Lake Suffers Fish Die Off, Remains Safe

City staff and partners working diligently to remove any fish

Post Date:05/30/2018 4:50 PM

UPDATE: The fish die off ended on Thursday, May 31, 2018. City staff, EVMWD staff and other crews were able to successfully remove all fish within 24 hours. The total estimated size of the fish die off was 43 tons. 


For the last three days, Lake Elsinore has experienced a minor Threadfin Shad fish die-off. While the quantity of fish has steadily increased each day, the fish die off appears to be minor so far.

Fish die offs are nature’s way of re-balancing the fish population and can ultimately improve the overall health the lake and the vitality of the fishery.

Lake Elsinore’s fishery can become imbalanced due to an overpopulation of Threadfin Shad and/or Carp, which are both detrimental to our water quality and very sensitive to declines in dissolved oxygen levels.

Shad are small, highly sensitive fish that hinder the water quality by eating microscopic zooplankton, which are needed to consume and reduce algae.

City and water district crews have been working extremely hard for the last two days to remove all fish as quickly as possible.

The City asks that our community remain on high alert and notify us should you see fish in areas that are not being addressed.

Why Fish Die Offs Occur? 

Lake Elsinore is Southern California’s Largest Natural Freshwater Lake. It is reliant on rain and runoff. With water levels well below the optimal level, higher temperatures, and an abundance of shad and carp, the lake becomes extremely vulnerable to algae blooms and fish die offs.

In 2015, the City and the Lake Elsinore & San Jacinto Watershed Authority (LESJWA) launched Lake Watch to Proactively Preparing to Preserve and Protect Lake Elsinore. Since then, each year, the City prepares for challenges related to our beautiful, complex lake. 

Recently, the City has noticed an increase in Carp and Shad in the lake. This is a typical sign that Lake Elsinore’s fishery is imbalanced. Shad are small, highly sensitive fish that hinder the water quality by eating microscopic zooplankton, which consume algae. With Shad feeding on the zooplankton in the lake, there will likely be an algae bloom thus reducing dissolved oxygen. Such conditions, ultimately lead to the demise of this delicate fish. It is nature’s way to re-balance the fish population and improve the overall health and quality of the lake.

Since 2000, LEJSWA in coordination with its partner agencies has greatly improved water quality and wildlife habitats in Lake Elsinore, as well as in the surrounding watershed. Successful projects to date include the following:

  • Lake Elsinore Wetlands Enhancement Project
  • Lake Elsinore Carp Removal
  • Island Wells Pump Station Improvements
  • Striped Bass Stocking
  • Lake Elsinore Destratification & Mixing System
  • Recycled Water Nutrient Removal & Conveyance Pipeline
  • Lake Habitat Improvements

Despite these efforts, Lake Elsinore is a natural lake. The current conditions have created a poor ecological condition for the lake that is difficult to sustain. A fish kill is one of Nature’s way of re-balancing the food chain.

Lake Watch

As part of Lake Watch , this summer the City of Lake Elsinore is asking the community to continue to monitor the lake and notify the City should you notice anything abnormal such as dead fish floating in the lake or washed up on shore.

To report, please call 951-674-3124 ext. 204, email or message the City at

If a major fish kill takes place, community volunteers may be needed. 

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