Humpback Whale (Megaptera novaeangliae) Distribution On Stellwagen Bank (New England, MA, USA)

Abstract

Humpback whales (Megaptera novaeangliae) are found in all oceans and complete one of the longest migrations of any mammal. Their movements in their feeding ground areas are difficult to track and therefore are largely unknown. This study used data from Whale and Dolphin Conservation (WDC) and Ocean Biogeographic Information System (OBIS) to map the movements of humpback whales for the year 2011 as well as between the decades of the 1980s, 1990s, 2000s, and for 20102012. GIS maps of humpback whale sightings from these data sets showed patterns of seasonal movement as well as high use areas. The distributions of the humpbacks in all four decades showed two concentrated areas where the whales were sighted more often: north of Cape Cod, in the Stellwagen Bank National Marine Sanctuary and to the southeast of Cape Cod. The percentages of humpbacks over different types of benthic substrate were also calculated and statistically analyzed using a Chi-square. The relationship between the number of sightings and the type of substrate was determined to be significant for the spring and summer months. The whales were more likely to be found over sandy substrate in the spring and summer. This is most likely because the schooling fish that they eat are most likely to be in those areas. However, this relationship did not hold for the fall months and this is likely because their prey has moved over a different substrate. These results agreed with those of NOAA’s study of the same area.