Snedaker Shrimp English
SHRIMP POND SITING AND MANAGEMENT ALTERNATIVES
I N MANGROVE ECOSYSTEMS I N ECUADOR
!
Final Report
USAID Grant No. DPE-5542-G-SS-4022-00
Prepared for t h e
U.S. Agency for International Development
Office of t h e Science Advisor
Samuel C. SnedakerT1Joshua C. Dickinson, IIIP2
Melvin S. Brown1 and Enrique J. Lahmannl
1Rosenstiel School of Marine and Atmospheric Science
University of Miami
4600 Rickenbacker Causeway
Miami, Florida 33149-1098 USA
*Tropical Research & Development, Inc.
6124 S W 30 Avenue
Gainesville, Florida 32608 USA
Miami, Florida
1986
NOTE TO READER
September 1, 2006
THIS IS A SEARCHABLE PDF DOCUMENT
This document has been created in Adobe Acrobat Professional 6.0 by scanning the best
available original paper copy. The page images may be cropped and blank numbered pages
deleted in order to reduce file size, however the full text and graphics of the original are
preserved. The resulting page images have been processed to recognize characters
(optical character recognition, OCR) so that most of the text of the original, as well as some
words and numbers on tables and graphics are searchable and selectable. To print the
document with the margins as originally published, do not use page scaling in the printer
set up.
This document is posted to the web site of the
Coastal Resources Center,
Graduate School of Oceanography,
University of Rhode Island
220 South Ferry Road
Narragansett, Rhode Island, USA 02882
Telephone: 401.874.6224
http://www.crc.uri.edu
Citation:
Snedaker, S., J. Dickinson, M. Brown and E. Lahmann 1986. Shrimp Pond Siting And
Management Alternatives In Mangrove Ecosystems In Ecuador. Quito: U.S. Agency for
International Development.
Preface................................................................ ii
List of Figures
vi
List of Tdles ........................................................vii
viii
Abbreviations. Symbols and Definitions
Acknowledgements
ix
........................................................
...............................
.......................................................
1.0.0. Introduction....................................................1
1.1.0. Scope of Project ........................................... 3
1.2.0. Major Froject Activities...................................G
2.0.0. Background......................................................7
2.1.0. Types and Levels of Mariculture Management .................7
2.1.1. Type I : Subsistence and Artisanal Open-System
mariculture..............................................7
2.1.2. Type 11: Extensive Closed-System Mariculture..............10
2.1.3. Type 111: Semi-intensive Closed-System Mariculture........ 12
2.1.4. Type IV: Intensive Artificial-System Mariculture..........12
3.0.0. Field Evaluations ............................................... 14
3.1.0. Introduction...............................................14
3.1.1. Interviews................................................. 14
3.1.2. Water Quality ..............................................16
3.1.3. Mangrove Forest Assessment .................................17
3.2.C. Shrimp Farm Evaluations.................................... 21
3 . 2 . 1 . Production Levels..........................................21
3 . 2 . 2 . Major Problems.............................................21
3.2.3. Ideal Conditions...........................................22
3 . 2 . 3 . T h e Future Outlook ......................................... .'
3.3.0. Water Quality .............................................. 25
4.0.0 Shrimp Mariculture in Ecuador ....................................32
4.1.0. Mariculture Types and Management Levels....................32
4.1.1. Type 11: Extensive Closed-System, Management Level 5.......32
4.1.1. T j ~ p e11: Extensive Closed-System, Management Level 6.......32
3 . 1 . 2 . Type 111: Semi-Intensive Closed-System, Management
Level 7 ....................................................33
4.1.3. Type 11 I: Semi-Intensive Closed..System, Management
Level 8....................................................33
4.2.0. Construction Cost .........................................34
4.3.0. Operational Costs..........................................24
4.4.0. Shrimp Pond Sitinff......................................... 35
4.4.1. Pond Size..................................................35
or
4.4.2. Pond Loi:ation ..............................................ad
4.5.0. Water Quality Management ...................................37
5.0.0. Environmental Considex-ations.................................... 38
5.1.0. Upstream Use and Misuse of Resources.......................38
5.2.0. Agriculture ................................................38
5.3.0. Mangrove-Rased F i s h e r i e s ...................................38
5.4.0. Effects On Mangrove Forests................................39
3
r;
....................................
................
..............
.......................
Socioeconomic Considerations
42
6.1.0. Marginal Habitats Converted to Economic Use
42
6.2.0. Maricultut-e Provides Employnent Opportunities
44
6.3.0. Dietary Protein Levels are Increased
45
6.4.0. Local Economic Benefits and Hard Currency Earnings
Stimulate Economic Development Within the Region ...........45
6.5.0. Government Revenue Base is Strengthened....................46
6.6.0. Construction of Hatcheries Will Solve the Major Problem
47
6.0.0.
....
7.0.0. CONCLUSIONS .....................................................48
7.1.0. Pond Siting and Management Intensification................48
7.2.0.
