Aquaculture and Biodiversity Conservation

1. Aquaculture and Biodiversity Conservation James S. Diana University of Michigan Aquaculture CRSP

2. Plans for today • Overview aquaculture and capture fisheries • Review some issues about aquatic biodiversity conservation in the U.S. • Examine the positive and negative aspects of aquaculture related to conserving biodiversity • Propose a couple of systems that are able to produce aquatic crops without major threats to biodiversity

3. Overview fisheries and aquaculture Fastest growing food production system globally at about 7.42 % increase per year since 1995 (9% 1985 to 1995) Can either exacerbate or reduce pressure on wild fisheries Increasing number of new species produced by aquaculture as other stocks decline (cod, hake, halibut, cobia, tuna) New industry with significant potential for innovation FAO forecasted global increase in seafood consumption of 1.5 kg/person, while catches remain static In US, a 1.5-2 billion kg increase in seafood consumption is anticipated by 2020, all from aquaculture Seafood exports generate twice as many $ for LDCs as coffee, tea, rubber, bananas, rice, meat combined—35% from aquaculture Why should we promote aquaculture?

4. What is aquaculture? • Controlled growing of some aquatic crop, mainly for food • Control can vary from complete life cycle to just placing appropriate medium for settlement • Level of inputs (intensity) varies • Extensive = just raise in appropriate place • Semi-intensive = add fertilizer and control water quality • Intensive = provide full feed, water exchange, aeration, other chemicals

5. Recent Trends in Aquaculture and Fisheries 38% 12.5% FAO 2005

6. Future Trends in Aquaculture and Fisheries 202573% 2011 50% FAO data and Diana projection

7. Top 24 Species Produced Globally Portion of wild fishery used for aquaculture feeds From Aaron McNevin (WWF)

8. Trends in cod and anchoveta (MMT) FAO 2005

9. Tuna yields (TMT) FAO 2005

10. Proportional culture of species in 2000 FAO 2005

11. Changes in culture yields (MMT) FAO 2005

12. Trends in 3 cultured species (TMT) FAO 2005

13. Global Significance of U.S. Freshwater Species Trends in aquatic biodiversity in the U.S. Master et al. 1998 (TNC)

14. Why worry about aquatic biodiversity • Among vertebrates, fish species outnumber all other vertebrates combined • Aquatic invertebrates are often sensitive indicators of pollution problems • Very high rates of endemism in several aquatic systems (caves, African great lakes, some isolated streams)

15. Proportion of U.S. Species at Risk Master et al. 1998 (TNC)

16. Number of species and endangered species by state

17. Known Causes of Animal Extinctions Cox 1993

18. Distributions of exotic fishes

19. Changes in shared species among pairs of statesHOMOGENIZATION Rahel 2000

20. Number of events changing species in a state Total = 901 Total = 196 Rahel 2000

21. Relative Importance of Aquaculture Impacts Positive and negative aspects of aquaculture Boyd et al. 2005

22. Impacts that Affect Biodiversity (my ranking) • Escapement and invasive species • Effluents and water pollution • Land use change • Use of fish meal in feeds • Predator controls • Genetic alteration from escaped organisms • Antibiotic and hormone use

23. Positive Impacts on Biodiversity • Production reduces pressure on wild stocks • Stocking organisms to enhance depleted stocks • Effluents and wastes increase production, abundance, and diversity of species in local area • Income generation replaces less sustainable income generating systems

24. Negative Impacts – Invasive species Virtually all of these traits are ones favored for species used in aquaculture! Ricciardi & Rasmussen 1998

25. Negative Impacts – Invasive species • Tilapia is poster child • More than half of documented introductions were not result of aquaculture but natural stocking (Canonico et al. 2005) • Many species also spread by aquarium trade and dumping

26. Negative Impacts – Invasive species • Factors limiting escapee impacts • Most fish have been little domesticated; that is, they are essentially wild fish

27. Negative Impacts – Invasive species • Escapement is inevitable with aquaculture species in almost any system • Best avoidance is not culturing outside of native or common current range

