Mono Lake Snapshot: Spring, 1998
Mono Lake is rising, and many changes are taking place. In this article, and subsequent Newsletter issues, we will try to convey a snapshot of the changes being observed at Mono Lake, along the rewatered streams, and in the lives of people living and working in the Mono Basin. Across the basin, these changes offer exciting opportunities to learn more about restoration.Changing shoreline
The recent wet winters have brought Mono Lake up an astounding nine feet since the State Water Board issued its decision in 1994. Probably the most noticeable result is change along the lake's shoreline. The rising lake is inundating vegetation, cutting new beachlines, and surrounding dusty tufa towers with water. Salt grass and rabbitbrush wave under water instead of in the wind. New berms and shallow lagoons are building, most prominently along Mono's southeastern and northeastern shores, a result of the combined dynamics of prevailing winds, lake currents, and sediment supply.
At the mouth of Rush Creek, a large bay now extends upstream mixing salt water with fresh. The bay, or "ria," is one of the new features of a restored Mono Lake. As Mono Lake fell, Rush Creek incised its channel--up to 25 feet at its lower end. At the stream's mouth, this canyon now creates a protected bay where lake water and stream water first meet. The fresh water quickly becomes saline, but it remains fresher and lighter than the lake's hypersaline water for a while, floating at the surface and creating a phenomenon known as hypopycnal stratification.
And tufa towers! The tufa-scape at Mono Lake is changing. As Gary Nelson wrote in the Winter 1998 Newsletter, some of the towers have fallen, undercut by the rising lake. Others, formerly stranded on land, now are now knee-deep in Mono's reflective water.
New habitats
Submerged vegetation provides a new substrate for the versatile alkali fly and its pupae. As the lake rises, and for sometime thereafter, this new substrate will be available to the flies. Ongoing monitoring will indicate how this new substrate plays a role in the lives of alkali flies at Mono Lake.
Last fall, on their migration south, eared grebes fell from the skies. Grebe "fallouts" are not unheard-of, and once this duck-like bird is on land, it is unable to take off again. No one really knows why so many became "beached" last fall; all we could do was put the birds we found back into the lake. An interesting grebe fact: Recent aerial surveys have shown that grebe numbers at Mono Lake have probably been underestimated for years. The total count is now estimated to be almost two million birds!
Gull researchers wonder whether the gulls will recolonize Negit Island this season. The gulls abandoned Negit in 1979, when coyotes first crossed the landbridge exposed by the falling lake. Last year, the landbridge was resubmerged, but no gulls were found nesting on Negit. Researchers wonder: how long will it take for gulls to recolonize former haunts? We'll watch for them in 1998.
Meromixis
Mono's water is changing too. As happened in the 1980s, large inflows of freshwater due to several wet winters have stratified the lake year-round. Typically, temperature and salinity differences cause the lake to stratify during the summer months, while cooling of the water in the fall causes the lake to mix completely from top to bottom. This mixing brings nutrients from the lake's lower levels to the surface waters. For the last two years, Mono Lake has not mixed thoroughly, and the lake has entered a state of chemical stratification, or "meromixis." Whether and to what degree meromixis will affect the lake's productivity are important questions we all are interested in.
Mono Basin streams
| Even as we wait for a State
Water Board decision on restoration at Mono Lake,
the streams are running and life along them is
coming back. The 1994 Water Board decision set
minimum and peak streamflows, which, thanks to
the series of wet winters, have provided healthy
flows in the streams (and one astonishing 80-year
flood event in January 1997). Along Lee Vining Creek, cottonwoods planted under court-ordered interim restoration in 1993 now stand up to 12 feet tall. Stream channels opened in the mid-1990s have significantly raised the water tables in certain sections of the bottomlands. Nonetheless, Lee Vining Creek, hard hit in the past by diversions compounded by fire and flood, remains in many places blown-out and shallow, lacking soils adequate to support vegetation. Scientists project that Lee Vining Creek will take far longer than Rush Creek to restore. Portions of Rush Creek are showing great promise. In October 1995, workers reopened a side channel (Channel 10) in the heart of Rush Creek's bottomlands. Two years later, ducks and fish were seen enjoying the deep, slow water. The aquatic plant Elodea had reestablished itself in many places along the channel, a sign of good water velocity and substrate. Other natural channels in the bottomlands, still dry, await rewatering. And the fish are there too. We've seen them hiding in the deep water. So did the osprey, we presume, who was hovering overhead. |
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Land management
"We're just trying to deal with it as it comes," says Janet Carle, ranger for the Tufa State Reserve, who's out there making changes in operations to keep up with the rising lake. By late winter, six or seven sections of County Park's wood boardwalk were floating in the lake, making it problematic to remove. The land area at South Tufa is shrinking, presenting a crowd-management challenge. So far, the South Tufa trail has had to be rerouted at least two times over the last two years.
Tufa Reserve staff have always vigorously discouraged boaters' disturbance of the tall tufa out in the lake where in recent years an osprey has nested. With the lake surface rising, they wonder, will the osprey still find the tower a safe place? We'll see.
Return to Spring-Summer 1998 Newsletter
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