Development of Maturation and Hatcilerv Facilities.........49
7.3.0. The Recurrent Post Larvae Crisis..........................50
7.4.0. Alternate and/or Exotic Culture Species...................50
7.5.0. Fishery Sector Development................................51
7.6.0. Intertidal Zone Management ................................53
7.7.0. Activities of Interest to Development 4. ssistance
Agencies ..................................................54
7.8.0. Research Needs ............................................ 55
8.0.0. LITERATURE CITED AND BIBLIOGRAPHIC REFERENCES ..................56
Appendix A . Some Traditional Uses of South American Mangrove Forests..A-1
Introduction.....................................................A-1
The Mangrove Forests of South America ............................A-2
Geographic Distribution ...................................... A-2
Forested Area ................................................LI-2
Species Cornl>osition.......................................... A-3
Historical and Traditional Uses ..............................A-3
Utilization and Economic Value ...............................A-4
Literature Cited................................................. A-6
Appendix B . Mangrove Forest Area in Ecuador ..........................B-1
Literature Cited ................................................. B-3
PREFACE
One of the most rapidly-expanding and profitable economic development
activities in South America has been the Penaeid shrimp-growout pond
(mariculture) industry in Ecuador which had i t s beginnings in the early 1970s.
I t now ranks -after
, -p
a s a major export commodity and --'
foreign currency earner for Ecuador. In addition, shrimp mariculture has
completely transformed much of the coast of southern Ecuador into a mosaic of
interlocking and contiguous growout ponds. In addition, i t has also stimulated
the development of a variety of local support industries.
Prior to the "El Niiio" event of 1982/83, the shrimp mariculture industry
began to experience increasingly severe and unpredictable shortages in the
wild post-larval shrimp (PL) that a r e harvested in shallow coastal waters to
stock commercial grbowout ponds. For several years, the demand for PL had
exceeded their natural availability and led the shrimp producers, represented
by such organizations a s ACEBA (Asociacion de Cultivadores de Especies
Bioacuaticas), to begin to seek a solution to the continuing shortage.
Although the El Nifio event destroyed a significant part of the physical
infrastructure upon which the industry relied, the chaotic period w a s also
characterized by a relatively large population of PL suitable for capture and
pond stocking. Nevertheless, the experienced producers recognized that the
long-term trend portended continued annual shortages in P L availability.
With respect to the decreasingly availability of PL stocks, i t was
known from a variety of published sources that coastal mangrove forests a r e
the primary nursery habitats f o r many species of marine shrimp a s well a s n
large number of other species of shellfish and finfish. These intertidal
forests provide a refuge from competitors and predators, and a r e a source of
nutrient-enriched organic matter which serves as a food substrate. I t was
therefore local1y concluded that the extensive conversion of the coastal
mangrove forests to shrimp growout ponds, particularly in the southern
provinces (e.g., Cuayas, El Oro, Manabi), was somehow implicated in tho
reduction of the availability of larval and juvenile shrimp. The local
producers, mainly ACEBA, made known their desire for a solution to the U. S.
Agency for International Developnient (USAID) relative to destruction of
mangrove forests and the problematic availability of PL. Among other points,
the producers argued that continued conversion of mangrove forest areas to
maricultural ponds could lead to the collapse of the mariculture industry.
After a series of discussions with the producers and USAID, the authors,
working through thc University of Miami, obtained a research g r a n t from the
USAID Office of the Science Advisor's Program in Science and Technology
cooperation (PSTC). rusted puruose of the ~ m n w
t e s e a r c h &he
manmerddhe
relationship among shrimp pond s%and
-cb&karw
i n both mangrove forest area and P L stocks. The
corollary g r a n t objective was to develop guidelines o r recommendations on
Shrimp Pand Siting and Mamgcment
S. Snedaker, J. Dickinson, M. Brown and E. Lahmnn
-
ii
siting and management which could lead to higher and stabilized levels of pond
production yields.
The research was formally initiated in mid-1984 and concluded in mid-1985.
The major part of the field work took place during February and March 1985
during which time experimental aerial photographs were taken and field
investigations made of representative ponds and surrounding mangrove forests
in Guayas, El Oro and Manabi provinces. In addition, information was acquired
on pond siting and management practices from a variety of Ecuadorean sources
for comparison with information obtained elsewhere by the authors (see, for
example, Dickinson 1983) a s well a s data and information reported in the
literature. This report summarizes and discusses the findings. I t is hoped
that this report represents a significant contribution to our increasing
knowledge of the practical benefits, problems and alternatives, associated
with the extensive globally-expanding shrimp mariculture industry.
Caveat: This draft of the final report was prepared without access to two
important bodies of data arid information. The f i r s t is a n inventory of
mangrove forest and shrimp-pond area which was completed by the Centro de
Levantamientos Integrados Recursos por Sensores Remotes (CLIRSEN), but was not
released to the principal investigators of this project. The absence of this
information precluded a broadened analysis of both pond siting preferences and
site-related problems in Ecuador. The second missing body of information i s a
socioeconomic description of the management of the sample ponds selected for
study in this project. This was to have been prepared by Dr. S. K. Meltzoff in
r e t u r n for grant support for team research participation in Ecuador. After
t
arriving in Ecuador, however, Dr. Meltzoff insisted on pursuing her own
personal interests instead of grant objectives. Regrettably, this precluded a
{
complete evaluation of the different socioeconomic aspects of management that
a r e still believed to be correlated with both pond location and the intensity
of management.
