Whales have fascinated humans for centuries. Back in the old days it was mainly the enormous size of these animals that fascinated our ancestors. Over time, we have learned to appreciate their complex social behavior, intelligence and many biological secrets. The topic is huge as a whale, but let’s try at least a shallow-dive into it.
First things first: how do whales relate to fish?
The systematic division may seem complicated to the layman, but it is good to know the basics to help understand the behavior of different groups and species of animals.
Whales are not fish, even though they swim in the oceans. They are mammals and they breathe atmospheric air. And when talking about marine mammals, we include whales, sirens (yup, that’s warm-blooded manatees and dugongs), pinnipeds (seals, sea lions and walruses), weasels (sea kale and Patagonian otter) and also polar bears [1].
When we think of whales, we think of sizeable mammals of the order Cetacea (Ceatacea). This order also includes dolphins and porpoises, among others. At least 12 different species of whales can be found in the waters surrounding Iceland (some sources count as many as 23 species). You can find a fairly detailed description of these species in a separate article: Whale Species You Can See in Iceland.
Distribution of currents around Iceland (Astthorsson et al., 2007).
This peculiar arrangement of warm and cold currents creates a dynamic environment, and creates conditions for the growth of phytoplankton and the larger animals that feed on them.
In spring, when the temperature rises slightly, the so-called phytoplankton bloom is observed – a phenomenon of mass development and multiplication of plant plankton. The high availability of food promotes the appearance of more zooplankton and herbivorous fish. This creates a huge food base for plankton-eating animals. The largest amounts of phytoplankton around Iceland appear between May and September. This is when the best feeding conditions are created for whale whales and plankton-eating fish, which are fed on by toothfish [5]
Most whales make seasonal migrations in search of food (in summer – to polar areas) and for breeding (in winter – to tropical waters). They travel thousands of kilometers to deliver their young to the world and return to cold waters to feed properly again.
Whale Watching in Iceland: All You Need to Know
Humbacks are among the animals that make the longest migrations in nature. During migration, they swim an average of about 5,000 kilometers. The record for this belongs to a female humpback whale, which covered almost 10,000 km in 2010!
Scientists point to one more reason for whale migrations. That is that they travel to warm waters to maintain healthy skin, which provides protection against parasites and microorganisms. It is observed that whales migrating to warm waters loose their epidermis and so also remove any microorganisms living there[6].
In 2015, scientists noticed changes in the whales’ migratory route. After careful analysis, they noticed a coincidence between some of the whales’ anomalous behavior and geomagnetic disturbances caused by solar flares. This may have disrupted the navigational abilities of sperm whales, among others, and contributed to the mass migrations of these animals to shore.
Nowadays, migrations are also affected by a warming climate, which shifts the limit of plankton occurrence toward the poles, causing whales to have to travel longer distances to feeding grounds. The whales’ behavior is also affected by underwater noise generated mainly by ship traffic and various underwater works, such as drilling, laying pipes or cables.
Whales are highly socially advanced animals. They communicate with each other with the help of sounds that can spread in the water for tens of thousands of kilometers (sic!).
Individual species are capable of producing sounds of varying frequencies, resulting in complex songs that can reverberate in the oceans for hours. Some species can hear as many as 12 octaves (compared to the 8 octaves heard by humans), and the extreme frequencies heard by some whale species range from 16 Hz to 200 kHz (for humans it’s usually 50 Hz to 16 kHz). Whales also have ears (or more accurately: organs of hearing) tuned to the fact that sound propagates almost 5 times faster in water than in air [7].
There are several hypotheses regarding whale songs. It is thought that they are probably used to establish hierarchy in a group, echolocation or to confuse the fish. We are not yet able to determine conclusively what the whales use these show-off arias for.
Many whales obtain food by swimming in groups (pods), making their attacks more organized and effective. This shows the social nature of these animals’ lives.
Most whales also take care of young, old and sick individuals and protect them from predators. Groups of females with their young are most often observed; males prefer a rather solitary lifestyle. Sometimes they form small groups of males of similar age and size. They also join larger groups of females for the breeding season.
Many whales also form interspecies pods. This is rather unusual behavior in the natural world. Such mixed groups include humpback whales, fin whales, blue fin whales, dwarf whales, gray whales, biscayne whales, butlogs and sperm whales [8] Within the groups formed, the animals help each other hunt and protect their young.
