SMART Indicator Report: Benthic Invertebrate Indices

1 Indicator category

[Fill by hand, needs decision by Council]

2 Indicator name

Benthic Invertebrate Indices

Includes variable(s): Fall Macrobenthos Biomass Index Estimate, Fall Macrobenthos Biomass Index Estimate SE, Fall Macrobenthos Eastward Center of Gravity, Fall Macrobenthos Eastward Center of Gravity SE, Fall Macrobenthos Northward Center of Gravity, Fall Macrobenthos Northward Center of Gravity SE, Fall Megabenthos Biomass Index Estimate, Fall Megabenthos Biomass Index Estimate SE, Fall Megabenthos Eastward Center of Gravity, Fall Megabenthos Eastward Center of Gravity SE, Fall Megabenthos Northward Center of Gravity, Fall Megabenthos Northward Center of Gravity SE, Spring Macrobenthos Biomass Index Estimate, Spring Macrobenthos Biomass Index Estimate SE, Spring Macrobenthos Eastward Center of Gravity, Spring Macrobenthos Eastward Center of Gravity SE, Spring Macrobenthos Northward Center of Gravity, Spring Macrobenthos Northward Center of Gravity SE, Spring Megabenthos Biomass Index Estimate, Spring Megabenthos Biomass Index Estimate SE, Spring Megabenthos Eastward Center of Gravity, Spring Megabenthos Eastward Center of Gravity SE, Spring Megabenthos Northward Center of Gravity, Spring Megabenthos Northward Center of Gravity SE

3 Indicator brief description

Aggregate macrobenthos and megabenthos invertebrate indices from fish stomach contents

4 Indicator visualization

Time series extend from 1980-2023. Macrobenthos and Megabenthos are included on separate plots for each EPU. Variables plotted are Fall Macrobenthos or Megabenthos Biomass Estimate and Spring Macrobenthos or Megabenthos Biomass Estimate with error bands from Fall Macrobenthos or Megabenthos Biomass Estimate SE and Spring Macrobenthos or Megabenthos Biomass Estimate SE, respectively. Eastward and Northward components of the Center of Gravity, along with the Center of Gravity SE are plotted for Fall and Spring Macrobenthos or Megabenthos Biomass.

5 Indicator documentation

5.1 Are indicators available for others to use (data downloadable)?

## Yes

5.1.1 Where can indicators be found?

## Data: https://noaa-edab.github.io/ecodata/index.html 
## Description:  https://noaa-edab.github.io/catalog/benthos_index.html 
## Technical documentation:  https://noaa-edab.github.io/tech-doc/benthos_index.html

5.1.2 How often are they updated? Are future updates likely?

[need sequential look at datasets for update frequency. Future requires judgement]

5.1.3 Who is the contact?

Sarah Gaichas (Sarah.Gaichas@noaa.gov)

5.2 Gather indicator statistics

5.2.1 Units

Indicator	Units
Fall Macrobenthos Biomass Index Estimate	relative grams per stomach
Fall Macrobenthos Biomass Index Estimate SE	relative grams per stomach
Fall Macrobenthos Eastward Center of Gravity	km
Fall Macrobenthos Eastward Center of Gravity SE	km
Fall Macrobenthos Northward Center of Gravity	km
Fall Macrobenthos Northward Center of Gravity SE	km
Fall Megabenthos Biomass Index Estimate	relative grams per stomach
Fall Megabenthos Biomass Index Estimate SE	relative grams per stomach
Fall Megabenthos Eastward Center of Gravity	km
Fall Megabenthos Eastward Center of Gravity SE	km
Fall Megabenthos Northward Center of Gravity	km
Fall Megabenthos Northward Center of Gravity SE	km
Spring Macrobenthos Biomass Index Estimate	relative grams per stomach
Spring Macrobenthos Biomass Index Estimate SE	relative grams per stomach
Spring Macrobenthos Eastward Center of Gravity	km
Spring Macrobenthos Eastward Center of Gravity SE	km
Spring Macrobenthos Northward Center of Gravity	km
Spring Macrobenthos Northward Center of Gravity SE	km
Spring Megabenthos Biomass Index Estimate	relative grams per stomach
Spring Megabenthos Biomass Index Estimate SE	relative grams per stomach
Spring Megabenthos Eastward Center of Gravity	km
Spring Megabenthos Eastward Center of Gravity SE	km
Spring Megabenthos Northward Center of Gravity	km
Spring Megabenthos Northward Center of Gravity SE	km

