Policies for Sustainable Fisheries & Stock Recovery in Caspian Sea: Sturgeon Depletion, Slides of Environmental Economics

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An Economic Analysis of the

Problem of Sturgeon depletion in

the Caspian Sea

Introduction

• Caspian sea famous as host to majority of Sturgeon Stocks
• Catches declined in the mid 20 th^ Century, but recovered with sound management
• Recent years, number of factors ⇒reduced stocks.
• Overview of factors contributing to loss of stocks
• Modelling fish stocks
  • behaviour under private fishery and open access
• Methods of regulation
• Externalities in the context of Caspian Sea sturgeon fisheries
• A numerical model: how economic analysis could help in devising policy options.

Habitat destruction: Loss of spawning grounds due to

dams, and possibilities of circumventing these

• Spawning grounds crucial to natural reproduction of

sturgeon

• Damming of major rivers (particularly Volga)

significant factor in decline of stocks Volgograd dam reduced the available grounds to 12% - lost all of Beluga grounds. Only on the Ural do sturgeon still reproduce naturally – but spawning population may have been destroyed by poaching and pollution

• Losses of fish in water uptakes

• Measures to mitigate effects:
  • Fishway on Volgograd relatively successful
  • Artificial spawning grounds – many now silted, but not a limiting factor due to stock depletion
  • Increased spring water discharge can increase spawning effectiveness
  • Fish protection devices on water uptakes

Water Pollution/ Oil spills

• 10 million people live on Caspian coast, 60

million in Volga watershed.

• Pollution from sewers and industry,

particularly oil and mining – 1 million m 3

untreated waste each year.

• Pollution

major ecological imbalance, especially in North severe effect on human health and both water and land quality. Effects on fish reproduction.

• Transboundary problems
• Before dissolution of USSR, well defined

catch quotas and rigorous enforcement

• Since, economic difficulties, and resources

shared by five states

• Fewer resources - and lower incentives to

invest in stock maintenance

• Benefits enjoyed by all countries: externalities
• Fish stocks common pool resources

international cooperation is essential.

Modelling fish population

dynamics

Modelling stock growth and harvesting

• Growth function: account for growth rate

of species, and limits of habitat

• growth = F(Growth rate r Stock (S), Carrying

Capacity C)

• E.g. Growth =
• E.g. with S = 3000, r = 20%…

10

 

  

 (^) − C

S rS 1

11

Growth

0

20

40

60

80

100

120

140

160

2 (^25049073097012101450169019302170241026502890) Fish Stock (Tons)

Growth in Stock (Tons)

Growth

The Optimal Effort Level

Converting levels of effort into the implied levels of total revenue^13

G

S

H 1 SS

H 4 SS (^) H 3 SS H 5 SS H 2 SS

$

E 1 E 2 E 3 E 4 E 5 E (^6)

H 6 SS

• • • •

      - 

Steady State Revenue

The Optimal Effort Level

14

Identifying the profit maximising level of fishing effort

Effort E 1 E 2 E 3 E 4 E 5 E (^6)

• • • •

      - 

Total

 Cost

π (^) max.

Total Revenue

External effects and the

management of transboundary fish

• Externalities: Party 1’s activitystocks costs/ benefits for Party 2
• Party 1 does not account for this effect in decision- making
• Externalities ⇒ resources used socially inefficient way Negative environmental externalities – pollution
  • Classic example of negative environmental externality
  • Relevant to the problems of Caspian sturgeon fisheries
  • If firm uses polluting input, likely to be over-used from a social point of view

17

The socially optimal use of an environmentally polluting input

MEC

MEB

Q

$

Q * Q P

19

Privately optimal and socially optimal levels of investment in hatchery provision

MIC

MSB

Q

IP^ I*

MPB

External effects: implications for the management of Caspian Sturgeon

• External effects inevitably affect management of transboundary fish stocks - Under open access: effort increased until rents dissipated.
• Transboundary fishery: many of characteristics of open access fishery - Limits to catch ⇒ benefits for the entire fishery
• Various policy options
• Best one remains: restrict total catch and minimise costs of landing this catch TAC quota for each country, additional restrictions on size, fishing location If tradeable, increases efficiency