1. Fishing Practices

2. 500 species regularly caught Employs 200 million people worldwide
Commercial fishing:
500 species regularly caught
Employs 200 million people worldwide
In 2002 the world fishing fleet numbered about four million vessels.
In 2005:
100 million tons taken
$70 billion
3. Principles and Terms
First, we need to become familiar with some terms used when discussing fish populations and the fishing industry.
Stock. A stock is the portion of a species or population that is harvestable.
Stock Assessment is the estimation of abundance of a resource, rate at which it is being removed, and reference rates for sustainable yields.
Fishing Mortality Rate is a function of the fishing effort (amount, types of gear, etc.)
Harvest Rate The harvest rate is the fraction or amount of stock harvested per year.
Production Rate. The production rate is the sum of growth in weight of individual fish, plus the addition of biomass from new recruits, minus loss in biomass to natural mortality.
Production Function shows the relationship between production rate and fishing effort. As effort increases, the biomass drops and the production function typically goes through a fairly stable maximum. 
To aid in fish management, we can assess stocks by using a combination of three methods: 
biological sampling
annual catch statistics
catch per unit effort statistics 

3. Global Fish Catch

4. Emptying the oceans
We are placing unprecedented pressure on marine resources
Half the world’s marine fish populations are fully exploited
25% of fish population are overexploited and heading to extinction
Total fisheries catch leveled off after 1998, despite increased fishing effort
It is predicted that populations of all ocean species we fish for today will collapse by the year 2048

5. (thousands of metric tons)
Fish Population Estimates
800
600
400
200
1960
1970
1980
1990
2000
Year 80 70 60 50 40 30 20
(thousands of metric tons)
Harvest
(kilograms/tow)
Abundance 10

6. We have long overfished
People began depleting sea life centuries ago
Some species hunted to extinction: Steller’s sea cow, Atlantic gray whale, Caribbean monk seal
Overharvesting of Chesapeake Bay oyster beds led to the collapse of its fishery, eutrophication, and hypoxia
Decreased sea turtle populations causes overgrowth of sea grass and can cause sea grass wasting disease
People never imagined that groundfish could be depleted
New approaches or technologies increased catch rates

7. Fishing Techniques

8. Fishing Methods Harpoon - whales, swordfish, bluefin tuna
Pole and line - mahi-mahi and used for tuna extensively in the 50‘s
Longline - swordfish, tuna (pelagic); cod, halibut (bottom)
Trolling - salmon, albacore, mahi-mahi
Drift (gill) netting - various pelagic fish
Trawl - anchovies (pelagic); cod, halibut (bottom)
Purse seine - sardines, herring, mackerel
Traps and Pots - Crabs, lobster, rock fish

9. Gillnetting
Uses curtains of netting suspended by a system of floats and weights
Either anchored to sea floor or float at the sea surface
Netting is almost invisible, fish swim right into it; and their gills get caught
A huge fleet of factory ships uses sophisticated electronic detection devices and aircrafts to find large schools of fish. Each ship then launches fast, small catcher boats to set hundreds to thousands of miles of drift nets, weighted to stay at a desired depths. After drifting overnight, the nets are hauled in by the factory ships, and the catch is processed on board by canning or freezing. Large scale drift net fishing was banned in 1993, but it continues in the Pacific and has begun in the Atlantic.
net size:
20 m x 65 km

10. Drift Netting Driftnets have earned the nickname “walls of death.”
Large floating nets
Unbreakable and invisible to most sea species
likely to entangle large pelagic species:dolphins, whales, sharks, turtles, and rays.

11. Longlining Longlines are horizontal sets of fishing hooks
Set on the ocean floor: demersal longlines
Set near the surface: pelagic longlines
Longlines can be tens of kilometres long
Can carry thousands of hooks
Baited hooks are attached to the longline by short lines called snoods that hang off the mainline.

12. Not anchored; set to drift near the surface of the ocean
Attached radio beacon tracks line to haul in catch
Usually used to catch large tuna and billfish species.