{
S h r i m p Pond Siting and Management
S. Snedaker, J. Dickinson, M. B r o w n and E. Lahmann
-
iii
ACKNOWLEDGEMENTS
The authors wish to acknowledge the strong support given to the project
producers, researchers, government officials and private citizens in Ecuador.
The following institutions and individuals provided especially-important help
and assistance in project planning, research implementation, laboratory
analyses, data acquisition, and the interpretation and synthesis of the
overall project results.
Center for Remote Sensing of Natural Resources (CLIRSEN):
Ing. Patricio Toledo
Ing. Jose Valdivieso
Escuela Politecnia del Litoral (ESPOL, Guayaquil):
Ing. Wilmo Jara, Director
Ing. Francisco Medina
Sr. Julio Ayona
Sr. Jofre Chica
Sr. Javier Piedra
Sr. Ivo Zambrano
Instituto Nacional de Pesca (INP, Guayaquil):
D r . Roberto Jimenez, Director
Dra. Lucia Solorzano
Sr. Pablo Intriago
Ministry of Foreign Affairs (Quito):
Amb. Diego Paredes
Subsecretary of Fishery Resources (Guayaquil):
D r . Ricardo Naboa
Ing. Rafael Horna
Sr. Orlando Crespo
U.S. Agency for International Development (Quito):
D r . Fausto Maldonado
M r . David Anderson, U.S. Peace Corps
Ing. Manuel Botero, shrimp producer and pilot
Sr. Jamie Crespo, shrimp producer (In Memorium)
Econ. Felipe Orellana, shrimp producer
Ing. Jose Villalon, fisheries biologist
The authors also wish to recognize the support provided by the staff of
the Rosenstiel School, in particular, M r s . Marlen Alvarez, who served a s
Administrative Assistant for the project. Marea Hatziolas and Stephen Olseri
a r c extended sincere thanks for critical and constructive reviews of an early
d r a f t of the manuscript. Sally Dickinson, President of Tropical Research &
Development, Inc., provided the airplane and piloting services fur the
reconnaissance flights in Ecuador. Tropic House International, Inc., computer
processed the draft and final manuscripts, and Kendall Grnphics, Inc.,
prepared the illustrations. Don Heuer assembled and printed the final report.
Shrimp Pond Siting and Management
S. Snedaker, J. Dickinson, M. Brown and E. Lahnlann
- ix
The extensive a n d diverse coastal zone of Ecuador (Figure 1.1) i s a major
focus of actual and potential economic development. Convergent in t h e coastal
plain a r e t h e presence of rich alluvial soils, a b u n d a n t water from rainfall
and river drainages, and a productive estuarine zone. The human response to
this wealth of resources has been t h e establishment of commercid agriculture
based on bananas, cacao, cotton, rice a n d other* grains, fisheries a n d
mariculture, urban-industrial centers, tourism, a n d a n extensive supporting
infrastructure. Coastal Guayaquil, for example, i s t h e business c e n t e r of
Ecuador. F u r t h e r sustained development of these economic activities, a n d t h e
resources upon which they a r e dependent, i s necessarily based on t h e
integrated management of human activities both i n t h e coastal zone a n d in
upstream watershed areas.
Among t h e various econoniic activities i n t h e coastal zone i s t h e 140
million dollar ( U S $ ) p e r year shrimp i n d u s t r y which now s u r p a s s e s bananas a s
t h e leading non-h ydrocarbon export (Table 1.1). The capability of Ecuador to
produce shrimp (Table 1.2) is related directly to t h e characteristics of t h e
country's coastal environment with i t s extensive estuaries, year round growing
season, suitable soil conditions, and a balance of f r e s h water and ocean
c u r r e n t inputs, except d u r i n g El Nido events.
Table 1.1. Foreign exchange earnings in Ecuador for t h e y e a r s 1978-84, given
in million U.S. dollars, FOB. (Source: Central Bank of Ecuador)
Year
Crude O i l
Bananas
Coffee
Shrimp
Shrimp Pond Siting and Management
S . Snedukcr, J. Dickineon, M. Brown and E. Lahmann
-
1
- uulemqn~-3pule um
Water
Controi
(d
>
Balao
uplands S:
mangrove
8.0
6
10-68
15-20
both
T-P
Chongon
uplands R
mangrove
0.3
7
20
65-75
none
PC
Machala ( a )
sal i n a
12.0
7
12-38
18-25
none
PC
Machala ( b j
mallgrove
?
5
?
?
feed
T-P
Machala ( c )
uplands
15.0
6
-120
?
none
T-P
Machala
salina &
mangrove
14.0
7
10-27
30
feed
PC
! d)
Islas de las
Conchitas ( a j
salina
2.5
7
9-20
45
none
PC
I s l a s de las
Co~ichitas( b )
salina
?
5
?
?
f ced
T-P
Rio Guayas
salina
4.0
7
12--18
100
both
PC
T-C
G
6.0
8-13
80-90
both
NaranSal
mangrove
------------- ------------aYrs. O p s . : Number of y e a r s in operation.
Level: This is a quulitative determination of t h e level of actual
bMa~~agcment
rnanagement a t each evaluated shrimp farm.
