For thousands of years, whales, dolphins, and porpoises (cetaceans) have played an essential role in human culture and mythology. The ancient Greeks and Romans celebrated these sentient animals through storytelling, art, and poetry in which they represented intelligence and kindness. Held in high esteem, dolphins were closely linked with the gods. The sun god Apollo, for example, assumed the form of a dolphin when he founded his shrine at Delphi on the slopes of Mount Parnassus and the hero Orion was carried into the sky on the back of a dolphin and given three stars. These became the famous constellation of stars known as Orion’s belt. In ancient Greek culture, killing a dolphin was so frowned upon that it was even punishable by death. Sadly, humans lost this reverence for cetaceans over time, and our respect for the sea turned into a sinister greed for wealth and power. Commercial whaling and overexploitation of great whales is an example of this greed.
Great whales, collectively known for their large size include baleen whales and sperm whales (Physeter macrocephalus). They have been hunted commercially and exploited in the northeast Atlantic by countries such as Ireland, Iceland, Norway, Scotland, Spain, and Portugal and by open-boat whalers in the Azores and Madeira. The meat taken from the whales provided a valuable source of protein while oil extracted from the blubber was used for fuel, and spermaceti, a waxy substance found in the head cavities of sperm whales, was used in the creation of candles, ointments, and industrial lubricants.
Commercial whaling allowed humans to create jobs and build economies. Still, the unsustainable nature of the practice and our poor understanding of how interconnected great whales are to the ecosystem’s overall health led to cascading effects that scientists are only now beginning to understand.
If you look at whaling operations close to home between 1908 and 1922, shore stations in Western County Mayo caught a total of 63 male sperm whales, and between 1904 and 1928, 76 male sperm whales were caught from the Outer Hebrides in the UK. It could be argued that the resources gained from these 139 individual whales outweigh the negative impact on the environment. But when man-made borders are removed and the collective impact of industrial whaling on great whales globally is assessed, the result becomes profound. Industrial whaling led to a 90% decline in great whale populations, driving some species to the brink of extinction.
To prevent a complete collapse of great whale populations, the International Whaling Commission was set up under the International Convention for the Regulation of Whaling in 1946. The convention intended to conserve, rebuild and regulate whale stocks allowing for the orderly development of the whaling industry. But humans no longer need whale blubber for oil, and with many better protein sources now available, it’s time to turn the tide on greed and overexploitation. It’s time for fair seas, for a renewed appreciation of the ocean.
Ancient Greek culture was right to respect cetaceans; where they saw godly figures, modern science sees ecosystem engineers. Great whales are the foundation of the food web and are a top predator. They create balance and equilibrium in the marine environment and we need them to fight the climate and biodiversity crises.
Sperm whales are fascinating; they are the largest of the toothed whales and are an apex predator of the deep sea. Feeding at depth helps mix up the water column moving nutrients from areas of high to low productivity. In addition, sperm whales deliver nutrients to otherwise barren areas of the ocean through there poo. Defecating at the water’s surface releases valuable nutrients such as nitrogen and iron that primary producers, like phytoplankton, need to thrive. These two processes of deep dives and releasing faecal plumes are known as the ‘whale pump’, which is necessary for the creation of phytoplankton blooms in the open ocean. These in turn support higher trophic level species such as sharks, larger commercial fishes, and other marine mammals and seabirds.
In addition to kick-starting the food chain with valuable nutrients, cetaceans are also important carbon sinks. Great whales, like sperm whales, are efficient carbon sinks due to their immense size. Their low mass-specific metabolic rate and longer life span relative to smaller animals means that they can remove more carbon from the environment by storing it in their blubber and removing it from the atmosphere when they die through ‘whale falls’.
Sperm whales are a highly vocal species producing long trains of characteristic clicks while hunting. Scientists can detect these clicks for several miles using towed and directional hydrophones. Although sperm whales are seldom sighted within 100km of Ireland’s coast, acoustic detections suggest that the offshore waters of Ireland and Scotland are significant foraging habitats for this species. Although commercial whaling is no longer practiced in Irish territorial waters and sperm whale numbers appear to be increasing, they are still vulnerable to threats such as active sonar and other forms of noise pollution.
Ireland has the potential to become world leaders in marine protection. Ireland has the potential to harness blue carbon and fight climate change. Ireland can turn the tide on biodiversity loss, but we need fair seas and great whales to do this.