Overfishing

Question 1

Why overfishing an interdisciplinary problem?

Answer 1

• fish (species & abundance)/ ecology
• managerial practices (fishing/econ)
• regulations (institutionalization of a field)/ politics

Question 2

lake victoria’s fisheries

Answer 2

• dynamic eco-history of the lake victoria basin
• high population density
• supports Africa’s largest inland fishery

Question 3

history of fishing in the area

Answer 3

• intensified with new tech
• intro of new species influenced faunal compositon & balance

Question 4

fish that flourished

even with gigantic nile perch “mputa”

Answer 4

• nile tilapia “ngege” ( has become abundant, commercially important )
• “mukene”, biomass 6x

Question 5

changes

lake victoria system composition

Answer 5

multi-species system exploting native fish –> 3 species almost all catch ( 2 are non-native)

Question 6

Similar changes have occured in which other lakes in the victoria basin?

Answer 6

Lake Nabugabo
Kyoga

Question 7

Changes in perch population

Answer 7

• increased fishing
• decrease in stock
• decrease in size

Question 8

lake ecology

not homogeneous

Answer 8

understanding habitat diversity is key to understand relative fish abundance and reproduction

Question 9

ecological morphology

Answer 9

refers to resource availability (oxygen, nutrients, protection etc..)

Question 10

Biodiversity Banks (3)

Answer 10

satellite lakes, rcky refugia, wetland refugia

Question 11

Beach management Units

Answer 11

promising solution/control of socioecological system

Question 12

BMUs structure

Answer 12

new institutions that regulate fishing in the lakes
- to fish, fisherman must register
- control gear used
- no territorial jurisdiction
- no jurisdiction over capture (type or quantity)

Question 13

Overfishing is class case of …?

Answer 13

tragedy of the commons or open access resources

Question 14

Collective Action Problem (CAT)

Answer 14

predicts a resource managed in common has more probability to be sustainably managed with certain characteristics

Question 15

increasing probability of sustainable management

Answer 15

• small size (group +resources)
• well-defined boundaries
• high level of dependence on resource
• fair allocation
• locally devised access and rules
• clear territoriality
• resource harvest restrictions match recovery

Question 16

flaws of BMU design

ID by CAT predictors

Answer 16

• lack of territorial jurisdiction
• no regulations on harvest
• fisheries highly unpredictables (spatial distribution, compositition..)

BMUs = insufficient institutional step

Question 17

Why are fisheries so hard to manage?

Answer 17

• difficult to institutionalize, and generate territorial jurisdictions?

Question 18

Data required to manage fisheries?

Answer 18

• ecological distributions of resources (ecological map, fish presence+mobility, ethnoecological mapping)
• spatial distributions of the fishing effort
• trade networks

Question 19

How to create a map of ecological structure?

in lake nabugabo

Answer 19

• ecological structure (depth+ shoreline ecotones: lilies, grass, forest edge)
• quantify fish movement (tag)
• etnoecological mapping (cognitive map +interviews)

Question 20

Collecting data on fishing effort

in lake Nabugabo

Answer 20

• use ecological map as base, recall interview designs to determine where BMU members fished during 5 days of each month

Question 21

example of fishing recall qs

Answer 21

• where did you fish today? how long? why there?

Question 22

catch landing surveys

Answer 22

both BMUs
boats, type of fish & gear

Question 23

expected results

Lake Nabugabo

Answer 23

define specific ecological patches with significant fish species distribution ==> define exclusive territorial jurisdictions for the BMUs*

worth defending

Question 24

consequences of no predictable pattern

in fishing efforts

Answer 24

• cannot design functional institutional structure
• no incentive for collective action