Whales are one of the worlds longest living animals.
In fact whales (actually their ancestors) are believed to have existed over 50 million years ago.
During the course of their time on earth whales have evolved from land dwelling animals to inhabitants of the sea.
Although it may be hard for some people to believe these marine mammals began their existence by living, hunting and surviving off of the land.
As the world changed so did their bodies in an attempt to help them adapt and continue thriving despite the demise of other animal species.
To understand how researchers have been able to learn about the origin of whales we’ll begin looking at the bone structure of these marine mammals.
From here we can see that several signs point to the existence of their ancestral background such as the shape, structure and function of their vertebrae and the bones located in their fins which resemble legs from prehistoric times, which have led scientist to conclude that whales were once land dwelling creatures.
Several excavations over the years have allowed researchers to collect prehistoric bones which help predict the evolutionary cycles of their physiological changes over millions of years.
Aside from their bone structure other factors include the mammalian physiology of whales and their need to breathe oxygen despite living in the sea.
Aquatic species such as fish use gills to extract oxygen directly from the water rather than rising to the surface.
Rather than developing gills (which evolution may have decided would require too much effort and energy) the whales nostrils were moved to the top of its head in order to make breathing and accessing oxygen easier.
In addition to this whales are warm-blooded and have developed a thick layer of blubber similar to the fat found on animals that live in cold environments such as polar bears and seals.
Without this blubber whales would likely freeze to death in icy cold waters.
Being a cold-blooded species fish and other aquatic animals do not need body fat or blubber to survive, they simply adapt to the changing climates and their body adjusts to the new temperature.
Because of this fish can consume fewer calories than whales since they do not have to generate much body heat to survive.
Warm-blooded animals on the other hand need to consume food on a frequent basis in order to maintain their energy and body heat.
One adaptation some whale species have developed to cope with this is to use their thick layer of blubber as a source of energy when there is no food source available.
In fact some species can survive for months without food by using their excessive supply of blubber as stored calories.
To clearly identify and separate whales from other aquatic animals these marine mammals form their own unique group along with dolphins and porpoise.
Whales are part of the cetacean species which is composed of all species of whale, dolphin and porpoise.
Currently there are around 80- 90 recorded species of cetacean estimated to be in existence today.
All species are broken down into two suborders known as the baleen whale and toothed whale suborders based on differences in their physiology.
Toothed whales as the name suggest are whales that are born with teeth.
These whales are sometimes referred to as the hunters of the sea (due to their aggressive nature and hunting methods) as compared to the baleen whale suborder.
In terms of size toothed whales are typically smaller than baleen whales (with the exception of the sperm whale).
Unlike baleen whales which are born with two blowholes toothed whales have a single blowhole used for breathing and rely on echolocation to hunt for food and navigate the ocean.
Some researchers believe that toothed whales may have developed one of their blowholes into an echolocation system to help them thrive and survive in the ocean.
While toothed whales are born with teeth baleen whales lack the presence of teeth.
Instead they have baleen plates which resemble the teeth found on a comb.
Because they do not possess teeth baleen whales are generally known as filter feeders.
They hunt their prey by swimming forward with their mouth open in order to trap their prey in their baleen bristles which are used to filter out water and debris, but keep in fish, krill and other prey.
The bristles can be thought of like an air filter that captures lint and large debris but allows air to pass through.
Once the baleen whale captures enough food it pushes the water out of its mouth with its tongue and swallows its prey whole.
As stated earlier baleen whales are the larger of the two suborders and have two blowholes for breathing.
Because of their large size the sounds created by baleen whales can often be heard many miles away.
In terms of size some baleen whales can grow to lengths of 70 – 90 ft. long and can weigh more than 300,000 pounds (150 tons).
Depending on the whales species these marine mammals can have very different diets.
Some whales eat small sources of food such as fish, mackerel, plankton, shrimp and krill.
Baleen whales are known for eating particularly small prey such as small shrimp and krill, which it can easily digest since they do not possess teeth, which would be necessary to tear larger prey apart and into smaller manageable chunks.
Various toothed whale species have been known to eat larger prey such as large fish, octopus, squid, marine birds, seals, sea lions, sharks and even other whales.
It’s important to note however that killer whales and false killer whales (both belong to the dolphin family and are part of the toothed whale suborder) are a couple of the only cetaceans known to hunt other marine mammals and large animals.
Most toothed whales stick to a diet of fish, octopus and squid among other consumable prey.
In addition to their diets the hunting methods used by whales can also vary with great intensity.
humpback whale for example will use a technique known as bubble netting to gather their prey together before attacking them.
One group of whales will circle around their prey while another group blows bubbles underneath the water to scare the prey to the surface of the water at which point the humpback whales can then take turns darting in and consuming their prey.
Gray whales on the other hand will swim to the sea floor, turn on its side and sift through the sand with its flipper to find sea sediments and other types of food that come up such as benthic crustaceans.
Blue whales will simply look for large swarms of krill and swim through the swarm with its mouth open using its baleen bristles to trap its prey.
killer whale will hunt in groups and use team strategies to chase and wear out their prey until it is not longer able to sustain its energy and gives up.