13. Anchored to the sea floor.
Buoys mark line
Same as Pelagic longline in all other respects

14. Purse seine Uses large wall of netting to encircle schools of fish
Drawstring pulls bottom of netting closed, like a purse
Herds schools of fish into center
Some purse seines can unintentionally catch other animals (dolphin caught when fishing for tuna)
Animation

15. Trawl bottom midwater http://www.youtube.com/watch?v=bUHcD_jTgVA

16. Effects of Trawling on Coral Reefs
As a result of scientific studies showing that bottom trawling kills vast numbers of corals, sponges, fishes and other animals, bottom trawling has been banned in a growing number of places in recent years. Now satellite images show that spreading clouds of mud remain suspended in the sea long after the trawler has passed.
But what satellites can see is only the "tip of the iceberg," because most trawling happens in waters too deep to detect sediment plumes at the surface, say scientists speaking a symposium session called Dragnet: Bottom Trawling, the World's Most Severe and Extensive Seafloor Disturbance at the American Association for the Advancement of Science 2008 Annual Meeting February 15. Speakers at the session include Dr. Elliott Norse, President of Marine Conservation Biology Institute in Bellevue WA; John Amos, President of SkyTruth in Shepherdstown WV, Dr. Les Watling, Professor of Zoology at the University of Hawaii in Manoa HI; and Susanna Fuller, Ph.D. Candidate in Biology at Dalhousie University, Halifax NS.
"Bottom trawling is the most destructive of any actions that humans conduct in the ocean," said Dr. Watling. "Ten years ago, Elliott Norse and I calculated that, each year, worldwide, bottom trawlers drag an area equivalent to twice the lower 48 states. Most of that trawling happens in deep waters, out of sight. But now we can more clearly envision what trawling impacts down there by looking at the sediment plumes that are shallow enough for us to see from satellites," he said.
"Bottom-trawling repeatedly plows up the seafloor over large areas of the ocean" said Mr. Amos. "Until recently, the impact was basically hidden from view. But new tools -- especially Internet-based image sites, like Google Earth -- allow everyone to see for themselves what's happening. In shallow waters with muddy bottoms, trawlers leave long, persistent trails of sediment in their wake."
Susanna Fuller studies impacts of trawling on sponges in the Northwest Atlantic Ocean. "Seafloor animals such as glass sponges are particularly vulnerable to bottom trawling," said Ms. Fuller, a graduate student of Professor Ransom Myers. Dr. Myers, who died last year, had published a series of papers showing that overfishing has eliminated 90 percent of the world's large predatory fishes and is devastating marine ecosystems.
"What is amazing is the level of damage these types of animals have suffered, after the cod fishery in Canada was closed. We immediately started trawling deeper with no restrictions, and continue to do so," she said. "There are ways to catch fish that are less harmful to the world's vanishing marine life. We need to start protecting the seafloor by using fishing gear, besides bottom trawls, especially in the deep sea. It's the only thing left," she said.
"For years marine scientists have been telling the world that fishing has harmed marine biodiversity more than anything else," said Dr. Norse. "And it's clear that trawling causes more damage to marine ecosystems than any other kind of fishing. Now, as the threats of ocean acidification and melting sea ice are adding insult to injury, we have to reduce harm from trawling to have any hope of saving marine ecosystems," Dr. Norse said.
Scientific findings about trawling impacts have led to increasing restrictions on this industrial fishing method. In 2005, the General Fisheries Commission for the Mediterranean banned trawling in the Mediterranean Sea below depths of 1,000 meters, and the United States closed vast deep-sea areas off Alaska to bottom trawling. In 2006, the United Nations General Assembly began deliberations on a trawling moratorium on the high seas, which cover 45% of the Earth's surface, and South Pacific nations effectively put an end to trawling in an area amounting to 14 percent of the Earth's surface.
There are tens of thousands of trawlers worldwide. They fish for shrimp and finfishes. Some bottom trawling operations catch 20 pounds of "bykill" for every pound of targeted species.

