1. EU FP7 BENTHIS & EU-HELCOM BalticBOOST
Baltic Case Study, Trawling impacts in regional seas,
BENTHIS WP7 & BalticBOOST WP3.2 (+3.1)
Grant Agreement number:
May 2016

2. BalticBOOST
The project is coordinated by HELCOM and has 10 partners from the HELCOM EU Member States and one international organisation (ICES)
Theme 3 members
The project implementation is guided by HELCOM groups, as well as HELCOM workshops carried out as part of the project.​

3. Theme 3 - Physical loss and damage to seabed habitats
Analyze physical loss and impact to the seafloor and explore ways to determine how much disturbance from different activities specific seabed habitats can tolerate while remaining in Good Environmental Status (GES)
WP 3.1 Continue the development of environmental targets in HELCOM by developing a methodology for integrating impacts from multiple pressures and guidelines for setting environmental targets
WP 3.2 Continue the BALTFIMPA project by producing a quantitative estimation of fishing gear impacts on seafloor habitats, with test-case examples
WP 3.3 Define information needs on pressures and activities that affect the seabed habitats

4. Theme 3 - Physical loss and damage to seabed habitats
WP 3.2 For fisheries:
Use fishing pressure (VMS) and habitat data to quantitatively assess impact according to EU-FP7-BENTHIS methodology
(Rijnsdorph et al. 2016; Eigaard et al. 2016; Eigaard et al. Submitted)
WP 3.1 For other impacts:
Use literature information to semi-quantitatively assess the extent of impacts
Test cases:
Use real data on a limited scale to detail general findings
Linkages:
Integration of fisheries and other impacts is still under investigation to bridge between different types of impacts and also connect with HOLAS II
Main challenge: Common definitions and units for benthic habitat sensitivity according to different (cross sector) types of impacts
The quantitative impact assessments under WP3.2 can be categorized, and potentially feed into the WP3.1 semi-quantitative impact assessment

5. Intensity of Fishing Pressure: Swept Area Ration (SAR)
Intensity of Fishing Pressure: Swept Area Ration (SAR). All mobile bottom contact gears 2013; All Countries;
Swept area ration: SAR = Swept Area in Cell / Area of the Cell. (0,05x0,05 degree grid cells ~ 3nm, c-square)
ICES WGSFD; HELCOM_mapping_fishing_intensity_and_effort_data_outputs_2015

6. Footprint and Dimensions of Gear Components
Otter trawl
1) Inventory of European
metiers
2) Review penetration
depth gear components
Twin trawl
Eigaard et al (2016) IJMS

7. Footprint: Initial literature study of gear specific abrasion,
Surface & Subsurface.
From Eigaard et al. (2016) IJMS. Initial literature study of gear specific abrasion.

8. Gear footprint (swept area per hour): surface (0-2 cm) & subsurface (<2cm)
Eigaard et al (2016) IJMS

9. Starting point: trawling intensity (SAR=Swept Area Ratio per year, c-square) - surface - subsurface

10. From Eigaard et al. (Submitted) IJMS - surface intensity given as number of times swept per year.

11. EUNIS Level 3 Habitats
From Eigaard et al. (Submitted) IJMS

12. Example: Cumulative surface layer fished by gear and (BALANCE) habitat (swept area), Kattegat / Western Baltic
(OT_CRU)
(OT_DMF)
(OT_MIX_NEP)
(OT_SPF)
(OT_MIX_DMF_PEL)
(SDN_DEM)

13. Integration by manage- ment area: Trawling Intensity Profiles (60% of effort covered) Eigaard et al. (Submitted) IJMS
Footprint:
- surface
- subsurface

14. Fishing Impact BENTHIS Approach:

15. Habitat sensitivities
Habitat sensitivity estimated from ecological data
Longevity (life span)
Population dynamics (mortality & recovery)

16. Habitat sensitivity
Longevity (life span) composition (% Biomass) of the untrawled community
van Denderen et al (2015) MEPS

17. Longevity composition infauna: logistic regression (Cb ~ log Longevity)

18. Sensitivity (longevity) – trawling intensity relation
0.067
0.1
0.05
0.2 1

19. Sensitivity – trawling intensity relation
(1/longevity)
0.067
0.1
0.05
0.2 1

20. Sensitivity – trawling intensity relation
(1/longevity)
0.067
0.1
0.05
0.2 1

21. Seafloor Integrity = SBI = Impact (Longevity)
– ATLANTIC, MEDITERRANEAN; Index Values.
From Eigaard et al. (Submitted) IJMS.

