13. Aquatic resource management issues

1. 13. Aquatic resource management issues Dan Minchin Marine Organism Investigations, Ireland Coastal Research and Planning Institute, University of Klaipeda, Lithuania, September/November 2013

2. OUTLINE • Environmental issues • Fishery issues • Aquaculture issues • Societal issues

3. Plastic debris Surface • Locally abundant and concentrated by current and wind vectors • Release in breakdown of toxic products • May be increasing some populations • Long time to deteriorate Bottom

4. Tsunami events

5. Mineral extraction • Concentrations of rare earth elements • Technology for mining being developed • Likely to be consequences for environment

6. Methane seeps and eruptions • Methane is toxic • Found below fish farms • Hydrates becoming unstable • Hydrates determined by pressure and temperature

7. Dead zones • From eutrophication • Collapsing algal blooms • Natural permanent/seasonal events • Deep water de-oxygenation

8. Increased acidity of seawater Norway • pH varies worldwide • Required for bone and shell • Corals and coccolithophorids vulnerable • Consequences for aquaculture

9. Extreme weather events • Damage to services • Loss of aquaculture species • Contamination • Flooding events • Raining fish, In Australia 522km from the nearest water!

10. Aral sea • Once world’s 4th largest lake • Alterations in climate • Salinities suppressed fish <growth & extinctions • to >30psu, water drop of 20m • Wetland degradation • Fishery ‘ended’ in 1983 • Most fish now in aquaculture • Marine fish introductions

11. Trading through Arctic Seas • First cold-water transport route • Higher survival possible • Will ballast water treatments be in time? Treatment trials aboard ‘OOCL Finland’ 2007

12. Deforestation • High turbidity • Greater flooding purges • Damage to benthos from siltation • Poor light penetration • Need to introduce resiliant fish

13. Tri-butyl-tin (TBT) • Used as an antifoulant on hulls and fish nets • Very toxic, environmental problems • Pacific oyster farmers, production decline • Banned since 1987, then 2005

14. Oil spills • Bacteria can use up much oxygen (One drop of oil requires 80l water) • Oil is biodegradable, temperature related • There will be more oil spills • Air breathing organisms likely population declines One month to clear surface oil

15. Fishing down the trophic system • Fewer large fishes • Industrial fisheries • Changes to ecosystem function • Some fished to commercial extinction

16. Decline of large fishes • Sturgeon: upriver barriers, keystone species (Margaratifera auricularia) • Mekong catfish • Freshwater rays • arapaima

17. Unapproved exploitation • Compromises good management • Underestimates landing statistics • Often destructive as non-target • Often organised criminal element • Fines often too leniant • Can result in job losses

18. Ghost nets • On bottom or near surface • Continue to fish • Often on wreck sites

19. Jellyfish • Blooms becoming frequent • Many species, ocean & coastal • Impacting on aquaculture/tourism • Plastics can simulate jellyfish • Few predators of jellyfish • Impair fishing activities

20. Fisheries mismanagement • Overfishing • Commercial extinction • Bycatch (27 million metric tons annually) • Targeting smaller species on the low end of the food chain

21. By-catch disposal • Returned to sea dying/dead • Can increase predatory pests • Fussy but quality food • Small fish valued in areas with high exploitation

22. Management of bycatch • Marketable when larger species are less available • May compromise a fishery • Often includes juveniles • Some strange management methods • Expand scavenger populations

23. Impact of dredges/ trawls • Impacts on benthos • Impacts on habitat • Recovery times vary • Deep-water and shallows • Resuspension of toxic materials • Areas may be important for recruitment • Lophelia may be 1-40k old

24. Managing salmon • Water quality a problems • Access to upstream regions • Habitat improvement • Occurs in wide range of environments • High exploitation Sockeye

25. Spread of pests, parasites & disease • Natural spread • Paratenic hosts • Stock transfers • Intermediate hosts

26. GMO technology • Not generally accepted by public • For aquarium species accepted • Triploid oysters bigger and sterile • Faster growth in salmonids • Anti-freezing gene introduced to salmon Brachydanio rerio

27. Diver tourism in barren niches • Making the best of a damaged environment

28. CITES • World trade ban on specific species • Many difficult to identify • Confusion on Tridacna • Biodiversity concept for humans!

29. Fish meal • Sandeels, gadoids, clupeids • 10kg of fishmeal = 1kg of salmon • Soyabean & algae oils as alternatives • Future developments for aquaculture expected

30. Energy turnover by whales Iron concentration in krill and whale faeces is 10 million times that in sea water

31. American musk-rat Rapid response Supportive legislation Knowledgeable trappers Exterminated

32. Exploitation of maerl • Use for liming land • Used for digestive disorder • Very slow growth

33. Artificial Reefs • Improving bio-density • attracting fish • providing habitats , shelter • May aid as nursery areas • Tires can be washed ashore • Tyres, wrecks and construction rubble

34. Unexpected events • Tristan da Chuna 2007 • Oil platform breaks away while under tow

35. Small craft and routes Many are idle Create large firm surface areas Small craft have special routes They avoid seasonal storms (shaded) Voyage to isolated areas Follow old sailing ship routes

36. Decommissioned vessels a risk U S A ENGLAND ? ? 71 auxillary vessels ~13 years moored in oyster area 3 vessels in Tees Haplosporidium nelsoni protozoan Perkensis marinus

37. Human health issues • Scombrotoxins • Ciguaterra • Dinoflagellate toxins • Cholera • Expansions of jellyfish

38. Technician, Biologist or Manager • You are a team • You won’t know everything • You need to keep an eye on where you are going • Matters will always change

39. Careful how you go!