Fisheries Oceanography

1. Fisheries Oceanography Lecture 9: 6/12/2014

2. Some terms... • Oceanography: physical, chemical, geological, biological, …fisheries • Fishery: a particular stock of fish (single or multi-species) and the fishing activities associated with their harvest (fisherman, gear, vessels, facilities) • Fisheries Management: “To ensure the sustainable production over time from fish stocks, …” (Hilborn and Walters 1992). • Fisheries Science: study of fisheries, including fisheries biology, marine ecology, social science, modeling, stock assessment, etc. • Fisheries Oceanography: ? • Understanding the factors affecting the spatial and temporal dynamics of marine fish populations • Some key variables? Temperature, Dissolved oxygen

3. Historically... • 1497: "the sea there is full of fish that can be taken not only with nets but with fishing-baskets" • 1600: “so thick by the shore that we hardly have been able to row a boat through them”

4. Shifts in Environmental Ethos • Preservation vs. Conservation • Prior to 1960s—Boundless Sea • 1970s to 1990s—Environmental Capacity • 1990s to 2000s—Precautionary Principle • 2000s to present—Ecosystem Based Management

5. Law of the Sea Treaty (1982 UN) • Arose from the rapidly developing marine drilling technology • Territorial: Out to 12 nm • Contiguous Zone: 12-24 nm • Exclusive Economic Zone (EEZ): State has sole exploitation rights over all natural resources

6. Significant Federal Conservation Legislation • Endangered Species Act (1973) • Magnuson Stevens Fishery Conservation Act (1976) • Clean Water Act (1972) • Oil Pollution (1990) • Sustainable Fisheries Act (1996) • American Recovery/Reinvestment Act (2009)

7. Magnuson Stevens Act (1976) • Established comprehensive federal management • Established EEZ to 200 nm (1983) • Created federal fishery management councils • Established loan programs to increase US fishing • Main goals: • Prevent overfishing while achieving optimum yield from each fishery for US fishing industry • Conservation and management based on the best scientific info available

8. Sustainable Fisheries Act (1996) • First attempt to institute a precautionary approach to management • Fishery management plans (FMPs) must specify stock status determination criteria • Rebuilding plans required for overfished stocks • Bycatch limits

9. Management

10. EEZ: United States www.whitehouse.gov

13. Linking Oceanographic Data  FishCase Study: The Bering Sea • Alaska - 40% of fisheries yield in US • Mainly Walleye Pollock (Pictured), cod, salmon • Landings (last decade) • Walleye Pollock 0.48-1.40 x 106 tons (Ianelli et al. 2011) SE Bering • Cod 0.12-0.18 x 106 tons (Thompson and Lauth, 2011)eastern Bering Sea • $1.7 billion economic value • What controls the Pollock?

14. The Oscillating Control Hypothesis (OCH)(Hunt et al. 2002, 2011) • Relates the timing of ice, stratification, phytoplankton to the abundance of age0 pollock’s food source … large crustacean zooplankton • Ice is dynamic (Stabeno et al. 2012, Ave days of ice cover in March and April … period important for phytoplankton bloom and zooplankton)

15. Oceanography of the OCH

16. Fisheries of the OCH

17. CombinedOCHModel(Fig by Krause & Lomas, 2013) Any issues in food web model?

18. A RevisedOCHModel(Fig by Krause & Lomas, 2013)Includes:- Microzoo- Diatom quality vs. quantity- More complex foodweb

19. Acoustic fingerprints of fish (Benoit-Bird et al. 2003)

20. Oceanographic/Ecological Variables explain distribution of pollack Benoit-Bird et al. 2013

21. Oceanographic/Ecological Variables explain distribution of pollack Benoit-Bird et al. 2013

22. Fisheries 101 All terms vary in response to changing oceanographic and ecological variables Fishable stock P (for population) Natural Mortality, M Recruitment, R Fishery Mortality, F Growth, G Also called the Yield

23. Recruitment: fish are ‘recruited’ to the stock when they are large enough to be harvested by the fishery (nets, crab pots, etc). Recruitment is highly variable, and depends on the number of eggs produced and survival of the young to recruitment size. Maximum recruitment rate At intermediate stock size High stock: the large number of old big fish compete with young fish for food, or even eat them, resulting in an upper limit of stock size Low stock: few adults, few eggs Recruitment rate, R Stock size, P

24. Growth: amount of biomass added per unit time varies with the age of the fish, typically with maximum growth rates at intermediate ages Age group with maximum growth rate Size of fish Age at first recruitment Age of fish

25. MSY: Maximum Sustained yield • The largest yield that can be taken from a stock • Maintain pop. Size for max growth and optimized mortality • Allow pop to be productive indefinitely

