1 Indicator category

[Fill by hand, needs decision by Council]

2 Indicator name

Expected Number of Species

Includes variable(s): Albatross-FALL, Albatross-SPRING, AlbatrossSD-FALL, AlbatrossSD-SPRING, Bigelow-FALL, Bigelow-SPRING, BigelowSD-FALL, BigelowSD-SPRING

3 Indicator brief description

Diversity metric from the Northeast Fisheries Science Center (NEFSC) Bottom Trawl Surveys.

4 Indicator visualization

Due to the shift to the NOAA vessel Henry B. Bigelow in 2009 and the inability to correct for species composition, the time series is broken into Albatross and Bigelow stanzas. There is an apparent trend in the data from the Albatross time period in the Gulf of Maine. There is a declining trend in the Mid-Atlantic data from the spring Bigelow period.

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/exp_n.html 
## Technical documentation:  https://noaa-edab.github.io/tech-doc/exp_n.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?

Andrew Beet ()

5.2 Gather indicator statistics

5.2.1 Units

## n species per 1000 ind

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

General overview: Spring (March-May) and Fall (September-November)

Indicator specifics:

Indicator

EPU

StartYear

EndYear

NumYears

MissingYears

Albatross-FALL

GB

1963

2008

46

0

Albatross-FALL

GOM

1963

2008

46

0

Albatross-FALL

MAB

1963

2008

46

0

Albatross-FALL

SS

1963

2008

46

0

Albatross-SPRING

GB

1968

2008

41

0

Albatross-SPRING

GOM

1968

2008

41

0

Albatross-SPRING

MAB

1968

2008

41

0

Albatross-SPRING

SS

1968

2008

41

0

AlbatrossSD-FALL

GB

1963

2008

46

0

AlbatrossSD-FALL

GOM

1963

2008

46

0

AlbatrossSD-FALL

MAB

1963

2008

46

0

AlbatrossSD-FALL

SS

1963

2008

46

0

AlbatrossSD-SPRING

GB

1968

2008

41

0

AlbatrossSD-SPRING

GOM

1968

2008

41

0

AlbatrossSD-SPRING

MAB

1968

2008

41

0

AlbatrossSD-SPRING

SS

1968

2008

41

0

Bigelow-FALL

GB

2009

2024

15

1

Bigelow-FALL

GOM

2009

2024

15

1

Bigelow-FALL

MAB

2009

2024

14

2

Bigelow-FALL

SS

2009

2024

15

1

Bigelow-SPRING

GB

2009

2024

15

1

Bigelow-SPRING

GOM

2009

2024

15

1

Bigelow-SPRING

MAB

2009

2024

15

1

Bigelow-SPRING

SS

2009

2024

15

1

BigelowSD-FALL

GB

2009

2024

15

1

BigelowSD-FALL

GOM

2009

2024

15

1

BigelowSD-FALL

MAB

2009

2024

14

2

BigelowSD-FALL

SS

2009

2024

15

1

BigelowSD-SPRING

GB

2009

2024

15

1

BigelowSD-SPRING

GOM

2009

2024

15

1

BigelowSD-SPRING

MAB

2009

2024

15

1

BigelowSD-SPRING

SS

2009

2024

15

1

5.2.3 Spatial location, scale and extent

General overview: By EPU

Indicator specifics:

Indicator

EPU

Albatross-FALL

GB

Albatross-FALL

GOM

Albatross-FALL

MAB

Albatross-FALL

SS

Albatross-SPRING

GB

Albatross-SPRING

GOM

Albatross-SPRING

MAB

Albatross-SPRING

SS

AlbatrossSD-FALL

GB

AlbatrossSD-FALL

GOM

AlbatrossSD-FALL

MAB

AlbatrossSD-FALL

SS

AlbatrossSD-SPRING

GB

AlbatrossSD-SPRING

GOM

AlbatrossSD-SPRING

MAB

AlbatrossSD-SPRING

SS

Bigelow-FALL

GB

Bigelow-FALL

GOM

Bigelow-FALL

MAB

Bigelow-FALL

SS

Bigelow-SPRING

GB

Bigelow-SPRING

GOM

Bigelow-SPRING

MAB

Bigelow-SPRING

SS

BigelowSD-FALL

GB

BigelowSD-FALL

GOM

BigelowSD-FALL

MAB

BigelowSD-FALL

SS

BigelowSD-SPRING

GB

BigelowSD-SPRING

GOM

BigelowSD-SPRING

MAB

BigelowSD-SPRING

SS

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?

Diversity estimates have been developed to understand whether the overall structure of the ecosystem has remained stable or is changing. There are a large number of diversity indices that can be used to measure diversity; for the purposes of the State of the Ecosystem report we report on the expected number of species in a sample size (E(Sn)). These “rarefied” samples allow for comparisons between sample sites with varying number of species present. The estimate of (E(Sn) is less biased than other diversity indices which usually increase with sample size. It also has a more meaningful biological interpretation than other indices. For example, if a predator eats 10 random individuals, E(Sn) will predict the number of species consumed.

6.2 What implications of the indicators are currently listed?

Diversity is used as a proxy for stability. Changes in ecological diversity over time may indicate altered ecosystem structure with implications for fishery productivity and management [53]. This indicator shows that the underlying ecosystem is relatively stable with the possibility that the Gulf of Maine is becoming more diverse. Increasing adult diversity in the Gulf of Maine suggests an increase in warm-water species and should be closely monitored. Recent declining adult diversity in the Mid-Atlantic should also be closely monitored for management implications.

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]

7.2 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