Description of forage fish:
Forage fish or otherwise known as small pelagics are fish and invertebrates (like squids) that inhabit - the pelagic zone - the open ocean. 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 pelagic fish are known to exhibit “boom and bust” cycles of abundance in response to these conditions. Examples of small pelagic fish include anchovies, sardines, shad, menhaden and the fish that feed on them.
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). They are a critical part of marine food webs and important to monitor because so many other organisms depend on them. We present the annual total biomass of small pelagics/forage fish in the Alaska, California Current, and Northeast regions, as well as selected taxa in the Gulf of Mexico region.
Data:
Data for forage fish and small pelagics were obtained from regional NOAA Integrated Ecosystem Assessment Program teams that produce indicators and Ecosystem Status Reports. For more information visit the IEA Program Website.
Understanding the Gauge plots
The gauge plots that accompany the indicator time series are meant to reflect the current status of that ecosystem component at the regional or national level. The numerical scores are determined as the percentile rank of the average (mean) value of that indicator over the last five years of the time series, relative to the series as a whole. The values typically represent quantitative scores, with more desirable conditions in the darker blue. Thus, some gauges are "right-handed" with the higher values being in darker blue, whereas other gauges are "left-handed" with lower values being in darker blue (indicating that lower values are preferable). In some instances (e.g. climate measures), the scores represented are unitless and are presented as two-way gauges, indicating that either high or low scores are observed, implying neither higher nor lower values are necessarily preferred.
Understanding the Time series plots
Time series plots show the changes in each indicator as a function of time, over the period 1980-present. Each plot also shows horizontal lines that indicate the median (middle) value of that indicator, as well as the 10th and 90th percentiles, each calculated for the entire period of measurement. Time series plots were only developed for datasets with at least 10 years of data. Two symbols located to the right of each plot describe how recent values of an indicator compare against the overall series. A black circle indicates whether the indicator values over the last five years are on average above the series 90th percentile (plus sign), below the 10th percentile (minus sign), or between those two values (solid circle). Beneath that an arrow reflects the trend of the indicator over the last five years; an increase or decrease greater than one standard deviation is reflected in upward or downward arrows respectively, while a change of less than one standard deviation is recorded by a left-right arrow.
Alaska - Eastern Bering Sea
The five-year forage fish biomass average is very low compared to the median value
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.
Gauge: Gauge value of 6 indicates that between 2016 and 2021 the biomass of forage fish in the Eastern Bering Sea was only greater than 6% of all forage fish biomass values between 1992 and 2021.
Gauge values
0 - 10: The five-year forage fish small pelagics average is very low compared to the median value.
10 - 25: The five-year forage fish small pelagics average is much lower than the median value.
25 - 50: The five-year forage fish small pelagics average is lower than the median value.
50: The five-year forage fish small pelagics average equals the median value.
50 - 75: The five-year forage fish small pelagics average is higher than the median value.
75 - 90: The five-year forage fish small pelagics average is much higher than the median value.
Indicator source information:
This indicator from the Gulf of Alaska Integrated Ecosystem Assessment Program’s East Bering Sea (EBS) team includes adult and juvenile pollock, herring, capelin, eulachon, sandlance, pelagic rockfish, salmon, squid, and other forage fish.
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:
- Information quality for this indicator ranges from a sophisticated highly quantitative stock assessment for pollock (the biomass dominant in the guild) through relatively high variance Eastern Bering Sea shelf survey data for forage fish, to no time series data for salmon and squid.
- 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 BSAI 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.
California Current - Southern CCE
Due to COVID-19 no data was collected in 2020 or 2021 so there is no proper status or trend update.
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.
Description of gauge:
Due to COVID-19 no data was collected in 2020 and 2021 so no gauge value is available
Gauge values
0 - 10: The five-year forage fish small pelagics average is very low compared to the median value.
10 - 25: The five-year forage fish small pelagics average is much lower than the median value.
25 - 50: The five-year forage fish small pelagics average is lower than the median value.
50: The five-year forage fish small pelagics average equals the median value.
50 - 75: The five-year forage fish small pelagics average is higher than the median value.
75 - 90: The five-year forage fish small pelagics average is much higher than the median value.
90 - 100: The five-year forage fish small pelagics average is very high compared to the median value.
