1. Pg. 92 RTW: What is one problem caused by invasive species? Objective: I will be able to describe the consequences of biodiversity due to invasive species and their effects on the marine ecosystems and their modes of introduction. Agenda: Gallery Walk Invasive Species (pg. 89) GOW Pg. 90 TOC Pg. 91 Homework: Study for Invasive/Overfishing Quiz on Friday Monday, February 8 th

2. Pg. 92 RTW: Should we kill invasive species? Objective: I will be able to describe methods of commercial fishing and their impact on the world’s oceans. Agenda: Tragedy of the Commons Lab Homework: Study for Invasive/Overfishing Quiz on Friday Tuesday, February 9 th

3. Pg. 92 RTW: What is the tragedy of the commons? Give an example of a public/global common Objective: I will be able to describe methods of commercial fishing and their impact on the world’s oceans. Agenda: Overfishing notes pg. 93 Homework: Study for Invasive/Overfishing Quiz on Friday Wednesday, February 10 th

5. Overfishing

6. Some of the Most Exploited Fish Stocks: Cod Tuna Sharks Grouper Swordfish

8. Maximum Sustainable Yield = the maximum level at which a natural resource can be routinely exploited without long-term depletion. Currently we are exploiting our fish stocks to such an extent that experts expect that the fishing industry will collapse by 2050!

9. The Consequences

10. Pg. 92 RTW: List the most threatened fish stocks. Objective: I will be able to explain the concept of overfishing in terms of maximum sustainable yield and cite examples of overfished stocks. Agenda: Overfishing Notes (pg. 93) Homework: Study for Invasive/Overfishing Quiz on Friday Thursday, February 11 th

11. Different Fishing Methods Gill nets Purse seine nets Trawling Long lines Drift nets

12. Different Fishing Methods

13. Gill Nets

14. Gill nets are vertical panels of netting normally set in a straight line. Fish may be caught by gill nets in 3 ways : 1. wedged – held by the mesh around the body 2. gilled – held by mesh slipping behind the opercula 3. tangled – held by teeth, spines, maxillaries, or other protrusions without the body penetrating the mesh. Mesh size, twine strength, as well as net length and depth are all closely regulated to reduce bycatch of non-target species.

15. Purse Seine Nets

16. A purse seine is a large wall of netting deployed around an entire area or school of fish. The seine has floats along the top line with a lead line threaded through rings along the bottom. Once a school of fish is located, a skiff encircles the school with the net. The lead line is then pulled in, "pursing" the net closed on the bottom, preventing fish from escaping by swimming downward.

17. Trawling

18. Trawls are nets towed behind a boat to collect organisms. Trawls can be divided into three categories based on where they sample the water column: 1. Surface 2. Midwater 3. Bottom

19. Long Lines

20. Long lines use a long line, called the main line, with baited hooks attached at intervals by means of branch lines called snoods. Longlines can be set to hang near the surface (pelagic longline) or along the sea floor (demersal longline)

21. Drift Nets

22. Drift nets hang vertically in the water column without being anchored to the bottom. The main difference between gill nets and drift nets is whether or not they are anchored to the bottom.

23. Drift Nets vs Gill Nets

24. Problems with Fishing Methods Bycatch= the unwanted fish and other marine creatures caught during commercial fishing for a different species. Trawling methods can damage coral reefs and other ecosystems Unsustainable

25. Solutions? Reduce bycatch with alternative gear (turtle exclusion hatch or circle hooks) Use sustainable methods Aquaculture= raising fish similar to livestock

26. Buoy Caught Swordfish Sustainable Fish Need for Sustainable Fishing

27. Pg. 92 RTW: Name one type of fishing method and how it negatively impacts the oceans. Objective: I will be able to explain the concept of overfishing in terms of maximum sustainable yield and cite examples of overfished stocks. Agenda: Quiz on Invasive Species/Overfishing Shark Finning Homework: None Friday, February 12 th

30. What if There Were No Sharks Shark Fin CSI Shark Finning