Whales: Vast Guardians of the Ocean Ecosystem

Since the first time a human being spotted a whale, breaching up from the surface of the waves, we have been awestruck by them. Whales are some of the most impressive and unusual creatures on the planet Earth, These awe-inspiring creatures are unique among mammals. They are adapted in ways that most terrestrial mammals are not, while still maintaining most of the core elements that we use to categorize mammalian animals.

Whales inspired myths and folklore all over the world, they swim through literature, and are main characters in some of our favorite movies. In terms of ecological importance, whales also play a critical role in maintaining the health and balance of marine ecosystems. They contribute to nutrient cycling, carbon storage, and food web dynamics, underscoring their importance for oceanic and global ecological stability. Despite all this, many whale species face significant threats from various human-derived sources, putting their populations and, by extension, the entire ocean ecosystem at risk.

In this article, we will dive down into what whales are, where they fit into their respective ecosystems, and why they are so important to the continued health of marine and human life everywhere. We will also examine the things that threaten whale populations and explore some ways that modern conservation efforts are helping to mitigate that.

Whales: Giants with a Purpose

Whales, both toothed and baleen, are vital to the continued health and biodiversity of the whole marine environment. Their daily activities and life cycles directly influence the ocean’s productivity and health in a myriad of ways. We have gathered some of the most important in the section below:

Nutrient Recycling: Whale Pumps

Many people don’t know this, but when whales dive deep to feed and return to the surface to breathe, they release nutrient-rich waste; poop for all those readers who are still a little confused. This behavior is often referred to as the “whale pump” or the “poop loop,” and it brings essential nutrients like nitrogen and iron from deep ocean waters up to the surface. The nutrients found in whale dung fuel the growth of phytoplankton, microscopic organisms that form the very foundation of the oceanic food chain. These plankton also happen to produce about half of the Earth’s oxygen, which seems awfully important for those of us who breathe air.

Carbon Sequestration

Believe or not, whales help us to breathe better in other ways too. Whales play a significant role in carbon storage and sequestration. When a whale dies, its massive body sink down onto the ocean floor, creating “whale falls.” These whale carcasses become hotspots of biodiversity, feeding deep-sea organisms like fish, sharks, crustaceans, and countless other invertebrates, often for decades. It takes a long time for organic material to decompose at that depth, and even eating as much as they want, it’s an awful lot of meat for hungry critters to devour. When the whale does decompose, however, the carbon stored in its body is locked away in the deep ocean, mitigating climate change. Think of these whale bodies as the fallen trees of the great ocean.

Regulating Prey Populations

As with most giant predators, whales help maintain balance in the marine ecosystem by regulating prey populations. Whales can swallow entire shoals of fish, devour seals, and ingest enormous undersea clouds of krill. Baleen whales, for example, consume vast amounts of krill and small fish, ensuring that these populations do not grow unchecked and disrupt the delicate undersea food web.

Endangered Whale Species and Their Struggles

Despite their ecological importance and the reverence that they inspire in people, many whale species are endangered due to human activities such as hunting, habitat destruction, and the persistent, ever-worsening threat of climate change.

North Atlantic Right Whale

Status: Critically Endangered
Population: Fewer than 350 individuals
The North Atlantic right whale faces multiple threats from humanity and some you might not expect. These amazing creatures are threatened by ship strikes and entanglement in fishing gear. Habitat loss and climate change are persistent and ever-present issues for right whales and many more on the list below, as they disrupt migration and feeding patterns.

Blue Whale

Status: Endangered
Population: Around 10,000-25,000 individuals globally
The blue whale is the largest animal on Earth. In the 20th century, these gentle giants were hunted to near extinction. Eventually, the whaling industry started to disband, and the mass hunting ceased. Unfortunately, they also have quite a few other threats in the modern day, either from ship strikes, entanglement, and noise pollution, which interferes with their sonar communication.

Vaquita (Porpoise, Not a Whale but Related)

Status: Critically Endangered
Population: Fewer than 10 individuals
The vaquita, found in the Gulf of California, is a small porpoise. More closely-related to dolphins than to whales, the vaquita shares similar ecological roles with whales in maintaining ocean health. Sadly, it is on the brink of extinction due to bycatch in illegal fishing operations.

Humpback Whale

Status: Varies by region; some populations are endangered
Humpbacks are known for their spectacular breaching and complex songs. They make seasonal migrations in the Pacific Ocean, traveling from the South Pacific to the Arctic Circle throughout the year. Their long sea journeys have been affected and threatened by everything from entanglement, to ship strikes, to climate change, which affects their prey availability.

Sei Whale

Status: Endangered
Population: Estimated at 80,000 individuals
Sei whales were heavily targeted during whaling’s peak years. Today, though the populations have somewhat recovered, they are still threatened by the likes of ship collisions, noise pollution, and habitat changes.

Fin Whale

Status: Vulnerable
Population: Around 100,000 individuals globally
Fin whales were another target of the old-time commercial whaling industry. Though their populations have since risen to safer levels, these animals still face dangers from pollution, ship strikes, and climate change.

Sperm Whale

Status: Vulnerable
Population: Estimated at 300,000 individuals
Sperm whales, known for their deep dives and large brains. These animals hunt giant squid in the deep ocean, but are affected by ship strikes, entanglement, and pollution, the same as other sea creatures. At the same time, plastics and chemical contaminants accumulate in their bodies, impacting their health and reproduction rates.