17. Trawl from space
Gulf of Mexico, near Louisiana coast. Individual vessels can be seen as bright spots at end of sediment trails. Other bright spots are fixed oil and gas production platforms. One sediment trail can be traced for 27 km. Assuming a standard trawling speed of 2.5 knots, sediment from this trawl is visibly persistent for nearly 6 hours. Water depth <20m. Large, indistinct bright blue patches at lower left and upper right are cloud/haze. (Credit: Landsat)

18. Sonar
Uses sound waves that allow fishermen to quickly locate fish and/or see the bottom
Targets specific species
Image:

19. Factory Ship Can haul in LARGE quantities of fish
Courtesy of Wikipedia Commons
Can haul in LARGE quantities of fish
Can process and freeze fish onboard
Up to meters long
Can be at sea for six weeks at a time with a crew of over 35 people.
Types: demersal (weighted bottom trawling)
pelagic (mid-water trawling)
pair trawling, two vessels, 500 metres apart, both pull huge net with a mouth circumference of 900 meters

20. Pole / Troll Uses fishing pole and bait to target fish
Environmentally responsible; alternative to longlining
pole/troll fishermen have very low bycatch rates.

21. Fisheries Problems
& Solutions

22. Fisheries mismanagement
Overfishing
Commercial extinction
Bycatch (27 million metric tons annually)
Targeting smaller species on the low end of the food chain

23. Fisheries Problems & Solutions
Maximum sustainable yield: maximum amount of fish that can be harvested without depleting future stocks
World‘s maximum sustainable yield estimated at 100 to 135 million metric tons
Present harvests are at about 100 million metric tons
For fisheries where numbers available, estimated that 45% are currently over-fished
A number of fisheries have already collapsed (Anchovy fishery off Peru, Cod fishery in the N. Atlantic)

24. Fisheries Problems & Solutions
F. Bycatch (or bykill): animals unintentionally killed during harvest of the target species
Trawling: Bycatch in shrimp trawling is very high (125 to 830% of the catch is discarded as bycatch), turtles often caught in trawls.
SOLUTION: trawls with trap doors to let turtles escape

25. Allows smaller fish to be caught
Allows turtles to escape
Lowers incidence of bycatch

26. Same concept as TEDs
Hatch kept open with inflatables

27. Modern fishing fleets deplete marine life rapidly
Grand Banks cod have been fished for centuries
Catches more than doubled with immense industrial trawlers
Record-high catches lasted only 10 years

28. Bycatch by Gear Type for 2002/2003

29. Purse seine: Tuna known to hang out under pods of dolphins, nets set around pods of dolphins would result in many drowning.
SOLUTIONS: Nets not set around dolphin pods and/or employ — “backing down”, a technique that lowers upper edge of net letting dolphins escape
Dolphins caught in tuna net

30. Fisheries Problems & Solutions
Driftnets: indiscriminate entangling of many sorts of marine animals
SOLUTION: banned in oceanic fisheries (but some countries still using them)

31. Fisheries Problems & Solutions
Long lining: Many albatross drown trying to snatch bait from long lines being deployed. snagged on hooks and pulled under.
SOLUTION: deploy in the dark or with special rig to let line out under water.