They’ll then surround the defenseless animal and attempt to distract it while another killer whale moves in for the kill.
Killer whales have also been observed flipping sharks over so that they cannot attack and leaping onto icebergs in an attempt to capture penguins and other marine animals.
As far as where whales live whales can be found traveling throughout the worlds oceans and are estimated to be in the millions as an entire species, however there are some species that are considered critically endangered due to excessive hunting during the whaling era and more recently aquatic construction, overfishing and pollution.
Modern day threats
Today there are a number of whale species that are currently considered endangered, however these marine mammals weren’t always an endangered species.
In fact before the whaling era of the 17th – 20th centuries whales were largely abundant throughout all of the worlds major oceans and most of the well known species of cetacea (cetaceans include all species of whale, dolphin and porpoise) appeared to be thriving (or at least fairly abundant) before the 16th century, however during the course of the whaling era many species of whale (especially baleen whales) were being hunted for their blubber which was used to create various products such as transmission oil, margarine, cooking chemicals and soap.
Between the 17th – 20th centuries millions of whales were being killed and various whale parts such as their meat and bones were also used for food, clothing (corsets and umbrellas) and tools/accessories (such as chess pieces, jewelry, tools and weapons).
Among the various species of whale being hunted baleen whales were the most commonly hunted due to their thick supply of blubber, which made them much more profitable for companies and corporations that participated in commercial whaling actives, especially since one baleen whale could produce much more oil for resources than many of the toothed whale species.
Unfortunately this excessive hunting of baleen whales left a number of these marine mammals endangered.
Although baleen whales (also known as the great whales) were frequently hunted some species of toothed whales were also being hunted and killed, which further declined overall whale populations.
In fact as some of the baleen whale species began declining in numbers and commercial whalers found it harder to find these marine mammals they started hunting large populations of toothed whales in order to meet their demands.
Aside from facing threats from commercial whaling towards the 2nd half of the whaling era there were a number of other factors that effected the smaller toothed whale species such as being accidentally trapped in fishing nets, pollution (garbage), ambiance pollution (the use of human echolocation and other artificial underwater sounds), collisions with boats and other types of fishing equipment, the construction of dams and global warming.
The decline of the whaling era
In 1946 the ICRW stepped in and created polices that numerous countries agreed to follow and enforce in order to stop and/or monitor the hunting and killing of whales so that several of the endangered species and many of the hunted marine mammals could have time to recover and hopefully rebound from being considered endangered and/or negatively hunted and in 1986 the IWC banned commercial whaling in order to improve the re population of the whale species in the hopes of preventing certain groups of whales from eventually becoming extinct.
Some countries which chose not opt into the IWC’s agreements or have opted out over time formed their own polices to monitor the whaling industry in their respective countries.
Additional prevention efforts
In addition to the efforts IWC and various other organizations there were a number of other factors that aided in the reduction of killed whales included the creation of alternative resources which helped replace the need for whale oil, blubber and bones; and the construction of whale conservation’s which were built to give populations of whales stable living conditions and protection from outside threats.
As the whaling era began to decline and the popularity of whale watching began to rise the awareness of how commercial whaling was affecting whale populations also began to soar leading to further declines in the interest of using products that were made from the parts of whales.
Lastly, the awareness of commercial whaling also created lots of negative press among countries and organizations that chose to continue hunting whales and over time some countries and/or organizations stopped commercial whaling activities to improve their public appearance and focus their efforts on high monetization strategies.
In fact some analysts have stated that countries involved in commercial whaling would likely improve not only their public appearance but also their tourism capital by replacing the commercial whaling industry with whale watching and other marine based tourist attractions.
Due to these new practices, alternative resources and the affects commercial whaling has public appearance of numerous countries numerous whale species have been saved from becoming extinct and some species have made great recoveries, however there are still other species that have not recovered and some species are still in fear of becoming extinct.
Even with all of the efforts put in place to stop commercial whaling there are still countries that continue to hunt whales, primarily for food since the creation of alternative resources caused the use of whale oil to become much less important and/or cost-effective.
Additional hazards
In addition to previous and existing commercial whaling activities many whale species (both baleen whales and toothed whales) are also being affected by noise and chemical pollution, moving boats/ships, over fishing, fishing equipment, aquatic construction and global warming.
As more and more boats take to the ocean some marine mammal populations are finding it difficult to compete with large scale commercial fisheries as they are constantly competing for food sources such as fish.
Chemical pollution from oil spills as well as waste can be significant issues in highly commercialized areas where whales and dolphins can be found living in and the construction of bridges, docks, oil refineries and other man made aquatic facilities have the potential to affect whale/dolphin distribution and populations.
As more and more people become aware of these hazards government agencies and organizations may step in to oversee how these activities are being performed and how they are affecting the lives of the marine mammals around them.
The end of the commercial whaling era is just one step towards improving the lives of marine mammals such as whales and dolphins.
Better care of the ocean needs to be taken into consideration if the cetacean species is to thrive and survive as a whole as well as provide a healthier environment for all animals that rely on the ocean for their survival.