CFecd/fcrtilizer: Identifies t h e use of supplemental feed a n d / o r fertilizer.
dWater control: This identifies t h e primary methods of filling and exchanging
water within thc: pond(s): "T" (tidal), "T-P" (tidal with auxiliary pumping),
and "PC" (continuous exchange of pond water via pumps).
--
--
Shrirn Pond Sitin and Management
S . Snadukor, J. &ckinaon, M. %=own and B. Lahmann
-
15
3.1.2.
W u t t w Quality
To evaluate pond conditions within and among different shrimp farms,
several water quality parameters were measured. The parameters used can be
divided into two major groups. The f i r s t g r o u p was for t h e characterization of
water clarity and color which would be used to ground-truth the aerial color
imagery. These consisted of Secchi disk, t u r b i d i t y and visual color readings.
The second g r o u p was for t h e establishment of basic water quality parameters.
This suite of analyses included pH, salinity, temperature, chlorophyll
content, biomass and species composition. The methodology t h a t was used was
consistent, with s t a n d a r d methods (EPA 1979; Greenberg, Connors and Jenkins
1981).
All water quality measurements and water samples were taken a t t h e
discharge point of t h e shrimp ponds and from t h e source waters, These sampling
points were chosen to determine t h e effect of management practices on water
quality (e.g., production stage, flushing rates, a n d t h e u s e of supplemental
feed and/or fertilizer). This also afforded u common sampling point for
standardization. Source waters were collected for u s e a s unaltered reference
samples to determine t h e impact t h a t management p~*act,iceshad on water
quality. The water samples were collected with a clean, 2 1 flask a t a depth
of 0.5 m. Two of t h e on-site measurements were dependent upon ambient light
conditions (Secchi Disk and color). Every effort was made to standardize these
readings by taking them between 1000 and 1500 h r s d u r i n g cloudless periods.
The Secchi Disk, a white circular plate which is used to determine t h e
degree of visibility ( t r a n s p a r e n c y ) in waters, i s lowered into t h e water and
t h e depth a t which the disk disappears from sight is t h e Secchi Disk
Transparency. This approxiinatcs one percent of t h e level of light a t t h e water
surface. I t should be noted t h a t with minor modification, t h i s technique is
the most common tool used to quantify shrimp pond water quality conditions in
Ecuador. Managers use this method to determine pond flushing r a t e s a n d t h e
need for feed and/or fertilizer. Values a r e reported i n centimeters.
Turbidity is a n expression of the optical p r o p e r t y t h a t causes light to be
scattered and absorbed r a t h e r than tranurnittod in r-t s t r a i g h t path Ihrough t h e
sample. Turbidity is similar to t h e Secchi Disk measurements in that both a r e
a measurr: of clarity (t~.ansparency).Turbidity was measured using a Hach Model
2100A direct reading lab nephelonieter. Values a r e reported in NTU's
(nephe1omr:tric turbidity u n i t s ) . N'I'U's arc: compnrablc? to .Jackson Turbidity
Units IJTU) and Formazin Turbidity Units (FTU) (EPA 1979).
Visual color was determined b y t h e platinum-cobalt mcthod. The method i s
useful for measuring t h e color of water in which t h e color is due to naturally
occurring rnat,erials. The color is determined by visual comparison of t h e pond
water with known concentrations of colored solutions. The coior determinations
are reported as a numerical unit frorri 1 to 21. I n several cases where t h e
color fell between two colors, a mid-point estimate was made.
Shrimp Pond Siting and Management
S. Snedaker, J. Dickinson, M. Brown and E. Lahmann
-
16
Salinity and temperature were determined with a Gold berg temperature
compensated refractometer and a mercury-filled thermometer, respectively.
Salinity vidues a r e reported in ppt., p a r t s p e r thousand. Temperature i s
reported in degrees Centigrade.
The pH of t h e water was determined with a specific-ion meter a n d
combination jell-filled electrode. The specific ion meter used in this project
was a n Orion Model 407A. The pH values a r e reported in s t a n d a r d p H units.
The chlorophyll, biomass and species composition determinations were to be
done b y t h e Instituto Nacional d e Pesca, but because of a severe illness
(hepatitis) contracted by t h e individual doing t h e analyses, only t h e
chlorophyll values a r e available a t t h e present time.
Chlorophyll pigments 5 b, 5 and pheophtiri a, were determined using t h e
method described b y Strickland a n d Parsons (1968). A known volume of
well-mised sample was filtered through a magnesium carbonate s a t u r a t e d glass
fiber filter. The filter paper was then folded upon itself, wrapped in
aluminum foil and placed on ice. Immediately upon r e t u r n to t h e base station,
t h e samples were frozen and held a t -100 until analysis could take place. The
samples were analyzed using a spectrophotometer for chlorophyll pigments 3 !,
c and pheophtin 2. Chlorophyll values a r e expressed in mg/m3 ( , ~ g / l ) .
3.1.3. Mangrove Forest Assessment
Six different locat,ions were selected for this s t u d y in an attempt to
obtain a n overview of t h e present s t a t u s of the Ecuadorean mangrove forests,
close to shrimp rnaricult.ure operations, u n d e r a range of environmental
conditions. In the following site descriptions, t h e mangrove-forest t y p e names
a r e taken from Lugo and Snedaker (1974). The designation of t h e operational
types and t h e Management Levels of t h e shrimp ponds a r e based t h e work
discussed elsewhere in this report.