32. Global swordfish catch
Swordfish are distributed worldwide.  The north Atlantic population is considered one interbreeding unit that is "managed" as a single "stock."  If they live long enough (perhaps 25 years), they can reach 2,200 lbs.  Like other billfish, all the large individuals are females since male swordfish rarely exceed 200 lbs. The first recorded sale of Atlantic swordfish was in The average size landed commercially has declined from lbs. in 1861 (newspaper story), lbs. by the turn of the 20th century, over 266 lbs. in 1961 (when longlining largely replaced harpoon, hand line and rod and reel as the primary commercial gear used) to 88 lbs. today.  The international longline fleets target swordfish and tunas because they are the most valuable commercially. Most swordfish - almost two of every three - are now caught before they have a chance to spawn.  On average, females do not mature until age 5 and about 150 lbs. and males mature at 3 years and 72 lbs.  Of the females caught commercially, 83% are still immature.  ICCAT's minimum size limit is now 41 lbs. (= 33 lbs. dressed weight), and U.S. longliners routinely "discard" 40-50% of the swordfish they catch because they are too small to sell legally.  Due to the trauma involved in longline retrieval (e.g., jaws and gills torn apart) virtually all of these fish (age 1 or 2) are either dead already or die soon thereafter.  In 1998, the U.S. fleet "discarded" 433 metric tons of such baby swordfish. This is the result of many (smaller) vessels fishing in the swordfish's primary nursery areas, particularly those surrounding Florida (and in the fall, off Charleston, SC).  See below for maps showing the locations of the spawning and nursery areas of this population.  The largest U.S. vessels (the "distant water fleet") have had to travel farther each year to find sufficient swordfish.  They now target them in their primary spawning areas between the Caribbean Islands and two large areas well east and south of the Virgin Islands in the Atlantic (the sites of major surface currents as shown below) during the early spring, then pursue the adults to their primary feeding areas on the Grand Banks until late fall.  At the bottom of this page you can find links to the maps showing where longline effort and catch is concentrated. After depleting the North Atlantic population, the international longline fleets moved to the South Atlantic and to the Pacific Ocean.  However, after only a few years, most U.S. vessels left the Pacific and are concentrating on the south Atlantic population (see below).  From the evidence we have, it is reasonable to conclude that all swordfish populations are in serious trouble, as noted below for the Atlantic.
Ave. wt. in lbs
year

33. Artificial Reefs Improve the local marine bio-density
attract schools of fish
providing habitats for the colonization of commercially valuable species
improve the local inshore marine harvest
May wash up
on beaches
tires
ship wrecks
construction rubble

34. AquaCulture

35. Aquaculture
(marine agriculture)- farming finfish, shellfish and algae under favorable conditions 35

36. One of every four fish eaten today was raised in either a fw or sw fish farm.

37. Aquaculture also produces:
Bait fish
Ornamental or aquarium fish
Aquatic animals used to augment natural populations
Algae for chemical extraction
Pearl oysters

38. History: 2000 years ago in Egypt, Rome, China <2000 years in Hawaii
600 years ago France developed mussel aquaculture
500 years ago Europe developed the idea of using pond fertilizer to promote plankton growth
400 years ago China discovered that oysters would grow on bamboo stakes
1960’s- Europe and U.S. catfish and salmon

39. Criteria for selecting species for farming:
- inexpensive to grow
- grows quickly
- high sales price
- resistant to disease and parasites

41. Hawaii open ocean aquaculture
HOT’s business is to deploy large fish cages some 65 feet below the surface in state waters off Kona, and to grow locally grown Ahi fingerlings using cutting edge technology in the feed, the cages and in the mechanisms that drive and hold them at their designated locations.
Kona Blue Water Farms LLC says it will slash farming by 40 percent annually, from about 500 tons to 300 tons.
The company sells amberjack, which is also known as kahala or Hawaiian yellowtail, under the brand name Kona Kampachi.
Kona Blue says it must become more efficient, largely by reducing the amount of labor required to feed the fish and clean the cages.
Kona Blue is seeking permits to increase the size and reduce the number of pens it uses. It also plans to test a variety of cage materials and designs to improve efficiency.
The company is moving forward with plans to establish a fish farm off Mexico.
What is the size of Hawaii's aquaculture industry?
There were currently more than 100 aquafarms in the state. In 2003, they produced products with a farm-gate value of $27.7 million. Research, training, and technology transfer activities added an estimated $10 million, for a total industry value of about $38 million. back to top
6. What species of plants and animals are being raised?
Aquaculture production is generally divided into four product groups, with a total of over 30 aquatic plant and animal species are being raised for research or commercial production. Product groups include: Shellfish (marine shrimp, freshwater prawns and abalone); Finfish (Pacific threadfin or moi, tilapia, catfish, carp, flounder, sturgeon, amberjack, snappers, and grouper); Algae (seaweeds and microalgae) and "Other" (non-food products such broodstock shrimp, oysters and clams seed, pearl oysters and a variety of freshwater and marine aquarium fish and invertebrates). back to top
7. Which species group is the largest in terms of total state production?
Algae has the highest production value of all product groups, followed by Shellfish, "Other" and Finfish. The microalgae, Spirulina (sold as a health food), and the popular seaweed, ogo or Gracilaria (sold as a sea vegetable), totaled $11.7 million. The value of finfish production is projected to increase sharply in the coming years due to the expansion of large-scale offshore cage culture. Hawaii's aquaculture industry generated a record $34.7 million in sales revenue in 2008, up 38 percent from $25.1 million in
Mio, big eye tuna, yellow tail
$34.7 million in 2008 41