5.2.2 Length of time series, start and end date, periodicity

General overview: Spring (January-June), Fall (July-December)

Indicator specifics:

Indicator	EPU	StartYear	EndYear	NumYears	MissingYears
Fall Macrobenthos Biomass Index Estimate	AllEPU	1980	2023	44	0
Fall Macrobenthos Biomass Index Estimate	GB	1980	2023	44	0
Fall Macrobenthos Biomass Index Estimate	GOM	1980	2023	44	0
Fall Macrobenthos Biomass Index Estimate	MAB	1980	2023	44	0
Fall Macrobenthos Biomass Index Estimate SE	AllEPU	1980	2023	44	0
Fall Macrobenthos Biomass Index Estimate SE	GB	1980	2023	44	0
Fall Macrobenthos Biomass Index Estimate SE	GOM	1980	2023	44	0
Fall Macrobenthos Biomass Index Estimate SE	MAB	1980	2023	44	0
Fall Macrobenthos Eastward Center of Gravity	ALLEPU	1980	2023	44	0
Fall Macrobenthos Eastward Center of Gravity SE	ALLEPU	1980	2023	44	0
Fall Macrobenthos Northward Center of Gravity	ALLEPU	1980	2023	44	0
Fall Macrobenthos Northward Center of Gravity SE	ALLEPU	1980	2023	44	0
Fall Megabenthos Biomass Index Estimate	AllEPU	1980	2023	44	0
Fall Megabenthos Biomass Index Estimate	GB	1980	2023	44	0
Fall Megabenthos Biomass Index Estimate	GOM	1980	2023	44	0
Fall Megabenthos Biomass Index Estimate	MAB	1980	2023	44	0
Fall Megabenthos Biomass Index Estimate SE	AllEPU	1980	2023	44	0
Fall Megabenthos Biomass Index Estimate SE	GB	1980	2023	44	0
Fall Megabenthos Biomass Index Estimate SE	GOM	1980	2023	44	0
Fall Megabenthos Biomass Index Estimate SE	MAB	1980	2023	44	0
Fall Megabenthos Eastward Center of Gravity	ALLEPU	1980	2023	44	0
Fall Megabenthos Eastward Center of Gravity SE	ALLEPU	1980	2023	44	0
Fall Megabenthos Northward Center of Gravity	ALLEPU	1980	2023	44	0
Fall Megabenthos Northward Center of Gravity SE	ALLEPU	1980	2023	44	0
Spring Macrobenthos Biomass Index Estimate	AllEPU	1980	2023	44	0
Spring Macrobenthos Biomass Index Estimate	GB	1980	2023	44	0
Spring Macrobenthos Biomass Index Estimate	GOM	1980	2023	44	0
Spring Macrobenthos Biomass Index Estimate	MAB	1980	2023	44	0
Spring Macrobenthos Biomass Index Estimate SE	AllEPU	1980	2023	44	0
Spring Macrobenthos Biomass Index Estimate SE	GB	1980	2023	44	0
Spring Macrobenthos Biomass Index Estimate SE	GOM	1980	2023	44	0
Spring Macrobenthos Biomass Index Estimate SE	MAB	1980	2023	44	0
Spring Macrobenthos Eastward Center of Gravity	ALLEPU	1980	2023	44	0
Spring Macrobenthos Eastward Center of Gravity SE	ALLEPU	1980	2023	44	0
Spring Macrobenthos Northward Center of Gravity	ALLEPU	1980	2023	44	0
Spring Macrobenthos Northward Center of Gravity SE	ALLEPU	1980	2023	44	0
Spring Megabenthos Biomass Index Estimate	AllEPU	1980	2023	44	0
Spring Megabenthos Biomass Index Estimate	GB	1980	2023	44	0
Spring Megabenthos Biomass Index Estimate	GOM	1980	2023	44	0
Spring Megabenthos Biomass Index Estimate	MAB	1980	2023	44	0
Spring Megabenthos Biomass Index Estimate SE	AllEPU	1980	2023	44	0
Spring Megabenthos Biomass Index Estimate SE	GB	1980	2023	44	0
Spring Megabenthos Biomass Index Estimate SE	GOM	1980	2023	44	0
Spring Megabenthos Biomass Index Estimate SE	MAB	1980	2023	44	0
Spring Megabenthos Eastward Center of Gravity	ALLEPU	1980	2023	44	0
Spring Megabenthos Eastward Center of Gravity SE	ALLEPU	1980	2023	44	0
Spring Megabenthos Northward Center of Gravity	ALLEPU	1980	2023	44	0
Spring Megabenthos Northward Center of Gravity SE	ALLEPU	1980	2023	44	0

