International Journal of Geosciences, 2013, 4, 54-59
http://dx.doi.org/10.4236/ijg.2013.45B009 Published Online September 2013 (http://www.scirp.org/journal/ijg)
Copyright © 2013 SciRes. IJG
Survey of Climate-Related Risks to Tilapia Pond Farms
in Northern Thailand
Pornpimol Pimolrat1, Niwooti Whangchai1, Chanagun Chitmanat1, Jongkon Promya1, Louis Lebel2
1Faculty of Fisheries Technology and Aquatic Resources, Maejo University, Chiang Mai, Thailand
2Unit for Social and Environmental Research (USER) Faculty of Social Science, Chiang Mai University, Chiang Mai, Thailand
Email: paqua50@gmail.com
Received July 2013
ABSTRACT
Climate is an important factor for aquacultur e production. This study aimed to understand how farmers that culture til a-
pia in earthen ponds perceive and respond to climate impacts. Important climate-related risks identified include extr eme
temperatures (hot and cold), excessive rainfall, prolonged cloud cover, flood and drought. Site visits and data collection
using questionnaires were conducted to identify important factors influencing farm profits, losses, decision to increase
or decrease ponds. Special attention was given to knowledge about fish markets and weather and the impacts of weather
and climate on fish growth, diseas e outbre aks and water quality in ponds . Altoge ther 585 fish farms in four prov inces in
northern part of Thailand selected to cover a range of elevations above sea level and thus climate were surveyed (Na-
kornsawan < 100 m, Lampang 100 - 300 m, Phayao 300 - 500 m and Chiang Mai > 500 m). Fish farms at different ele-
vations reported different climate and weather-related impacts. In the area where elevation above sea level is < 100 m,
farmers were affected more by floods and extreme hot weather which caused fish deaths and stress that reduced feeding
and growth rates. Conversely, fish farmers in the area where elevation above sea level is >500 were impacted mainly by
drought and cold weather. These conditions also caused disease outbreaks and reduced feeding rates. Farmers respond-
ed by reducing the amount of feed supplied and considering non-fish pond or non-farm supplementary occupations as
an adaptation strategy. Among non-climate related factors high prices of feed were most commonly identified as a key
issue by farmers. The differences among sites at higher and lower elevation provided insights into the kind of changes
in risks farmers may face as climate changes that could be helpful in developing adaptation strategies for individual
farmers and the sector as a whole.
Keywords: Climate; Tilapia Pond Culture; Aquaculture; Thailand
1. Introduction
Climate is an environmental factor that is strongly asso-
ciated to aquaculture productivity [1]. Being coldblooded
animal, fish is affected by the temperature of the sur-
rounding water which influences the body temperature,
growth rate, food consumption, feed conversion, and
other body functions [2,3]. Over the past few years, ris-
ing global temperatures have received much attention
because of their worldwide impact on ecosystems. The
climate models referenced by the Intergovernmental
Panel on Climate Change (IPCC) [4] predicted that glob-
al temperatures are likely to increase by 1.4˚C to 6.4˚C in
this century.
Nile tilapia (Oreochromis niloticus) is a freshwater
fish of great commercial interest. It is easy to cultur e and
adapts well to a range of environments. Tilapia culture is
one of the largest aquaculture industries in Thailand [5].
In the mountainous northern region, relatively high alti-
tude and latitude contribute to more pronounced seasonal
temperature variation, with cooler winters than in other
regions. Numerous climate variables vary with elevation
[6].
Some farmers rear fish in cages suspended in rivers.
This culture system is sensitive to extreme weather
events, such as floods or droughts [7,8]. It is also sensi-
tive to seasonal differences in water temperature, flow
speeds and water quality. Ponds, however, are the most
common production systems on a worldwide basis. Tila-
pia fish culture in earthen ponds in northern Thailand can
be divided into three categories: commercial, integrated
(with pig or chicke n) and subsistence.
