We have a lot of great progress at Mountain Lake to report.
Starting tomorrow, Science Saturdays will continue through October every second Saturday of the month from 2 to 3 pm.
Saturday, July 11 – Science Saturday at Mountain Lake
Saturday, July 11 is our next talk: Mussel Beach at Mountain Lake. Niveen Ismail of Stanford University will discuss how native mussels, soon to be reestablished at Mountain Lake, will help restore water quality. Her talk describes the results of her experiments at the lake and the potential these native bivalves have to remove pollutants and pathogens from the water. Click here for more information.
Saturday, July 18 – First Release of our Native Western Pond Turtles
We’re very excited to announce the first release of Western pond turtles will be on Saturday, July 18, at 12:30 pm. Find us near the benches on the south shore.
This will be a low-key event, probably no more than 20 minutes, but come join us if you’d like to be a part of this huge moment in the life of the lake. Our partners from Sonoma State, who collected the turtle eggs and hatched them, and from the San Francisco Zoo, who have been raising these turtles for us for the last two years, are very excited to share this moment too. We’re all hoping to give you a good, close look at the lake’s newest residents before we row them over to their new, west shore basking grounds.
Pacific Chorus Frogs and Three-spine Stickleback Fish
Reestablishment of native Pacific chorus frogs and three-spine stickleback fish began in April. We’re happy to report that in that time we’ve released more 600 frogs and 220 fish. We’ll continue to collect and release these two species throughout the summer. After decades of absence, it’s exciting to welcome these two species of animals back.
You may have noticed that the lake is bubbling! Last week we finished the installation of an aeration and water-mixing system. Air is being pumped through hoses to 12 locations around the lake. Before we get the lake’s aquatic plant communities rebooted, the lake is still vulnerable to unhealthy algae blooms. Algae thrive in the kind of high-nutrient, stagnant, low-oxygen waters that are characteristic of disturbed lakes. This new aeration system aims to keep blooms in check by mixing and adding oxygen to the water. Limiting algae also means that the waters will be clearer, creating better conditions for reestablishing submerged aquatic plants.
For more information about the Mountain Lake Enhancement project and volunteer opportunities, please visit our website or contact the Presidio Trust at (415) 561-5331.
Thanks so much for your continued support, and hope to see you at the lake!
Content courtesy of:
The Presidio Trust • 103 Montgomery Street, PO Box 29052 • San Francisco, CA 94129
Copyright © 2015 Presidio Trust, All rights reserved.
Science Saturdays at Mountain Lake – First of the Season – May 9th, 2PM-3PM
Returning Local Wildlife to Mountain Lake
with Jonathan Young, Presidio Trust Wildlife Ecologist
When: Saturday, May 9th, 2PM-3PM
Where: North Arm of Mountain Lake, (see map below)
Join wildlife ecologist Jonathan Young as he shows Pacific Chorus Frogs and the Three-spine Stickleback fish. Once eliminated from Mountain Lake by urban disturbances, scientists are now helping these two species make their long-awaited return to Mountain Lake. Ask Jonathan your questions about all of the cool wildlife in the Presidio.
Jonathan Young is a wildlife ecologist for the Presidio Trust. He began working in the Presidio as a habitat restoration volunteer in 2010. He then completed two ecological-based internships where he immersed himself in the local natural and cultural history. During this time, he completed a Master’s degree at San Francisco State University focused on amphibian conservation and disease ecology.
He is a contributing author for the Trust’s Wildlife Management Plan, and is leading the Park’s effort to reintroduce several species of local wildlife to Mountain Lake, including freshwater mussels, Pacific chorus frogs, three-spine stickleback fish, and western pond turtles.
Second Saturdays aren’t just Science Saturdays! Join your neighbors at Mountain Lake every Second Saturday from 9:00 am to noon for Service Saturdays. Volunteer and help restore Mountain Lake’s precious natural resources.
Join the Presidio Trust’s Wildlife Ecologist Jonathan Young for the very first reintroduction to Mountain Lake of a long-lost species of native fish. Three-spine stickleback, Mountain Lake’s only species of native fish, were wiped out of the Lake because of invasive species and habitat loss. Ecological restoration work over the last several years has led to this important moment: The lake is now healthy and clean enough for the stickleback to make their splashy return!
Wednesday, April 1st at 2:30pm
Near the east shore benches
Come see these cool, local fish up close! Ask Jonathan your questions about these amazing creatures and other park wildlife.
No RSVP required.
Contact Jason Lisenby at [email protected] or (415) 561-2709.
PS. If you cannot make this event, the Presidio Trust will be doing additional Mountain Lake reintroductions several more times throughout this summer (and beyond). These events will be announced or built into events like our popular Science Saturdays.
In a final effort to rid thousands of invasive fish from the Presidio’s historic Mountain Lake and make room for native species, biologists will use a standard fish-killing chemical called rotenone, park officials said this week.
The decision came after three years of netting, trapping, electric stunning and hand-capturing failed to empty the lake of scores of large alien carp, bass and sturgeon, in addition to at least 27,000 alien fingerlings.
For clearance to finish the job, officials have received permits from water quality agencies and local, state and federal regulators to use the short-lived chemical in single applications early next month, they said.
“The chemical only kills animals with gills — which means only fish — and before we can introduce the native species of wildlife we need to restore the lake, we must clean it of the species that never belonged there,” Michael Boland, the Presidio Trust’s projects chief, said at a public meeting in the Presidio’s observation building Thursday.
