Pen-and-Cage Fish Farming Systems PDF

# PEN AND CAGE CULTURE - Open systems, where interactions between the fish culture unit and the immediate environment can take place with few restrictions, and they are often established in publicly-owned multipurpose water bodies. ## Note For an old but useful reference on site selection for cag...

# PEN AND CAGE CULTURE - Open systems, where interactions between the fish culture unit and the immediate environment can take place with few restrictions, and they are often established in publicly-owned multipurpose water bodies. ## Note For an old but useful reference on site selection for cages check out: UNDP/FAO Regional Seafarming Development and Demonstration Project Network of Aquaculture Centres in Asia. 1989 Site selection criteria for marine finfish netcage culture in Asia. http://www.fao.org/docrep/field/003/AC262E/AC262E00.htm # PEN AND CAGE CULTURE - Both cage and pen culture are types of enclosure culture, and involve holding organisms captive within an enclosed space while maintaining a free exchange of water. The two methods, however, are distinct from one another. A cage is totally enclosed on all or all but the top, sides by mesh or netting, whereas in pen culture the bottom of the enclosure is formed by the lake or sea bottom. # Classification of cage systems by technical characteristics (Huguenin 1997) | Characteristic | Description | |---------------------------|--------------------------------------------------------------------------------------| | Way of operating | Surface: Submerged. | | Place of operating | Marine. Estuarine. Freshwater. | | Means of support | Fixed to bottom (usually via pilings) Floating (buoyancy) | | Type of structure | Rigid (usually structure and mesh) Flexible (usually mesh only) | | Access for servicing | Cat walked No catwalks (usually boat/barge serviced) | | Operating parameters | Biomass loading (intensive-extensive) Species and Feeding practices (fed/unfed) (hand/auto) | | Environmental severity | Sheltered/exposed / open water | ## A classification system for cages (Beveridge 1996). **Fixed** - No rotating - Wide collar - Rigid collar - Rigid bag - Net floor **Floating** - Rotating - Narrow collar - Flexible collar - Flexible bag - Solid floor **Submersible** - Suspended from surface - Rigid - Rotation by adjustment of float buoyancy **Submerged** - Adjustable buoyancy - Flexible - Rotation by adjustment of float position # Principal components of a fish cage (Beveridge 1996) The image is of a cage, a structure that suspends a net in the water to hold fish. The image highlights the following parts: - Services system - Floating system - Mooring system - Cage bag - Anchor system # CAGE CULTURE SYSTEMS The image depicts several cages floating in a body of water. The cages appear to be constructed with wood and are connected to a floating platform by ropes. # CAGE CULTURE SYSTEMS The image depicts a closer view of the cages, showing the wooden structure and the mesh netting. # CAGE CULTURE SYSTEMS The image shows a close up of a single net cage. # Sea bass grow out cage (5x5 m) The image is depicting a cage in a body of water being used to farm Sea Bass. The text below it reads **www.seafdec.org.ph**. # CAGE CULTURE SYSTEMS The image depicts a person standing on a platform surrounded by cages, feeding fish. # CAGE CULTURE SYSTEMS The image depicts a single floating platform that has two gazebos and a cage connected to it. # CAGE CULTURE SYSTEMS The image depicts a submerged cage being constructed. On the right side of the image is a cross section of the cage, highlighting the depth at which it sits and the fact that it is attached to the bottom. # CAGE CULTURE SYSTEMS The image depicts four different cages or cage systems. # CAGE CULTURE SYSTEMS The image depicts four different cage systems. # CAGE CULTURE SYSTEMS The image depicts four different cage systems. The text below the image reads **Bass Harbour** and **H60s Istard Salmon Ltd.