I N MANGROVE ECOSYSTEMS I N ECUADOR
!
Final Report
USAID Grant No. DPE-5542-G-SS-4022-00
Prepared for t h e
U.S. Agency for International Development
Office of t h e Science Advisor
Samuel C. SnedakerT1Joshua C. Dickinson, IIIP2
Melvin S. Brown1 and Enrique J. Lahmannl
1Rosenstiel School of Marine and Atmospheric Science
University of Miami
4600 Rickenbacker Causeway
Miami, Florida 33149-1098 USA
*Tropical Research & Development, Inc.
6124 S W 30 Avenue
Gainesville, Florida 32608 USA
Miami, Florida
1986
NOTE TO READER
September 1, 2006
THIS IS A SEARCHABLE PDF DOCUMENT
This document has been created in Adobe Acrobat Professional 6.0 by scanning the best
available original paper copy. The page images may be cropped and blank numbered pages
deleted in order to reduce file size, however the full text and graphics of the original are
preserved. The resulting page images have been processed to recognize characters
(optical character recognition, OCR) so that most of the text of the original, as well as some
words and numbers on tables and graphics are searchable and selectable. To print the
document with the margins as originally published, do not use page scaling in the printer
set up.
This document is posted to the web site of the
Coastal Resources Center,
Graduate School of Oceanography,
University of Rhode Island
220 South Ferry Road
Narragansett, Rhode Island, USA 02882
Telephone: 401.874.6224
http://www.crc.uri.edu
Citation:
Snedaker, S., J. Dickinson, M. Brown and E. Lahmann 1986. Shrimp Pond Siting And
Management Alternatives In Mangrove Ecosystems In Ecuador. Quito: U.S. Agency for
International Development.
Preface................................................................ ii
List of Figures
vi
List of Tdles ........................................................vii
viii
Abbreviations. Symbols and Definitions
Acknowledgements
ix
........................................................
...............................
.......................................................
1.0.0. Introduction....................................................1
1.1.0. Scope of Project ........................................... 3
1.2.0. Major Froject Activities...................................G
2.0.0. Background......................................................7
2.1.0. Types and Levels of Mariculture Management .................7
2.1.1. Type I : Subsistence and Artisanal Open-System
mariculture..............................................7
2.1.2. Type 11: Extensive Closed-System Mariculture..............10
2.1.3. Type 111: Semi-intensive Closed-System Mariculture........ 12
2.1.4. Type IV: Intensive Artificial-System Mariculture..........12
3.0.0. Field Evaluations ............................................... 14
3.1.0. Introduction...............................................14
3.1.1. Interviews................................................. 14
3.1.2. Water Quality ..............................................16
3.1.3. Mangrove Forest Assessment .................................17
3.2.C. Shrimp Farm Evaluations.................................... 21
3 . 2 . 1 . Production Levels..........................................21
3 . 2 . 2 . Major Problems.............................................21
3.2.3. Ideal Conditions...........................................22
3 . 2 . 3 . T h e Future Outlook ......................................... .'
3.3.0. Water Quality .............................................. 25
4.0.0 Shrimp Mariculture in Ecuador ....................................32
4.1.0. Mariculture Types and Management Levels....................32
4.1.1. Type 11: Extensive Closed-System, Management Level 5.......32
4.1.1. T j ~ p e11: Extensive Closed-System, Management Level 6.......32
3 . 1 . 2 . Type 111: Semi-Intensive Closed-System, Management
Level 7 ....................................................33
4.1.3. Type 11 I: Semi-Intensive Closed..System, Management
Level 8....................................................33
4.2.0. Construction Cost .........................................34
4.3.0. Operational Costs..........................................24
4.4.0. Shrimp Pond Sitinff......................................... 35
4.4.1. Pond Size..................................................35
or
4.4.2. Pond Loi:ation ..............................................ad
4.5.0. Water Quality Management ...................................37
5.0.0. Environmental Considex-ations.................................... 38
5.1.0. Upstream Use and Misuse of Resources.......................38
5.2.0. Agriculture ................................................38
5.3.0. Mangrove-Rased F i s h e r i e s ...................................38
5.4.0. Effects On Mangrove Forests................................39
3
r;
....................................
................
..............
.......................
Socioeconomic Considerations
42
6.1.0. Marginal Habitats Converted to Economic Use
42
6.2.0. Maricultut-e Provides Employnent Opportunities
44
6.3.0. Dietary Protein Levels are Increased
45
6.4.0. Local Economic Benefits and Hard Currency Earnings
Stimulate Economic Development Within the Region ...........45
6.5.0. Government Revenue Base is Strengthened....................46
6.6.0. Construction of Hatcheries Will Solve the Major Problem
47
6.0.0.
....
7.0.0. CONCLUSIONS .....................................................48
7.1.0. Pond Siting and Management Intensification................48
7.2.0.
