Mangrove dependence and socioeconomic concerns in shrimp hatcheries of Andhra Pradesh

Study Number:

43

Author:

P. Ronnback, M. Troell, T. Zetterstrom & D.E. Babu

Abstract:

There are many environmental and socio-economic concerns about the shrimp aquaculture industry. This study, based on interviews, direct observations and literature reviews, shows that the Indian hatchery industry is heavily dependent upon the continuous support of natural resources and ecosystem services generated by marine, freshwater and terrestrial ecosystems. The mangrove ecosystem support area (‘ecological footprint’) needed to supply the hatcheries with Penaeus monodon shrimp broodstock, and the aquaculture grow-out ponds with postlarvae, exemplify the dependence on external ecosystems. Each hectare of mangrove in the Godavari River delta generated an annual fisheries catch of 0.8–1.5 P. monodon spawners (gravid females), valued at US$ 92–184. The entire Godavari mangrove delta had a partial gross economic value of US$ 3.0–6.0 million per year for the provision of shrimp spawners alone. The average hatchery, producing 75 million postlarvae annually, had an ecological footprint of 534 ha mangrove for the life-support input of shrimp spawners. The ecological footprint of intensive shrimp ponds was up to 11 times the pond area for postlarval input alone. The shrimp ponds in the State of Andhra Pradesh needed 35 000–138 000 ha of mangroves to satisfy the spawner requirement to hatcheries, and this implied a need to appropriate mangroves in other regions. Hatcheries were prepared to pay up to US$ 2000 for a single shrimp spawner, which also illustrated that the mangrove support areas regionally available were too small. Other concerns about the industry are the net loss of employment if hatcheries replace wild postlarvae collection, the extensive use of groundwater creating direct resource-use conflicts, bycatch problems in broodstock fisheries, and pollution by effluents. The risk of hatcheries introducing, amplifying and propagating disease affecting both cultured organisms and wild biota is another concern that can, and should, be addressed.

Main Results and Conclusions:

• Without the ecosystem services of the natural environment, shrimp farming would be virtually impossible: “The productivity and sustainability of the shrimp aquaculture industry is thus directly dependent on the continuous support of natural resources and ecosystem services from viable mangrove ecosystems”(345).
• The results/ecological footprint analysis from the study are as follows, which discusses the capacity, production and monetary value of Penaeus monodon shrimp:
  • “The average production capacity of the hatcheries in East Godavari and Vishakhapatnam Districts was 75.5 +/- 10.0 (mean +/- SE) million PL yr-1. In total, the 61 hatcheries in production were estimated to have a capacity of more than 4.6 billion PL yr-1…The actual production was 57.6 +/- 4.8 million PL hatchery-1 yr-1, and all the hatcheries were estimated to be producing around 3.5 billion PL yr-1”(346).
  • “The total input of Penaeus monodon spawners to shrimp hatcheries in East Godavari and Vishakhapatnam Districts was 25 000–49 000 spawners annually (Table 1)”(348).
  •  “A partial gross economic value of US$ 92–184 ha-1 could be attributed to the Godavari mangroves, based on an average market price of US$ 122 per spawner. The entire Godavari delta would…have had a partial gross economic value of US$ 3.0–6.0 million per year for the provision of P. monodon spawners alone”(348).
  • “There were 128 hatcheries producing 7374 million Penaeus monodon PL yr-1, and 58 200 ha of mangroves in the State (Table 1). These mangroves support a fisheries catch of 52 000–103 000 spawners, and each hectare of mangrove thus generated 0.9–1.8 spawners, valued at US$ 108–216, annually”(348).
  • “The corresponding ecological footprint calculated for the entire State of Andhra Pradesh was 455 ha mangroves per hatchery”(348).
  • “The ecological footprint for all shrimp ponds in the State amounted to 0.4–1.6 times the total pond cover. The mangrove ecosystem support area ranged from 0.2–0.7 to 2.8–11.2 times the pond area for extensive and intensive systems, respectively (Table 2)”(349).
  • “Each hatchery in the East Godavari and Vishakhapatnam Districts had an average ecological footprint of 534 ha mangrove for their life-support inputs of P. monodon spawners alone. The corresponding ecological footprint for extensive shrimp ponds is less than the pond area, whereas intensive ponds may require a mangrove ecosystem support area up to 11 times the pond cover”(349).
  • “Each hectare of mangrove in the Godavari River delta generates a fisheries catch of 0.8–1.5 Penaeus monodon spawners per year, valued at US$ 92–184”(349-350).
• Problems associated with shrimp farming (350):
  • Groundwater usage to maintain shrimp farmers can be detrimental to surrounding communities 
  • Shrimp farming risks declining natural wild stocks due to overexploitation.
  • Little money from shrimp farms themselves is actually invested back into the community