In recent years, production of pond-raised tilapia in
northern Thailand has been hampered by climate-related
risks including extreme temperatures (hot and cold), ex-
cessive rainfall, prolonged cloud cover, flood and
drought all of which potentially cause fish deaths, stress
and reduced feeding and growth rates. In order to better
understand the effects of climate on tilapia pond farms
P. PIMOLRAT ET AL.
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55
this study compared sites along an elevation gradient in
northern Thailand. The specific objective of this study
was to improve understanding of how fish farmers in
different elevation perceive and respond to climate im-
pacts. The differences among sites at higher and lower
elevation provided insights into the kind of changes in
risks farmers may face as climate changes that could be
helpful in developing adaptation strategies for individual
farmers and the sector as a whole.
2. Material and Methods
2.1. Sampling of Fish Farms
A total of 585 fish farmers were interviewed for this
study. The tilapia farmers were randomly selected from
the list of farmers in collaboration with the fisheries of-
ficers of the Department of Fisheries. An effort was
made to interview fish farmers currently or recently hav-
ing reared tilapia in fish ponds in nine provinces in
northern part of Thailand. Not all who had recently
stopped farming could be contacted. Local fisheries offi-
cials, community leaders and private sector feed and
stock suppliers were used to help locate farmers. Almost
all farmers approached agreed to participate in the survey
and were able to answer all questions. Interviews were
carried out using a structure d questionnaire with farmers.
The questionnaire covered individual, farm and site level
characteristics as well as more detailed sections about
impacts from extreme temperatures (hot and cold), ex-
cessive rai nfal l, prol onged cl ou d cove r, fl ood a nd droug ht .
Sites were grouped by provinces into four elevations
for analysis: <100 meters above sea level (masl) (Nak-
honsawan, Pichit, Kamphengphet, Uttaradit and Phitsa-
nulok), 100 - 300 masl (Lampang), and 300 - 500 masl
(Phayao and Chiangrai) and >500 masl (upland areas in
Chiangmai). The characteristic climate of each elevation
are described and summarized in Tabl e 1.
2.2. Data Analysis
The data were compared between elevations for each fish
farm. All reports about difference in this text were sig-
nificant at the P < 0.05 or better level; Tukey HSD tests
were used post-hoc to separate means following detec-
tion of a significant main effect in ANOVA when there
was three or more means.
3. Results and Discussion
3.1. Characteristics of Fish Farmers
The characteristic of the farms and farmers’ obtained
from the present study are presented in Table 2. The re-
sults show that there were more male farmers than fe-
males. Fish farmers were mostly middle-age and had a
primary school level of education. Approximately 30%
of households had a monthly income in the range of
5,000 - 10,000 Thai Baht. The fish farmerscommonly
had pond-culture experience ranged from 3 - 10 years.
3.2. Climate Impacts at Di f f erent Elevation
The likelihood of climate impacts on farms in different
range of elevation (masl) is shown in Figure 1. Fish
farms at different elevations reported different climate
and weather-related impacts. In the area where elevation
above sea level is <100 m, farms were affected more by
floods (36%) and extreme hot weather (31%). Farms at
elevation above sea level 100 - 300 had higher drought
(35%) problem than other areas. The highest long cloud
cover (51%) impact was foun d in 300 - 500 sites. On the
other hand, fish farmers in the area where elevation
above sea level is >500 were impacted most by extreme
cold weather.
Table 1. Climate in the four study areas (between years 1990-2010). Provinces for which precipitation and temperature data
are shown bel ow are underlined.
Conditions E levation MASL (m)
<100 100 - 300 300-500 >500
Provinces Nakon-swan Kamphengphet Phitsanolok Uttaradit Lampang Phayao Chiangrai Chiangmai
Mean minimum temp in coldest month 18.6 (Jan) 15.7 (Jan) 13.3 (Jan) 12.6 (Dec)
Mean maximum temp in coldest month 37.6 (Apr) 37.9 (Apr) 35.4 (Apr) 27.4 (Apr)
Mean precipitation in wettest month 250.2 (Sep) 218.6 (Sep) 281.2 (Sep) 186.8 (Sep)
Mean precipitation in driest month 4.4 (Jan) 3.9 (Jan) 7.4 (Jan) 3.3 (J an)
Average mean annual precipitation (mm) 1289.4 900.3 1398.9 1233
CV (mean annual precipitation) 0.07 0.47 0.30 0.16
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Table 2. Selected demographic characteristics of the fish farmers (n = 585).
