Fisheries Case Studies

• Japanese Pilchard (Anchovy)

• Norwegian Spring-Spawning Herring

• Canadian Pacific Herring

• Canadian Atlantic Cod

• North Sea Cod

• North Sea Herring

Clupeid & Gadoid Fisheries

r – Selected Species

~1/3 Global Fisheries

Instability Management Challenges

2.36.8

64.5

42.75

phytoplankton (150)

flagellates (12.9)

ciliates (2.6)crustacean zooplankton

(9.1)

invertebrate carnivores (1.4) pelagic fish (9.3)

natural mortality and fishing

42.75

Anchovies

Sardines

Herring

Commercial catch of Japanese pilchards

Geographical distribution of the four subpopulations of Japanese pilchards and annual catch by region from 1972 to 1976. Numbers in circles are catch in thousands of tonnes.

Kuroshio Current

Survival of young Japanese pilchards from eggs to post-larvae at an age of ten weeks.

Commercial catch of Japanese pilchards

Norwegian spring-spawning Herring

Migration routes of the Norwegian spring-spawning herring.

Commercial catch, recruitment of 3-year old fish, and spawning biomass of Norwegian spring spawning herring.

Percentage contribution of year classes of Norwegian spring spawn herring to the adult stock from 1954 through 1962. The very good year class of 1950 began first appearing in significant numbers in 1954 and dominated the adult stock throughout this period.

Migration routes of the Norwegian spring-spawning herring during the period 1963-1966.

Growth curves of Norewgian spring-spawning herring during various periods of time.

The location of the nine major populations of

British Columbia herring.

Drum seining (small) vessels

Time series of British Columbia herring catch

Cod, Haddock, Pollock

2816.316.3

102306

29

20

97

225408

1,800

6,000

1,200

phytoplankton (9,000)

flagellates (1,200)

ciliates (240)

crustacean zooplankton (408)

invertebrate carnivores (61)

bacteria (322) meiobenthos (19)

macrobenthos (49) epifauna (4)

pelagic fish (32.6) demersal fish (10)

large demersal fish (0.4)

natural mortalityand fishing

Commercial cod landings in the northwestern Atlantic Ocean

Social Concerns

Information Quality

Natural Var iability

Commercial catches of cod in the North Sea

(A) Catch of North Sea Herring and (B) spawning stock biomass of the autumn spawning herring. The dashed line in panel B is the target spawning stock of 1.3 Mt recommended by the ICES.

Harvest of sexually immature fish

Over Capitlizat’n

Habitat destruction

Recruitm’t overfishing

Closure of fishery

Japanese Pilchards

Norwegian spring-spawning Herring

Canadian Pacific Herring

Canadian Atlantic Cod

N. Sea Cod

N. Sea Herring

Species to Avoid

• Chilean Sea Bass

• Orange Roughy

• Atlantic Halibut

• Bluefin Tuna

• Shark

• Atlantic Swordfish

Chilean Sea Bass

• Dissostichus eleginoides• Patagonian toothfish• Z = 150 – 12,500 feet• W ≈ 20 lb; age ≤ 50 yr• Sexual maturity ≈ 6-10 yr • Population doubling time ≈ 5=14 yr• Very long w.r.t. many Com’l fisheries• K-species

Orange Roughy

• Hoplostelhus altanticus• Mesopelagic habitat (3-9°C, 200-2000 m)• Atlantic and Pacific Oceans• Age ≤ 150 yr• Large spawning aggregations• 20,000 eggs/clutch; ferthatch =10-20d• Sexual maturity at 25-30 yr• K-species

Atlantic Halibut

• Hippoglosus hippoglossus

• Z = 50 -2,200 m

• Among largest boney fish in the world

• Age ≤ 50 yr; L ≤ 5m; W ≤ 700 lb

• Sexual Maturity: 7 – 12 yr ( m – f)

• “Endangered-list” since 1996

• K-species