Coming off the heels of Hope for small sea turtle populations, there is yet another stint of positive ocean conservation news; this time for our cetacean friends. A new publication in Conservation Biology has actually documented voluntary cooperation by shipping vessels to avoid whale strikes.
Fin, humpback, right and gray whales have the unfortunate distinction of being the most frequently reported victims of collisions based on historical records. But whale strikes are not limited to only those species as deaths have been noted for sei, blue and minke whales as well. However, one particular cetacean stands out above the whale strike crowd with victimhood reaching 2 orders of magnitude above the others. Perhaps its affinity for urbanized coastal waters around the globe, the endangered North Atlantic right whale is in need of a little shipping compassion. Especially when a 2008 report found that 53% of North Atlantic right whale deaths were attributed to vessel strikes.
To curb the problem, conservation policies have been discussed and even implemented, including the establishment of an ‘area to be avoided.’ In 2007, “The International Maritime Organization adopted the Roseway Basin Area to be avoided on the Scotian Shelf as a voluntary conservation initiative to reduce the risk of lethal vessel strikes to right whales.” This voluntary area to be avoided went into effect on May 1, 2008 and was designed to be seasonally effective from June 1 to December 31st of each year. With shipping companies traditionally against the execution of speed reduction regulations and alteration of shipping lanes (i.e. time is money), the notion of a voluntary avoidance area was definitely a concept that needed confirmation of compliance.
To my surprise, the researchers found:
” Estimates of vessel-operator voluntary compliance ranged from 57% to 87% and stabilized at 71% within the first 5 months of implementation. Our estimates showed an 82% reduction in the risk of lethal vessel strikes to right whales due to vessel-operator compliance. We conclude that the high level of compliance achieved with this voluntary conservation initiative occurred because the area to be avoided was adopted by the International Maritime Organization.”
But the caveat with ocean-going vessels avoiding a conventional shipping lane was that they needed to find a new travel route. And although the newly adopted course was quite favorable to the right whale, it has the potential to increase fin whale ship strikes by approximately 7%. The argument, however, is that the fin whale population is 250 times more than that of the endangered North Atlantic right whale, right whales are more abundant than fin whales in the ‘area to be avoided’ , and the ship-strike risk to humpback whales and to sei whales will be reduced by 11% and 74% respectively.
So what does a reduction in ship strikes ultimately mean to the endangered North Atlantic right whale, well it may very well be the difference between recovery and extinction.
“Preventing as few as two female deaths per year would increase the population growth rate to replacement levels that would initiate recovery. Such prevention is particularly relevant given that contemporary probability estimates of deaths from vessel strikes could be as high as 10 individuals in any given year.”
Reference: Vanderlaan, A.S.M., Taggart, C.T.(2009) Efficacy of a Voluntary Area to Be Avoided to Reduce Risk of Lethal Vessel Strikes to Endangered Whales. Conservation Biology