approaches they migrate southward to the mating and calving grounds of the Antilles.

The behavior patterns of the humpback whale in the northern latitudes depends on the type of prey it forages on- from sandlance on the Stellwagen Banks in New England to krill in Nova Scotia to capelin in Newfoundland and Labrador. The humpbacks spend the summer months opportunistically gathering huge quanties of prey to put on enough blubber to sustain its winter migration period without food. During their winter gathering in the Caribbean the females are gentle and flirtatious, but the males become vocal and surface active, aggressive, brutal and competitive.

The winter mating and calving season finds male humpbacks trying to secure their position next to a female and protecting that position from any challenging whale or whales in the area. If a challenger moves into the area, the escort will display surface postures to warn off all competitors. If this is unsuccessful, a competitive group will form and will use their 16-foot pectoral fins to swat at approaching males, ram each other or chin breach on top of competing males to get positioned next to the female.

I returned to the Silver Bank again this year for two weeks to better understand the North Atlantic humpback whales and to film them in their breeding and mating grounds. The trip started off badly with winds of 35-45 knots and seas as high as 16 feet. We were scheduled to depart Peurto Plata Saturday evening arriving at Silver Bank 80 miles offshore early Sunday morning, but we were unable to leave Peurto Plata until Tuesday. The crossing, at 2 knots, took 30 hours to a point where we could anchor. It took another 20 hours to get to our moorings off the reef line.

          

Despite the stormy conditions, or perhaps because of it, everywhere we looked we could see humpback whales breaching or tail lobbing. They may take advantage of the cooler temperatures during a storm or squall to cool their bodies down. It seemed with the winds coming predominantly from the south east, the whales, especially those with young calves, were crammed in close to the breakers for protection from the waves.We were able to get out on the tenders Wednesday afternoon and all day Thursday and for a couple of hours Friday morning.

 

   

   

Although we were often confined to our mother boat, we seemed to be surrounded by whales and were provided with spectacular shows, sometimes very close.

  

When we finally got in the tenders, we really didn't have to go far to find the whales... and some of the whales came to find us...