Photo Credit: Flickr | National Marine Sanctuaries
Edited with Permission by Frontier
After rebounding in recent decades from the brink of extinction, today’s right whales now face a similar fate. An estimated 100 females remain in the whole population and scientists predict that if the current rate of mortality continues the species could become extinct in as little as 20 years, making them the first member of the great whales to vanish in modern times.
Historically, right whales have faced tremendous pressure, hunted to the brink for their oil and blubber. They were the perfect target for hunters due to their slow mobility and were aptly named right whales as they were deemed the ‘right whales’ to hunt (Aguilar, 1986). In 1986 the IWC implemented a global ban on commercial whaling. The majority of nations have halted their participation; however some nations still continue to find loopholes in the dated legislation, for example whaling for scientific purposes.
The Impact of Commercial Fishing & Shipping
Since the 16th and 17th centuries, right whale numbers have never quite rebounded. Commercial fishing has strongly influenced right whale distribution. Right whales in the western North Atlantic now rely exclusively on the feeding grounds around Maine (Win et al., 1986). Variability of prey abundance within feeding grounds may have affected reproductive success and hindered the right whale’s ability to rebound to their original numbers post whaling (Kenny et al 2001).
North Atlantic whales also migrate across one of the busiest shipping passages in the world – from Florida, US up the coastline to Eastern Canada. Mark Baumgartner, a marine ecologist at the Wood Hole Oceanic Geographic Institution in Massachusetts, states the population was healthy 7 years ago, however over the last century shipping lanes have become increasingly congested. The volume of shipping traffic across the North Atlantic has consequently made it increasingly problematic for right whales to navigate and collisions have become more common.
Photo Credit: Flickr | NOAA Photo Library
Right whales are also vulnerable to net entanglement. Over the last decade fishing has intensified and so has the infrastructure. Fishing industries now use stronger ropes when lobster fishing to mark buoys, and whales that are foraging in these patches are susceptible to entanglement. Entangled whales may not die from the initial impact, but it can have serious knock-on effects on their health. For example marine biologist Julie Van der Hoop of Aarhus University, Denmark, documented a case of a male right whale named ‘Ruffian’ that dragged a 61kg snow crab trap from Eastern Canada to Florida. Tests revealed that the whale’s drag was increased by 160% and the trap had burdened him to expend over 27,000 calories per day. Once he reached Florida he was noticeably thinner.
Reproducing females require a high calorie diet to gain weight for gestation and to produce rich milk for their calves. Regina Asmutis-Silvia’s findings suggest that carrying debris and fishing gear, for weeks, months and sometimes even years can cause female whales undue amounts of stress and consequently affect their ability to reproduce. Entanglement may also leave lacerations across the skin, restrict mobility and in the worst circumstances obstruct breathing, causing suffocation. Field reports state that on average 50 right whales become entangled each year with 83% of the population having been entangled at least once. In 2009 58% of deaths were as result of entanglement compared to 25% in 2007 and 2008 (Kraus, S.D. 1990).
Typically right whale births reach their peak during January and February but a recent trend casts doubt over their future. Thus far scientists have not observed a single calf in 2018. It is possible births have occurred but out of sight of coastal monitors. This is following a record breaking year for right whale deaths – 17 in 2017.
Flickr | NOAA Photo Library
Both Regina Asmutis-Silvia’s and Kraus, S.D.’s (1990) studies confirm that fewer calves are being born each year. Kraus, S.D.’s (1990) study outlines females are calving just every 9 years in comparison to the 1980s when it was every 3 years and believes this is the main cause of population decline. Regina Asmutlis-Silvia believes that population decline is linked to lack of food in present day abnormal waters, influenced by climate change, obstructing females’ ability to gain enough weight to become pregnant.
What are the Solutions?
Preventing entanglements will be challenging but is certainly necessary. Technological fixes such as using weaker ropes, or electronically controlled traps that don’t require lines would be a significant improvement. Amy Knowlton, a whale expert from the New England Aquarium, claims "there needs to be paradigm shift in the fishing industry." Right whale extinction would be disastrous and no one wants that but economic considerations may be problematic unless governments take action.
Ship strikes, although a common cause of death, are more mysterious according to marine ecologist Mark Baumgartner. Precautions in the past have been taken such as reducing speed limits, however Mark Baumgartner believes more attentive surveying is required to mitigate the impacts. If these steps are not taken, due to the high mortality rates and decreased fertility, right whales are likely to go extinct within 20 years.