MANGROVE ECOSYSTEMS Implications for biological shrimp aquaculture

180 Pages·2014·8.03 MB·English

í
EDING ECO .GeY QF PENAEID SHRIMP IN KENYAN
; MANGROVE ECOSYSTEMS
y i f - '
Implications for biological shrimp aquaculture

FEEDING ECOLOGY OF PENAEID SHRIMP IN KENYAN
MANGROVE ECOSYSTEMS
Implications for biological shrimp aquaculture
Warima Charles Gatune
Promoter: Prof. Dr. Ann Vanreusel (Gent University, Belgium)
Promoter: Dr. Reni son K. Rima (KMFRI, Kenya)
Co-Promoter: Prof. Dr. Peter Bossier (Gent University, Belgium)
Co-Promoter: Dr. Marleen De Troch (Gent University, Belgium)
Academic year 2012-2013
Thesis submitted in partial fulfillment of the requirements for the degree of
Doctor in Science: Biology
Members of the reading committee
Prof. Magda Vincx
Gent University, Gent, Belgium
Prof. Tom Moens
Gent University, Gent, Belgium
Prof. Patrick Sorgeloos
Gent University, Gent, Belgium
Members of the examination committee
Prof. Dominique Adriaens
Gent University, Gent, Belgium
Prof. Ann Vanreusel
Gent University, Gent, Belgium
Prof. Magda Vincx
Gent University, Gent, Belgium
Prof. Tom Moens
Gent University, Gent, Belgium
Prof. Patrick Sorgeloos
Gent University, Gent, Belgium
Dr. Reninson K. Ruwa
Kenya Marine and Fisheries Research Institute, Kenya
Dr. Marleen De Troch
Gent University, Gent, Belgium
Prof. Peter Bossier
Gent University, Gent, Belgium
Prof. Nico Koedam
Vrije Universiteit Brussel
FEEDING ECOLOGY OF PENAEID SHRIMP IN KENYAN
MANGROVE ECOSYSTEMS
Implications for biological shrimp aquaculture
Ghent University
Faculty of Science
Marine Biology Research Group
Campus Sterre - S8
Krijgslaan 281
B-9000 Gent
Belgium
Email: [email protected]
UNIVERSITEIT
GENT
Publically defended on November 19th, 2012
Chairman of the defense: Prof. Dr. Dominique Adriaens
For citation, please refer as below:
Gatune, W.C., 2012. Feeding ecology of penaeid shrimp in Kenyan mangrove ecosystems:
Implications for biological shrimp aquaculture. Ghent University. Belgium. 153 pp.
I Table of Contents
Table of Contents
Acknowledgements.........................................................................................................................i
Summary.........................................................................................................................................iii
Samenvatting...................................................................................................................................ix
1. Chapter 1...................................................................................................................................1
1.1 General Introduction..........................................................................................................1
1.1.1 Potential of penaeid shrimp aquaculture in Kenya..................................................1
1.1.2 Shrimp biology of relevance to ecological aquaculture..........................................5
1.1.3 Nutritional requirements for penaeid shrimp..........................................................6
1.1.4 Potential natural diet for penaeid shrimp in a mangrove ecosystem......................8
1.1.5 Microbial diet for penaeid shrimp............................................................................9
1.1.6 Microbial biofilm in mangrove systems.................................................................10
1.1.7 Biological shrimp culture and the mangrove ecosystem health...........................12
1.2 Aims, objectives and thesis outline...............................................................................13
1.2.1 General aim...............................................................................................................13
1.2.2 Specific aims and thesis outline..............................................................................14
2 Chapter 2 .................................................................................................................................17
13
2.1 C stable isotope labeled bacteria highlight that shrimp post larvae can alternatively
assimilate mangrove detritus.....................................................................................................17
2.1.1 Abstract.....................................................................................................................18
2.1.2 Introducti on..............................................................................................................19
2.1.3 Material and methods..............................................................................................20
2.1.4 Results and discussion.............................................................................................23
2.1.5 Acknowledgements.................................................................................................27
3 Chapter 3................................................................................................................................29
3.1 Decomposing mangrove litter supports a microbial biofilm with potential nutritive
value to penaeid shrimp post larvae.........................................................................................29
3.1.1 Abstract....................................................................................................................30
3.1.2 Introducti on..............................................................................................................31
3.1.3 Materials and methods............................................................................................33
3.1.4 Results......................................................................................................................37
3.1.5 Discussion................................................................................................................46
3.1.6 Conclusion................................................................................................................52
3.1.7 Acknowledgements..................................................................................................53
4 Chapter 4 .................................................................................................................................55
4.1 Effect of micro-algae and epifauna biofilm on decomposing mangrove litter on the
growth and survival of shrimp post larvae of Penaeus monodon..........................................55
4.1.1 Abstract....................................................................................................................56
4.1.2 Introducti on..............................................................................................................57