How Human Activities Threaten Whales

Commercial Whaling: A Lingering Threat to Whales

Whaling was once one of the most lucrative industries in the world. People came from all walks of life to try their hand at battling and catching some of the biggest creatures on the planet. Even though whaling has fallen out of favor in the 21st century, it is still considered a significant contributor to the decline of whale populations for the past several centuries. Despite international bans, commercial whaling continues to this day. In some regions, whaling still poses a persistent threat to these majestic creatures.

Even though the International Whaling Commission (IWC) was established in 1986 as a way to regulate whaling, whaling still continues. Countries like Japan and Iceland still hunt whales, often citing cultural traditions and scientific research as justifications. In Japan, whaling is framed as part of the nation’s heritage, while Iceland argues that whale populations in its waters can sustain limited hunting. However, the folks who participate in these practices don’t realize that they often target species that are still recovering from historical overhunting.

At the same time, loopholes in the moratorium placed on individuals whaling for specifically threatened species of whale, have been exploited by unscrupulous whaling fleets. Countries hunting for scientific research or under the guise of cultural practices are exempt from the rules, it seems. As a result, the continuation of these activities undermines global conservation efforts and jeopardizes the recovery of endangered species like fin whales and minke whales.

Bycatch: An Unseen Killer

The fishing industry is just as culpable here. Accidental entanglement in fishing gear, known as bycatch, is one of the leading causes of injury and death for whales. In areas where intensive fishing operations take place, such as the North Atlantic and parts of the Pacific, whales frequently become entangled in nets, lines, and traps. These incidents have often led to severe injuries, such as deep lacerations and infections.

Bycatch is particularly devastating for small and localized whale populations, like the critically endangered North Atlantic right whale. We touched on it earlier, but only about 350 individuals remain, so the loss of even a single whale due to bycatch has significant implications for the ultimate survival of the species. Efforts to mitigate bycatch, such as modifying fishing gear and implementing exclusion zones, are underway but these initiatives still require broader adoption and enforcement to make a substantial impact on already declining whale populations.

Ship Strikes: Collisions on the Rise

As global shipping traffic increases, so too do the risks of ship strikes on whales. These strikes happen when large seafaring vessels, such as cargo ships and cruise liners, collide with whales. These collisions often cause fatal injuries and are particularly pronounced in heavily trafficked areas like the North Atlantic, the Mediterranean, and the Indian Ocean.

Pollution: A Growing Crisis for Whales

Marine pollution has become a severe and multifaceted threat to whales. Plastic debris, including fishing lines, bags, and microplastics, have ended up in the ocean for years, often forming giant, island-sized garbage patches on or just beneath the water’s surface. Marine life of all sorts are affected by plastic pollution, and whales are particularly prone to accidentally ingesting plastic while feeding, leading to blockages in their digestive systems, malnutrition, and even death.

Chemical pollutants, such as mercury, polychlorinated biphenyls (PCBs), and pesticides, have also made their way into the ocean from industrial discharge or agricultural runoff. These chemicals accumulate in whale tissues over time, causing a vast array of health issues, including reproductive problems and weakened immune systems. As we mentioned above, the effects of pollution are particularly acute for long-lived species like sperm whales, which accumulate higher concentrations of toxins over their lifespans.

Climate Change: A Looming Threat to Whale Habitats

Climate change is perhaps the most pervasive and long-term threat to marine life. Rising ocean temperatures and melting polar ice are constantly disrupting the habitats and food sources of many whale species. Krill, a primary food source for baleen whales like blue whales and humpbacks, are highly sensitive to temperature changes and their numbers have declined in recent years. This means that whales have less to eat, must travel farther to find food, and can become malnourished as a result.

Ocean acidification, another consequence of climate change, further compounds the many ecological challenges whales face. As the oceans absorb more carbon dioxide, the resulting chemical changes affect the availability of calcium carbonate, a critical component for many marine organisms; krill included! This has a cascading effect on the food web, ultimately impacting whale populations that sit at the top.

The Need for Collective Action

Addressing the threats that whales continue to face requires coordinated global efforts, including stricter enforcement of whaling bans, advancements in bycatch prevention technology, rerouting shipping lanes, and reducing pollution at its source. None of this is easily accomplished, however. It’s hard enough to make political and policy changes, let alone combatting the rising tide of climate change. Unfortunately, facing the problem of climate change is particularly critical, as it underpins many of the challenges facing marine animal populations, as well as those facing the human race. Still, by taking action now, we might just be able to help secure a future for these vital marine giants and the ecosystems they support.

Whale-Watching: A Conservation Tool

Whale-watching has become a popular eco-tourism activity, and one that is actually quite good for the whales themselves. That’s because whale-watching generates economic incentives to protect whales and their habitats. Responsible whale-watching practices educate the public about these magnificent creatures and promote conservation efforts.

Whales and Indigenous Cultures

For many Indigenous communities, whales hold cultural, spiritual, and subsistence significance. In these cultures, sustainable whale hunting and cultural practices are able to coexist with conservation efforts. This mutually-beneficial arrangement further highlights the importance of respecting traditional knowledge and practices.

True Investigator Says…

As you can see, preserving whale populations is not just about saving a single species—it’s about maintaining the health of the entire ocean ecosystem, as well as the health of our planet. Whales are keystone species wherever they dwell, which means that their presence and activities have a disproportionate impact on their environment than other local species. The continued survival of whales supports biodiversity, carbon sequestration, and the global food chain. So keep that in mind the next time you throw away a plastic cup.