Northwest Atlantic

Historic
It is not clear when Basque whaling began in the northwestern North Atlantic, but it had been established no later than 1530. It has long been thought that large numbers (tens of thousands) of right whales were taken off Labrador and Newfoundland by the Basques between 1530 and 1610 (Aguilar 1986, Reeves 2001) but recent genetic evidence suggest that many if not most of these were bowheads (Rastogi et al. 2004). Shore-based whaling along the US east coast began in the mid 17th century and continued at least sporadically over the next two and a half centuries (Reeves et al. 1999, IWC 2001a). Reeves et al. (2007) estimated as a lower bound that some 5,500 right whales (and “possibly twice that number”) were removed by whaling in the western North Atlantic between 1634-1951.

Current
The current population is of about 300–350 individuals off the east coast of North America. IWC (2001a) obtained a minimum estimate of 263 in 1996 from identified animals known to be alive at that time, and indicated that the true population was probably not much higher. Kraus et al. (2001) provided a minimum estimate of 299 in 1998 based on animals presumed to be alive at that time (and not missing for more than 5 years). Preliminary analysis of more recent data have yielded estimates similar to those above. The whales are regularly surveyed in the winter calving ground off Florida and Georgia, and in spring/summer feeding grounds in Cape Cod Bay, the Great South Channel off Massachusetts, the Gulf of Maine, the Scotian Shelf, and the Bay of Fundy, but not all the whales using the wintering ground are seen in these major summering areas (IWC 2001b). There have been a few sightings in recent years in the Gulf of St Lawrence, two off Iceland in 2003, and one in the former whaling ground off Cape Farewell in 2004 (IWC 2005). A sighting off Norway in 1999 was identified as a well-known animal from the western North Atlantic population (Jacobsen et al. 2004).

Calf counts have been collected since 1980 but counts in the 1980s were probably underestimates, due to non-coverage of the winter calving grounds. Calf production has fluctuated, possibly linked to environmental conditions (Greene et al. 2003). It was low during 1998-2000 (av. 3 per year, with an associated calving interval of 5.7 years, Kraus et al. 2001) but high during 2001-2005 (av. 23 per year) (Clapham 2005). Nineteen calves were recorded in 2006, and the average interbirth interval of the mothers concerned was 3.2 years (Anon. 2006).

An analysis of survival and reproductive rates (Caswell et al. 1999) concluded that survival rates had declined and that, as of 1995, the population was in decline. However, the finding of population decline was based on the assumption that only 38% of mature females were reproductively active, whereas the true figure appears to be over 70% (IWC 2001b). A subsequent review of survival rates concluded that survival rates probably were lower in the 1990s than in the 1980s (Clapham 2003). No more recent data on survival rates have been published to date; while reproduction has noticeably increased in this population, mortality has remained high and is a source of serious concern (IWC 2006).

Increase, if any, in this population is at a much lower rate than in the southern right whale. Per capita calf production and calving intervals have been highly variable over the last decade. The occurrence of skin lesions, of a kind not seen in Southern Hemisphere right whales, was recorded during the period 1995 to 2002, and appeared to be correlated with the failure to reproduce of females that would normally be ready to calve (Reeves et al. 2001; Rolland et al. 2007). Over the same period, body condition as measured by blubber thickness was poorer in the North Atlantic than in Southern Hemisphere right whales (IWC 2001c). Mortality rates are higher than in Southern Hemisphere right whales, due largely to human-caused deaths (IWC 2001b) (see Threats below).

Northeast Atlantic

Historic
The first records of Basque whaling in the Bay of Biscay are from the 11th century. At least dozens of whales were taken each year in the Bay of Biscay until a marked decline was evident by 1650, and whaling declined during the 18th century. Basque whalers arrived in Iceland as early as 1412, and participated in the right whale fishery around the British Isles and Norway from the 14th to the 18th century, but probably many more whales were taken by Dutch, Danish, British and Norwegian whalers. Quantitative estimates of catches are not available. Historic right whale catches as far north as Iceland and Norway appear to have been mainly E. glacialis, with Balaena mysticetus (bowhead) being the main species only in the far north (Greenland and Svalbard) (Aguilar 1986). Smith et al. (2006) documented extensive whaling for E. glacialis in the North Cape area (northern Norway) in the 17th century. Right whaling in the northeastern Atlantic seems to have declined from the mid-17th century and all but disappeared by the mid-18th century, but there was a brief period of right whale catches by modern whalers operating from shore stations in the British Isles and off Iceland, with at least 120 right whales were taken during 1881-1924 (Collett 1909, Brown 1986). The last recorded catch was a cow-calf pair off Madeira in 1967, accompanied by a third individual that escaped.

Current
It is not clear whether there is a remnant Northeast Atlantic population or whether the animals seen there in modern times are strays from the west. There have been only eight confirmed sightings from 1960 to 1999, including the animal sighted in Norway in 1999, which was matched with the western north Atlantic population (IWC 2001b). A possible right whale was sighted in the Bay of Biscay in 1977 (Aguilar 1981) and a cow-calf pair was sighted off Cape Vincent, Portugal in 1995 (Martin and Walker 1997). A recent survey of the former Cintra Bay calving ground off Western Sahara failed to locate any right whales (Notarbartolo di Sciara et al. 1998), although survey conditions were often poor.

Unknown