Characteristic Percentage Characteristic Percentage
Age in years Education
<=30 3.6 No formal 4.5
31 - 44 15.7 Primary 60.2
45 - 57 42.7 Lower Secondary 12.6
58 - 71 30.8 Upper Secondary 11.8
72 + 7.2 University 3.8
Household average monthly income (Thai Baht)
Gender
Male 55.9
Female 44.1
<5000 12.8 Pond-culture experience (yrs)
5000 - 9999 30.3 <= 2 7
10000 - 14999 19.3 3 - 10 62.6
15000 - 19999 9.9 11 - 20 19.0
20000 - 29999 12.8 21 - 29 9.2
30000+ 14.5 30+ 2.2
Figure 1. Percentage of climate impacts in different range of
elevation above sea level.
3.3. Effects of Elevation on Culture Type,
Purpose of Culture and Farm Size
Most farmers in northern Thailand cultured tilapia for
consumption (94% of total 585) and many cultured mul-
tiple fish species in ponds (Figure 2(b)). About 47% of
farmers cultured tilapia fish for sale. Commercial farms
were most common at 300-500 masl sites and these sites
also had higher farm size (4+ ponds) than other elevation
sites (Fi gure 2(a) and (b)).
3.4. Perception of Non-Climate-Related and
Indirectly-Related Risks
In present study, w e explored the concern of fish farmers
Figure 2. Percentage of farm size (total ponds) and culture
type of tilapia fish in different range of elevation above sea
level.
about various risk such as disease outbreak, fish theft,
poor feed and fingerling quality, and feed prices. Patterns
of association with elevation varied among risk types.
Fish farmers were most concerned about risks to profita-
bility from low quality fingerlings in all elevation area
(Figure 3). Disease outbreak was of comparatively less
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57
Figure 3. Level of concern of fish pond farmers over five types of non-climate-related and indir ectly-related risks in four ele-
vations in northern Thailand. Concern was scored on a scale of 1 (not concerned) to 5 (very concerned). Plotted are means
and 95% confidence intervals for the means.
concern relative to other risks in the area where elevation
above sea level is <100 masl and >500 masl. Concern
with feed price and fish theft were lower at the >500
masl elevation site than in other three sites (p < 0.05,
Tukey’s HSD after ANOVA) conversely fish farmers at
300 - 500 masl had highest level of concern about feed
prices.
4. Discussion
Aquatic systems in which animals are reared are directly
influenced by climate. Climate-related risks increase
production costs by making it harder to manage the farm
efficiently and as a result of direct production losses [9].
The climate data from Table 1 indicated that there were
variations in temperatures a mong sites at different elev a-
tions as would be expected. Air and water temperature
are generally cooler at higher elevations [10] and the
temperature of the water is regulated mainly by the tem-
perature of the surrounding air. The importance of dif-
ferent climate-related risks to pond aquaculture varied
with elevation. As elevation increases (>500 masl),
mostly tilapia fish farmers face the extreme cold weather
impact which resulted in reduced feeding and growth due
to the negative effects on the rate of metabolism, chemi-
cal reaction and oxygen consumption [11]. Temperature
is one of the most important environmental factors with
the greatest influence on the growth performance of ani-
mals [12]. Hamdan and colleagues [1] reported that the
significant association between production loss and the
decrease and increase of water temperature indicating
that climate indicators especially temperature is most
influential in the aquaculture production. Water temper-
ature affects the quantity of oxygen dissolved in the wa-
ter, evaporation and aquaculture productivity directly
[13]. The aquaculture species are growing dynamically in
the minimum and maximum tolerance limit of tempera-
ture and survive in optimal temperature. Although tilapia
fish has proven popular for its ease of culture, robustness,
palatability and tolerance of a range of environmental
conditions [5] but these fish do not grow well at temper-
ature below 16˚C and cannot usually survive for more
than a few days below 10˚C [14]. Watanabe [15] re-
ported 25˚C to be the optimum temperature for nutrient
digestibility in tilapia, O. niloticus (L.) and the optimum
temperature for feeding, growth and reproduction is be-
tween 26˚C and 30˚C [16]. Additionally, the highest
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58
percentage of small farm size (one pond) was also found
in this elevation (>500 masl) one reason possible because
of the unsuitable temperature for culture tilapia fish.
