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The diet of whales is wide and varied – from small fish to squid and crustaceans – with species such as orcas consuming large amounts of seals or sea lions. Depending on their size, some whale species will feed exclusively off krill while others may only eat planktonic organisms such as copepods or amphipods.

In this article, we will investigate further the culinary habits of cetaceans and delve deeper into what do whales eat?


Small Fish

The diet of whales is mainly composed of small fish. This type of prey can be found near the surface or in the deep ocean, depending on the species and their fishing techniques.

To catch these food sources, cetaceans use a variety of hunting methods such as herding, lunge-feeding, ramming and bubble netting. These behaviors are widely used among various whale species to capture large amounts of small fish with minimum energy expenditure.

Whales also feed on planktonic organisms like krill and copepods which are often available in abundance due to their short life cycles. The distribution and availability of these prey items vary seasonally, so some whales migrate long distances in order to find suitable feeding grounds throughout the year.

Baleen whales have an advantage over toothed whales since they don’t need to chase after their prey; instead they filter out what they want from seawater using specialized plates known as baleen plates located inside their mouths.

In summary, most whales rely heavily on small fish for sustenance but there are exceptions that feast primarily on other types of marine organisms such as crustaceans or mollusks. Foraging behavior is largely dependent upon habitat characteristics and seasonal variations in prey abundance which ultimately dictate where certain species will roam during different times of the year.


In addition to small fish, whales also consume squid as part of their diet. Squid are attractive prey for many whale species due to their physical characteristics and mouth structure.

The large beaks found in some species allow them to capture and hold onto the slippery cephalopods easily. Furthermore, the digestive process of whales is designed to break down the tougher tissues more efficiently than smaller prey items.

Squid provide an additional nutritional benefit due to their high fat content compared with most other marine invertebrates. A study conducted by researchers at Monterey Bay Aquarium Research Institute (MBARI) showed that a single adult-sized squid could supply enough energy for a whale’s entire daily needs.

This makes them a valuable resource for providing necessary nutrition during long migrations when other food sources may become limited or difficult to find. The unique structural features of squid make them advantageous prey for baleen whales, especially those that feed on larger organisms like Humpback Whales and Fin Whales which require higher amounts of protein intake than plankton-feeding species such as Blue Whale and Gray Whale.

By incorporating squid into their diets, these whales can supplement their nutrient requirements while avoiding competition with smaller predators living within their habitats.

Sperm Whales’ Predators Exposed: Unveiling the Threats


Crustaceans make up a significant component of the diet of whales, and their presence can be seen in most species. According to recent surveys conducted by marine mammal nutritionists, over 80% of baleen whale diets contain crustaceans. This is largely due to the structure of baleen plates, which are highly effective at straining planktonic organisms such as shrimp and krill from seawater.

These findings suggest that dietary habits may have an impact on the evolution of baleen structures in whales. The type and size of crustacean consumed by whales appears to vary between different species, with some consuming larger specimens than others. Baleen whales tend to feed on smaller-sized krill or copepods; however, they occasionally consume large squid or crab species depending on availability.

On the other hand, sperm whales prefer to prey upon squid rather than any other type of crustacean. These differences in feeding behavior appear to be strongly linked not only to body size but also to preferred habitat types and water depths. For many species of cetaceans, crustaceans provide an important source of calcium for bone development and energy production.

The nutrients provided by these organisms even play a role in maintaining healthy levels of hormones within the body – including those responsible for reproductive processes – providing further evidence that this food group is essential for whale health and welfare. In light of this information, it is clear that understanding more about how various forms of marine life interact within their environment can help us gain insight into complex ecological relationships found throughout our oceans today.


Krill are a type of zooplankton that serve as the primary food source for many whale species. Krill migrate around coastal waters in large swarms, providing an abundant and accessible food source for most whales. Feeding behavior varies depending on the species of whale; some feed directly on krill while others filter out plankton or other small organisms from the water.

