Overview of a project to assess the impact of shrimp fishing on the benthic habitats of Greenland. Talk given by Chris Yesson to A-Level students for the Edexcel talk series at the Zoological Society of London in November 2013

1. How does fishing affect the
seabed of Greenland?
Chris Yesson

2. Where's Greenland?

3. Where's Greenland?

4. Shrimp fishing – a 1bn DKK industry

5. Marine Stewardship Council

6. Marine Stewardship Council
• Recognise and reward fisheries that fish sustainably
• Work with fishery and commercial partners to build a
market for sustainable seafood
• Give buyers and consumers an easy way to find
seafood from a sustainable fishery - the blue MSC
ecolabel

7. Potential impact of trawling gear
• Some trawling has been likened to
forest clear cutting
• Gear that is dragged along the
bottom of the seabed can disturb,
damage or destroy many organisms
• But the 'right gear' used in the 'right
habitat' can have negligible impact
Unimpacted
Impacted
Collie et al (2000)
ICES J. Mar. Sci 57: 987-1000
Watling & Norse (1998)
Cons. Biol. 12: 1180-97

8. Our mission
• What benthic habitats are
there on the west Greenland
shelf?
• Are there any vulnerable
marine ecosystems?
• What is the impact of shrimp
trawling on these habitats?

9. Pamuit – survey ship

10. Bycatch of large vulnerable organisms

11. Example seabed images

12. Some things are easy to identify

13. Some things are difficult to spot

14. Some things we can't ID

15. A guide to the benthic fauna

16. Biodiversity is...
• "The variability among living organisms from
all sources including terrestrial, marine and
other aquatic ecosystems, and the ecological
complexes of which they are part; this includes
diversity within species, between species and
of ecosystems." - Convention on Biological
Diversity

17. Which has higher biodiversity?
A
B

18. Which has higher biodiversity?
C
B

19. Diversity
• Number of organisms
• Number of species
• Biomass
• Shannon index
– An measure that tries to
balance species and
organisms

20. Calculate diversity for all stations
H=0.4
H=0.9

21. … and find fishing impact
H=0.4
Impact=0
H=0.9
Impact=Low

22. Low
Diversity
High
Scatter plots
High
Low
Fishing impact

23. High impact
→ Low diversity
High
Low
Fishing impact
Low
Diversity
High
Scatter plots

24. High
Scatter plots
Low
Diversity
Low impact
→ High diversity
High
Low
Fishing impact

25. High
Scatter plots
Low
Diversity
?
High
Low
Fishing impact

26. Diversity
Scatter plots – detecting patterns
Fishing impact

27. Diversity
Scatter plots – detecting patterns
Fishing impact

28. Scatter plots – detecting patterns
Inverse correlation
No correlation

29. Diversity and fishing impact
Weakly negative impact

30. Are all sites directly comparable?
• Sites with rocks have different species composition to
those with only sand & mud
• Impact of fishing may be different for these habitats
Most soft corals are
permanently attached to rock
Many soft sediment species can
bury themselves in the sand/mud

31. Different response of habitats

32. Habitats differ by environment too

33. What effects diversity?
Muddy seabed:
●
Fishing impact
Rocky seabed:
●
Depth
●
Salinity
●
Slope
●
Temperature

34. Conclusions
• Benthic (seabed) habitats in Greenland are diverse
• Rocky and muddy seabeds are home to different
species
• Rocky habitats have seen lower fishing impact and
seem less disturbed by fishing activities
• Muddy habitats may be negatively impacted by fishing

35. Thanks
• At IOZ
–Kirsty Kemp
–Irina Chemshirova
–Poppy Simon
• Others
–Sustainable Fisheries Greenland
–Peder Munk Pedersen
–Greenland institute of natural resources
–Nanette Hammeken
–Martin Blicher