Spineless Wonders of Lake Merritt

…or, more technically, invertebrates…

Lake Merritt is justly famous for the many species of birds that overwinter on the lake . The occasional appearance of a sea lion or river otter makes headlines but did you know that the lake is also home to a great variety of micro-charismatic critters?

The most obvious (and perhaps least charismatic?) are the mussels that line the edges of the lake. They stick out in a low tide. Gulls love to feed on them — you may often see a gull with one in its bill. Gulls will also deliberately drop a closed mussel onto the pavement to open the shell and get at the meaty interior. Take a look inside an open mussel shell and there you will find yet other organisms.

Mussel inside

Less obvious but more important for the food chain is the plankton in the lake. Plankton consists of tiny critters that one needs a microscope to see and can include diatoms, protozoans, small crustaceans, and the eggs and larval stages of larger animals. The Nature Center (when we reopen again!) has microscopes that school groups and other visitors can use to get an idea of the diversity of life in the lake.


The most “famous” invertebrate at the lake is a new kind of beach hopper discovered many years ago by a 14 year old boy, Jim Carlson, who went to great lengths to find out what it was.  (You can find his story at Bay Nature Magazine). Like most of the rest of the lake’s flora and fauna this “bug” probably was introduced on the hull of a ship. No one could identify this critter and it turned out to be a new species dubbed Transorchestia enigmatica. These beach hoppers may still be present on the small stretch of remaining beach near the bandstand. See if you can find one. You’ll find a more typical species of beach hopper along the channel.


My all time favorite invertebrate — seen at the lake back in 2015 — was a family of sea hares hanging out under the pedestrian bridge. Sea hares are related to octopuses and can eject a stream of ink to hide from potential predators.

Sea hare

Take a walk around the lake at low tide and see what you can find in the water.

— Dianne

Lake Merritt Advocates

A couple weeks ago (November 13th, 2017), our group joined a whole slew of other groups who exist around the lake at the Lawn Bowling clubhouse to learn about each other and how we can support each other. This included people from some of the institutions around the lake: The Gardens, Fairyland, the Camron-Sanford House; there were environmental advocates from Lake Merritt Institute, Audubon, Laney College. There was the Lake Merritt Breakfast Club, Lake Merritt Band, and the Lake Merritt runners, city employees, and interested citizens.

We were all a little amazed that there were so many groupsLakeMerritt.org the creation of a an individual originally interested in showing off his awesome photography, but grew to be a resource for all the goings on at the lake. This will be our — the Lake Merritt Advocates — hub, the place you can find to find a fun event, or a volunteer activity. We’ll be sharing our opportunities there as well.

We hope that the advocates as a whole will provide a place where we can share larger concerns, and work together with the City and their departments to make the Lake that much more of a great place to be.

Where have the Eared Grebe’s gone?

One of my favorite winter residents of the lake is the Eared Grebe. It’s a small diving water bird (most closely related to Flamingos) that is flightless much of the year. The males turn into demonic looking birds just before they head out for mating season in the Spring. If your lucky, you can also sometimes glimpse their forays underwater. Their favorite food seems to be the the Bay Pipefish which seem to provide the grebes a run for their money.

The pipefish seem to be getting a reprieve this year with no Eared Grebe’s in their “traditional” hunting grounds (aka the spots I’ve seen them in over the past few years). I had seen one Eared Grebe on the lake near the bird islands earlier this year, but I have not seen it since. Things have been left to the Pied-billed Grebes, an equally cute species but which seems to mostly confine itself to the the refuge area on the northern side of the lake. Eared Grebes in my observations have favorite spots dotted around the lake. Last year, I’d remarked a trio showing up by the pedestrian bridge at the Southern end of the lake in early October where they could be reliably found for months after.

