SMART Indicator Report: Species Richness

1 Indicator category

[Fill by hand, needs decision by Council]

2 Indicator name

Species Richness

Includes variable(s): lower-Richness, mean-Richness, median-Richness, Shannon, upper-Richness

3 Indicator brief description

Species richness is the number of unique species predicted to be captured in NEFSC bottom trawl survey tows, conducted within each of four ecological production units (EPUs) in each year between 2000 and 2019. This is based on simulations from a joint-species distribution model fitted to presence-absence data for 55 species routinely collected by spring and fall surveys during the corresponding time period. Vessel-specific differences in capture efficiency are estimated by the model, and then predictions are generated at the Albatross IV scale. See SOE Tech Doc for details of the model, species considered, and environmental covariates included.

4 Indicator visualization

An overall trend of declining richness can be seen in the more southerly Mid-Atlantic Bight (MAB) region during the modeled time period (2000-2019), while the more northerly regions (i.e., the Gulf of Maine and Georges Bank) are characterized by concurrent gains in richness. These patterns reflect the increasingly rare occurrence of cooler-water species (e.g., Atlantic cod, American plaice, and Atlantic pollock) in southern waters and the growing prevalence of warmer-water species (e.g., weakfish, spotted hake, and black sea bass) in the north, likely as a direct result of warming ocean temperatures.

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

Chris Haak (chrishaak@gmail.com)

5.2 Gather indicator statistics

5.2.1 Units

## no Units field

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

General overview: Spring (March-May) and fall (September-November) NEFSC bottom trawl surveys from 2000-2019

Indicator specifics:

Indicator	EPU	StartYear	EndYear	NumYears	MissingYears
lower-Richness	GB	2000	2019	20	0
lower-Richness	GOM	2000	2019	20	0
lower-Richness	MAB	2000	2019	20	0
lower-Richness	SS	2000	2019	20	0
mean-Richness	GB	2000	2019	20	0
mean-Richness	GOM	2000	2019	20	0
mean-Richness	MAB	2000	2019	20	0
mean-Richness	SS	2000	2019	20	0
median-Richness	GB	2000	2019	20	0
median-Richness	GOM	2000	2019	20	0
median-Richness	MAB	2000	2019	20	0
median-Richness	SS	2000	2019	20	0
Shannon	GB	2000	2019	20	0
Shannon	GOM	2000	2019	20	0
Shannon	MAB	2000	2019	20	0
Shannon	SS	2000	2019	20	0
upper-Richness	GB	2000	2019	20	0
upper-Richness	GOM	2000	2019	20	0
upper-Richness	MAB	2000	2019	20	0
upper-Richness	SS	2000	2019	20	0

5.2.3 Spatial location, scale and extent

General overview: Ecological production units (4) on the Northeast US continental shelf (as sampled by NEFSC spring and fall bottom trawl surveys)

Indicator specifics:

Indicator	EPU
lower-Richness	GB
lower-Richness	GOM
lower-Richness	MAB
lower-Richness	SS
mean-Richness	GB
mean-Richness	GOM
mean-Richness	MAB
mean-Richness	SS
median-Richness	GB
median-Richness	GOM
median-Richness	MAB
median-Richness	SS
Shannon	GB
Shannon	GOM
Shannon	MAB
Shannon	SS
upper-Richness	GB
upper-Richness	GOM
upper-Richness	MAB
upper-Richness	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?

Species richness can indicate the health of the ecosystem as a metric of biodiversity, and changes in richness over time may reflect distribution shifts or community reorganization. In the present context, richness in a given EPU is presented in terms of 55 commonly sampled fish species, as they are predicted to be observed (i.e., present or absent) in NEFSC spring and fall bottom trawl surveys each year over the modeled time period (conditional on a common level of gear efficiency across years).

6.2 What implications of the indicators are currently listed?

The contrasting EPU-specific trends displayed here highlight changes in the composition of marine fish assemblages that are consistent with expected species distribution shifts under warming water temperatures. It is important to note, however, that these estimates of richness consider only a certain (pre-specified) subset of community members, and are not representative of the entire fish community. For instance, it is probable that southerly (warmer-water) species not included in our analysis may be occurring in the MAB with increased frequency, effectively offsetting richness declines in that region. Still, decreases in the prevalence of cooler water taxa in the MAB may signal that fisheries in this region should reassess any reliance on stocks that are fished near the southern extents of their range, and/or shift fishing effort to more southerly species. Simultaneously, an apparent influx of southerly species in the GOM and GB may eventually necessitate the adjustment of management quotas across regions.

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