Development of Maturation and Hatcilerv Facilities.........49
7.3.0. The Recurrent Post Larvae Crisis..........................50
7.4.0. Alternate and/or Exotic Culture Species...................50
7.5.0. Fishery Sector Development................................51
7.6.0. Intertidal Zone Management ................................53
7.7.0. Activities of Interest to Development 4. ssistance
Agencies ..................................................54
7.8.0. Research Needs ............................................ 55
8.0.0. LITERATURE CITED AND BIBLIOGRAPHIC REFERENCES ..................56
Appendix A . Some Traditional Uses of South American Mangrove Forests..A-1
Introduction.....................................................A-1
The Mangrove Forests of South America ............................A-2
Geographic Distribution ...................................... A-2
Forested Area ................................................LI-2
Species Cornl>osition.......................................... A-3
Historical and Traditional Uses ..............................A-3
Utilization and Economic Value ...............................A-4
Literature Cited................................................. A-6
Appendix B . Mangrove Forest Area in Ecuador ..........................B-1
Literature Cited ................................................. B-3
PREFACE
One of the most rapidly-expanding and profitable economic development
activities in South America has been the Penaeid shrimp-growout pond
(mariculture) industry in Ecuador which had i t s beginnings in the early 1970s.
I t now ranks -after
, -p
a s a major export commodity and --'
foreign currency earner for Ecuador. In addition, shrimp mariculture has
completely transformed much of the coast of southern Ecuador into a mosaic of
interlocking and contiguous growout ponds. In addition, i t has also stimulated
the development of a variety of local support industries.
Prior to the "El Niiio" event of 1982/83, the shrimp mariculture industry
began to experience increasingly severe and unpredictable shortages in the
wild post-larval shrimp (PL) that a r e harvested in shallow coastal waters to
stock commercial grbowout ponds. For several years, the demand for PL had
exceeded their natural availability and led the shrimp producers, represented
by such organizations a s ACEBA (Asociacion de Cultivadores de Especies
Bioacuaticas), to begin to seek a solution to the continuing shortage.
Although the El Nifio event destroyed a significant part of the physical
infrastructure upon which the industry relied, the chaotic period w a s also
characterized by a relatively large population of PL suitable for capture and
pond stocking. Nevertheless, the experienced producers recognized that the
long-term trend portended continued annual shortages in P L availability.
With respect to the decreasingly availability of PL stocks, i t was
known from a variety of published sources that coastal mangrove forests a r e
the primary nursery habitats f o r many species of marine shrimp a s well a s n
large number of other species of shellfish and finfish. These intertidal
forests provide a refuge from competitors and predators, and a r e a source of
nutrient-enriched organic matter which serves as a food substrate. I t was
therefore local1y concluded that the extensive conversion of the coastal
mangrove forests to shrimp growout ponds, particularly in the southern
provinces (e.g., Cuayas, El Oro, Manabi), was somehow implicated in tho
reduction of the availability of larval and juvenile shrimp. The local
producers, mainly ACEBA, made known their desire for a solution to the U. S.
Agency for International Developnient (USAID) relative to destruction of
mangrove forests and the problematic availability of PL. Among other points,
the producers argued that continued conversion of mangrove forest areas to
maricultural ponds could lead to the collapse of the mariculture industry.
After a series of discussions with the producers and USAID, the authors,
working through thc University of Miami, obtained a research g r a n t from the
USAID Office of the Science Advisor's Program in Science and Technology
cooperation (PSTC). rusted puruose of the ~ m n w
t e s e a r c h &he
manmerddhe
relationship among shrimp pond s%and
-cb&karw
i n both mangrove forest area and P L stocks. The
corollary g r a n t objective was to develop guidelines o r recommendations on
Shrimp Pand Siting and Mamgcment
S. Snedaker, J. Dickinson, M. Brown and E. Lahmnn
-
ii
siting and management which could lead to higher and stabilized levels of pond
production yields.
The research was formally initiated in mid-1984 and concluded in mid-1985.
The major part of the field work took place during February and March 1985
during which time experimental aerial photographs were taken and field
investigations made of representative ponds and surrounding mangrove forests
in Guayas, El Oro and Manabi provinces. In addition, information was acquired
on pond siting and management practices from a variety of Ecuadorean sources
for comparison with information obtained elsewhere by the authors (see, for
example, Dickinson 1983) a s well a s data and information reported in the
literature. This report summarizes and discusses the findings. I t is hoped
that this report represents a significant contribution to our increasing
knowledge of the practical benefits, problems and alternatives, associated
with the extensive globally-expanding shrimp mariculture industry.
Caveat: This draft of the final report was prepared without access to two
important bodies of data arid information. The f i r s t is a n inventory of
mangrove forest and shrimp-pond area which was completed by the Centro de
Levantamientos Integrados Recursos por Sensores Remotes (CLIRSEN), but was not
released to the principal investigators of this project. The absence of this
information precluded a broadened analysis of both pond siting preferences and
site-related problems in Ecuador. The second missing body of information i s a
socioeconomic description of the management of the sample ponds selected for
study in this project. This was to have been prepared by Dr. S. K. Meltzoff in
r e t u r n for grant support for team research participation in Ecuador. After
t
arriving in Ecuador, however, Dr. Meltzoff insisted on pursuing her own
personal interests instead of grant objectives. Regrettably, this precluded a
{
complete evaluation of the different socioeconomic aspects of management that
a r e still believed to be correlated with both pond location and the intensity
of management.
