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. 90TOC Pg. 91

Homework:Study for Invasive/Overfishing Quiz on Friday

Monday, February 8th

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 9th

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 10th

Overfishing

Some of the Most Exploited Fish Stocks:

CodTunaSharksGrouperSwordfish

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!

The Consequences

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 11th

Different Fishing MethodsGill netsPurse seine netsTrawlingLong linesDrift nets

Different Fishing Methods

Gill Nets

Gill Nets

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 opercula3. 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.

Purse Seine Nets

Purse Seine NetsA 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.

Trawling

TrawlingTrawls 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. Surface2. Midwater3. Bottom

Long Lines

Long LinesLong 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)

Drift Nets

Drift NetsDrift 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.

Drift Nets vs Gill Nets

Problems with Fishing MethodsBycatch= 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

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

Buoy Caught SwordfishSustainable FishNeed for Sustainable Fishing

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/OverfishingShark Finning

Homework:None

Friday, February 12th

What if There Were No Sharks

Shark Fin CSI

Shark Finning