O. niloticus is known to tolerate high temperatu res: up
to 40˚C - 42˚C [17]. However, rapid temperature varia-
tion will have a negative effect on these species growth
due to the less dissolved oxygen in the warm water [12].
The present study clearly showed that farmers growing
fish above sea level, <100 and 300 - 500 masl, were af-
fected more by extreme hot weather than other areas.
Especially, farms at 300 - 500 elevation sites which are
in the highest commercial categories, and the larger farm
sizes (4+ ponds) are usually found in this elevation, the
farmers should be more aware of this important risk be-
cause the association between high temperature and dis-
solved oxygen (DO) have impact on fish production. In
addition, the temperatures above 32˚C may significantly
results in slow growth, reduce feeding efficiency and
increase mortality [12].
Floods are seasonal phenomena happening frequently
during rainy season in certain regions [13]. In 2011,
many areas in Thailand had severe flooding leading to
highest ever damage costs [18]. The present study clearly
showed that the fish farmers at elevation <100 masl
(Nakonswan, Phijit, Kamphengphet, Phitsanolok and
Uttaradit) faced higher impact from floods than in other
regions. According to the flood, many farmers have to
leave their houses, farms, and lose their job therefore
most farms in this site are smaller (one pond) and were
mostly subsistence culture. For reduction and adapting to
this impact, some farmers who cultured tilapia in these
areas changed to culture other fish species for example
Mekong giant catfish (Pangasianodon gigas) or used the
bigger fingering to reduce time of culture per crop. This
strategy will help them minimize the production loss and
ensure that the percentage of new fish stock rises suc-
cessfully and survive in the massive raining season that
occurs at year end. Generally, the impact of drought or
amount of precipitation (Table 1) has been associated
with the volume of water for exchange during culture.
The long drought season and raining fluctuation impli-
cated less DO problem to the pond water [1]. In this
study, the impacts from drought were mostly founded at
100 - 300 masl where highest percentage of poly culture
system has been carried out.
Finally, levels of concern on non-climate risks are as-
sociated between elevation and culture type of fish. It
was found that the unqualified fingering and feed prices
implicated more concerned to culture tilapia fish, espe-
cially at the large commercial tilapia culture of northern
Thailand (at 300 - 500 masl, Phayao and Chiangrai
provinces). To reduce or solve this problem, research in
genetics and selective breeding will be needed to im-
prove pr od uc tion effi c iency.
5. Conclusions
This study showed that the climate-related events and
phenomenon (flood, drought, long cloud cover, and ex-
treme hot and cold weather) to tilapia pond culture var ies
with elevation and culture systems. The extreme cold
weather are mostly presented at >500 masl elevation
where the highest percentage of small farm size (one
pond) was found. On the other hand, the fish farmers at
<100 masl elevation (Nakonswan, Phijit, Kamphengphet,
Phitsanolok and Uttaradit) faced higher impact from
flooding than in other regions. Moreover, the data from
our quantitative survey indicated that low quality finger-
ings and high feed price are factors of high concern to
tilapia farmers, especially at the large commercial tilapia
culture of northern Thailand (at 300 - 500 masl, Phayao
and Chiangrai provinces). The findings of our survey
improve understanding of how fish farmers at different
elevation obtain the climate impacts that could be helpful
in developing adaptation s trategies for individual f armers
and the sector as a whole. Future work should focus on
how farmers manage risks and awareness of climate
change.
6. Acknowledgements
The work was carried out with the aid of a grant from the
International Development Research Centre, Ottawa,
Canada, as a contribution to the AQUADAPT project.
Thanks to the many field assistants, students, officials
and farmers who he lpe d with the surveys.
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