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Delight Lake Weir Is Key to Sockeye Management

Delight Lake is not the easiest place to operate a salmon weir, but it provides key data that helps accurately count salmon.

by | August 2, 2022

The Kenai Mountains surround Delight Lake. Jacob Lohraff, CIAA

The Delight Lake Weir, operated by the Cook Inlet Aquaculture Association (CIAA), is located on the outer coast of the Kenai Peninsula within the Kenai Fjords National Park boundaries. Seasonal weir workers track the number of sockeye salmon that return to the lake, a measurement called “escapement.” Together with aerial surveys, these numbers help resource managers know the best time to open and close commercial fisheries. They also help set sustainable escapement goals.

In 2018, CIAA took over operation of the Delight Lake Weir from the  Alaska Department of Fish and Game (ADF&G). The state had operated a physical weir at Delight Lake from 1997­ to 2014. The state had conducted aerial surveys since the 1980s and had to close the weir in 2014 after its funding was cut.

The Problem with Aerial Surveys

Aerial surveys undercount actual salmon escapement by 30% to 50%. This can be seen in the graph below comparing weir count to aerial surveys at Delight Lake. This difference is due to multiple factors, including:

  • Delight Creek is short and covered by trees.
  • Sockeye salmon spawn deep in the lake and are undetectable during aerial surveys.
  • The weather makes observation difficult. On average Delight Lake sees almost 150 inches of precipitation a year.
This graph demonstrates the variability between aerial surveys vs weir counts at Delight Lake. CIAA

The Challenges at Delight Lake Weir

Every weir CIAA operates has its specific challenges and benefits for crews tasked with operating them throughout the season. Delight Lake is incredibly beautiful and unique from our other weir sites. It’s situated in a coastal temperate rainforest surrounded by towering spruce trees and a forest floor covered in moss. Most of the lake is surrounded by the steep Kenai Mountains. 

The largest challenge crews face at Delight Lake is dealing with the fluctuating water level. The lake is surrounded by steep mountains, which leads to quick water changes when it is raining. During setup this season, the water level rose over two feet in one day! With the rain and high water, fish moved quickly through the system from the ocean into the lake.

In some years, the crews struggle with low water conditions. This happened in both  2020 and 2021. It’s not uncommon for the water level to drop so much that the mouth of Delight Creek doesn’t reach the ocean, blocking the passage of salmon. If the fish are lucky they will be able to push into the freshwater lagoon during high tide. Sometimes, the fish can’t migrate from the freshwater lagoon to the creek because the water is too low. This can strand fish in the lagoon where temperatures can rise so high it can kill the salmon.

Aerial view of Delight Creek on July 6, 2021.  The creek is dry in two areas, which can be seen in this photo. Emily Heale, CIAA

How Delight Lake Weir Helps Fishermen

The Delight Lake Weir opens new commercial fishing opportunities. Along with Desire Lake, Delight Lake has wild salmon stocks found within the Outer District making it important for commercial, sport, and subsistence harvests. These lakes contribute to most of the commercial salmon catch within the East Nuka Bay Subdistrict.

Commercial fishing opportunities are split into different districts simplifying management for ADF&G; gear type and fishing openers and closures vary depending on district. As the 2022 counting season winds down, Delight Lake was one of the first adult weirs to close. This year the preliminary numbers are higher than the escapement goal for the lake.

This allowed the commercial fishery to open with few restrictions. This is good news for commercial, sport, and subsistence fishermen harvesting salmon that return to Delight Lake. There are a lot of fish to go around.

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