Underwater Enigma – Are there sharks in San Francisco bay?

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Are there sharks in San Francisco Bay? This may surprise you, but the answer is yes! Although not commonly seen, various species of sharks can be found inhabiting this iconic body of water. In this blog post, we’ll explore what types of sharks live in the area and where they typically hang out so you can understand one of San Francisco’s lesser-known inhabitants.

Some sharks live in San Francisco Bay. The most common species of shark found in this area is the Leopard Shark. This type of shark prefers shallow and warm coastal waters, so it perfectly suits its home in the Bay. Other species that can be spotted occasionally include the Brown smoothhound shark, the Spiny dogfish shark, and the Broadnose Sevengill Shark.

Are there sharks in San Francisco Bay?

The Bay Area boasts a diverse population of 12 distinct shark species – fortunately, most dangerous sharks prefer to remain in open waters away from the area. This makes it relatively safe for those who wish to enjoy beaches there.

During the past century, there were only a few assaults, with the most serious occurring near San Francisco but not in the Bay.

Most common sharks in San Francisco Bay

Great White Sharks ( Carcharodon carcharias)

Great white sharks are considered one of the most feared predators in San Francisco Bay. Blending in with the color of the rocky coastal sea floor, these creatures have a slate-gray upper body that stands out against their stark white underbellies, giving them their unique name.

Sleek and streamlined, these torpedo-shaped aquatic creatures can travel at an impressive speed of up to 15 mph with the power of their powerful tail fins.

They measure about 3.4-4.9 m and weigh about 680 – 1.100 kg. They usually swim alone but have occasionally been seen in small groups. Great whites are mainly found in the open sea but can sometimes be spotted near the coasts.

A Great White Shark

Leopard Sharks (Triakis semifasciata)

Leopard Sharks are the most common species of shark found in San Francisco Bay. They measure around 2 m and weigh up to 40 kg. Its name comes from a striking pattern of dark spots on a grey or silver body.

Leopard sharks are usually seen near sandy areas where they dig for spoonworms. They also feed on crustaceans, bony fish, fish eggs, and shrimp.

They are wary and harmless to humans. They often swim away or bury themselves in the sand when disturbed or threatened.

Brown Smooth-hound Shark (Mustelus henlei)

The Brown smoothhound is a small species of shark found in San Francisco Bay. It is a small, slender shark boasting an elongated, rounded snout and enormous eyes.

These fascinating ocean dwellers display reddish-brown hues on their topsides, while the undersides exhibit off-white colors. The initial dorsal fin is triangular with frayed trailing margins to complete its distinct appearance. It typically measures around 1 m and weighs up to 7 kg.

These sharks prefer muddy, sandy, shallow waters. Depending on the season, they feed mainly on crabs, shrimps, squids, and small fish, such as herring, anchovies, and sardines.

Spiny Dogfish Shark (Squalus acanthias)

The spiny dogfish shark is a small species found in San Francisco Bay. It is easily recognizable by its long snout and two dorsal fins positioned far back on its body. These sharks typically measure 60-84 cm and weigh up to 10 kg. These sharks feed on small fish, crabs, squid, and other invertebrates like sea cucumbers and shrimp. They live in shallow waters or temperate waters and further offshore.

Soupfin Shark (Galeorhinus galeus)

The soupfin shark is a medium-sized species found in San Francisco Bay. It can be identified by its pointed, long snout and slender body. A distinctive identifier of the soupfin shark is an additional dorsal fin above its anal fin. This shark typically measures up to 1.8 m and weighs up to 25 kg. The soupfin shark consumes bony fish, squid, and small invertebrates. It is usually found in shallow waters but can be found further offshore during certain times of the year.

Broad nose Sevengill Shark

Found mainly in San Francisco Bay, the Broad nose Sevengill Shark stands out from other species due to its seven-gill slits. This is a key identifier for this medium-sized creature, as most sharks have just five gills – with only Hexanchiformes and six-gill saw sharks being exceptions. 

Boasting an impressively hefty, robust build and a broad head with a blunt nose, this shark is truly something to marvel at. Broad nose Sevengill Shark typically measures from 1.5 to 2.2 m and weighs up to 59 kg. 