22. Sensitivity, Population dynamics: Calculate equilibrium biomass: Carrying Capacity Mortality and Recovery
Relative community biomass
Recovery in years = RT = Recovery Time

23. Mortality (d) & recovery (r) rates - averages community/habitat level
Meta-analysis: Collie et al (2000); Kaiser et al (2006)
Habitat
Gear d
r (y-1)
Biogenic OT
0.39
3.03
Gravel
0.48
Sand
0.37
15.59
Mud
0.27
6.39 BT
0.45
0.53
0.43
0.33 TD
0.67
0.72
0.66
0.61

24. Equilibrium community (!) biomass – trawling intensity relationship

25. Seafloor integrity = SBI = Impact (population dynamics)

26. Discussion
Longevity & population dynamics parameters representative for the habitat?
Combination of different metiers
Method in development and not tested
Potential applications
- assess trawling impact (maps, aggregated indicator)
- assess consequences of changes in fishing pressure over time
- define thresholds for pressure * sensitivity

27. Femern Belt Case Study: Example
Invertebrate Sampling in Femern Belt Area: Femern Belt Project
Figure 1. Benthic sampling stations with partly grab sampling stations and video monitoring stations repeatedly sampled in spring 2009, autumn 2009, spring 2010, and autumn 2010, as well as different habitat types and benthic sediment types in the Femern Belt area of the Western Baltic Sea.

28. Impacts of cod trawl fishery in the Femern Belt area
Figure 2. Effort allocation and fishing intensity of the Danish demersal otterboard trawl fishery (OT_DMF métier) in spring 2009 & autumn 2009 as well as overlapping benthic sampling with partly grab sampling stations and video monitoring stations sampled in spring and autumn 2009 in the Femern Belt area of the Western Baltic Sea.

29. Meta-Correlation-Plots on Multi-Factor Impacts (Femern Belt):
Bio-Diversity per sample
vs Fishing Intensity (Swept Area)
Combined
All Species,
All Habitats, 2009 & 2010,
All quarters, Fishing intensity for all DK + D Mobile Gears

30. Meta-Correlation-Plots on Multi-Factor Impacts (Femern Belt):
Bio-Diversity
per sample vs Fishing Intensity (Swept Area)
Habitat 1: Sublitt. Mud
Combined
All species,
2009 & 2010,
All quarters,
Fishing intensity for all DK + D Mobile Gear

31. Meta-Correlation-Plots on Multi-Factor Impacts (Femern Belt):
Biomass
per sample
vs Fishing Intensity (Swept Area)
(Not log)
Example Individual
Species
Combined
All Habitats,
2009 & 2010,
All quarters,
Fishing intensity for all DK + D Mobile Gear

32. Meta-Correlation-Plots on Multi-Factor Impacts (Femern Belt):
Biomass per sample vs Fishing Intensity
(Swept Area)
(Not log)
Example Individual
Species
Combined
All Habitats,
2009 & 2010,
All quarters,
Fishing intensity for all DK + D Mobile Gear

33. Meta-Correlation-Plots on Multi-Factor Impacts (Femern Belt):
Biomass per
sample
vs Fishing Intensity (Swept Area)
(Not log)
Example Individual
Species
Combined
All Habitats,
2009 & 2010,
All quarters,
All DK + D Mobile Gear

34. Individual Vessel Cumulative Fishing Intensity as Swept Area;
Theoretical Example: DISPLACE scenario Evaluation
Individual Vessel Cumulative Fishing Intensity as Swept Area;
Effect on populations and fishery of certain habitat Closures; Baseline
Ongoing work

35. Individual Vessel Cumulative Fishing Intensity as Swept Area;
Theoretical Example: DISPLACE scenario Evaluation
Individual Vessel Cumulative Fishing Intensity as Swept Area;
Effect on populations and fishery of certain habitat Closures;
Scenario 1, Mitigation on sensitive areas (e.g. Balance 525)
Ongoing work

36. Theoretical Example:
Gradient of fishing pressure and response on each Baltic Balance habitat incl. habitat 525
I enclosed here few slides about our progress with DISPLACE for BENTHIS WP7. This is basically building on the work we do with Pascal and just giving the flavor of it. So more and better materials will come in a close future along his work and his reporting.

37. Theoretical Example: BENTHIS DISPLACE evaluation –
Mitigation on sensitive areas (e.g., Balance 525)
Evaluation of the
Displacement of the fishing pressure on different habitats,
Effects on the Benthic communities (biomass, etc.),
Effects on the economy of the vessels (per fisheries, etc.),
Effects on the stocks with respect to selective extraction, i.e. species / stock and age specific fishing mortality (not shown).
Ongoing work!!