Indicator source information:
This indicator is produced by the California Current Integrated Ecosystem Assessment team and includes the following species:
- larval anchovy (Engraulis mordax);
- coolwater larval fish (NA, multi-species);
- warmwater larval fish (NA, multi-species);
- larval hake (Merluccius productus);
- larval market squid (Doryteuthis opalescens);
- larval pac jack mackerel (Trachurus symmetricus);
- larval sanddab (Citharichthys spp.);
- larval sardine (Sardinops sagax);
- larval shortbelly rockfish (Sebastes jordani)
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)). For more information, review the California Current IEA Ecosystem Status Report.
Northeast
Between 2017 and 2022 the spring biomass of planktivores in the Northeast was greater than the median value of all spring planktivore biomass between 1978 and 2022.
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.
Description of gauge:
The gauge value of 67 indicates that between 2017 and 2022 the spring biomass of planktivores in the Northeast was greater than the median value of all spring planktivore biomass between 1978 and 2022.
Gauge values
0 - 10: The five-year forage fish small pelagics average is very low compared to the median value.
10 - 25: The five-year forage fish small pelagics average is much lower than the median value.
25 - 50: The five-year forage fish small pelagics average is lower than the median value.
50: The five-year forage fish small pelagics average equals the median value.
50 - 75: The five-year forage fish small pelagics average is higher than the median value.
75 - 90: The five-year forage fish small pelagics average is much higher than the median value.
90 - 100: The five-year forage fish small pelagics average is very high compared to the median value.
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.
Southeast
Due to COVID-19 no data was collected in 2020 or 2021 so there is no status or trend update.
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.
Description of gauge:
Due to COVID-19 no data was collected in 2020 and 2021 so no gauge value is available.
Gauge values
0 - 10: The five-year forage fish small pelagics average is very low compared to the median value.
10 - 25: The five-year forage fish small pelagics average is much lower than the median value.
25 - 50: The five-year forage fish small pelagics average is lower than the median value.
50: The five-year forage fish small pelagics average equals the median value.
50 - 75: The five-year forage fish small pelagics average is higher than the median value.
75 - 90: The five-year forage fish small pelagics average is much higher than the median value.
90 - 100: The five-year forage fish small pelagics average is very high compared to the median value.
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.
Resources
CalCOFI Small Pelagic Fish Management
The California Cooperative Oceanic Fisheries Investigations (CalCOFI) are a unique partnership of the California Department of Fish & Wildlife, NOAA Fisheries Service and Scripps Institution of Oceanography.
What are pelagic fish?
An explainer that defines what "pelagic fish" are from the National Ocean Service of NOAA
Northeast IEA Small Pelagic Indicator
Small-medium pelagic schooling fish and squid species are important to both fisheries and food webs. This group includes Atlantic herring, river herrings, Atlantic mackerel, butterfish, menhaden, and sandlance in the Northeast US. Forage fish in general can include any small pelagic plankton feeders, whether fished or unfished. Predation on forage fishes creates an important trophic link between the plankton and higher trophic levels. In the Northeast US, commercial fishing of all forage fishes combined contributes less to the removal of fish biomass than does natural predation on this category in aggregate. Regulating fishery catch for forage species is important to maintain both sustainable fisheries and predator populations. Commercial catches of Northeast US forage fish (Atlantic herring and mackerel) peaked in the 1970s, with lower catches since then, and surveys showing aggregate forage biomass increases from an early 1980s low.
Southwest Fisheries Science Center Coastal Pelagic Species
The Fisheries Resources Division conducts research on coastal pelagic and highly migratory marine species in the Eastern Pacific Ocean. They focus on the ecology, ecosystems, and fisheries of sardine, anchovy, mackerels, tunas, and sharks, as well as conduct research on abalone. Our programs collect fishery data, conduct stock assessments and economic analyses, conduct surveys on fish and invertebrate life stages using various advanced technologies, and study their genetic structure and aquaculture potential.
Gulf of Mexico Ecosystem Status Report data
GitHub portal for data sets and plotting codes for Gulf of Mexico Ecosystem Status Report
Alaska IEA Ecosystem Status Report
Ecosystem Status report information from the Alaska Integrated Ecosystem Assessment Program.