Some whales, such as humpback whales and sperm whales, also protect animals of other species. There are well-documented attempts to protect seals, walruses and penguins from attack by orcas, as well as to support smaller whales of other species when threatened. Humpback whales have also been observed protecting divers. When they recognize that there is a threat of attack from a predator, such as a tiger shark, they are able to shield humans and try to draw them away from danger. Thus, they present altruistic behavior, selflessly helping representatives of another species.
In 2012, during behavioral observations of sperm whales, scientists noticed an unexpected member of the herd. Upon closer inspection, they found that the sperm whales had taken care of a disabled, deformed dolphin – a common bottlenose. The dolphin was observed traveling with the sperm whales, who helped it get food, and the younger sperm whales played with it.
A very interesting behavior of whales is their acrobatic, aerial feats. They always inspire the greatest awe during whale-watching cruises. These leaps are most often observed performed by humpback whales and sperm whales, but sometimes you can see fin whales, blue whales, purse seals or dwarf whales jump out of the water, too.
The reason for these jumps has not yet been clearly established, but most likely it is a peculiar way of taking food (before jumping, the animal, emerging, consumes huge amounts of water with zooplankton), and also serves to communicate with members of the herd. It is also probably a form of play.
It is also believed to be a way to demonstrate its strength and establish dominance in the herd. As in other sea creatures in which aerial evolutions are observed (such as manta rays, mobiles, some sharks, and rays of the genus Rhinoptera), it is suspected that the cause may be a mechanism for clearing the skin of debris and parasites.
Whaling cutters rusting in Reykjavik harbor
It left its mark on the numbers of many species, which were caught for their fat, meat and bones. These were used to make lamp oil, lubricants, waxes, cosmetics, medicines, ornaments, corsets and many other items of daily use. As long as these were the activities of quite a few whalers, using fairly primitive tools, nature compensated for the losses without trouble. The real problems began when people approached whaling industrially and professionally.
Many whale populations were driven to near extinction. In the 1930s, about 50,000 whales were killed annually [9]. Large-scale whaling was banned in several countries in 1969, but it wasn’t until 1986 that the International Whaling Commission banned it completely worldwide.
Despite the ban, some countries still engage in regular whale fishing on cultural or scientific grounds. Currently there are only two such countries: Japan and Iceland [11], with Icelandic whaling companies announcing in 2019 that they will stop whaling and it is unclear whether they will return to it in the future.
Today, many whaling companies have transformed themselves into entities that support the conservation of these animals and organize whale-watching tours. These companies often put pressure on whalers and persuade them to stop their hunts [10]. In Iceland, the consumption of whale meat has been declining year after year, and not a single whale was caught for consumption in 2019.
Another factor, highly detrimental to whales, is environmental pollution. They are particularly adversely affected by the presence of heavy metals in the water and food. These metals are accumulated throughout the whale’s life and negatively affect its health, immunity and reproductive capacity.
They are also very badly affected by increasing plastic pollution, which they often ingest with their food, which can lead to poisoning or suffocation. They are also destructively affected by ocean acidification, which reduces the amount of available food.
Speaking of the dangers affecting whales, one must also mention amusement parks that hold representatives of species such as orcas, dolphins and belugas in pools.
Certainly, a visit to a zoo or water park is the easiest way to learn about these beautiful animals and instill a love for them among children. However, we should remember that whales are very bad at tolerating confinement, limited space and the absence of other flock members. Very rarely are they provided with really good conditions in captivity, and even the largest pool is microscopically small, in relation to the ocean. Even self-harm and suicide have been observed among whales kept in captivity. So it is best to watch them in the wild.
But also when going to observe these magnificent animals in their natural environment, let’s keep in mind the dangers that these huge mammals have to face. Let’s choose cruise organizers carefully to limit the negative impact on marine animals. It is safest to choose companies affiliated with one of the organizations that care about good practices in whale-watching (such as the The Icelandic Whale Watching Association so-called IceWhale or Orca Guardians Iceland). We are then assured that the employees are trained and know the rules of boat handling when approaching whales, while ensuring the safety of both the animal and the cruise participants.
