"The End of the Line" Documentary Film

My assignment this week was to watch the film "The End of the Line" and answer questions about it:

1. Fishermen in Newfoundland, Canada had been experiencing declining cod harvests for years when a sudden change was announced in 1992. What was the change? Mark it with a line on the graph.

A moratorium on cod fishing until 1994

2. What was the economic impact on Newfoundland of this decision? Did the stocks of Atlantic Cod recover?

40,000 people lost their jobs overnight. The cod recovered only slightly.

3. In 2001, records showed that local stocks of fish were down worldwide. Yet, records of harvests indicated that fish were being taken at record rates. What was actually happening?

China was falsely reporting inflated statistics.

4. Stocks of Bluefin tuna have dropped by 80%. What reasons are given for this and other population declines seen in commercial fish?

There are too many boats, and not enough fish.

5. Why is Bluefin tuna particularly at risk?

The Bluefin Tuna's flesh is widely sought after and makes fishermen a lot of money.

6. List the recommended quota limit for Bluefin tuna, the recovery limit (so stocks could replenish), thequota set by the politicians, and the actual estimated catch.

Recovery Limit – 10,000 tons

Recommended Limit – 15,000 tons

Established Quota – 29,500 tons

Actual Catch - 61,000 tons

7. The documentary alleges that the Japanese corporation Mitsubishi is hoarding tons of frozen Bluefin tuna. Why would they?

Greed. Once there are no more Tuna left to catch, they can sell the frozen stocks at whatever price they demand.

8. Why are native fishermen having such a difficult time making a living along the West coast of Africa?

Because the European boats are using massive industrial scale fising boats, leaving the natives almost nothing.

9. What species of marine animals make up “bycatch”? What percent of total catch does this make up?

Bycatch makes up one tenth of the total catch, and consists of Turtles, Seabirds, Sharks, and Dolphins.

10. Which trophic level of fish is hunted in the Coral Triangle?

Tertiary Consumers

11. What impacts have been observed at Chesapeake Bay as a result of selective hunting like this?

The population of Cownose rays exploded.

12. Atlantic Cod in Newfoundland occupied a similar level on theecological pyramid – how has their absence impacted the food web?

There are now large populations of Lobsters, as well as jellyfish. algae and worms.

13. Describe four ways that fishing in Alaska is more tightly controlled and regulated, thus preventing a collapse of their fishing stocks.

Alaska keeps control of how many fishing boats are in their waters. They drive away boats without proper liscences. They have scientifically derived quotas, and they enforce the 200-mile limit. They give fisherman a limited time to fulfill their quota.

14. What is Marine Stewardship Council (MSC) certification?

It is essentialy a certificate of sustainibility.

15. What is the problem with fish farming or aquaculture? How many kilos of anchovy are needed to produce a kilo of salmon? What would be a better option for consumers?

Fish farming uses wild fish to feed the farmed fish and kills more than it produces. Five kilograms of anchovy per one kilogram of salmon. It would be better just to eat the anchovies.

16. What are marine reserves? How do ecosystems respond once an area is declared a reserve?

Marine reserves are areas where no commercial fishing is allowed, which often leads to popularion recovery.

17. (a) What percent of the ocean would need to be reserves to maintain sustainable fishing stocks? (b) What percent is currently part of a reserve?

(a) 20-30%.

(b) Less than 1%

18. Are ocean fish as we are harvesting them a renewable or nonrenewable resource?

Nonrenewable. They can't replace themselves at the rate they are being caught and killed.

19. Bottom-trawling is frequently mentioned in the documentary as one of the worst, most damaging forms of commercial fishing. Explain why.

Trawling not only targets the Fish, but it also targets the entire ocean floor ecosystem by destroying habitat.

20. According to the documentary, 50% of Atlantic Cod is caught illegally. One quote given is “every other cod in your plate is stolen – from you.” Is this accurate? Are the oceans a commons area?

The oceans are all interconnected, and what somebody does on one side of the ocean can affect the entire ecosystem, so they are a common area. Overfishing is a global problem.

21. If a gourmet restaurant were to put dishes with endangered mammals on the menu – such as orangutan or lions, it would be a huge public scandal. Why isn’t there a similar reaction to endangered fish?

Because by the time a fish gets on to a consumer's dinner plate, it no longer looks like a fish. People don't really sympathize with fishsticks. And most people don't even know what species are endangered. And we have a pro- cute furry mammal bias that doesn't apply to fish, which many people see as primitive or strange by comparison.

Bony Fish Body Plans

Threre are three major body types in bony fish: Fusiform, Compressed, and Depressed.

I used Tinkercad software to build a digital 3D-model of each type.

A Fusiform body plan is streamlined, elongated laterally, with a long, muscular tail. This body type is helpful for predators to catch their prey, and for prey to try and escape. A good example of this would be a Sailfish (Istiophorus albicans).

A Depressed body plan is squahed vertically, like a pancake. This is advantageous to benthic dwellers, such as Hogchokers (Trinectes maculatus), who need to be able to grab food from the sea floor, and to hide from predators.

A Compressed body plan is flattened laterally, and is useful for maneuverability. and for hiding in tight spaces, like in a coral reef. One example is the Angelfish (Pterophyllum sp.)

Here are all 3 shapes together from several angles, for comparison.

Sharkwater

My assignment this week was to watch the filim "Sharkwater" and answer questions about it.

Shark Myths

1. Why are sharks so hard to photograph?

They often feel threatened by humans and avoid us.

2. What prey defenses have evolved in fish in response to predators like sharks?

Schooling, camouflage, speed, size, and communication

3. What strategies are given for repelling sharks in the black and white film?

Sounds, a stream of bubbles, shredding paper to confuse the shark.