For more information, please refer to David Perlman’s article on SFGATE
Thanks to those who made it to our public meeting last Thursday.
Michael Boland led by outlining our vision for a healthy lake, in the context of the challenges we currently face. Folks were then invited to ask questions of some of our project partners, including experts and academic researchers who specialize in algae, amphibians, aquatic plants, invasive fish removal, outdoor education, water quality, and western pond turtles.
You’ve likely heard that we’re moving forward with our plan to use a botanical fish toxicant in the lake this November, because eradicating invasive fish is essential to restoring the lake to ecological health. We’ve set up a Fish Eradication Project webpage that offers more information: and please feel free to send me any questions too.
Another key component to revitalizing the lake is restoring its once vibrant and diverse aquatic plant communities. Aquatic plants will lock the nutrients now free-floating in the water in Mountain Lake into their shoots and roots. Without excess nutrients in the water column, algae cannot bloom out-of-control. That’s a benefit of aquatic plants in addition to their enormous value to wildlife as food and habitat. Very cool!
This Saturday, October 25th, you are invited to a demonstration where I will plant seeds for a species of local aquatic plant once found in the lake and since wiped out by the invasive carp. I think the whole process is very novel and engaging, so I wanted to extend an invitation to a short list of folks like you who have been interested and involved in improving the health of the lake.
Planting Aquatic Plants at Mountain Lake Saturday, October 25th,
Gather at the top of the steps to the beach
The process will be easy to observe from the trail, and you should feel free to bring little ones. I’ll offer a casual talk about our local aquatic plant species and their significance to the lake’s health. It may only take 15 minutes or so, depending on how many questions you all offer. I’ve also invited a colleague of mine to point out birds as well, and we’ll have some binoculars to share.
I hope to see you Saturday!
Biological Science Technician
Mountain Lake Update – Public Meeting
Invasive Fish Eradication and Future Restoration Plans
Thursday, October 16, 6:30 pm
The Observation Post, 211 Lincoln Boulevard
(adjacent to the Transit Center on the Presidio’s Main Post)
Join us for an informational “state of the lake” meeting to learn about upcoming plans for Mountain Lake. Presidio Trust staff will discuss the installation of an aeration system, plans for eradication of remaining invasive fish, planting Submerged Aquatic Vegetation (SAV), reintroduction of native plant and animal species, and restoration of the East Arm as a wetland.
Following the presentation, a panel of staff, project partners, and issue experts will answer questions.
More than 80 volunteers gathered in the rain on Saturday February 8 to plant at least 600 native plants in Mountain Lake Park and in the “north arm” of Mountain Lake.
The Presidio Trust has done extensive work to open up both the north and east arms of the lake. Both of these areas had become overgrown with invasive non-native plants such as Himalayan Blackberries and Eucalyptus.
For the first time in generations, a visitor can see all the way from the north end of the lake across the water to the park and houses to the south. A walk around the back road may surprise you!
The Presidio Trust has transitioned the Mountain Lake project from the “remediation” to the “restoration” phase. In the first stage, the lake was dredged to remove toxic materials and restore its depth. The so-called “east arm” and “north arm” were cleared of accumulated noxious plants and debris. In the second stage, the lake and two “arms” will be restored with native plants and, in the lake, native fauna.
Remediation of Mountain Lake
August – December 2013
As reported last month, the discovery of additional contaminated sediment in the bottom of the lake and around the North Arm will require an additional 3,100 cubic yards of materials be removed. In order to keep our commitment to complete remediation activities this year and to avoid working into the rainy season, dredging work hours will increase from a 12-hour work day, to a 18-hour work day, Monday – Friday. The new work schedule will generally be from 7 am to 1 am beginning on Monday, August 26 and is expected to last up to two months. Construction and trucking activities will remain limited to 8 am to 6 pm.
If you have any questions about the accelerated dredging schedule please contact the Presidio Trust at 415-561-5331. For more general information about the Mountain Lake Remediation and Enhancement projects, please visit.
Remediation of Mountain Lake
August – December 2013
December 2013 – Spring 2014
Equipment used for remediation will be removed. The staging area north of the lake and the east shore access route will be restored and planted with a mix of wetland and woodland species including oak, pine, willow and native shrubs.
Wetland Expansion and Tree Removals in East Arm
August – October 2013 Tree and Vegetation Removals
The Mountain Lake Enhancement Plan includes revitalization and wetland expansion of the East Arm of the lake, which has not been ecologically functional due to a history of disturbance and unchecked growth of invasive species. With mitigation funding from the San Francisco International Airport, the Presidio Trust will begin wetland expansion work in August 2013 by removing eucalyptus trees and understory vegetation from the bottom of the East Arm. This will open the area to improved air circulation, sunlight and views, and create rearing habitat for long-absent animal species that will be reintroduced to Mountain Lake. Preparation for the construction work will require equipment mobilization on West Pacific for one or two evenings in mid-August. The section of Park Trail through the golf course will be used as the primary haul route.
Summer 2014 Restoration and Enhancement
The Presidio Trust will remove years of accumulated sediment, and plant native wetland and riparian woodland species to create a larger and better-functioning wetland.
To ensure public safety, portions of Mountain Lake trail and Park trail will continue to be intermittently closed on weekdays to accommodate material hauling and other heavy construction activities. Mountain Lake Beach will be closed only when work is occurring in the lake.