Let’s visit Richardson Bay

Richardson Bay is located to the north of San Francisco.

You may wonder why someone in Ireland is talking about a bay in America.

But it is very important that we understand how other areas of the world operate when it comes to helping our ocean.

Richardson Bay is a shallow inlet with two stories to be told—one of man and one of nature.

On the western side of the bay, you will find several marinas and harbours, whilst the eastern side is a quiet affair with mudflats and large properties overlooking the Bay.

One thing that struck me was how urbanised the bay was; humans have placed their stamp, but yet the area is renowned for its wildlife.

I was excited to learn about the relationship between humans and nature here, and why it has allowed both to thrive, or perhaps "thrive" is the wrong term.

So firstly, who looks after the Bay? There are a couple of organisations that play an active role in the Bay's management.

The first is the government body, known as the Richardson Bay Regional Agency, which is the overarching local government agency.

You will also find the Richardson Bay Audubon Center & Sanctuary, which is responsible for looking after 900 acres of the subtidal habitat.

The Sanctuary operates out of a beautiful yellow Victorian building, which was actually built on the far side of the bay.

The building fell into disrepair after an earthquake and was transported across the bay via barge to be restored. What a sight that would have been.

But how did they end up owning the area?

In 1957, the shore was purchased to prevent the bay from becoming a large marina, which was the result of campaigning by various people and donations.

The National Audubon Society then offered to manage the new sanctuary.

Part of Richardson Bay was now protected for the foreseeable future—a great achievement for all involved.

We have talked about who manages the bay, but why should this Bay be protected? What resides in the bay that makes it so special?

I mentioned the presence of mudflats earlier, and as I have said before in other blogs and podcasts—mud is pretty amazing.

I should have dedicated my life to studying mud, actually. Anyway, no time for epiphanies…

In reference to the shape of the coastline, bays like this offer mud a home; i.e., particles floating about in the water need to settle down eventually, and this happens somewhere sheltered.

Over time, this mud builds up, creating a flat surface which the tide can wash over as it pleases.

The result is a beautiful mudflat, full of life, which might surprise you.

From a distance, mudflats may look barren, but get a bit closer and you will find everything from worms to shellfish to plants.

Mud provides a home for a variety of life.

The animals that find refuge in the mud are not safe all the time, and this is where the food web expands.

Birds have evolved to hunt in mudflats for shellfish and crustaceans, and these birds are known as waders.

They normally, but not always, have long legs and bills, adapted to help them hunt in the shallow waters.

So we understand Richardson Bay is a vital home to animals and provides food for some birds.

This makes it of interest to birds that obtain high air miles, but without the carbon emissions.

These are migrating birds, normally travelling to or from the place they breed in order to take refuge from harsh weather or find a reliable source of food.

And this is why Richardson Bay is a vital stopover point in the Pacific Flyway.

This is a critical migration route for birds travelling between North and South America.

We have talked about birds and shellfish so far, but what about the plants you find on the mudflats? I never see any.

That is a fair point, but in Richardson Bay, a plant lives just below the water called Zostera marina, a species of seagrass known as Common Eelgrass.

Eelgrass is great for storing carbon and is also a food source for some birds, such as geese.

How is it good for storing carbon? Do you remember I mentioned particles floating in the water looking for a nice sheltered area to call home?

Common eelgrass provides a nice sheltered area between the lush blades of grass and their roots (known as rhizomes).

These particles are normally known as organic matter (small parts of plants, dead animals, faeces), which contain carbon.

If these particles were subject to decomposition, they would release carbon into the atmosphere.

But as these particles get locked away into the seabed, or mud, they do not decompose.

Instead, the carbon lies there for a long time until it is released or disturbed.

This is what we call blue carbon sequestration, or simply blue carbon storage.

The "blue" simply refers to the fact this process is taking place in the marine or coastal environment, rather than on land.

This same ‘locking away’ mechanism also helps stabilise the shoreline, reducing erosion or accretion (the build-up of sediment) in the area.

The blades of grass also provide a welcoming habitat for juvenile fish species.

The fish enjoy hanging out in the 3D structure created by the grass, which makes them feel safe until they are ready to venture out into the big bad ocean.

Species of note in the bay are the Pacific Herring, which lay their eggs (called roe) on the eelgrass, which also provides a valuable food source for birds.

The spawning herring also coincides nicely with the arrival of wintering birds, which is a great example of the complex food web at work.

Now, sustainable fishing practices is another topic I could delve into, but I will park it for now. It’s important to highlight the need for lush green seagrass beds to support fisheries in the first place.

Hopefully, I have explained why Richardson Bay is a unique paradise for wildlife, but now we must talk about the human relationship with the Bay—what are the main problems and what can be done?

