Lower Cook Inlet Management Area
Anchor River Weirs
Weirs are installed on the South and North forks of the Anchor River by mid-May to monitor the returning king salmon run. The North Fork is a smaller drainage with lower flows in the spring, allowing for a floating resistance board weir with an underwater video system to be installed right away. The larger South Fork typically requires the use of a sonar through the end of May when flows subside and allow for a floating video weir to also be installed on that fork. The video weirs use DVR technology to record a video each time motion is triggered by a fish swimming through the passage chute. Video quality is good enough that species are easily identified.
The Anchor River king salmon escapement has been monitored by weirs since 2003 and was monitored by aerial survey beginning in the 1960s. Weir escapements have ranged from a low of 2,499 in 2014, to a high of 12,016 in 2004. The escapement counts, harvest data from the SWHS, and the age, sex, and length composition data collected during biological sampling are used to assess productivity of the stock. The Sustainable Escapement Goal for the stock is assessed every 3 years using spawner-recruit analysis. The current escapement goal (3,800 to 7,600) has been in place since 2016. The king salmon run typically peaks in mid to late-June, but lasts from mid-May through early August. King salmon in the Anchor River and other lower Kenai Peninsula streams spend 1 year as juveniles in freshwater and 1 to 4 years in saltwater before spawning. Here’s a link to our most recently published Anchor River report.
Coho salmon have been monitored via weir on the Anchor River periodically since the late 80s, including 2004-2011 and 2020-2021. Escapements have ranged from 2,246 to 20,187 fish. There is not currently an escapement goal for the Anchor River coho salmon stock. Anchor River Coho Salmon typically spend 2 years rearing in freshwater and 1 year in saltwater before spawning.
Steelhead have been monitored intermittently on the Anchor River, and the average annual run size is believed to be about 1,000 fish. The only complete weir count occurred in 2020 with a total count of 552 steelhead, although one previous incomplete weir count was about 1,200 steelhead. Steelhead begin entering these streams in early August, but peak run timing occurs between mid-September and early-October. Steelhead that are returning to spawn in these rivers for the first time are typically 20 to 25 inches long, while steelhead that are on their third or fourth spawning trip can be greater than 34 inches in these streams. Steelhead spend the winter in the river, spawn in the spring, and migrate back to the ocean after spawning as “kelts”. More than 500 kelts have been counted some springs through the weirs set up to monitor Chinook salmon on the Ninilchik River and the North Fork of the Anchor River.
Ninilchik River Chinook Salmon Escapement
Ninilchik River Chinook salmon escapement was counted by aerial survey from the 1960s until the broodstock collection weir began also monitoring escapement in 1999. Chinook salmon escapement is currently monitored at the broodstock collection weir (river mile 5) and at a downstream weir (river mile 2) using instream video technology. The current escapement goal of 750 – 1,300 wild Chinook salmon is based on counts at the broodstock weir. Approximately 15% of the wild Chinook salmon spawn between the two weirs based on count comparisons while operating both. The high video quality in the instream video monitoring easily allows for identification of the presence or absence of the adipose fin, allowing weir counts to be differentiated by wild and hatchery.
Chinook Salmon Broodstock Collection and Stocking
Every year, Ninilchik River adult Chinook salmon are collected and spawned at the broodstock collection weir in order to provide the next generation of smolt to be stocked into the Ninilchik River and to stock the terminal fisheries in the Nick Dudiak Fishing Lagoon on the Homer Spit and Seldovia Lagoon across Kachemak Bay. Chinook salmon are collected and held at the weir until they’re ripe for spawning. Wild Chinook salmon are not held until the wild escapement goal has been met, and all hatchery Chinook salmon are held at the weir in order to reduce the hatchery contribution to the escapement. Egg takes typically occur the last two weeks of July and first week of August, when Chinook salmon are naturally ripe and ready to spawn.