It consumes octopuses, rays, other sharks, bony fishes, and carrion. It is usually found near the Golden Gate Bridge and Alcatraz Island, in shallow waters or the deep channels of bays, but the older ones can be found further offshore as far down as 446 feet (136 m).

Pacific Angel Shark (Squatina californica)

The Pacific angel shark is a unique species amongst the 23 known angel sharks, and its distinctive shape resembles that of skates or rays. Its wide pectoral fins and largemouth enable it to generate powerful suction forces when hunting for food.

Though angel sharks may appear like rays, a closer inspection of the pectoral fins will immediately help you differentiate. These appendages are always connected to the head on skates and rays, while in angel sharks and other flat sharks, this is never true.

This shark typically measures from 1 m to 1.2 m and weighs up to 27 kg. The Pacific Angel Shark feeds mainly on bony fish and eats squids in winter and early spring. They can be found in shallow waters near sandy areas in the Bay.

Pacific Sleeper Shark (Somniosus pacificus)

The Pacific Sleeper Shark is a large species in San Francisco Bay. This particular shark is identified by its heavy, cylindrical, grayish-brown body and two dorsal fins of equal size. Unlike other sharks, it lacks a frontal spine in both the top fins and an anal fin. These sharks typically measure about 3.65 m and weigh up to 363 kg.

The Pacific Sleeper Shark is known to be a pretty voracious eater. Its diet consists of bottom-dwelling teleost fish, soles, flounders, Alaska pollock and rockfishes, shrimps, hermit crabs, and marine snails. Moreover, it’s been observed that larger specimens also have an appetite for swifter prey, such as squids, Pacific salmon & harbor porpoises!

Pacific Sleeper Sharks live in deeper waters than the other species mentioned above. Although they seldom encounter people, these creatures can still pose a serious threat.

Salmon Shark (Lamna ditropis)

The salmon shark is a species of mackerel shark that lives in San Francisco Bay. The short, stout body and conical snout of the shark often lead to mistaken identity with the Great White Shark. These creatures boast a unique color pattern, ranging from deep navy to light grey and black on their back and white bellies speckled with dark spots. The salmon shark is a large species that typically measures up to 3 m and weighs up to 450 kg.

The primary diet of the Salmon Shark consists of Pacific salmon, hence their name. They also feed on smaller fish such as herring, sablefish, and walleye pollock. These sharks are usually found inshore to just off beaches in San Francisco Bay.

Basking Shark (Cetorhinus Maximus)

The Basking Shark is a giant shark found in San Francisco Bay. The basking shark is typically a grayish-brown hue with mottled accents. Its caudal fin has an exceptional lateral keel and crescent shape, while its teeth are minuscule yet abundant – usually one hundred per row! This shark can be up to 7.9 m long and weigh up to 5.2 tons! It feeds mainly on plankton and small crustaceans. Once the most abundant species in San Francisco Bay, its population has drastically diminished over the last few years.

Blue Shark (Prionace Glauca)

Gliding elegantly through the deep, blue sharks boast a mesmerizing light-bodied figure with long pectoral fins. Showcasing an exquisite contrast of colors, these apex predators are counter-shaded: dark blue on top and lighter from the sides to white underneath. It measures about 1.8 – 2.4 meters in length and weighs up to 52kg.

Despite its size, the blue shark is a timid species that poses no threat to humans. It feeds mainly on pelagic fish and other crustaceans. The blue shark is known for its long-distance migrations in search of cooler waters, meaning you may or may not spot it at the Bay.

Conclusion

The San Francisco Bay is home to various species of sharks, from the small Pacific Angel Shark to the large Basking Shark. Despite their differences in size and shape, all these creatures have one thing in common: they call the Bay their home. These Sharks play an integral role in keeping the marine ecosystem healthy.

Any environmental changes can cause serious harm to the Shark population, which is why it’s essential to be aware of how our actions affect them. By doing our part, we can ensure that these creatures continue to thrive and remain an integral part of San Francisco Bay for generations to come.