{
S h r i m p Pond Siting and Management
S. Snedaker, J. Dickinson, M. B r o w n and E. Lahmann
-
iii
ACKNOWLEDGEMENTS
The authors wish to acknowledge the strong support given to the project
producers, researchers, government officials and private citizens in Ecuador.
The following institutions and individuals provided especially-important help
and assistance in project planning, research implementation, laboratory
analyses, data acquisition, and the interpretation and synthesis of the
overall project results.
Center for Remote Sensing of Natural Resources (CLIRSEN):
Ing. Patricio Toledo
Ing. Jose Valdivieso
Escuela Politecnia del Litoral (ESPOL, Guayaquil):
Ing. Wilmo Jara, Director
Ing. Francisco Medina
Sr. Julio Ayona
Sr. Jofre Chica
Sr. Javier Piedra
Sr. Ivo Zambrano
Instituto Nacional de Pesca (INP, Guayaquil):
D r . Roberto Jimenez, Director
Dra. Lucia Solorzano
Sr. Pablo Intriago
Ministry of Foreign Affairs (Quito):
Amb. Diego Paredes
Subsecretary of Fishery Resources (Guayaquil):
D r . Ricardo Naboa
Ing. Rafael Horna
Sr. Orlando Crespo
U.S. Agency for International Development (Quito):
D r . Fausto Maldonado
M r . David Anderson, U.S. Peace Corps
Ing. Manuel Botero, shrimp producer and pilot
Sr. Jamie Crespo, shrimp producer (In Memorium)
Econ. Felipe Orellana, shrimp producer
Ing. Jose Villalon, fisheries biologist
The authors also wish to recognize the support provided by the staff of
the Rosenstiel School, in particular, M r s . Marlen Alvarez, who served a s
Administrative Assistant for the project. Marea Hatziolas and Stephen Olseri
a r c extended sincere thanks for critical and constructive reviews of an early
d r a f t of the manuscript. Sally Dickinson, President of Tropical Research &
Development, Inc., provided the airplane and piloting services fur the
reconnaissance flights in Ecuador. Tropic House International, Inc., computer
processed the draft and final manuscripts, and Kendall Grnphics, Inc.,
prepared the illustrations. Don Heuer assembled and printed the final report.
Shrimp Pond Siting and Management
S. Snedaker, J. Dickinson, M. Brown and E. Lahnlann
- ix
The extensive a n d diverse coastal zone of Ecuador (Figure 1.1) i s a major
focus of actual and potential economic development. Convergent in t h e coastal
plain a r e t h e presence of rich alluvial soils, a b u n d a n t water from rainfall
and river drainages, and a productive estuarine zone. The human response to
this wealth of resources has been t h e establishment of commercid agriculture
based on bananas, cacao, cotton, rice a n d other* grains, fisheries a n d
mariculture, urban-industrial centers, tourism, a n d a n extensive supporting
infrastructure. Coastal Guayaquil, for example, i s t h e business c e n t e r of
Ecuador. F u r t h e r sustained development of these economic activities, a n d t h e
resources upon which they a r e dependent, i s necessarily based on t h e
integrated management of human activities both i n t h e coastal zone a n d in
upstream watershed areas.
Among t h e various econoniic activities i n t h e coastal zone i s t h e 140
million dollar ( U S $ ) p e r year shrimp i n d u s t r y which now s u r p a s s e s bananas a s
t h e leading non-h ydrocarbon export (Table 1.1). The capability of Ecuador to
produce shrimp (Table 1.2) is related directly to t h e characteristics of t h e
country's coastal environment with i t s extensive estuaries, year round growing
season, suitable soil conditions, and a balance of f r e s h water and ocean
c u r r e n t inputs, except d u r i n g El Nido events.
Table 1.1. Foreign exchange earnings in Ecuador for t h e y e a r s 1978-84, given
in million U.S. dollars, FOB. (Source: Central Bank of Ecuador)
Year
Crude O i l
Bananas
Coffee
Shrimp
Shrimp Pond Siting and Management
S . Snedukcr, J. Dickineon, M. Brown and E. Lahmann
-
1
- uulemqn~-3pule um
Water
Controi
(d
>
Balao
uplands S:
mangrove
8.0
6
10-68
15-20
both
T-P
Chongon
uplands R
mangrove
0.3
7
20
65-75
none
PC
Machala ( a )
sal i n a
12.0
7
12-38
18-25
none
PC
Machala ( b j
mallgrove
?
5
?
?
feed
T-P
Machala ( c )
uplands
15.0
6
-120
?
none
T-P
Machala
salina &
mangrove
14.0
7
10-27
30
feed
PC
! d)
Islas de las
Conchitas ( a j
salina
2.5
7
9-20
45
none
PC
I s l a s de las
Co~ichitas( b )
salina
?
5
?
?
f ced
T-P
Rio Guayas
salina
4.0
7
12--18
100
both
PC
T-C
G
6.0
8-13
80-90
both
NaranSal
mangrove
------------- ------------aYrs. O p s . : Number of y e a r s in operation.
Level: This is a quulitative determination of t h e level of actual
bMa~~agcment
rnanagement a t each evaluated shrimp farm.
CFecd/fcrtilizer: Identifies t h e use of supplemental feed a n d / o r fertilizer.
dWater control: This identifies t h e primary methods of filling and exchanging
water within thc: pond(s): "T" (tidal), "T-P" (tidal with auxiliary pumping),
and "PC" (continuous exchange of pond water via pumps).