5.2.3 Spatial location, scale and extent

General overview: by EPU and full shelf

Indicator specifics:

Indicator	EPU
Fall Macrobenthos Biomass Index Estimate	AllEPU
Fall Macrobenthos Biomass Index Estimate	GB
Fall Macrobenthos Biomass Index Estimate	GOM
Fall Macrobenthos Biomass Index Estimate	MAB
Fall Macrobenthos Biomass Index Estimate SE	AllEPU
Fall Macrobenthos Biomass Index Estimate SE	GB
Fall Macrobenthos Biomass Index Estimate SE	GOM
Fall Macrobenthos Biomass Index Estimate SE	MAB
Fall Macrobenthos Eastward Center of Gravity	ALLEPU
Fall Macrobenthos Eastward Center of Gravity SE	ALLEPU
Fall Macrobenthos Northward Center of Gravity	ALLEPU
Fall Macrobenthos Northward Center of Gravity SE	ALLEPU
Fall Megabenthos Biomass Index Estimate	AllEPU
Fall Megabenthos Biomass Index Estimate	GB
Fall Megabenthos Biomass Index Estimate	GOM
Fall Megabenthos Biomass Index Estimate	MAB
Fall Megabenthos Biomass Index Estimate SE	AllEPU
Fall Megabenthos Biomass Index Estimate SE	GB
Fall Megabenthos Biomass Index Estimate SE	GOM
Fall Megabenthos Biomass Index Estimate SE	MAB
Fall Megabenthos Eastward Center of Gravity	ALLEPU
Fall Megabenthos Eastward Center of Gravity SE	ALLEPU
Fall Megabenthos Northward Center of Gravity	ALLEPU
Fall Megabenthos Northward Center of Gravity SE	ALLEPU
Spring Macrobenthos Biomass Index Estimate	AllEPU
Spring Macrobenthos Biomass Index Estimate	GB
Spring Macrobenthos Biomass Index Estimate	GOM
Spring Macrobenthos Biomass Index Estimate	MAB
Spring Macrobenthos Biomass Index Estimate SE	AllEPU
Spring Macrobenthos Biomass Index Estimate SE	GB
Spring Macrobenthos Biomass Index Estimate SE	GOM
Spring Macrobenthos Biomass Index Estimate SE	MAB
Spring Macrobenthos Eastward Center of Gravity	ALLEPU
Spring Macrobenthos Eastward Center of Gravity SE	ALLEPU
Spring Macrobenthos Northward Center of Gravity	ALLEPU
Spring Macrobenthos Northward Center of Gravity SE	ALLEPU
Spring Megabenthos Biomass Index Estimate	AllEPU
Spring Megabenthos Biomass Index Estimate	GB
Spring Megabenthos Biomass Index Estimate	GOM
Spring Megabenthos Biomass Index Estimate	MAB
Spring Megabenthos Biomass Index Estimate SE	AllEPU
Spring Megabenthos Biomass Index Estimate SE	GB
Spring Megabenthos Biomass Index Estimate SE	GOM
Spring Megabenthos Biomass Index Estimate SE	MAB
Spring Megabenthos Eastward Center of Gravity	ALLEPU
Spring Megabenthos Eastward Center of Gravity SE	ALLEPU
Spring Megabenthos Northward Center of Gravity	ALLEPU
Spring Megabenthos Northward Center of Gravity SE	ALLEPU

