What Lives at the Bottom of the Puget Sound?

Written by Kristin Hitchcock
Updated: July 28, 2023
© Greg Amptman/Shutterstock.com
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Key Points:

  • Puget Sound is a unique and diverse ecosystem.
  • While it is connected to the sea, it also possesses distinct characteristics that set it apart. This combination allows for a variety of habitats and supports a wide array of life.
  • In Puget Sound, you’ll find mostly bottom-dwellers such as oysters and octopuses.

The Puget Sound is a system of interconnected marine waterways and basins. This provides lots of habitat for animals, supporting a diversity of life. You’ll find tons of different animals at the bottom of Puget Sound for this reason.

The sediments at the bottom of Puget Sound offer refuge for bottom-dwellers like oysters and octopuses. You’ll also find an array of underwater plants, like kelp. However, Puget Sound also offers a host of other mysteries to unlock if you look a bit closer.

Interesting Facts

  • The Puget Sound region formed when several microcontinents collided and attached together. Later, glaciers shaped the region further.
  • The Puget Sound has a surface area of 1,020 square miles and a shoreline length of 1,332 miles. It also includes more than 200 islands. It would take 18 days to walk the whole shoreline.
  • The sound is home to many species, including 3,000 invertebrates and over 200 fish species. Dozens of birds and marine mammals also call the sound home.
  • Puget Sound is home to the world’s largest octopus species, the giant Pacific octopus. This species can reach over 150 pounds and have an arm span of up to 20 feet. In the 1960s, the sound used to host the annual World Championship of Underwater Octopus Wrestling, which is exactly what it sounds like.

What is Puget Sound?

Kayaks in Puget Sound waters with skyline and cityscape of Seattle, WA in background.
Puget Sound is part of the Salish Sea and an inlet of the Pacific Ocean.


You’ve probably heard of Puget Sound. However, what exactly this sound is can be complicated.

A sound is a smaller body of water that is connected to a larger sea or ocean. It can refer to an inlet wider than a fjord but deeper than a bight. It may also be a narrow sea or ocean channel between two bodies of land. (Who thought there were so many ways to talk about bodies of water?)

Puget Sound is an inlet of the Pacific Ocean and part of the Salish Sea. It’s located along the northwestern coast of Washington state in the U.S. The marine waterways and basins are interconnected in a complex system. In fact, it has one major and two minor connections to the open Pacific Ocean.

It stretches about 100 miles from Deception Pass to Olympia. On average, its depth is 450 feet, though its maximum depth is closer to 1000 feet.

At present, Puget Sound ranks as the second-largest estuary in the United States, following Chesapeake Bay.

Why is Puget Sound So Deep?

Puget Sound was formed partially by glacial erosion. In other words, a glacier pushed through the area during the last ice age, cutting through the land. This glacier carved out the coast and then melted after the ice age ended, which left a deep gap in the land. The sea then flooded the basin, leaving us with Puget Sound.

Glaciers are huge fortresses of ice that are basically unstoppable. They cut through the land like butter. Therefore, they are able to leave very huge basins.

What Lives at the Bottom of Puget Sound?

A view of Mount Rainier across the Puget Sound.
Puget Sound is named after Peter Puget, a Huguenot lieutenant.


Puget Sound is a complex ecosystem of life. It’s part of the sea, but also not part of the sea. Therefore, it hosts a wide range of different habitats and life.

On the very bottom of the Puget Sound, you’ll find lots of sediments. These sediments may not look like much, but they provide a habitat for many different animals. (As it turns out, a lot of animals evolved to live in dirt.)

These animals include things like oysters, octopuses, sea urchins, clams, crabs, and sea stars. The area is known for its high population of Dungeness crabs, in particular. These animals just live in the sediment, though they also improve the surrounding water for other species.

They play a key role in releasing nutrients and controlling pollution. Plus, many animals eat them, making them a key part of the marine food web. Many of these invertebrates also provide a source of income and food for people.

Besides invertebrates, you’ll also find a range of underwater plants at the bottom of Puget Sound. These plants include kelp and eelgrass, for the most part. These underwater plants provide shelter, food, and spawning grounds for various animals. In fact, they’re part of the life of most species in the area.