42. Industrialized fishing depletes populations
Catch rates drop precipitously with industrialized fishing
90% of large-bodied fish and sharks are eliminated within 10 years
Populations stabilize at 10% of their former levels
Marine communities may have been very different before industrial fishing
Removing animals at higher trophic levels allows prey to proliferate and change communities

43. Several factors mask declines
Industrialized fishing has depleted stocks, global catch has remained stable for the past 20 years
Fishing fleets travel longer distances to reach less-fished portions of the ocean
Fleets spend more time fishing and have been setting out more nets and lines, increasing effort to catch the same number of fish
Improved technologies: faster ships, sonar mapping, satellite navigation, thermal sensing, aerial spotting
Data supplied to international monitoring agencies may be false

44. We are “fishing down the food chain”
Figures on total global catch do not relate the species, age, and size of fish harvested
As fishing increases, the size and age of fish caught decline
10-year-old cod, once common, are now rare
As species become too rare to fish, fleets target other species
Shifting from large, desirable species to smaller, less desirable ones
Entails catching species at lower trophic levels

45. Consumer choices influence fishing practices
Buy ecolabeled seafood
Dolphin-safe tuna
Consumers don’t know how their seafood was caught
Nonprofit organizations have devised guides for consumers
Best choices: farmed catfish and caviar, sardines, Canadian snow crab
Avoid: Atlantic cod, wild-caught caviar, sharks, farmed salmon

46. The Big Question Fish Populations are declining
The Human Population is increasing exponentially
What can be done to sustain fish as a viable food resource for the human population?
What YOU can do: Choose to eat sustainably harvested seafood

47. Aquaculture Methods Is Aquaculture the Answer? Trade-Offs Aquaculture
Highly efficient
High yield in small
volume of water
Increased yields
through cross-
breeding and genetic
engineering
Can reduce over-
harvesting of
conventional fisheries
Little use of fuel
Profit not tied to price
of oil
High profits
Advantages
Large inputs of land, feed,
And water needed
Produces large and
concentrated outputs of
waste
Destroys mangrove forests
Increased grain production
needed to feed some
species
Fish can be killed by
pesticide runoff from
nearby cropland
Dense populations
vulnerable to disease
Tanks too contaminated to
use after about 5 years
Disadvantages
Trade-Offs
Aquaculture
Aquaculture Methods
Is Aquaculture
the Answer?

48. More Sustainable Aquaculture
Reduce use of fishmeal as a feed to reduce depletion of other fish
Improve pollution management of aquaculture wastes
Reduce escape of aquaculture species into the wild
Restrict location of fish farms to reduce loss of mangrove forests and other threatened areas
Farm some aquaculture species (such as salmon and cobia) in deeply submerged cages to protect them from wave action and predators and allow dilution of wastes into the ocean
Set up a system for certifying sustainable forms of aquaculture
Solutions
More Sustainable Aquaculture

49. Relevant Laws UN Law of the Seas
Magnuson-Stevens Fisheries Management and Conservation Act (Magnuson Act)
Marine Sanctuaries Act
Oceans Act of 2000
Endangered Species Act (ESA)
Convention on International Trade in Endangered Species (CITES)
Lacey Act of 1900

50. Laws Related to Fishery Management
UN Law of the Seas
Nations have jurisdiction over Exclusive Economic Zones (200 Miles)
Sea Floor sovereignty up to 12 miles offshore
Allows for Individual Transferable Quotas which can be sold to others
Magnuson Act
Establishes 200 mile fishing area
Set up regional councils that
Set quotas
Set size limits
Set seasons
Protects habitat
Minimizes bycatch
Rebuilds overfished stocks

