Impact of Shrimp Farming on Mangrove Forest and Other Coastal Wetlands: The Case of Mexico - Aquaculture and the Environment: A Shared Destiny - page 17

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Impact of Shrimp Farming
on Mangrove Forest and Other
Coastal Wetlands: The Case of Mexico
César Alejandro Berlanga-Robles 1 , Arturo Ruiz-Luna 1
and Rafael Hernández-Guzmán 2
1 Centro de Investigación en Alimentación y Desarrollo A. C.,
Unidad Regional Mazatlán
2 Posgrado en Ciencias del Mar y Limnología, UNAM
Mexico
1. Introduction
Since the middle of the twentieth century, the shrimp farming industry has shown steady
growth along the tropical and subtropical coasts of the world. The world's cultivated shrimp
production in 1950 was 1325 tons, amounting just 0.3% of the total production for these
crustaceans, which were mainly extracted from coastal and estuarine environments. Thirty
years later, by 1982, the global shrimp production surpassed one million tons. By 2009,
shrimp production grew to nearly 3.5 million tons valued at approximately 14.6 billion
dollars, amounting to 34% of the world's shrimp production, including marine and
estuarine catches (Fig. 1) (FAO, 2011).
This escalation has seen intense debate regarding the economic, social and, particularly,
environmental impacts produced by this activity. There is special concern for wetland
losses, increased organic loading in coastal waters, the introduction of exotic species and the
dispersal of harmful diseases (Boyd and Clay, 1998; Primavera, 2006).
The most controversial impact of shrimp farming is related to habitat loss. One of the main
concerns is the deforestation of mangrove, a coastal vegetation type recognized as a highly
productive shelter habitat for many commercial aquatic species. It has been estimated that
between 1.0 and 1.5 million hectares of the world's coasts are covered by some type of
shrimp farming (extensive, semi-intensive or intensive systems), and between 20 and 40% of
this area is blamed as a cause of mangrove loss (Primavera, 2006). Thailand is considered to
be an extreme example of this problem, as mangrove cover in this country was halved from
1960 to 1996. Approximately 200,000 ha of mangroves were deforested, with a third of the
area being transformed into shrimp farming ponds (Aksornkoae & Tokrisna, 2004).
Although shrimp farming impacts have been widely documented and discussed, there is
little evidence on the real mangrove deforestation rates at regional or national scales due to
this activity. Thus, some of the global estimates on mangrove deforestation for shrimp pond
construction are imprecise projections based on very local studies or generalizations of
extreme cases such as Thailand.