INTEGRATION OF MANGROVES AND AQUACULTURE J.H. Primavera SEAFDEC Aquaculture Department Tigbauan, Iloilo, Philippines • Aquaculture • Mangroves • Are they compatible? - Mangrove-Friendly Aquaculture in Asia - Mangroves as aquaculture filters - Mud crab culture in mangrove pens • Mangrove rehabilitation (typhoons, sealevel rise)
33
Embed
INTEGRATION OF MANGROVES AND AQUACULTURE · INTEGRATION OF MANGROVES AND AQUACULTURE J.H. Primavera SEAFDEC Aquaculture Department ... grouper, snapper Freshwater fish: ...
This document is posted to help you gain knowledge. Please leave a comment to let me know what you think about it! Share it to your friends and learn new things together.
Ecological impacts of aqua-culture (Naylor et al, 2000)
Flow chart of capture and farmed fisheries products from aquatic primary production (in 2001 million metric tons of fish = 48.4 Mmttot.) (Naylor et al, 2000)
• passing pond effluents through mangroves reduced nutrient levels (in day but not night)
• reduced nutrients due to biol. transformation (plant uptake, denitrif.), rather than physical dilution (nighttime increases) or tidal flushing
• nutrient removal function of mangroves supports paradigm shift for aquaculture to clean up effluents before release
• mangrove: pond ratio for effluent processing: 2-9:1 for N, 2-22:1 for P
• implications for Philippines: compliance with national laws: greenbelt (20-, 50- and 100-m) and mangrove rehabili tation of abandoned ponds
• need to reverse present 0.5 ha mangrove: 1 ha pond ratio in the Philippines
Mudcrab Culture in Mangrove Pens Mudcrab Culture in Mangrove Pens
2.6 3.6Payback period (years)
38.5 %27.5%Return on investment
83.90NegativeNet return yr-1 (2 crops)
41.95 NegativeNet returns crop-1
7,033.89 5,018.88Net cash return yr-1 (2 crops)
3,516.952,509.44Net cash return crop-1
24,425.2323,171.01Total operating cost run-1
3,475.003,475.00Sub-total
1,500.001,5,00.00Caretaker’s salary
1,975.001,975.00Non-cash costs:
Depreciation
24,467.1822,205.45Revenue
Total Value (PhP)aTotal Value (PhP)aItem
82 kg 164 kg
74 kg148 kg
Production: 1 crop2 crops
252 g211 gCorresponding body weight (Table 5)
37.2%40.4%[Survival rate (Table 5)
Pellets + Fish BiomassFish BiomassProduction data
Cost and return analysis for 1000 m 2 mud crab Scylla serrata pens using two feeding treatments.
0.590.450.52Shannon Index of Sp. Diversity
13.513.98.057.07Total
7.88.26.455.96Trees
3.939.61.411.01Saplings
1.890.00.190.10Seedlings
Basal area(m2 per ha)
104,63370.315,9509,368Total
1,26737.11,6001,167Trees
12,53339.95,0033,216Saplings
90,83397.69,8504,984Seedlings
Stems/ha
Jan 2004% changeJan 2004May 2002
ControlPens
Impacts of crab pen culture on mangrove community struc ture in Zarraga, Aklan, central Philippines.
Conclusions
• Incomplete, low-cost pellets can replace fish requirement in mud crab diets• Economic analysis showed viability of crab culture in mangrove pens using fish biomass + pellets to reduce requirement for (low-value) fish, a food item of poor coastal communities• Presence of crabs results in fewer mangrove seedlings and saplings, but did not affect trees
Code of Practicefor Sustainable Use of Mangrove Ecosystems
Module Writers - Purita P. Bilbao, Crisanto Lopez, Jr.,Ruth L. Gelvezon, Marievic M. Violeta
Module 1. Starting a Walk to the MangrovesModule 2. Mangroves: Forests Growing by the SeaModule 3. Mangroves: Take a Closer LookModule 4. Mangroves: Our Natural Treasure
Traditional uses (Forestry/ Fishery Products)ServicesEcological BenefitsSocial BenefitsValues DerivedMedicineWildlife Habitat