What Are Anthropogenic Factors Affect The Right Whale Population Growth?

Due to the small population size of North Atlantic right whales (~300 plus or minus 10%) and the low annual reproductive rate of about every five years, suggests that anthropogenic activities affecting mortality may be more prevalent for right whale population growth than for any other whale species. Ship strikes and fishing gear entanglements are considered the main factors contributing to reduced growth and recovery of the right whale population. Data collected from 1970 through 1999 indicates that the anthropogenic activities (ship strikes and gear entanglements) is responsible for at least two-thirds of the confirmed and possible mortality of non-neonate right whales. The data indicates that there were approximately 45 right whale mortalities
during this time period, 16 of which were caused by ship strikes and three caused by entanglement in fishing gear, there also 26 other deaths of neonates and non-calves that are of unknown causes. In addition to the mortalities, there are 56 right whale injuries that occurred in the data from 1970 until 1999—25 from ship strikes and 31 from entanglement. Using the photo-ID catalogue, scarification analysis can provide more evidence for right whales that have survived ship strikes and fishing gear entanglements. Based on data collected from 1935 through 1995, it is estimated that 61.6% of right whales exhibit injuries caused by entanglement, and 6.4% exhibit signs of injury from vessel strikes. In addition, several right whales have been entangled on more than one occasion and some right whales that have been found entangled were subsequently involved in ship strikes.