28. Negative Impacts – Effluents and Pollution • Common concern in cages/pens • In oligotrophic waters, actually seems to increase biodiversity • Probably a major issue in eutrophic waters • We rely on the assimilative capacity of waters as an important ecosystem service

29. Negative Impacts – Effluents and Pollution • Oligotrophic studies • 43 Chilean farms, only negative effects on benthic invertebrates in ‘fallout’ zone, much increase in pelagic diversity and production • Soto and Norambuena 2004 • Aegean farms showed increases in pelagic and benthic fish diversity and production in farmed zones • Machias et al. 2004, 2005

30. Effluents and pollution • Clear that impact depends greatly on the density of fish in cages and of cages in area • We need to know more about the assimilative capacity of waters and the resultant limits to cage culture • Some pen facilities have the combined loading of phosphorus and nitrogen equivalent to domestic discharge of a fairly large city

31. Effluent discharge, nutrient loss and pollution • Effluents can also be a concern in ponds, especially for intensive culture • May be remediated by plant co-culture or by draining and harvesting techniques

32. Negative impacts - land use change • Poster child is loss of coastal mangroves to shrimp culture

33. Mangroves and shrimp culture FAO 2005

34. Abandoned shrimp ponds Cycle of intensity, disease, pond failure, and abandonment Results in altered land Causes salinization of soils Often land taken from other productive use

35. Mangrove losses • Important nursery and storm buffering area • Coastal development has caused large losses (33%) from many sources, including pond shrimp culture (Alongi 2002) • Many specific studies show aquaculture and others are responsible for mangrove loss

36. Abandoned shrimp ponds and society Thai ponds – not abandoned but cycle of use Most local people perceive that they have a better life as a result of shrimp culture Obvious economic benefits as well as development of an industry for rural areas Disease and abandonment has been a major problem in some countries – Taiwan, China convert Original agricultural pursuit (rice, fish, pigs, etc.) Poor Management, disease and pollution lead to Longer-term options Shrimp Culture Collapse Invest More Immediate Options Fallow Abandon Rent land to others New land use (salt pan, extensive culture, housing, industry, fish)

37. The Fishmeal Issue • 20-30 MMT of biomass currently harvested to produce 6-7 MMT of fish meal • Aquaculture uses approximately 50% of all fishmeal and 80% of global fish oil (80 & 95% respectively by 2020) • Salmon aquaculture uses 2-3% of all fish caught for feed • Shrimp aquaculture uses 3-4% of all fish caught for feed • Antarctic krill biomass estimated at 62-137 MMT in 2000 but only 1.5 MMT of krill can be harvested without impacting krill predators From Aaron McNevin (WWF)

38. Fishmeal Species Produced Globally Portion of wild fishery used for aquaculture feeds From Aaron McNevin (WWF)

39. Aquaculture’s Share of Small Pelagics From Aaron McNevin (WWF)

40. Trends in anchoveta (MMT) FAO 2005

41. Atlantic Salmon case • Mainly commercial fishery • Important and popular sport fish as well • Aquaculture began in 1960s • As aquaculture grew, pressure on wild fish declined • Now some rejuvenation of wild stocks as well

42. Changes in Atlantic salmon yields

43. Environmentally friendly aquaculture systems Cage-cum-pond system Feed Solid waste Fed fish Sediment Caged fish Soluble waste Water Waste feed Phytoplankton Open filter- Feeders Solids Intensive pond culture system Liquids

44. Catfish – tilapia co-culture Only works where both species are native or very common!

45. Tilapia-tilapia co-culture • Can also work with other local combinations of species, with fed fish in cages, best when not using fish meal feed, and filter feeding fish in ponds • Climbing perch – rohu in Bangladesh

46. Fish and plant culture • Many ponds are grown with multiple use in mind • Can even use in restoring communities • Value added by second crop can make the operation successful

47. Added revenue from new plant crop

48. Conclusions • Older aquaculture crops often used systems that damaged biodiversity in local area • Modern certification and organic standards are forcing aquaculture to use less damaging systems • Overall effects have been both positive and negative to biodiversity, and can be managed • Management balance of cost of technology, benefit in sales, and regulations or forcing by market