Blue Whale

  • Coloration and Dorsal Fin

    Contrary to their name, blue whales appear mostly grey with mottling patterns on their bodies. However, when just under the surface they appear to glow light blue, which is where their name comes from. Blue whales have a relatively small dorsal fin that varies between individuals. It may be a small nubbin, triangular, hooked, or even falcate (as pictured above). The dorsal fin sits three quarters back on the whale’s body.

  • Flukes

    A blue whale’s tail flukes are massive extending nearly 7m (22 feet) across! They are long and triangular in shape with a smooth edge and a notch in the center. Because of their size, a blue whale fluking (raising their tail during a terminal dive) can be seen on the horizon from some distance away. Their flukes are smooth and grey and lack the mottling found on the body. Not all blue whales fluke when they are going on a terminal dive, but many do. It is one easy distinction between their close relative, the fin whale, as nearly all fin whales do not fluke when going on a terminal dive.

  • Rostrum and Head

    Blue whales have a relatively flat head on top, with a u-shaped rostrum . They have a fleshy, prominent splash guard in front of the blow holes that deflects water from entering the blow holes during breathing. Their head is smooth and grey with no mottled pattern that is found on their body. Blue whales have 60-88 ventral pleats or throat grooves that extend to the naval that expand and collapse during feeding. Blue whales appear gray on the surface of the water, however this image shows how a blue whale glows turquoise blue under the surface of the water giving it its namesake.

  • Blow

    Blue whales have a tall, columnar blow that can be as tall as 6-12m high.

Blue Whale Behavior

  • Blow

    A blue whale has a tall, columnar blow that can extend nearly 6-10 meters high above the ocean’s surface. As with many whales, the first exhale after a dive sequence tends to be the strongest. The blow of a blue whale is denser and broader than the fin whale. Additionally, a fin whale’s blow is typically visible on the first exhale, waning with each additional breath, while a blue whale’s blow tends to stay visible for each surfacing breath. This fact , although not always true, makes the two easier to distinguish in the field at a distance. During feeding, blue whales will take several recovery breaths at the surface, often while logging (staying in place), before diving down again. The final exhale before a dive tends to be stronger and sometimes even audible as they prepare for a long dive. This final exhale can signal that a whale may fluke (raise its tail from the surface of the water as it dives) which provides an excellent photo opportunity.

  • Dive Sequence

    During feeding, blue whales dive anywhere from 8 to 15minutes. Dive times usually reflect the depth at which a blue whale is feeding. Blue whales typically dive around 250m (approx 800ft) when feeding and less than 70m (approx 200ft) when traveling or resting. After surfacing from a foraging dive, blue whales will often complete a foraging circle. During this surfacing they swim in a slow, tight circle in order to reposition themselves above a patch of krill. In addition to completing a foraging circle, blue whales may also log (float) in one place to remain in a desired position for feeding. While breathing, the dorsal fin usually stays below the surface of the water. During a sounding dive the head drops below the surface, the back (and dorsal fin) rolls into view, and occasionally a blue whale raises its flukes.. See an example of a dive sequence in the video below.

  • Fluking

    Fluking is a behavior where a whale raises its tail above the water during a sounding dive. Not all blue whales fluke but many do. Fin whales (easily mistaken for blue whales) almost never fluke, so seeing a tall columnar blow followed by flukes on the horizon likely indicates a blue whale. For photographers, “fluke photos” are often desirable. Researchers can even identify individual whales by characteristics of the flukes and of the dorsal fin (similar to humpback whales).

Watch a dive sequence from a blue whale. This whale took 12 breaths total during this sequence and stayed at the surface for 2 minutes and 46 seconds. Notice how during the resting breaths the whale is logging and prior to its final breath it pumps its tail to initiate a sounding dive. Observe also how each breath is visible above the surface of the water and that this whale raises its fluke during the dive (not all blue whales fluke).

Where are Blue Whales in Southern California?

Although blue whales can be found throughout the Southern California Bight during the summer and fall months, the highest concentration of blue whales have been observed by cetacean researchers in the areas highlighted above. In 2015, these researchers identified biologically important areas for the North-East Pacific blue whale population based on high concentrations of blue whales feeding in those areas. The recreated image above shows six of these areas within the Southern California Bight including the Santa Barbara Channel, San Miguel Island, San Nicholas Island, Santa Monica Bay to Long Beach, San Diego, and the Tanner-Cortez Bank. These findings give us insight into where blue whales are in here Southern California.