Kelp are a very large type of seagrass that tends to form thick forests in Puget Sound. They can support many different animals, including crabs, snails, birds, and sea otters. They’re both a source of food and a reliable hiding spot.

Eelgrass is a smaller type of seagrass known for its flowers. They often grow in soft sediments in shallower water, while kelp grows in deeper waters and rockier sediment.

Eelgrass is used as a nursery by many fish species. It provides a place for smaller fish to hide until they are large enough to venture into open water. They also stabilize sediments and prevent erosion.

Rare Animals of Puget Sound

1. Chinook Salmon

Chinook salmon has a long, tapered body with a blue-green back, a silver sheen on their sides, and a white belly.
The highly-prized Chinook Salmon is one of the fish species that lives at the bottom of the Puget Sound.

©Kevin Cass/Shutterstock.com

Chinook Salmon are some of the most prized salmon that live in the Pacific. They’re commonly called blackmouth salmon or king salmon (on account of their size). However, they are endangered in Puget Sound, largely due to overfishing and habitat loss.

The Salish Sea Chinook’s population has declined by 60% since tracking began in 1984. However, the salmon population has been stable since 2002, though there was a decrease in salmon that returned to spawn over the last few years.

Of course, fewer salmon breeding means fewer babies. Therefore, the salmon population is expected to drop again soon.

2. Tufted Puffin

It’s rare to see, but the tufted puffin is one of the Puget Sound animal residents.

©Alan D. Wilson / Creative Commons

The tufted puffin is another species that are important to the Puget Sound ecosystem but is also quite rare. These colorful seabirds have yellow tufts on their head, which is how they got their name.

They’re becoming endangered in Puget Sound for several reasons, including human disturbances, oil spills, and reduced food availability. Currently, researchers are concerned that the area may lose the tufted puffin altogether.

3. Sixgill Shark

A close-up of a Sixgill Shark.
The ancient sixgill shark lives deep at the bottom of the sound.

©Greg Amptman/Shutterstock.com

These large, ancient sharks have (unsurprisingly) six gills. They live in the very deep water of Puget Sound, where they feed on squids, crabs, and fish. These sharks can tolerate a low salt level in their water, allowing them to live in Puget Sound.

They do not prey upon humans, though they do have plenty of teeth. Sixgill sharks live very deep, though, so seeing them is extremely rare.

4. Orca

The animals of Puget Sound include orcas, also known as killer whales.


Orcas are known to swim in every ocean on Earth. Therefore, it’s not surprising that they have ended up in Puget Sound, too.

There are three main types of orcas that live in Puget Sound: resident, transient, and offshore. While these three types are very similar, they eat different foods, which has led to different behaviors.

Resident orcas consume mostly fish (particularly salmon). They are divided into two groups based on location: southern and northern. The southern group is endangered due to pollution, prey depletion, and noise. There are about 75 individuals left today.

Offshore orcas are rarely seen. They eat mostly sharks and other fish. Transient orcas are much more elusive and feed on mostly marine mammals, like seals.

While each type of orca has different behaviors and populations, seeing any of them is pretty rare.

5. Marbled Murrelet

Small seabirds with brown-marbled feathers known as marbled murrelets live near Puget Sound.

©John Yunker/Shutterstock.com

Marbled murrelets are small seabirds that grow brown-marbled feathers during the breeding season. They mostly nest in old-growth forests near marine waters, eating various small fish and invertebrates.

These birds are a bit picky about where they settle. Therefore, with the loss of old forests, their populations have declined. Decreases in local fish populations may also affect their populations.

Currently, studies on the species’ diet are underway, which may help researchers determine if lowering fish populations is affecting them.

Where is the Puget Sound Located on a Map?

Puget Sound can be found along the northwestern coast of the U.S. state of Washington. It is an inlet of the Pacific Ocean and forms part of the Salish Sea. This water body is a significant sound in the Pacific Northwest region.

Here is the Puget Sound on a map:

The Featured Image

A close-up of a Sixgill Shark.
A close-up of a Sixgill Shark.
© Greg Amptman/Shutterstock.com

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