Chris Yesson - IoZ Annual Conference - December 2013

Shrimp trawling and the benthic Shrimp trawling and the benthic habitats of West Greenlandhabitats of West Greenland

Chris YessonChris Yesson

Shrimp fishing – a >1.9bn DKK industry

• To carry the label everyone in the To carry the label everyone in the supply chain must conform to the supply chain must conform to the MSC Chain of Custody standardMSC Chain of Custody standard

• other ecolabelling schemes are available

• MSC - An independent, global, non-profit organisation MSC - An independent, global, non-profit organisation working to enhance responsible development of seafood working to enhance responsible development of seafood resourcesresources

• Standard for sustainable fishing and seafood traceabilityStandard for sustainable fishing and seafood traceability

Impacted

Watling & Norse (1998)Cons. Biol. 12: 1180-97

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' could have negligible ecosystem impact

Althaus et al (2009) M.E.P.S 397: 279-294

Unimpacted

Our mission

• What benthic habitats are there on the west Greenland shelf?

• Are there any vulnerable marine ecosystems?

• Where are they?

• What is the impact of shrimp trawling on these habitats?

• Feed back into the MSC certification process

Pamuit – survey ship

Example seabed images

Computer assisted recognitionCollaboration with UCL

A guide to the benthic fauna

Find diversity and fishing impact

H=0.4H=0.4Impact=0Impact=0

H=0.9H=0.9Impact=LowImpact=Low

Diversity and fishing impact

Weakly negative impact

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

Are all sites directly comparable?

• 3D MDS plot (3d stress=1.47)

Different response of habitats

Habitats differ by environment too

What effects diversity?

Rocky seabed:+ Depth***- Current Speed***

Generalised linear modelsDiversity ~ Fishing + Environment

Muddy seabed:- Fishing impact**

A historical perspective

• Per Kanneworff's benthic images (1975-1986)

• 50 reels of film (~40,000 images)

• Measure change over 40 years

Bycatch of large vulnerable organisms

Identifying vulnerable habitats

• Submarine telecoms cable planned

• Offering advice on potential impact

Identifying vulnerable habitats

• Submarine telecoms cable planned

• Offering advice on potential impact

Conclusions

• Benthic (seabed) habitats in Greenland are diverse

• Rocky habitats have seen lower fishing impact and seem less disturbed

• Muddy habitats may be negatively impacted by fishing

• 3 more years of surveys will give us more robust data

• A historical perspective will be useful

• Our observations are feeding back into monitoring and marine spatial planning

Contributors & Collaborators

• At IoZ

–Kirsty Kemp

– Irina Chemshirova

–Poppy Simon

• Others

–Ed Johns

–Sustainable Fisheries Greenland

–Peder Munk Pedersen

–Greenland institute of natural resources

–Nanette Hammeken

–Martin Blicher

–Crew of M/T Pamiut