Whale – Hello There, Keepers of our Oceans.
Whale – Hello There, Keepers of our Oceans.
The oldest living mammals.
Megaptera novaeangliae – also known as The Humpback Whale – is most commonly seen in the Indian ocean off the coast of KZN. They are usually spotted in the winter months (June-August). These magnificent mammals have been in existence for as long as 30 million years and can certainly teach us a thing or two about the evolution of this planet.
Humpback Whales are a species of Baleen whale and their average life span is generally between 40-100 years.
Adults reach a full-grown length of 14-17 metres as they mature. Sexual maturity occurs for the females at the age of 5, while males mature at age 7.
Male humpbacks are slightly smaller than females, weighing an estimated 27 tons. The females will reach a weight of up to 35 tons. The gestation period for the females is around 11.5 months, and the mother will continue to nurse her calf for a further 6-10 months. Only one calf is born per mother every 1-3 years.
Although there is a lot we don’t know or understand about whales and their role in our ocean, scientists have dedicated years to understanding the importance of whales, their role in the planetary evolution and how humans influence their survival, and that of our beloved Earth.
Just how important are they for all life on Earth?
The life cycle of a humpback whale is very important to all contributes to all life in the ocean and on land. Their staple diet consists of Euphausiids, known as shrimp/krill and they also ingest small fish. Once enough food has been consumed, the whale excretes their digested food waste back into the ocean.
One might think: ” Oh goodness! What a large mammal! How gross.!!…..”.
However, next to fungi, whale excretion is one of the most required forms of organic matter needed to keep the planet and all its living forms, alive.
Not only is whale excretion an important aspect, but the whales’ diving between the surface and deep seas, feeding activity and migratory routes play a huge role in sequestering Carbon Dioxide (CO2) from the atmosphere. On average, a Humpback whale can sequester up to 30 tons of CO2 in its life. And when the whale reaches the end of its life span, it takes all that carbon with it to the ocean floor.
The way in which whales live their life results directly in the creation of oxygen that is essential to most life forms on Earth.
Nutrients, pumped through the ocean by the whales, increases the population of Phytoplankton in the ocean. Phytoplankton is known to sequester between 30-50 billion metric tons of CO2 as they photosynthesize. As they capture CO2, these microscopic plants produce up to 70% of the oxygen on Earth.
However, seismic blasting is devastating the Plankton populations across our oceans.
“Phytoplankton is the base of several aquatic food webs. In a balanced ecosystem, they provide food for a wide range of sea creatures.“
Images sourced from National Oceanic and Atmospheric Administration.
We need to Save our Seas…
One of the biggest challenges being faced by whales is plastic pollution and sesimic blasting.
Humpbacks have what are known as ‘baleen plates’-grooves inside the mouth that allow for substantial expansion. This allows large amounts of water and food to be taken in, as well as plastics that are present in the water.
Because plastic cannot be digested, it sits in the whale’s stomach and tricks it into thinking it is full. It cannot eat anymore, and soon enough the whale begins to starve, eventually starving to death.
There have been multiple recorded instances of whales having died from starvation. Upon inspection, huge quantities of plastic were found stuck in the stomachs of deceased whales. One instance recorded a Sperm-whale with approximately 6kg of plastic lodged inside its stomach.
The other risk that the whale populations face, is the impact of seismic blasting. This human activity is becoming devastating to oceanic life, as the underwater blasts affect the echo-location of ocean mammals. These blasts cause hearing loss, disturb feeding and breeding behaviours, and disturb the communication between individual whales and dolphins. The impacts of this cause whales and dolphins to beach themselves and die.
In May of 2022, a whale carcass washed up on the shore of St Mikes Beach, on the lower south coast of KZN. A few weeks later, another whale had washed up on Shelly beach, alive. It was soon assisted back into the waters.
It is important that we learn to embrace and appreciate the life of all oceanic species, just as much as we should embrace and appreciate all the living forms on land. If we do not take into account our impact on the environment, we soon will no longer have a world to live in, or on.
The Green Net website;
Images sourced from:
North Coast Courier