26. Natural Mortality, M This is very difficult to determine It is often approached by mark and recapture: tagging and releasing a certain number of individuals in the fish stock, and then keeping track of the proportion of tagged individuals are recaptured (by the fishery or by the taggers) Problems: • tagged individuals may be ‘catch-prone’, not representative of the population; • statistics are lousy since only a small fraction of tagged individuals are likely to be recaptured • The process of tagging can cause mortality in the tagged and released fish

27. 3 Modes of Fishing • Recreational: • No sell • Commercial: • Catch and sell • Artisanal: • Low tech • Developing countries • Small scale www. knowledge.allianz.com www. nmfs.noaa.gov

28. The units involved: • • 1 metric ton = 1000 kg = 2200 lbs • = 1 large fish box • • 1 million metric tons = 109 kg • = average football stadium full of fish • • Approx. annual world catch • = 90 million metric tons • = 90 football stadiums

29. Ecosystem Based Management • Diverse ecosystem service provision • Importance of natural boundaries • Integrated management • Accounting for cumulative impacts and tradeoffs among services • Making decisions under uncertainty Goal: Sustain long-term capacity of systems to deliver ecosystem services. • Shortfall of management: All assessments are based on individual stock instead of incorporation into system

30. Ecosystem Services • Gas regulation • Water regulation/supply • Soil formation • Nutrient supply • Waste treatment • Refugia • Biological control • Genetic resources • Recreation • Cultural

32. The Case of Marine Mammals and Whaling • History of Whaling: 8,000 yrs BP • Early modern whaling 16th C. • Oil and meat • 50k+ whales killed by 1930s • Marine mammal populations • Moratorium on blue whale in 1966: all great whales 1986 www.christchurchcitylibraries.com www.school.discoveryeducation.com

33. Aquaculture: What is cultured? • Ornamentals and Aquaria • Research • Stock Enhancement • Food www. windmill.co.uk www. do-while.com www. fau.edu www. en.wikipedia.org

34. Aquaculture: The Blue Revolution • The rapid increase in aquaculture production in the past 25 years and the technology that made it possible • CHINA – BY FAR the global leader • The 2 great promises of aquaculture: • To supply protein to a global human population that is in desperate need of additional sources of protein • Aquaculture is touted by some as a panacea for overfished natural populations because it theoretically would • Make up for shortfalls in natural production • Recover natural stocks by alleviating fishing pressure as reported by http://faostat.fao.org/site/629/default.aspx Main aquaculture countries in 2010 http://en.wikipedia.org/wiki/Aquaculture#mediaviewer/File:Global_aquaculture_production_by_country_2010.png

35. Aquaculture: Negative Issues • Environmental effects great in some forms of aquaculture • Destruction of natural habitats • Eutrophication and sedimentation • Excessive usage of resources • Negative effects on native fishes • Disease transfer • Parasite transfer—sea lice • Invasive species • Genetic impacts • Antibiotics • Predator conflicts www.seagrant.uaf.edu Sea Lice www.earthaction.org

36. Aquaculture: The Future www. foodfreedom.wordpress.com www. fis.com

37. The Argument of Fishing down the web vs. Fishing through the web • Fishing down the web: start with the top predators then move down the smaller and smaller species • Fishing through the web: start with meso-predators then started on the extreme ends with sharks. Pauly (1998) What do you think? Which is worse?

38. Fishing down marine food webs: Presently the catch of ‘small pelagics’ (10-30 cm in length) is about 1/3 of the total global marine fish catch. Small pelagics are vitally important as food for larger fish, such as cod. Depleting prey fish stocks keeps larger fish stocks from recovering, and disrupts marine ecosystems. …a strong lobby exists which …challenges the obvious to maintain the unacceptable. (Daniel Pauly 2003)

39. Atlantic cod: a text-book example of over-harvesting a fish stock Cod abundance has declined sharply since the late 80s in most areas of its distributional range. For some cod management units, spawning stock biomasses are sufficiently low that fisheries have been closed since 1993.

40. 1900 1950 1975 1999

41. As traditional fish stocks have declined, alternate fish populations are being exploited, including deep water species (which grow and reproduce slowly so are highly vulnerable to overfishing).

42. Status of World Fisheries • Capture fisheries are unlikely to increase production in the future • Likely increasing importance of aquaculture Tilapia - aquaculture success story

43. A solution? Personal choices AVAILABLE FOR DIFFERENT SECTIONS OF THE COUNTRY: http://www.mbayaq.org/cr/cr_seafoodwatch/download.asp

44. A solution? Local choices

45. A solution? Government regulation Locations of current US marine sanctuaries

46. Marine reserves : ocean areas fully protected from activities that remove animals and plants or alter habitats, except as needed for scientific monitoring Protected Areas: multiple types Marine Reserves/Sanctuaries

47. A solution? International efforts From Greenpeace, Roadmap to Recovery: A Global Network of Marine Reserves