Let's start with birds.

Aramburu Island is located across the bay from the Richardson Bay Audubon Sanctuary HQ.

The island formed from dredge spoils, which were deposited from channel maintenance and construction.

That’s ironic because now it’s a key habitat for birds in the bay.

So much so, it saved the lives of birds during an oil spill in 2007, as it provided clean refuge whilst the rest of the bay was contaminated.

Anyway, until recently, the island was left unmanaged, falling victim to erosion and invasive species.

An Enhancement Plan for the island was published and construction was completed in 2012.

Here are some of the habitats created or restored on the Island:

• Tidal Marshes are at risk due to coastal squeeze. This is when coastal habitats get squeezed between human development and rising sea levels. This habitat was created on the north and south ends of the island.

  
  

• Native saltgrass meadows were created along the shore. These plant species are adapted to cope with saltier conditions, and some birds prefer nesting in grassy areas.

  
  

• A new beach was introduced, which provided a roosting area for bird species such as terns. Groynes were also placed along the beach to hold the sand in place and reduce the rate of erosion on the exposed side of the island.

  
  

• A deep-water channel was constructed to provide access to harbour seal haul-out sites. Seals use these sites to raise their young or moult (replace their fur).

The island has been a success for the local wildlife.

But it required a serious amount of volunteering—over 1060 hours.

It is also not a finished project; it will take continuous work to maintain the habitats, remove invasive species, and monitor bird populations as well.

This is a reminder that there is a labour of love element to projects like this.

There are also measures to protect the area of the bay looked after by the Audubon Society.

The area is closed between October and March to boat traffic and water users to provide a safe place for waterbirds.

The Audubon Society suggests one vessel passing through the sanctuary can disturb up to 20,000 birds, mainly sea ducks.

Constant disturbance reduces the energy for migrating birds, who have a long way to travel, and reduces their chance of survival.

So we have talked about helping birds on the shore, but it’s now time to get our feet wet.

Let me return to the common eelgrass.

Until recently, eelgrass was only protected in the sanctuary in Richardson Bay. The main risk being from anchoring boats (I will explain the problem below).

However, the need for protection quickly grew as anchored boats were moving into the shallower waters.

This problem of anchoring on seagrass meadows is not unique to Richardson Bay.

This is because sheltered bays are ideal for anchoring boats, and also for seagrass beds!

What is the problem, I hear you ask?

As boats are at anchor, their chain lies along the seabed.

But when the boat swings around the anchor in response to the wind or tide, the anchor scrapes away any habitats on the seabed, such as seagrass.

Drone footage provides great visuals of this, as you can see the circles of barren seabed around the boats from the air.

In comes the introduction of the Eelgrass Protection Zone, which came into effect in 2024.

As part of this protection zone, new laws were passed to prevent anchoring in specific areas of the bay.

This 700-acre protection zone is in addition to the 900-acre sanctuary area on the east side of the bay, which already did not permit anchoring.

Upon reading about these boats using the area for anchoring, known as ‘anchor-outs’, it is clear there is a social and economic problem in Richardson Bay.

Let’s just say there is a strong contrast in the images of the rundown boats where the anchor-outs reside with the large beachfront properties in the background.

A temporary anchoring field was to be provided for the anchor-outs to allow transition; however, this was scrapped.

These boats are anchored here on a near-permanent basis as a form of residence, rather than a temporary nature.

The residents of these boats have nowhere else to reside, and most of the boats are in a bad state of repair.

It should be noted that anchor chains can be altered to reduce the scouring on the seabed by adding floats to the chain.

So, as it stands, it appears that the agenda is to remove these boats after finding alternative accommodation for the boat owners.

From the perspective of the ‘anchor-outs’ in Richardson Bay, the freedom of the ocean is slowly disappearing around the coast and regulation and governance are closing in.

I am all for the environmental work, but like I say, social work is also required here by the looks of things, which is a key pillar of sustainability.

It will be interesting to see how 1) the eelgrass beds recover and 2) what happens to the anchor-outs of Richardson Bay.

Nonetheless, Richardson Bay is an interesting case of environmental protection in the face of a heavily urbanised and busy coastline.

Reading about the benefits of mudflats reminded me of Strangford Lough.

When comparing these two areas, despite being oceans apart, provide similar ecological value.

Albeit Strangford Lough is less urbanised than San Francisco.

The pressure facing Richardson Bay is intense and lessons should be noted for managing areas yet to be subject to urbanisation.

But critically, there is a strong community supporting the protection of Richardson Bay, placing it in good hands.

Like I said mud is amazing and we must look after it.

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