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 Ian Craick Bernice Longouo Jeremy Raynor A Case Study on the removal of sharks and wolves.

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Presentation on theme: " Ian Craick Bernice Longouo Jeremy Raynor A Case Study on the removal of sharks and wolves."— Presentation transcript:

1  Ian Craick Bernice Longouo Jeremy Raynor A Case Study on the removal of sharks and wolves

2  Apex predators are the top level predators in an ecosystem. This means that they have no natural predators  Humans become predators – upset the natural balance

3  What is removal?  How are predators removed?

4  Ecosystems Services  Ecosystem dynamics and function  Energy and nutrient flow  Human Health

5 The importance of predation - predators have a fundamental influence on structure and function of ecosystem - Predators influence prey population and community - Predation affect prey behavior. Presence of predator allow prey to use behavioral mechanism to reduce predation risk.


7  Large shark populations down by about 90% or more regionally  Found out of 547 species studies 20% were threatened (sharks, rays, chimaeras)  Difficult to measure due to mobility and low populations of target species Nicholas Dulvy 2006 Heithaus et al. 2008

8  How do apex predators influence Nutrients flow?  Mainly through Biologic factors  Two methods: -Top Down Control -Trophic Cascades

9  Changes in top predators influence the abundance and behavior of organisms in lower trophic levels

10  Top predators influence trophic levels two or more levels below them Post 1999

11  Wolf removal has seen major spikes in Deer, Elk, Moose and other prey populations  Wolf re-introduction has seen decreases in prey populations and significant increases in foliage

12  Last Wolves exterminated in 1926 within the park  Re-introduced in 1994-95  Pack reached a record high of approximately 40 individuals  Elk populations rise when wolves are exterminated, decreased after peak (resource limited) then decreased to ~pre-extermination levels after re-introduction of wolves

13  Shark presence shapes prey behavior  Shark Bay, Australia  Behavior changes -Spatial -Temporal

14 Fear – Politics – Apathy – Ignorance - Greed

15 North American Gray wolf (canus lupus) Black Tip Shark population off the East Coast of the United States Heithaus et al. 2008 article FIURipple et al 2005

16 Shark Finning Fear – Ideas of sharks as competitors and dangerous Money – Shark fin soup market growth in China Accidental Catch (bycatch) Long Lines, Trolling, Siene Netting



19  Defenders of Wildlife Wolf Video Clip Defenders of Wildlife Wolf Video Clip State-funded culling programs Last month, Idaho’s Governor Otter signed a bill creating a $400,000-per-year wolf extermination fund. Approximately 1,300 Wolves have been killed in Idaho alone since 2011

20  There ARE solutions  There ARE things YOU can do to help  Scientifically proven equations for success

21  MPA (Marine Protected Areas)  National Parks  IUCN Red List ( International Union for Conservation of Nature )  CITES (International Trade Regulations)  Magnuson-Stevens Act (Fishery Conservation, Mgmt. USA)  Shark Finning Prohibition Act (USA)  ESA - Endangered Species Act (USA)  Biodiversity Hot Spots

22  Education based on Long Term Scientific Studies  Advocacy based on the facts, environmental lobbyists  Awareness & Action: 1. Know the issue from multiple perspectives (Volunteer) 2. Know the history and current situation (Investigate) 3. Make a difference voice your opinion & support research

23  Abesamis, R A, and G R. Russ. "Density-dependent Spillover from a Marine Reserve: Long-Term Evidence." Ecological Applications. 15.5 (2005): 1798-1812. Print.  Beschta, R L, and W J. Ripple. "River Channel Dynamics Following Extirpation of Wolves in Northwestern Yellowstone National Park, Usa." Earth Surface Processes and Landforms : the Journal of the British Geomorphological Research Group. 31.12 (2006): 1525-1539. Print.  Dulvy, Nicholas K. "Conservation Biology: Strict Marine Protected Areas Prevent Reef Shark Declines." Current Biology. 16.23 (2006). Print.  Graham, Nicholas A. J, Mark D. Spalding, and Charles R. C. Sheppard. "Reef Shark Declines in Remote Atolls Highlight the Need for Multi-Faceted Conservation Action."Aquatic Conservation: Marine and Freshwater Ecosystems. 20.5 (2010): 543-548. Print.

24  Heithaus, MR, A Frid, AJ Wirsing, and B Worm. "Predicting Ecological Consequences of Marine Top Predator Declines." Trends in Ecology & Evolution. 23.4 (2008): 202-10. Print.  Kareiva, Peter. “Conservation Biology: Beyond Marine Protected Areas” Current Biology. 16.14 (2006). Print.  Knip, D.M, M.R Heupel, and C.A Simpfendorfer. "Evaluating Marine Protected Areas for the Conservation of Tropical Coastal Sharks." Biological Conservation. 148.1 (2012): 200-209. Print.  Ripple, William J., and Robert L. Beschta. "Linking wolves and plants: Aldo Leopold on trophic cascades." BioScience 55.7 (2005): 613-621.  Robbins, William D, Mizue Hisano, Sean R. Connolly, and J H. Choat. "Ongoing Collapse of Coral-Reef Shark Populations." Current Biology. 16.23 (2006): 2314-2319. Print.  Post, Eric, et al. "Ecosystem consequences of wolf behavioral response to climate." Nature 401.6756 (1999): 905-907.

25  Ian Craick Bernice Longouo Jeremy Raynor A Case Study on the removal of sharks and wolves “ To keep every cog and wheel is the first precaution in intelligent tinkering” –Aldo Leopold

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