Alaska fisheries biologists have set the guideline harvest level (GHL) for the 2024 Sitka Sound sac roe herring fishery at 81,246 tons (162.5 million pounds) with a forecasted average weight of 120 grams across all age classes. That’s greater than any prior forecast or estimate of spawning biomass for Sitka Sound herring.
The forecast is an increase from the model estimate of the 2023 mature pre-fishery herring biomass of 292,669 tons, Alaska Department of Fish and Game (ADF&G) biologists said, in announcing the GHL on Dec. 22.
The magnitude of the 2024 forecast is largely the result of the 2023 model estimated pre-fishery herring biomass—which was much larger than the forecast and influenced in part by the unforeseen size of the 2020-year class—and the forecasted abundance of age-4 (2020-year class) and age 8-plus fish (the 2016-year class), ADF&G biologists said.
The 2020-year class, first observed as age-3 fish in 2023, makes the 2020-year class the second largest ever estimated.
Herring egg abundance is estimated using aerial, vessel and scuba diving surveys. Shorelines with herring spawn are mapped and followed by dive surveys to estimate egg density and width of egg deposition.
ADF&G mapped 83.8 nautical miles of unique shoreline with herring spawn in the Sitka Sound area during the spring of 2023, compared to the recent 10-year (2013–2022) average of 66.8 nautical miles.
The total harvest for the sac roe herring fishery in 2023 was roughly 10,200 tons of herring, plus an additional 253 tons of herring harvested in test and bait fisheries.
The 2023 egg deposition estimate was substantially higher than in 2022 and was the fourth highest on record since the department began egg deposition surveys, biologists said.