51. Fisheries management Based on maximum sustained yield
Maximal harvest while keeping fish available for the future
Managers may limit the harvested or restrict gear used
Despite management, stocks have plummeted
It is time to rethink fisheries management
Ecosystem-based management
Shift away from species and toward the larger ecosystem
Consider the impacts of fishing on habitat and species interactions
Set aside areas of oceans free from human interference
Fisheries management

52. We can protect areas in the ocean
Marine protected areas (MPAs) = established along the coastlines of developed countries
Still allow fishing or other extractive activities
Marine reserves = areas where fishing is prohibited
Leave ecosystems intact, without human interference
Improve fisheries, because young fish will disperse into surrounding areas
Many commercial, recreation fishers, and businesses do not support reserves

53. Reserves work for both fish and fisheries
Found that reserves do work as win-win solutions
Overall benefits included…
Boosting fish biomass
Boosting total catch
Increasing fish size
Benefits inside reserve boundaries included…
Rapid and long-term increases in marine organisms
Decrease mortality and habitat destruction
Lessen the likelihood of extirpation of species

54. Areas outside reserves also benefit
Benefits included…
A “spillover effect” when individuals of protected species spread outside reserves
Larvae of species protected within reserves “seed the seas” outside reserves
Improved fishing and ecotourism

55. How should reserves be designed?
20-50% of the ocean should be protected in no-take reserves
How large?
How many?
Where?
Involving fishers is crucial to fisheries to determine the answers

56. Laws Related to Habitat Protection
Marine Sanctuaries Act
Protects habitat of marine organisms
Protects animals from being harvested in that area
Oceans Act of 2000
Established Presidential Commission to
Examine Federal Ocean Policy
Promote protection of marine environments
Prevent marine pollution

57. Laws Related to Species Protection
CITES
Identifies and lists endangered species
Prohibits international trade in listed species
ESA
Identifies and lists endangered species
Prohibits the harm or harvesting of listed species
Protects habitat
Lacey Act of 1900
Prohibits sale of illegally harvested species
Forces legal methods

58. Conclusion
Oceans cover most of our planet and contain diverse topography and ecosystems
We are learning about the oceans and coastal environments, intensifying our use of their resources, and causing severe impacts
Setting aside protected areas of the ocean can serve to maintain natural systems and enhance fisheries
We may once again attain the ecological systems that once flourished in our waters

59. QUESTION: Review
Which of the following does not mask the decline of fisheries?
Fishing fleets travel longer distances
Fishing fleets spend more time fishing
Fishing fleets use traditional methods of fishing
Data supplied to monitoring agencies may be false
Answer: c

60. QUESTION: Review
Marine reserves have all the following benefits except:
Fishing increases in the reserve
The size of fish increases
Larvae can “seed” areas outside the reserve
Decreased mortality and habitat destruction
Answer: a

61. QUESTION: Interpreting Graphs and Data
What does this graph show about the future of global fisheries catch?
China will be a major player in applying fishing pressure
China will be playing a smaller role in applying fishing pressure
The world will decrease its fishing pressure
The U.S. is not included in this graph
Answer: b

62. QUESTION: Interpreting Graphs and Data
Which conclusion can you draw from this graph?
Oceans today contain far fewer fish
Oceans today contain far more fish
It is easier to find fish today
There is little correlation between fishing and fish stocks
Answer: b

63. QUESTION: Viewpoints
If a developer wants to build a community on an estuary, providing jobs but eliminating the marsh, what should be done?
Let the developer build; we need the jobs
Let the developer build, but make him/her pay for any damage from storms
Let the surrounding landowners vote whether to let the developer build
Prevent the development; the potential damage is too great
Answer: any

64. QUESTION: Viewpoints
Do you plan to alter your decisions about eating seafood?
Yes; I will be more selective about what I eat
No; I will continue to eat the same type and amount of seafood as always
Answer: any