Forage Fish

Values correspond to estimated total forage biomass in millions of tons

Description of time series:

The time series describes the aggregate forage fish biomass in the Eastern Bering Sea from 1987 to 2021. While there was no trend between 2016 and 2021 in the biomass of forage fish, values were below the 10th percentile historically. Due to COVID-19 no data was collected in 2020.

Indicator source information:

This indicator from the includes adult and juvenile pollock, herring, capelin, eulachon, sandlance, pelagic rockfish, salmon, squid, and other forage fish. More information about the EBS Forage indicator can be found on the Ecosystem Status Reports For The Gulf Of Alaska, Bering Sea And Aleutian Islands page

Data background and caveats:

This index aggregates survey biomass estimates for key forage fish species in the eastern Bering Sea. The constituents are members of the “forage fish” group included as Ecosystem Components in the Bering Sea - Aleutian Islands Fishery Management Plan: eulachon, Pacific capelin, sand lance species, rainbow smelt, Pacific sandfish, and a group of minor smelt species. This aggregate does not include important forage species such as age-0 walleye pollock or Pacific herring. The biomass estimates are from the eastern Bering Sea shelf bottom trawl survey including the northwestern survey strata 82 and 90. Because this survey is not optimized for small pelagic fishes, the data should be viewed with caution.

Values correspond to relative coolwater forage abundance index score

Description of time series:

Due to COVID-19 no data was collected in 2020 or 2021 so there is no proper status or trend update. 

Indicator source information:

This indicator is produced with data curated by the California Current Integrated Ecosystem Assessment team. This general indicator of average combined forage biomass includes the following species but is often dominated by anchovy and sardine: 

• larval anchovy (Engraulis mordax);
• larval California smoothtongue (Leuroglossus stilbius);
• larval croakers (Genyonemus spp.);
• larval eared blacksmelt (Lipolagus ochotensis);
• larval English sole (Parophrys vetulus); 
• southern mesopelagic  larval fish (NA, multi-species);
• larval hake (Merluccius productus);
• larval jack mackerel (Trachurus symmetricus);
• larval market squid (Doryteuthis opalescens);
• Larval northern lampfish (Stenobrachius leucopsarus); 
• larval Pacific mackerel (Scomber japonicus) ; 
• larval sanddab (Citharichthys spp.); 
• larval sardine (Sardinops sagax); 
• Larval rockfishes (Sebastes spp.);
• larval slender sole (Lyopsetta exilis)

Data background and caveats:

Units, time series, and species vary by region for this indicator, so no national score is provided. Best practices and caveats vary by region:

• CCE
  • This indicator only includes data from surveys of the southern extent of the California Current region in the Spring. Index calculations are as follows: Larval fish data summed across all stations of the CalCOFI survey in spring (units are in number under 10 sq. m of surface area; ln(abundance+1)).

Values correspond to forage biomass observed per tow in kg

Description of time series:

Between 2018 and 2022 the biomass of spring planktivore forage fish showed a significant trend upward but values remain within the 10th and 90th percentile. 

Indicator information:

Forage fish or otherwise known as small pelagics are fish and invertebrates (like squids) that inhabit - the pelagic zone - the open ocean. Small pelagic species are often important to fisheries and serve as forage for commercially and recreationally important fish, as well as other ecosystem species (e.g. seabirds and marine mammals). The number and distribution of pelagic fish vary regionally, depending on multiple physical and ecological factors (i.e., the availability of light, nutrients, dissolved oxygen, temperature, salinity, predation, abundance of phytoplankton and zooplankton, etc.). Small pelagics are known to exhibit “boom and bust” cycles of abundance in response to these conditions. Examples include anchovies, sardines, shad, menhaden and the fish that feed on them.

This indicator is produced by the Northeast Integrated Ecosystem Assessment team and represents Spring Planktivore biomass in kg^tow -1.

Data background and caveats:

Units, time series, and species vary by region for this indicator, so no national score is provided. Best practices and caveats vary by region.

No Caveats.

Values correspond to catch per unit effort index score

Description of time series:

The data presented in this time series is South Atlantic Menhaden adults (age 1+). Due to COVID-19 no data was collected in 2020 or 2021 so there is no status or trend update.

Indicator information:

Forage fish or otherwise known as small pelagics are fish and invertebrates (like squids) that inhabit - the pelagic zone - the open ocean. Small pelagic species are often important to fisheries and serve as forage for commercially and recreationally important fish, as well as other ecosystem species (e.g. seabirds and marine mammals). The number and distribution of pelagic fish vary regionally, depending on multiple physical and ecological factors (i.e., the availability of light, nutrients, dissolved oxygen, temperature, salinity, predation, abundance of phytoplankton and zooplankton, etc.). Small pelagics are known to exhibit “boom and bust” cycles of abundance in response to these conditions. Examples include anchovies, sardines, shad, menhaden and the fish that feed on them. 

The Southeast Atlantic forage indicator is the Menhaden CPUE Index score used by the Southeast Integrated Ecosystem Assessment team in their upcoming Ecosystem Status Report. Menhaden (Brevoortia tyrannus) are thought to play a substantial role in ecosystem structure and function. At the time of writing, the report is under review and data are not publicly available.

Data background and caveats:

Units, time series, and species vary by region for this indicator, so no national score is provided. Best practices and caveats vary by region. 

No Caveats.