There seems to have been some e-Bird sitings over the last couple of days, so perhaps they are still to arrive. I did note, however, the week they arrived last year would have coincided with the fires in Sonoma and Napa. With the air quality so bad, I wonder if the birds thought better of flight, and decided to stick it out where they are. According to my Bay Area Birds (David Lukas, 2012), Eared Grebe’s make great use of the South Bay Salt Ponds, and nest down in the Hayward.

Data in my various sources of citizen science data (iNaturalist and eBird) seems too thin to make any kind of call on that hypothesis. And at the end of the day, I hope they still show up.


Lake Spot: the Rocky Shore

A couple of years ago they finished the shoreline from the Boating Center up to the Geodesic dome. There’s a nice wide path, some benches looking over the lake, and new landscaping around the parking lot, and a healthy bit of shoreline between the path and water. It can be a good spot to see the comings of goings of birds and boats if you are so inclined.

Parts of the shoreline are still fenced off — letting plants get situated and take good root, I presume, there is a path of old rip wrap and stone set on dirt where one can sit at the shoreline and take it in.

I found myself there the other day on a lovely fall day, I unintentionally flushed a Green Heron from the bank. It did my the favor of sitting on a white float for a few minutes, a rare chance to hang out with the most elusive heron of the lake.

I’d passed a Great Blue Heron earlier in the day sitting in shallow water seemingly unconcerned by the humans stopping to goggle at it. It seems like it is the only Great Blue on the lake but it is often out in the open. Great Egrets and Snowy Egrets come in bunches and are hard to miss, and one can often find a Snowy Egret right at your feet as it forages the edges of the lake.

The Green Heron seems more secretive and has a rather narrow range on the lake (all the iNaturalist observations are in the Northern part of the Lake, though I’ve it a time or two further west).

The little heron flew on a few minutes later, and I settled in to watch a sparrow — before I was graced with a final visit from a White Pelican, flying not too far overhead.

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Oakland Autumn Lights Festival

In just a couple days, the Lake Merritt Garden will be opening up for its annual Autumn Lights Festival. Community for Lake Merritt is helping out the Pollinator Posse with a butterfly themed exhibit in the pollinator garden.

We’ll also be having a little UV light critter hunt — no live critters — but some exemplars of cooly lit local California fauna.

The festival is Thu, Fri, and Sat, October 19-21, 6-11pm. Make sure to get tickets in advance, it does sell out. The even is rain or shine.



Freedom to Roam!

2017 - 1 (1)At long last, the 10th street bridge and pedestrian paths underneath are complete. It has been quite some time in the making. The bridge opened to traffic earlier in the year, but the paths opened sometime in early to mid October. It was a nice feeling to be able to bike nearly alway down the channel without crossing a road.

There’s already been a bunch of tagging, but we can hope that the city is maybe planning for a mural or two along those walls. I’m sure Laney college has enough talent to share.

Rotary Nature Center: Opening This Fall (2018)

Updated – Jan 1st, 2019: the Center will have a grand opening Saturday February 16, 2019.

If you’ve been by the Rotary Nature Center in the last year, you will have noticed that the Center has been closed. The building is undergoing inspection and assessment, and a planning process to reopen it. Animals and the bees have been relocated from the building.

Good News: The Oakland Parks, Recreation, & Youth Development department is accepting program proposals for a reopened Rotary Nature Center. The city held a series of meeting with the community this spring and summer of 2018. This meeting was led by facilitator Alan Briskin along with a small committee including CJ Hirschfield of Fairyland, Jennie Gerard of Weed Warriors, and James Robinson of LMI.

11 proposals were submitted before the last meeting, and 5 were discussed at the meeting (and a 6th was accepted as well). The proposals were great and we look forward to helping to see them fulfilled. Karis Griffin said that the center would open sometime this summer.

Recent news (mid July) from the core committee tells us that the opening is now in the fall.

You can dig into the proposals here.

In the meantime, the Oakland Capital Improvement Program is an additional place we might be able to get funds. They are holding meetings in June to gather feedback on their process and priorities.

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