SpeciesPreferred Food SourceMigration Pattern
Blue WhalePlanktonSeasonal migration following cold currents
HumpbackKrillLong-distance seasonal migrations
Fin WhalesFishMigrate over long distances at certain times

Marine mammal nutritionists have conducted research to better understand how different types of whales interact with their prey sources, such as krill. For example, studies suggest that humpback whales may follow krill during their seasonal migrations by swimming close to them and feeding off them along the way. Additionally, there is evidence suggesting that blue whales use baleen filters to consume large amounts of plankton during their own migratory journeys. In order to survive, fin whales must hunt down fish stocks wherever they can find it which requires travelling across vast areas throughout the year.

These findings demonstrate how intricately related marine mammals’ diets and migration patterns are, highlighting the importance of studying these connections when examining how environmental changes will impact wildlife populations in the future.

Humpback Whales’ Predators Unveiled: A Battle for Survival

Planktonic Organisms

The diet of whales consists mainly of krill, but they also feed on numerous planktonic organisms. In fact, the majority of their caloric intake is derived from these tiny marine creatures and plants.

Recent studies have shown that approximately 80% of a whale’s daily food consumption consists of zooplankton such as copepods, euphausiids, and amphipods. Additionally, 20% comprises microalgae and other marine plants.

When it comes to feeding habits, baleen whales use suction to swallow large amounts at once while odontocetes create bubblenet techniques for capturing prey in swarms or schools. This allows them to consume greater volumes than baleen species since they can trap multiple organisms with each bubble net created by exhaling air underwater.

The most common among this group includes dolphins and sperm whales who rely heavily on cephalopods like squid and octopus for sustenance; however, some may even hunt larger fish depending on species size and tactics employed.

A variety of strategies are used when hunting planktonic organisms due primarily to differences in body shape sizes between species. Smaller whales often utilize surface skimming techniques as well as deep diving approaches which require specific adaptations in order to succeed. On the other hand, larger specimens tend to employ more complex methods such as herding schooling prey into tight clusters before consuming them whole.


Copepods And Amphipods

Whales feed mainly on copepods and amphipods, which are tiny planktonic crustaceans that inhabit the world’s oceans. Copepods form a major part of whale diets, with some species consuming up to 500 million individuals per day. They range in size from 0.2 mm to 2 cm, and can be found in both shallow and deep waters where they usually remain near the surface or at mid-depths.

Amphipods comprise an important component of whale nutrition as well; these shrimp-like organisms measure between 1–10 millimetres long and can be found living among sand grains, rocks, coral reefs, hydrothermal vents, and even within kelp forests.

Marine algae and sea grasses also provide substantial amounts of nutrients for whales. Marine algae includes seaweeds such as red macroalgae, brown macroalgae (kelp), green microalgae (phytoplankton) as well as diatoms which are unicellular microscopic plants suspended in ocean water columns. These serve as food for many aquatic animals including fishes, invertebrates and marine mammals like whales.

Sea grasses grow underwater in coastal regions providing shelter to numerous marine species while serving as nourishment to filter feeding baleen whales who graze along seagrass meadows just above the seafloor using their fine bristles called baleen plates to strain out small prey items such as zooplankton or larval fish.

In addition to these primary components of their diet, whales may consume other types of foods depending on location or availability including squid, octopus, euphasiids (krill), mysids (opossum shrimps), isopods (wood lice), polychaetes (bristle worms) and various species of small fishes.


Whales feed primarily on small fish such as herring, mackerel and cod; squid are also a common food source.

Additionally, these mammals consume crustaceans like crabs and shrimp, seals and sea lions, krill, planktonic organisms like zooplankton, copepods and amphipods.

As the old proverb goes ‘you are what you eat’, understanding whale diets is key in unlocking why they behave the way they do in their environment.

Though there is still much to learn about cetacean eating habits, this knowledge can be used to help protect them from human-caused threats that may harm or disrupt their natural ecosystems.