The trans-Atlantic slave trade is one of the most grotesque periods in human history. Whilst slavery in itself existed for a long time in many cultures, this form of it was unique in its inherent racial angle. This has led to contemporary attitudes on race in Western society, including conflicts such as the US Civil War and the Haitian Revolution. The Civil War to date remains the biggest conflict the USA has ever fought, with more casualties than the Revolutionary War, War of 1812, and the World Wars. And of course, the Confederacy seceded to ensure its “states rights” to own slaves.
As one can note, the slave trade caused carnage, distress and barbarity in various guises over a long period.
The US Congressman Donald Payne stated in 2007 that shark migratory patterns were altered by the Middle Passage of the trans-Atlantic slave trade.
Is there any truth to this?
Yes, there is.
Predator patterns
Sharks, along with other carnivores, have senses to gauge the location and size of prey. It’s often said that they can smell blood in the water from a long distance, perhaps 10-20 miles away. Wolves can literally smell prey from miles away, which is why domestic dogs have retained a keen sense of smell. If there is any scent or sign of prey, then generally carnivorous species will sense and seek it out accordingly.
Slave ships were often wrecked with disease and human waste, and not just occuring amongst the slaves. Crews were often subject to the same conditions and were at times subject to harsh punishment when transgressing rules or orders.
It is well-known that ship captains would often throw slaves overboard - in cases of sickness or death, to save or reserve space, or to punish defiant and resistant slaves. It’s estimated that between a quarter and a third of slaves were treated in this manner, with the rest facing a lifetime of bondage and suffering on plantations and mines in the New World.
Such vessels, of course, would travel in the territories and ranges of sharks, and thus it was an easy meal for them. Slaves thrown overboard, especially if living, would be chained more often than not. Thus, they wouldn’t have had much chance to fight back or resist shark attacks, with the weight of the chains weighing them down accordingly. Dead slaves would have naturally been an easy meal for sharks, with no apparent resistance at all.
It is very plausible that sharks, if they could literally sense humans in the water periodically from structures travelling on the surface, would feast on the deceased or living slaves thrown overboard.
In a disparate example, sharks were known to attack survivors of an attack on the USS Indianapolis in the WW2 Pacific Theatre. Provided it can be sensed, and is palatable/edible, predators wouldn’t hesitate to eat it. Humans aren’t usually a shark’s favoured prey item - however, humans are large enough to be consumed and as far as we know we aren’t toxic to them. Whilst some predators are picky, or eat a limited diet, sharks aren’t often such.
With literally hundreds of slave ships passing through their ranges every year, this was noted by the records of ship captains, crew and passengers.
Abolitionists used this reality to highlight the horror of the trade. Alexander Falconbridge, Thomas Clarkson, and James Tytler all wrote pieces detailing shark attacks as a means of punishment for both slaves and crew alike.
Rediker (2008) collated various narratives on how sharks became a symbol of horror and also a means to punish slaves and ships’ crews alike.
Fallaciousness
It is said by some that shark migration patterns today are still affected by this.
This is implausible for several reasons.
Slave traffic ceased in the mid-19th century. Whilst numerous merchant and naval vessels travel in the Atlantic today, there are no large quantities of bodies to consume at this point.
Secondly, all species use their senses to obtain food. With no human bodies, living or dead, to feast on, they would seek out and eat plenty of non-human prey available.
This view stems from a fallacy of animal migration patterns. And really how all species seek out sustenance, including our own.
Rediker’s aforementioned piece references this well, and it is interesting to see the recorded history of this phenomenon.