Shallow groundwater flow and inverted fresh/saline-water ...
SHRIMP FARMING IN SALINE GROUNDWATER IN ARIZONA, USA...
Transcript of SHRIMP FARMING IN SALINE GROUNDWATER IN ARIZONA, USA...
SHRIMP FARMING IN
SALINE GROUNDWATER IN
ARIZONA, USA
Kevin Fitzsimmons
University of Arizona
Tucson, Arizona
ABSTRACT
� Environmental restrictions on shrimp
aquaculture.
� Inland culture avoids problems.
� Low salinities will support growout.
� Problem areas with aquaculture.
� Reuse of effluent for field crops.
� Sustainable and profitable?
INTRODUCTION Environmental Constraints
� Loss of mangroves and other coastal
vegetation.
� Effluents and nutrient enrichment
� Impacts (real and imagined) on wild
shrimp and other species (diseases,
exotic species, genetic contamination).
� Changes in estuarine flow patterns.
INTRODUCTION Low salinity inland culture
� Florida, Harbor Branch Oceanographic
� Mexico, Colima; Aquagranjas
� Thailand, multiple
� India, Andhra Pradesh
� Texas, Texas A&M
� Arizona, Gila Bend and Aztec
INTRODUCTION Source water
� Low (1-2 ppt or 1000 -2000 ppm TDS).
� Med (3-5 ppt or 3000 - 5000 ppm TDS)
� Low can be used on conventional crops.
� Medium salinity effluent constitutes a
disposal problem.
� Medium salinity effluent can be used for
algae culture or halophyte crops.
INTRODUCTION Reuse of low salinity (1-2 ppt) effluent
water
� Has been used for olive trees, sorgum,
and cotton.
� Could be used for sugar beets,
asparagus and dates.
INTRODUCTION Reuse of medium salinity (3-5 ppt) effluent
water
� Halophyte agriculture.
� Seaweed culture.
� Bivalve culture.
INTRODUCTION Halophytes
� Many families of plants have halophytic
representatives.
� Grasses, bushes, trees
� Many are from arid regions
� Native species are usually available
� Can be used for forage, biomass,
landscaping, and dust control
RESULTS Gila Bend, Low salinity
� Stocking Litopenaeus vannamei
– 35 shrimp/m2 @ 0.4 g
� Feed - Rangen
� Water exchange: 10-15%
� Aeration
– Paddlewheels
– Diffusers
RESULTS Gila Bend, Low salinity
� Survival 47%
� Harvest after 85 days, @ 19 g
� Yield
– 4,000 kg/ha
– 10 ha of ponds
RESULTS Gila Bend, Low salinity
� Algae bloom
– more characteristic of freshwater
– nutritional value for shrimp needs to be
studied
� Problems
– Hemocytic enteritis
– Gill fouling
RESULTS Gila Bend
Typical algae counts in August 1998
� Cyanophyta (Blue-Green algae)
– Gomphosphaeria (104 cells/ml)
– Lyngbya (104 cells/ml)
– Microcystis (104 - 106 cells/ml)
– Merismopedia (104 - 105 cells/ml)
RESULTS Gila Bend
Typical algae counts in August 1998
� Chlorophyta (Green algae)
– Chlorella (104 - 105 cells/ml)
– Coelastrum (104 cells/ml)
– Pediastrum (103 cells/ml)
– Scenedesmus (104 cells/ml)
RESULTS Gila Bend
Typical algae counts in August 1998
� Diatoma (Diatoms)
– Gomphonema (104 cells/ml)
– Navicula (103 cells/ml)
– Nitzchia (103 -104 cells/ml)
– Synedra (102 cells/ml)
RESULTS Aztec, Medium salinity
� Stocking L. vannamei, L.. stylirostris
– 5 to 10 shrimp/m2 @ PL 20
� Feed - Rangen
� Water exchange: limited
� Aeration:none
RESULTS Aztec, Medium salinity
� Survival L. vannamei, L. stylirostris
– 0 to 30%
� 3 grams per week at one point
� Harvest after 120 days, @ 10 -20 g
� Yield
– 0 to 1,000 kg/ha
– 40 ha of ponds
Conclusions
� Shrimp can be produced in low salinity
groundwater.
� Commercial quantities can be
produced.
� Low salinity effluent waters can be used
for conventional field crops.
� Medium salinity effluent can be used for
halophyte crops.
Conclusions
� Sustainability will not be demonstrated
until salt levels in soils are tested after
several years of irrigation.
� Need to determine manipulation of
algae species.
Conclusions
� Markets are prepared to pay a premium
for fresh, locally grown shrimp.
� Profitability will be determined if more
crop cycles can be completed without
significant losses due to disease or
other environmental conditions.
Additional information
� Websites
– http://ag.arizona.edu/azaqua
– http://www.desertsweetshrimp.com
– http://www.shrimp.ga.com
– http://www.sciam.com/1998/0898issue