1. Technical Briefing Northern Shrimp Stock Assessment
Newfoundland & Labrador
February 16, 2018

2. Outline Purpose of this briefing Science advice
How we estimate the Northern Shrimp stock size
Stock status
Additional considerations
Next steps
Questions

3. Purpose of this briefing
Feb 13-14, DFO held its Canadian Science Advisory Secretariat (CSAS) regional peer review meeting on Northern Shrimp in the Newfoundland and Labrador Region.
Science advice on the Northern Shrimp stock was determined at this meeting and will be provided throughout this presentation.
What is CSAS?
A national body that oversees the review and provision of science advice to inform DFO management decisions. Specifically, this group helps organize meetings where DFO scientists, biologists and others, including fish harvesters, university researchers, and other technical experts get together to review scientific information and help inform how commercial fish stocks are managed.

4. Science advice & the precautionary approach
The precautionary approach is a management framework used to determine catch limits or other management measures with the intention to:
keep removals moderate when stocks are healthy;
promote rebuilding when stocks are low; and,
ensure low risk of harm to the stocks.
DFO science uses the stock status zones to provide clear and consistent advice to fisheries management.
Limit reference point (LRP): boundary between the critical and cautious zones, and represents the stock status below which serious harm is occurring to the stock. Fishing is to be kept to the lowest possible level below the LRP.
Upper stock reference (USR): boundary between the cautious and healthy zones, and represents a threshold below which catch must be progressively reduced in order to avoid reaching the limit reference point.

5. Science advice So, how was this advice formed?
Northern Shrimp in shrimp fishing areas 4-6 is managed under the precautionary approach, based on the female spawning stock biomass (the changes in the overall weight, in tonnes, of female population).
Shrimp Fishing Area 4: Stock remains in the Healthy Zone.
Shrimp Fishing Area 5: Stock remains in the Healthy Zone.
Shrimp Fishing Area 6: Stock remains in the Critical Zone.
So, how was this advice formed?

6. How we ESTIMATE STOCK SIZE
The science behind our advice

7. Northern Shrimp fishing & assessment areas
Northern Shrimp are targeted by the commercial fishery throughout Shrimp Fishing Areas (SFAs) 4-6.
Previously, assessments of Northern Shrimp in SFA 4-6 occurred every 2 years, with interim updates every other year. However, SFA 6 will be assessed annually for the foreseeable future.

8. Multispecies survey
The status of Shrimp in SFA 5-6 is assessed based on data from the DFO fall multi-species trawl survey (1996–2017).
The status of Shrimp in SFA 4 is assessed based on data from the Northern Shrimp Research Foundation (NSRF)-DFO summer trawl survey (2005–17).
These surveys tell us where shrimp are located, their length, number of shrimp per size, and spawning stock biomass.

9. Stock status

10. How we monitor changes to the stock
Changes in the overall weight (tonnes) of all males and females larger than 17mm. This is the fishable biomass.
Changes in the overall weight (tonnes) of female population. This is spawning stock biomass.
Exploitation rate is the percentage of shrimp that are removed from the fishable biomass by fishing.

11. Shrimp Fishing Area 4 – stock status
13% in fishable biomass between (weight of male/females larger than 17 mm).
There was no significant change in spawning stock biomass between (weight of females).
19.4% of the fishable biomass was caught in
Fishable biomass was 82,700t in 2017.
Spawning stock biomass was 55,600t in 2017.
The stock is currently in the Healthy Zone of the Precautionary Approach Framework.

12. Shrimp Fishing Area 5 – stock status
31% in fishable biomass between (weight of male/females larger than 17 mm).
3% in spawning stock biomass between (weight of females).
20.6% of fishable biomass will be caught in if total allowable catch is taken.
Fishable biomass was 140,000t in 2017.
Spawning stock biomass was 55,700t in 2017.
The stock is currently in the Healthy Zone of the Precautionary Approach Framework.

13. Shrimp Fishing Area 6 – stock status
16% in fishable biomass between (weight of male/females larger than 17 mm).
19% in spawning stock biomass between (weight of females).
10% of fishable biomass will be caught in if total allowable catch is taken.
Fishable biomass was 87,300t in 2017; the lowest in the time series.
Spawning stock biomass was 52,700t in 2017; the lowest in the time series.
The stock is currently in the Critical Zone of the Precautionary Approach Framework.

14. Additional considerations:
Predation, fishing and environment all affect shrimp production, although precise relationships are not clear.
Shrimp production has declined since the mid-1990s and is expected to remain at low values for next 2-3 years.
Shrimp is an important forage (prey) species, particularly when there is a scarcity of high energy prey such as capelin.
Research indicates that shrimp larvae mostly drift from North to South due to strong currents. As such, an adult shrimp in one SFA may have begun life as a microscopic larva in a different SFA.

15. Next steps
Stock assessment results will be posted to the CSAS website in the near future. Previous assessments are currently available.
Fisheries management is holding the Northern Shrimp Advisory meeting on March 7, DFO science advice is presented and discussed with industry stakeholders and indigenous groups at this meeting.
The stock assessment advice, along with recommendations from DFO Fisheries Management, and input from industry will be considered by the Minister in developing future Total Allowable Catch (TAC) and other management actions.

16. Questions?