Ninilchik River Supplementation
The Ninilchik River has been supplemented with hatchery Chinook salmon smolt since 1987. Only wild Ninilchik River Chinook salmon are used to create smolt to re-stock the Ninilchik River. The eggs are reared over the winter in the William Jack Hernandez Sport Fish Hatchery on Ship Creek in Anchorage, and are stocked the following summer in the Ninilchik River. Smolt are stocked at a location upstream of the broodstock collection weir in mid-June, which is the same time that wild juvenile Chinook salmon become smolt and outmigrate from the system. The number of smolt stocked into the river has varied over the years, but is currently at approximately 150,000.
Kachemak Bay Saltwater Stocking
The hatchery Chinook salmon that are collected at the Ninilchik River broodstock collection weir are spawned to create smolt to stock in the enhanced fisheries in Kachemak Bay, including the Nick Dudiak Fishing Lagoon on the Homer Spit and Seldovia Lagoon on the south side of Kachemak Bay. Approximately 300,000 Chinook smolt are stocked in the Nick Dudiak Fishing Lagoon each year and about 100,000 are stocked in Seldovia. Smolt are held in net pens in the NDFL for about 12 hours to assist with imprinting and allow them to adjust to the saltwater and feed before being released.
Deep Creek Chinook Salmon Assessment
Deep Creek Chinook salmon escapement has been monitored primarily by aerial survey since the 1960s. A weir was briefly operated on the river in the late 1990s, and from 2018-2020. The weir escapements from 2018-2020 ranged from 2,190 to 3,516 Chinook salmon. The escapement goal is evaluated with the aerial survey with a lower bound goal of 350 Chinook salmon. The goal has been met in most years that the survey is flown. No survey was conducted in 2020 or 2021.
Cook Inlet Razor Clam Stock Assessment
East Cook Inlet
The East Cook Inlet razor clam stock is intensely monitored with annual abundance surveys, size and age surveys, and maturity assessments. Check out the most up to date information on the stock since the 2015 fishery closure with our YouTube video: Online Fishing Forum: What's Going on With East Cook Inlet Razor Clams? - YouTube
Abundance surveys are conducted annually in the spring at both Ninilchik and Clam Gulch beaches. They’re conducted by using a water pump to emulsify plots of substrate on transect lines within beach sections. The razor clams float to the top of the plot when the substrate is liquified and are captured so they can be enumerated, measured, aged, and placed back unharmed. These surveys produce data for estimates of juvenile and adult sized razor clam abundances, rates of natural mortality between years, and the recruitment estimates of juvenile and adult razor clams.
Size and age (hand digging) surveys
Department staff collect samples from 9 beach sections in East Cook Inlet during a single tide series in June annually. The shells are processed in the lab so they can be measured and aged. Each individual annulus on the shell is measured, providing annual growth rate by cohort of clam. This data set is extensive and is annual beginning in the 1960s. The samples are collected by hand digging as they are meant to represent the size and age composition of the harvest.
Razor clams are broadcast spawners that release their gametes into the water column between July and September in Cook Inlet. One female can release approximately 6-10 million eggs. Department staff have periodically collected razor clams during that timeframe to assess the timing of the spawn by observing the maturity of the gametes under a microscope in the lab.
West Cook Inlet
Department staff also collects razor clams through hand digging to assess the size and age compositions of the harvest in West Cook Inlet on multiple beaches.
Marine Recreational Groundfish Research
The department monitors sport harvest of groundfish species (halibut, rockfish, lingcod, etc.) in Kachemak Bay and Cook Inlet (as well as the other marine waters of Southcentral Alaska) and has since the early 1980s. Department port samplers are stationed at popular sport fish landing sites such as Homer, Deep Creek, and Anchor Point and are tasked with collecting biological samples as well as angler effort data. Biological sampling involves getting lengths and sexes of fish as well as ages. The ages are obtained by collecting a bony structure from the carcass such as the otolith (ear bone) or fin rays. Interview questions are asked to obtain data about the time spent fishing for different species and which areas were fished.