5.2.4 Management scale: all species, FMP level, species level, can it be aggregated or separated to different scales?

[Classify by hand, note gridded data if available could be applied to different species ranges]

5.2.5 Uncertainty metrics

5.3 Are methods clearly documented to obtain source data and calculate indicators?

## Yes

5.3.1 Can the indicator be calculated from current documentation?

[Build link to Tech-doc, look for current and previous methods]

5.3.2 Is code publicly available? up to date?

[Build link to Tech-doc, look for current and previous methods]

5.3.3 Have methods changed over time?

[Build link to Tech-doc, look for current and previous methods]

5.4 Are indicator underlying source data linked or easy to find?

[Build link to Tech-doc, look for source, may require judgements]

5.4.1 Where are source data stored?

[Build link to Tech-doc, look for source, may require judgement]

5.4.2 How/by whom are source data updated? Are future updates likely?

[Build link to Tech-doc, look for source, may require judgement]

5.4.3 How often are they updated?

[Build link to Tech-doc, look for source, may require judgement]

6 Indicator analysis/testing or history of use

6.1 What decision or advice processes are the indicators currently used in?

Benthic invertebrates provide supporting ecosystem services as important prey for many economically important fish species on the Northeast US shelf. Changes to the benthic invertebrate forage base could have important implications for regional food webs. However, we lack direct measurements of benthic invertebrate biomass for most unexploited taxa. Spatially explicit indices of abundance for benthos groups were estimated using spatio-temporal modeling (VAST, [10]; [11]). We define Macrobenthos as bottom-dwelling invertebrates retained on a 0.5-1.0 mm sieve. These include polychaete worms, small crustaceans, bivalves (non-commercial), gastropods, nemerteans, tunicates, cnidarians, brittle stars, sea cucumbers, and sand dollars. We define Megabenthos as sea stars (Echinodermata: Asteroidea) and large Arthropods (horseshoe crabs (Merostomata), mantis shrimp (Crustacea: Stomatopoda), and crabs (Crustacea: Decapoda: Brachyura and Anomura other than hermit crabs)). The indices developed here use similar methods to the Forage Fish Index. The spatially-explicit macrobenthos and megabenthos indices estimate the combined biomass of 833 and 105 taxa, respectively, using stomach contents information from 88 predator/size combinations from fish collected on bottom trawl surveys. In addition to an index of benthic invertebrate biomass in each EPU, the coastwide center of gravity for the combined benthic biomass was estimated to evaluate whether distributions of benthic invertebrate biomass have changed over time.

6.2 What implications of the indicators are currently listed?

Macrobenthos indices show long term declines in spring in all EPUs. In contrast, Megabenthos indices show long term increases in fall in GOM and GB, and in spring in MAB. Megabenthos indices also show a recent trend in spring in GB. Center of gravity indicators show recent trends towards the north and east in spring for Megabenthos in all EPUs. Macrobenthos center of gravity shows a significant long term trend towards the west over time. This is the opposite direction observed for aggregate forage fish and surveyed fish species in aggregate.

6.3 Do target, limit, or threshold values already exist for the indicator?

[Fill by hand; if not in key results or implications, likely does not exist]

6.4 Have the indicators been tested to ensure they respond proportionally to a change in the underlying process?

[Fill by hand; if not in introduction, key results, or implications, likely not tested]

6.5 Are the indicators sensitive to a small change in the process, or what is the threshold of change that is detectable?

[Fill by hand; if not in introduction, key results, or implications, likely not tested]

6.6 Is there a time lag between the process change and the indicator change? How long?

[Fill by hand; if not in introduction, key results, or implications, likely not tested]

7 Comments

[Fill below by hand once above data complete]

7.1 Additional potential links to management in addition to uses listed above

7.2 What additional work would be needed for the Council to use the indicator?

7.3 What issues are caused if there is a gap or delay in data underlying the indicator