Aquaculture of Fishes Biology of Fishes 11 6
Aquaculture of Fishes Biology of Fishes 11. 6. 12
Overview n Presentation Guidelines n Syllabus Revisions n Guest Lecture 2 – Dr. Charles Madenjian – USGS Great Lakes Science Center n Aquaculture – related to fish ecology & diversity
Presentation Guidelines online n All groups submit written reports 11. 27. 2012 n Attendance required at all student presentations n Student Presentations material will be on Final Exam
Syllabus Revisions n November 13 – Biogeography, conservation, genetics n November 15 – Conservation ecology case study synthesis n November 20 – Exam 2 n November 22 – Thanksgiving Break n November 27 – Student Presentations n November 29 – Guest Lecture 3 n December 4, 6, 11 – Student Presentations
Guest Lecture 2 n Dr. Charles Madenjian – USGS Great Lakes Science Center n Dynamics of the Lake Michigan Food Web 1979 -2000 n Assignment Part 1 hard copy due at start of class
Aquaculture n Aquaculture – the farming of aquatic organisms under controlled conditions (fishes, crustaceans, mollusks, aquatics plants, etc). n Farming of fishes is the most common form (what we will focus on). n 2 Primary categories we will focus on (often overlap) n Grow-out aquaculture for direct human consumption n Hatchery and stocking operations – release fishes into wild to supplement exploited or declining stocks
Aquaculture n Aquaculture – example types n Mariculture – cultivation of marine organisms in seawater n Polyculture – cultivation of multiple species n Integrated Multi-Trophic Aquaculture – by-products of one species are recycled as inputs for another species
Aquaculture n Aquaculture – example types n Extensive – utilizes cages/pens, but relies on natural food supply n Semi-intensive – feeding supplements or fertilizer to encourage feed production n Intensive – highly subsidized, large inputs of feed; highest yields, but highest ecological impacts
Aquaculture n Aquaculture – the farming of aquatic organisms under controlled conditions n Practiced by humans for thousands of years n 6000 BC Australia – eel culture via landlocked ponds n 2500 BC China – carp aquaculture n 1000 years ago in Hawaii – oceanic ponds
Aquaculture Global harvest of aquatic organisms in million tons, 1950– 2010, (Food & Agriculture Organization of UN)
Aquaculture n Fisheries provide 16 -19% of human animal protein consumption n ~1 billion people rely on fish for most of their protein (especially in developing nations) n Increased pressure on fisheries with increasing population n n Wild supply/CPUE leveled off at 90 MMT in late 1980 s n Yields increased in recent years to 120 MMT largely due to aquaculture n Aquaculture expanded from 5 MMT (1950) to 30 MMT (1990 s) Aquaculture will be needed, but can it be done sustainably?
Aquaculture n n Pros n Economically important n Access to animal protein n Relieve pressure of overfishing n Restocking wild populations, conservation (captive propagation) Cons n Ecological efficiency (lack thereof) n Pollution (disease, parasites, nutrient loading) n Escapes
Genetically Modified Organisms (GMOs) n Usually done to enhance growth rate n Highly debated, lack of solid research n Growth hormones n Antifreeze genes
Genetically Modified Organisms (GMOs) n Pros n Increased growth & feeding efficiency (market size faster) n tilapia +60 -80% faster growth, 2. 9 x feed conversion, 3. 6 x less food n Chinook salmon – 10 -30 x growth rate w/ hormone & antifreeze genes n Increased disease resistance n Potential health benefits (lower cholesterol)
Genetically Modified Organisms (GMOs) n Cons n Deformities n Non-adaptive characteristics (feeding behavior, swimming ability) n Perceived potential health hazards (not well-supported*)
Aquaculture n Example species/systems n Atlantic salmon – sea ranching n Bluefin tuna – sea ranching n Tilapia – intensive aquaculture n Carps – polyculture n Air-breathing fishes – sustainable aquaculture
Aquaculture n “Sea Ranching” - process of growing out salmon in net pens until market size. n Atlantic salmon (Salmo salar) most common species n International scale practice (Norway, Chile, Canada = ~85% production in 2005) n 1. 3 million metric tons (2005), 90% S. salar; $4 -5 billion USD n Pros: increased economic activity; healthy animal protein at reasonable price; pressure off wild stocks n Cons: low ecological efficiency, 2. 5 kg fishmeal: 1 kg salmon
Sea Ranching n Cons n Low ecological efficiency n Socioeconomic hardships (compare to wild-stock fisheries) n Pollution (high density – high waste, nutrient pollution, organic sewage of 40 salmon ~ 1 person) n Parasites, disease, antibiotics, pesticides (although debatable in some comparisons to wild fish) n Escapes (disease, hybridization, competition)
Sea Ranching n Cons
Aquaculture n Bluefin tuna (Thunnus thynnus) n Very early stages, minimal success n Large species, special requirements n May contribute to current overfishing n Valuable species ($396, 000 for one fish)
Aquaculture n Bluefin tuna (Thunnus thynnus)
Aquaculture n Tilapia (Oreochromis spp. )
Aquaculture n Carps (various cyprinid species), commonly polycultured n Grass, silver, bighead, common carps n Cultured primarily in Asia n Introduced in US and elsewhere
Aquaculture n Air-breathing fishes – several species (Channa, Clarias, Osphronemus, Arapaima, Protopterus, Atractosteus) n Numerous advantages over other fishes
Aquaculture n Air-breathing fishes – several species (Channa, Clarias, Osphronemus, Arapaima, Protopterus, Atractosteus) n Numerous advantages over other fishes n Tolerant of lower water quality (conducive to high-density culture) n Lower technology required for culture n Most species exhibit rapid growth and readily accept artificial feed n May be more adaptive options for culture in the face of climate change
Air-breathing Fishes
Air-breathing Fishes
Aquaculture n Will likely be a necessity to meet future fish & seafood supply and demand n Sustainable practices necessary to reduce negative impacts n High economic potential n Much further research is necessary
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