Why are blue whales concentrating in these areas?

We know surprisingly little about the world’s largest animal and much of their lives remain a mystery to us. Nonetheless, we do know that blue whales feed exclusively on a small animal called krill and they eat lots of it! Blue whales will travel thousands of miles in search of krill; krill abundance depends on sea surface temperatures (they prefer cold water) and ocean nutrients. When it comes to ocean nutrients, there are several factors that affect the food chain in the ocean. One important factor is upwelling. If the ocean is calm with no wind or currents, it will stratify itself into layers. Cold, nutrient rich water sinks to the bottom while warm, nutrient poor water sits at the top. These nutrients need to be mixed throughout the water column or driven to the surface in order to support the growth of algae and plankton - which provides food for fish, birds, and mammals. Upwelling caused by winds and currents mixes the stratified layers of the ocean creating concentrated areas of food along the coastline.

Specific features of the ocean floor such as submarine canyons, drop offs, and underwater mountains create concentrated areas of upwelling. Wind and currents push ocean water against these features, driving cold water up to the surface. Krill blooms in these regions under the right conditions creating feeding areas for blue whales. The map shown is an example of several of these ocean floor features here in Southern California where blue whales have been observed feeding. Right off of Rancho Palos Verdes is a deep submarine canyon known as Redondo Canyon. The dramatic drop off from shallow water to much deeper water in front of Point Vicente also creates a concentrated area of upwelling. Well known areas that are rich with biological abundance and diversity are often associated with specific ocean floor features that impact productivity such as the deep submarine canyon of Monterey Bay. It is in and around these underwater features that blue whales are observed feeding.

Even though we can identify areas where upwelling occurs and identify these areas as hot spots for feeding blue whales, that doesn’t mean they are always at these specific areas or even return there the following year. Interestingly, researchers have found that blue whales have spatial memory for krill hot spots and their memory of past years can help them predict good and bad conditions for krill at the time of their next northward migration. Further, it is thought blue whales will use the previous year’s sea surface temperatures as a marker for krill availability the following year.

A blue whale dives just off the coast of Laguna Beach, California

How can you see blue whales in Southern California?

Southern California is one of the few places in the world where blue whales can be observed close to shore. The underwater drop-off just off the coast of Newport Beach and Laguna Beach, for example, is just three miles from shore attracting the world’s largest animal to feed just off the bustling Orange County beaches (see image above).

Blue whales can be observed during whale watching tours in Southern California from Santa Barbara to San Diego from June to October, usually peaking in June and July. Choose a whale watching tour that leaves from Santa Barbara harbor (Condor Express), Long Beach harbor (Harbor Breeze Cruises), Newport Beach harbor (Newport Coastal Adventure) Dana Point harbor (Dana Wharf), or San Diego harbor (Gone Whale Watching) to name a few. Blue whales are not feeding in the area at all times. Pay attention to a whale watching company’s recent sightings report and social media posts, or contact their offices to inquire about recent sightings. Blue whales may either be passing through an area or stopping to feed so keep in mind just because they are seen on one trip does not mean they will be seen on the next or even the next day. For photographers determined to photograph blue whales, book a private charter with a company that has a smaller vessel, communicate with their team, and plan an excursion focused on finding blue whales. Keep in mind you may need to make several attempts before having a good experience with a blue whale as wildlife in the ocean is unpredictable.

Sources and further Reading

CARWARDINE, M. A. R. K. (2020). Handbook of Whales, dolphins, and porpoises of the world. PRINCETON University PRES. 

Reeves, A. E. R. R. (2021). National Audubon Society Guide to Marine Mammals of the World. New York: Alfred A. Knopf, 2009. Third printing.

Bortolotti, D. (2008). Wild Blue: A Natural History of the World’s Largest Animal. Thomas Allen Publishers.

Calambokidis, J., Steiger, G. H., Curtice, C., Harrison, J., Ferguson, M. C., Becker, E., DeAngelis, M., & van Parijs, S. M. (2015). 4. Biologically Important Areas for Selected Cetaceans Within U.S. Waters – West Coast Region. Aquatic Mammals, 41(1), 39–53. https://doi.org/10.1578/am.41.1.2015.39