Topic Area: Aquaculture
Geographic Area: Ecuador
Focal Question: How can shrimp mariculture survive when
breeding habitats are a free access resource?
Sources:
(1) Parks, Peter J. and Bonifaz, Manual "Nonsustainable Use of
Renewable Resources: Mangrove Deforestation and Mariculture in
Ecuador" found in Property Rights in a Social and Ecological
Context The World Bank, Washington D.C.1995: 75-82. also in
Marine Resource Economics 9(1): 1-18.
(2) Leung, PingSun and Lee, Donna J. And Hochman, Eithan "Bioeconomic
modeling of Shrimp and Prawn: A Methodological Comparison" found in
Hatch, Upton and Kinnucan, Henry Aquaculture: Models and
Economics Westview Press, Boulder, 1993: 39-54.
Reviewer: Conrad Saam, Colby College '96
Review:
Ecuador has traditionally been the largest supplier of shrimp to the
United States; however, in recent years Ecuador's maricultural shrimp
industry has suffered losses. This can be partially explained by
market forces; fluctuations in prices and increased competition from
Asia which uses more efficient methods have both hurt Ecuador's
exports. However, the most important factor is the current scarcity
of post larval shrimp caused by the destruction of the mangrove
habitat.
Shrimp mariculture requires the creation of ponds below the high tide
line, which is often accomplished by the clearing the mangrove
forests. These ponds are then stocked with post larval shrimp
(Pennaeus vannamei have proved to be the most productive species in
Ecuador) which are harvested upon maturation with nets. The post
larval shrimp are supplied by artesanos who collect them from
estuaries and beaches along the coast. Artesanos face a very low cost
of entry, in that the only equipment they need is a small hand net.
This ensures a very competitive industry which supplies
mariculturalists with post larval shrimp at minimal cost.
The larval stage of Pennaeus vannamei occurs in the open ocean, but
the post larval shrimp spend three to five months growing in the
mangrove lined estuaries in Ecuador. This nutrient rich environment
is ideal for fast growth and also offers protection from natural
predators. The shrimp then return to sea to reproduce. The mangroves
also serve to maintain water quality and provide sufficient oxygen
for a variety of marine species. This externality is not considered
in the shrimp pricing or the destruction of the habitat.
Shrimp mariculturalists originally developed ponds among intertidal
salt flats; however, as the demand for shrimp continued to grow these
flats became crowded and they began to clear the mangrove forests.
Between 1979 and 1991, one fifth of Ecuador's mangrove forests were
cleared for shrimp mariculture.
During the early eighties markets shrimp production in Ecuador rose
by 600%. This was primarily caused by two factors. In 1982, the area
experienced the El Nino phenomenon which was a southward shift in
warm ocean current. This increased the reproduction rate among
Pennaeus vannamei which created an unusually high supply of post
larval shrimp. A large demand, maintained the price for shrimp in the
United States. The abundance of post larval shrimp and high demand
induced mariculturalists to clear more and more mangrove forest to
create ponds. Natural and market forces caused a huge overexpansion
of shrimp pools at the expense of the mangrove forests. The
destruction of the forests caused future declines in the shrimp
population. The sad result is that since 1985, half of the ponds are
being utilized, and mariculturalists are paying higher and higher
prices for the diminished supply of post larval shrimp. Ecuador now
faces a very tough situation due to increased competition from more
productive foreigners, lower shrimp demand and most importantly, a
lower supply of post larval shrimp.
To answer these problems, the author suggests a tax to internalize
the externalities caused by the loss of the mangroves. As proposed,
the tax should include discounted stock effects of additional habitat
and also non-shrimp related environmental benefits. The author seems
to believe that a tax to reduce mangrove deforestation would halt the
reduction of the post larval shrimp supply; however, this seems to be
a case of too little too late. If half of the ponds are not even
being used due to lack of post larval shrimp, no incentive to clear
mangroves currently exists anyway. The author suggests a tax on
artesanos to internalize the marginal scarcity rent for post larval
shrimp to allow the shrimp population to recover. It seems, however,
that it would be very difficult if not impossible enforce a tax on a
group of people whose only market entry requirement was the price of
a hand net.
The major problems seem to be with the allocation of property rights
and the legal system. All mangrove ecosystems, beaches and estuaries
are considered public access for shrimp collection. This causes
drastic exploitation of the post larval shrimp. No attempts have been
made to regulate the artesano suppliers. The enforcement of laws has
also been lax. Laws were passed in 1975 and 1985 outlawing the
conversion of mangrove forest to shrimping ponds; however,
deforestation continues at a rate of 3,000 hectares annually.
Extremely underpriced concessions to build shrimp ponds are given for
a ten your period. This is clearly too short a time period to develop
a sustainable focus. The Ecuadorian government should concentrate on
a long run approach and protect habitats that enhance the stock of
post larval shrimp.
A potential private solution to the problem would be to create
successful, cooperative zones, where the mangroves are protected
which leads to high availability of post larval shrimp. This requires
a focus on a local area. The effects of deforestation must have a
local effect on the shrimp population. Secondly agreements between
mariculturalists and artesanos must be exclusive, ensuring that
shrimp stay within the same geographical area throughout their life
cycle. Parks (1995) indicates that this strategy has been successful
in Bahia, Brazil.
It seems that the shrimp industry has created an artificially high
capacity to satisfy the high demand of the early eighties at the
expense of long-run sustainability. This overinvestment occurred at
the expense of the mangrove forests, which in turn led to a
decimation of the post larval shrimp supply. Ecuador must act quickly
to maintain its position in the market in the face of increased
foreign competition; however, as their own lesson points out, they
must not take a short run focus.