--
--
Shrirn Pond Sitin and Management
S . Snadukor, J. &ckinaon, M. %=own and B. Lahmann
-
15
3.1.2.
W u t t w Quality
To evaluate pond conditions within and among different shrimp farms,
several water quality parameters were measured. The parameters used can be
divided into two major groups. The f i r s t g r o u p was for t h e characterization of
water clarity and color which would be used to ground-truth the aerial color
imagery. These consisted of Secchi disk, t u r b i d i t y and visual color readings.
The second g r o u p was for t h e establishment of basic water quality parameters.
This suite of analyses included pH, salinity, temperature, chlorophyll
content, biomass and species composition. The methodology t h a t was used was
consistent, with s t a n d a r d methods (EPA 1979; Greenberg, Connors and Jenkins
1981).
All water quality measurements and water samples were taken a t t h e
discharge point of t h e shrimp ponds and from t h e source waters, These sampling
points were chosen to determine t h e effect of management practices on water
quality (e.g., production stage, flushing rates, a n d t h e u s e of supplemental
feed and/or fertilizer). This also afforded u common sampling point for
standardization. Source waters were collected for u s e a s unaltered reference
samples to determine t h e impact t h a t management p~*act,iceshad on water
quality. The water samples were collected with a clean, 2 1 flask a t a depth
of 0.5 m. Two of t h e on-site measurements were dependent upon ambient light
conditions (Secchi Disk and color). Every effort was made to standardize these
readings by taking them between 1000 and 1500 h r s d u r i n g cloudless periods.
The Secchi Disk, a white circular plate which is used to determine t h e
degree of visibility ( t r a n s p a r e n c y ) in waters, i s lowered into t h e water and
t h e depth a t which the disk disappears from sight is t h e Secchi Disk
Transparency. This approxiinatcs one percent of t h e level of light a t t h e water
surface. I t should be noted t h a t with minor modification, t h i s technique is
the most common tool used to quantify shrimp pond water quality conditions in
Ecuador. Managers use this method to determine pond flushing r a t e s a n d t h e
need for feed and/or fertilizer. Values a r e reported i n centimeters.
Turbidity is a n expression of the optical p r o p e r t y t h a t causes light to be
scattered and absorbed r a t h e r than tranurnittod in r-t s t r a i g h t path Ihrough t h e
sample. Turbidity is similar to t h e Secchi Disk measurements in that both a r e
a measurr: of clarity (t~.ansparency).Turbidity was measured using a Hach Model
2100A direct reading lab nephelonieter. Values a r e reported in NTU's
(nephe1omr:tric turbidity u n i t s ) . N'I'U's arc: compnrablc? to .Jackson Turbidity
Units IJTU) and Formazin Turbidity Units (FTU) (EPA 1979).
Visual color was determined b y t h e platinum-cobalt mcthod. The method i s
useful for measuring t h e color of water in which t h e color is due to naturally
occurring rnat,erials. The color is determined by visual comparison of t h e pond
water with known concentrations of colored solutions. The coior determinations
are reported as a numerical unit frorri 1 to 21. I n several cases where t h e
color fell between two colors, a mid-point estimate was made.
Shrimp Pond Siting and Management
S. Snedaker, J. Dickinson, M. Brown and E. Lahmann
-
16
Salinity and temperature were determined with a Gold berg temperature
compensated refractometer and a mercury-filled thermometer, respectively.
Salinity vidues a r e reported in ppt., p a r t s p e r thousand. Temperature i s
reported in degrees Centigrade.
The pH of t h e water was determined with a specific-ion meter a n d
combination jell-filled electrode. The specific ion meter used in this project
was a n Orion Model 407A. The pH values a r e reported in s t a n d a r d p H units.
The chlorophyll, biomass and species composition determinations were to be
done b y t h e Instituto Nacional d e Pesca, but because of a severe illness
(hepatitis) contracted by t h e individual doing t h e analyses, only t h e
chlorophyll values a r e available a t t h e present time.
Chlorophyll pigments 5 b, 5 and pheophtiri a, were determined using t h e
method described b y Strickland a n d Parsons (1968). A known volume of
well-mised sample was filtered through a magnesium carbonate s a t u r a t e d glass
fiber filter. The filter paper was then folded upon itself, wrapped in
aluminum foil and placed on ice. Immediately upon r e t u r n to t h e base station,
t h e samples were frozen and held a t -100 until analysis could take place. The
samples were analyzed using a spectrophotometer for chlorophyll pigments 3 !,
c and pheophtin 2. Chlorophyll values a r e expressed in mg/m3 ( , ~ g / l ) .
3.1.3. Mangrove Forest Assessment
Six different locat,ions were selected for this s t u d y in an attempt to
obtain a n overview of t h e present s t a t u s of the Ecuadorean mangrove forests,
close to shrimp rnaricult.ure operations, u n d e r a range of environmental
conditions. In the following site descriptions, t h e mangrove-forest t y p e names
a r e taken from Lugo and Snedaker (1974). The designation of t h e operational
types and t h e Management Levels of t h e shrimp ponds a r e based t h e work
discussed elsewhere in this report.