Nearshore Resource Allocation Program

NRAP Focus Area Key Photo

Lake Tahoe’s nearshore is the portion of the lake that people interact with when viewing the lake from the shore, wading, swimming, enjoying paddle sports, and boating. In recent years, visitors and residents alike have perceived changes in the nearshore environment, with increased algae and general water quality decline being the most common concerns.

The Nearshore Resource Allocation Program (NRAP) directs nearshore science and monitoring investment through a systematic framework to better understand nearshore conditions and processes, and reduce uncertainty about management actions. The NRAP is structured around a series of environmental focus areas, each with unique conditions and challenges. Each focus area page provides a brief state-of-the-knowledge summary, descriptions of recent research findings, and links to applicable monitoring programs.

For more information regarding nearshore conditions at Lake Tahoe, please contact Robert Larsen with the Lahontan Water Board or Dan Segan at TRPA.

Focus Areas

Algae

Description: Anecdotal reports suggest the distribution and abundance of algae in Lake Tahoe’s nearshore environment has changed over the last fifty years. Perceived increases in both attached algae (periphyton) and floating algae (metaphyton) are primary concerns among resource managers, residents, and visitors.
NRAP Focus Area Key Photo

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Aquatic Invasive Species

Description: Aquatic invasive species such as thick growths of invasive aquatic weeds, clams, snails, and even warm water fish threaten waterways in a number of ways. Consequences of establishment include degradation of water quality, loss of important habitat to native species, impacts to water conveyance structures, and negative economic impacts to the Lake Tahoe Region.
NRAP Focus Area Key Photo

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Community Structure

Description: Community structure reflects the ecological conditions that affect diversity, distribution, and the interactions among producers and consumers able to survive in nearshore environment. Macroinvertebrates (including crayfish), fish, and macrophytes are visible aquatic organisms that interact to create the community structure representative of Lake Tahoe’s nearshore ecosystem. Detection of changes in this community structure can infer changes in the status of Lake Tahoe’s nearshore condition, which has changed over time as a consequence of changing patterns in land use, recreational activities, climate, species distributions, and other unidentified factors.
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Nearshore Clarity

Description: Nearshore clarity refers to the transparency or clearness of water in the nearshore. Both California and Nevada recognize the unique ecological and aesthetic values of the nearshore environment, and both have adopted standards to protect the beneficial use and water quality of the nearshore, including water clarity. Secchi disk transparency is measured in the pelagic zone of Lake Tahoe, but this approach does not work in the littoral (nearshore) zone where water depth is insufficient for the method. Instead, instrument measurements of turbidity and light transmissivity are used as metrics of nearshore clarity.
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Public Health

Description: Human interactions with nearshore waters are primarily associated with recreational activities and with consumption of treated and untreated waters drawn from the lake. The characteristics and quality of water used for consumption are regulated under separate state and U.S. EPA provisions. Existing state and local programs for tracking presence of harmful micro-organisms and toxic compounds serve as nearshore human health indicators. Ultra-oligotrophic lakes do not generally have issues with toxicity or harmful microorganisms, unless there are discharges of sewage or waste. Sewage and industrial discharges are not allowed into Lake Tahoe, although surface stormwater runoff to the lake from urban areas and some recreational activities could conceivably contribute toxic chemicals or pathogens.
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Trash

Description: While working to removed aquatic weeds, Marine Taxonomic Services Environmental Consulting collected underwater litter from September 21 - October 20, 2016. In 23 days, they removed 6,686.5 pounds of litter from 39.65 miles throughout Lake Tahoe. This included boat wreckage, cement blocks, construction materials, firework debris and 3,372 pieces of plastic. Of those, 219 were plastic bottle caps, 158 plastic cups and 1,145 cigarette butts.
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