4.1.3 Materials and methods............................................................................................59
4.1.4 Results......................................................................................................................62
4.1.5 Discussion................................................................................................................68
4.1.6 Conclusion................................................................................................................74
4.1.7 Acknowledgements..................................................................................................75
5 Chapter 5.................................................................................................................................77
5.1 The importance of light intensity and the presence of sediment for ecological shrimp
aquaculture..................................................................................................................................77
I Table of Contents
5.1.1 Abstract.....................................................................................................................78
5.1.2 Introducti on...............................................................................................................79
5.1.3 Materials and methods.............................................................................................80
5.1.4 Results.......................................................................................................................83
5.1.5 Discussion.................................................................................................................91
5.1.6 Conclusion.................................................................................................................97
5.1.7 Acknowledgements..................................................................................................98
6 Chapter 6.................................................................................................................................99
6.1 Overall performance of Penaeus monodon shrimp post larvae feeding on
decomposing mangrove litter as evidenced by fatty acid biomarkers....................................99
6.1.1 Abstract...................................................................................................................100
6.1.2 Introducti on.............................................................................................................101
6.1.3 Materials and methods...........................................................................................102
6.1.4 Results.....................................................................................................................106
6.1.5 Discussion...............................................................................................................114
6.1.6 Conclusion...............................................................................................................119
6.1.7 Acknowledgements................................................................................................119
7 Chapter 7................................................................................................................................121
7.1 Synthesis........................................................................................................................121
7.1.1 Prospects for implementation................................................................................122
7.1.2 General conclusion and recommendation.............................................................130
8 References.............................................................................................................................134
9 Appendices............................................................................................................................153
9.1 Appendix 1 : Univariate tests of significance for the percentage weight loss of the
decomposing leaf litter relative to the week, light and sediment conditions.........................153
9.2 Appendix 2: Univariate tests of significance for the log transformed total abundance
of micro-algae on the decomposing mangrove leaf litter relative to the week, light and
sediment conditions..................................................................................................................153
9.3 Appendix 3 : Univariate tests of significance for the log transformed abundance of
Diatoms on the decomposing mangrove leaf litter relative to the week, light and sediment
conditions...................................................................................................................................153
Acknowledgements
Acknowledgements
No work is difficult, nothing is impossible unless I would rather do some other work.
God always answers my prayers and gives me strength, I will always believe in you.
My late father, Paul Simon Warima, sincerely believed in my academic capability, I will
forever respect you.
My mother, Enestina Njeri, loves me and never losses hope in me, I will forever adore you.
My wife, Wairimu, Son; Warima, Daughters; Njeri and Wangui, have undergone long
periods of pain in my absence but they have never lost faith in me, I will forever love you.
I, the author of this PhD thesis express my sincere gratitude to the Kenya Ministry of
Fisheries Development for awarding me study leave and infrustracture to pursue my PhD
studies. I feei indebted to Flemish InterUniversity Council (VLIRUOS) of Belgium for the
financial support to follow an international PhD program in Biology at Ghent University,
Belgium. I am much pleased by the staff of VLIRUOS, Micheline, Heike, Sam Geert,
Karolien for your tireless assistance.
I sincerely feei obliged to the much tireless guidance, patience and encouragement i received
from my promoters Prof. Ann Vanreusel and Dr. Marleen De Troch of Marine Biology at
Gent University, Belgium; Dr. Renison Ruwa of Kenya Marine and Fisheries research
Institute (KMFRI), Prof. Peter Bossier and Prof. Patrick Sorgeloos of the Laboratory of
Aquaculture and Artemia Reference Center at Gent University, Belgium.
I feei humbled by youth of the Majaoni Silvofishery project based in Mtwapa creek in
Mombasa, Kenya for providing me space for the field research and especially Daniel, Patrick
and Kalton for their unconditional assistance in the field. Deep felt thanks goes to the KMFRI
laboratory technicians Eric Magara, Omondo, Mwendwa Mbaluka, Boaz, Onduso, Kilonzi,
Andugosi and Emily.