4. According to the documentary, elephants kill more people than sharks. Why then, do people fear sharks so much more?

Psychological revulsion to a "cold monster of the deep".

5. What conditions around the Galapagos Islands of Darwin and Wolf make them so favorable for the hammerhead sharks?

Undersea currents bring plankton, which attracts creatures that eat the plankton, which attracts hammerheads.

6. What two additional senses do hammerhead sharks have that humans do not?

Lateral lines and electromagnetic detection.

7. How many humans have been killed by hammerhead sharks?

Zero

Long Line Fishing

8. List the fish found in the long line recovered by the film crew.

Sailfish, Dorado, Sharks, and Tuna

9. Explain why sharks are not equipped to tear flesh from animals larger than them. What causes moast human deaths from shark attack?

A shark's teeth are not designed for tearing flesh. Most shark related deaths are caused by blood loss.

10. As illustrated by the book Moby Dick, people used to be afraid of whales. How have public perceptions of whales changed since then.

People have come to see them in a new light as beautiful.

11. What does Captain Paul Watson and the Sea Shepherd Conservation Society do to protect whales and sharks from illegal fishing?

They intervene directly to provide enforcement of fishing and whaling regulationsm and treaties, sometimes at the request of governments, sometimes on their own. They sometimes ram whaling ships..

12. The Sea Shepherd caught the Varadero I, an illegal shark fishing boat. Why didn't the fishermen stop on orders from the ship? What are shark fins used for?

The fishermen would lose their ship, their fishing license, and their profits. Shark fins are used to make shark fin soup, which is seen as a status symbol in some Asian cultures.

13. What is the basis for the belief that shark fins have medicinal properties?

Sharks appear to be more resistant to disease, though there is no scientific basis for this. Some people think eating their fins will give them the shark's power to resist disease.

14. How did the Varadero I eventiually escape? Why was the crew of Sea Shepherd arrested?

Varadero agreed to follow Sea Shepherd to port, but they called the Guatemalan authorities and lied about what happened, saying the Sea Shepherd people tried to kill them. They paid off corrupt officials. Sea Shepherd was ordered to disengage, and the crew were charged with attempted murder.

15. Upon their return to the Galapagos Islands, the crew comes across fishermen hunting sea cucumbers. One of them was badly afflicted with the bends. What causes this sickness? Why weren't they returning to shore for treratment?

The bends are caused by rapid differential in pressure: diving too deep and surfacing too quickly. The fisherman did not want to return to shore because they would lose time and money.

16. Why did fishermen want long-line fishing legalized on the Galapagos Islands?

So that they could fish for sharks.

17. Overall shark population is estimated to have declined by ____.

90%

18. Explain how a decline in top predators like sharks can affect producers like plankton.

Plankton feeders are eaten by sharks When sharks decline, the plankton feeders increase their population and eat up more of the plankton, which provide most of our oxygen..

19. As Rob Stewart returns to Costa Rica, he was concerned about being arrested or caught by the mafia. What did he discover was happening there instead? What change was brought about in part because of public pressure?

Protests against finning and in favor of conservation were happening. Public pressure made long lining in the Galapagos illegal again.-More than 100 countries have banned shark finning.

For my assignment, I also had to look up the status of several shark species featured in the film:

A. Scalloped Hammerheads (Sphyrna lewini) often gather together in large groups, which makes them easy targets for fishermen. They have a long age of maturity, which means their population will not be sustainable, because they can not replace themselves as quickly as they are being killed. They are endangered.

B. Whale shark (Rhinchodon typus) fins are highly valuble, and juveniles are easy targets. It is estimated that there is a more than 50% decline in whale shark populations worldwide. They are also classified as endangered.

C. Carcharhinus longimanus, or the oceanic whitetip shark, is a common victim of by-catch. Although their population is declining, they have not reached endangered levels yet, and are classified as vulnerable.

Constructing an Elasmobranch Dichotomous Key

This is my attempt at a dichotomous key for sharks, rays and skates.

1. Is the body Fusiform or Depressed?

a. if depressed--------->2

b. if fusiform------------>5

2. Are the pectoral fins attached to the head?

a. yes ----------------->3

b. no-------------------> Order Squatiniformes (Angel Sharks)

3. More than one dorsal fin?

a. yes------------------>4

b. no------------------->Order Myliobatiformes (Manta and Sting Rays)

4. Produces electricity?

a. yes------------------>Order Torpediniformes (Electric Rays)

b. no------------------->Order Rajiformes (skates)

5. Number of gill slits

a. more than five------->Order Hexanchiformes (Frilled, Six Gill and Seven Gill Sharks)

b. five----------------->6

6. Eye position

a. in front of mouth---->7

b. behind the mouth----->Order Orectolobiformes (Carpet Sharks)

7. Anal fin?

a. no------------------->8

b. yes------------------->9

8. Does it have ventral gill slits and a dramatically elongated snout that resembles a saw blade?

a. yes------------------>Order Pristiformes (Sawfish)

b. no------------------->Order Squaliformes (Dogfish and Cookie Cutter Sharks)

9. Does it have different types of teeth in the front and back of its jaw?

a. yes------------------>Order Heterodontiformes (Horned Sharks)

b. no------------------->10

10. Do its eyes have nictitating membranes?

a. yes----------------->Order Charcariformes (Tiger, Bull, and Hammerhead Sharks)

b. no------------------>Order Lamniformes (Sand Tiger, Thresher, Megamouth, Basking, Mako, Goblin and Great White Sharks)