** # CAGE CULTURE SYSTEMS The image shows two cage systems. The first is a large area of the water surface that’s covered in cages. The second is a single float being used for multiple cages. The text under the image reads **THE SEA SYSTEMTM** and **Upwelling Pump**. The text at the bottom reads **http://www.futuresea.com** # Knotless Netting The image shows an example of knotless netting. The netting appears to be tightly woven, with no visible knots. # Knotted Netting The image depicts a section of a knotted net. The knots are visible in the image. # 19mm nylon nursery netting The image depicts a close-up of a net. It is made of a thin black nylon material. The text at the bottom says **19mm nylon nursery netting**. # 35.5mm TUC 4 ply netting The image depicts a close up of a net. The text below reads **35.5mm TUC 4 ply netting 1.2mm twine diameter 75kg minimum break strength**. # Mariculture Zones and Parks of the Philippines - Mariculture Parks where breeding and grow-out production of commercially important marine species are grown in zonified marine cages. - The concept is similar to the land-based industrial zones and estates, where in this case fish farmers has to pay for an annual lease which amounts to only a fraction of what it would have cost to acquire and develop the cage facilities themselves. # Mariculture Zones and Parks of the Philippines - Has a communal storm-resistant mooring system and boundary markers. It is subdivided into individual “farm plots” for fish cage operation, seaweed farming and other marine aquaculture activities. - At present, there are 50 established and operational mariculture parks all over the country catering to local, national and foreign investors - Total of 2,168 cages covering 49,950 ha - http://mariculture.bfar.da.gov.ph/ # Mariculture Zones and Parks of the Philippines - Mariculture in the Philippines categorically refers to the culture of finfishes, shellfish, seaweeds and other commodities in cages, pens, stakes and rafts in marine environment. # Location of Existing Mariculture Park/Zone (As of April 20, 2010) The image is a map of the Philippines which highlighted the presence of mariculture/zones. It notes the following: - Region I: Alaminos, Pangasinan (300 ha) - Region IV-A: Talisay, Batangas (100 ha) Nasugbu, Batangas (100 ha) - Region IV-B: Calapan City, Oriental Mindoro (200 ha) - Region II: Sta. Ana, Cagayan (100 ha) - Region III: Cabuyao, Laguna (320 ha) - Region V: Paracale, Camarines Norte (105 ha) Sorsogon City (200 ha) Sorsogon (100 ha) - Region VII: Talibon, Bohol ( 370 ha) Calape, Bohol (100.45 ha) Canuljey, Bohol (100 ha) - Region IX: Sindangan, Zamboanga del Norte (1,000 ha) Zamboanga City (200 ha) - Region VIII: San Jose, N. Samar (300 ha) N. Samar (2,500 ha) Calbayog, Samar (200 ha) - Region XIII: Davao Oriental (1,000 ha) San Jose, Surigao del Norte (1,000 ha) - Region XI: Panabo City, Davao Del Norte (1,073 ha) Davao Del Norte (220 ha) - ARMM: Davao City, Davao del Sur (4,480 ha) # BFAR MARICULTURE ZONE SQUARE FISH CAGE MODEL The image is a diagram of a square fish cage. The text below it provides the following information: - The cage is 6m x 6m x 5m. - It is made of galvanized iron. - The cage is designed for milkfish (bangus) and grouper culture. - The stocking density of the cage is as follows: - Minimum bangus: 2,000 - Maximum bangus: 3,000 - Grouper: 800 # BFAR MARICULTURE ZONE SQUARE FISH CAGE MODEL The image depicts a diagram of a square fish cage. The text below it provides the following information: - The cage is 10m x 10m x 5m. - The cage is designed for grouper and high value finfish. - The stocking density of the cage is 2,400 for grouper. # Effects of cage fish farming on the environment - In flowing water (especially when large structures are placed in shallow water) the cages tend to act as a floating barrier causing differences in speed, direction and eddies as well. - However the most discussed question is the effect of cage fish farming on water quality. It is a fact that in those waters where cage fish farms are operating, deposition of bottom sediment can occur, including the undesirable build-up of waste materials (uneaten food, metabolic wastes). # Cage fish farming activity Cage fish farming activity however can be done in conformity with the requirements of the environment, taking into account the following considerations: - The size of the cage culture facility and thus the volume of production has to be adjusted to the conditions provided by the given water body. - Maximum 10% of area of water body. - Proper feeding technology should be applied with special respect to the following: - Feed quantity - Feed Quality - Feeding Method # Cage Farming Considerations - The quantity of feed should be adjusted properly according to the water temperature and the condition of the fish. - Overfeeding should be avoided. - The feed should be water stable and easily acceptable by the fish - dry, pelleted food and automatic feeders are recommended. # Cage Farming Considerations - Aeration can also be applied in order to improve the environmental conditions. - The water body outside of the cages can be stocked with certain species of fish in order to control the growth of plankton and benthic organisms – actually, wild fish tend to stay around cage farms. - The sediment accumulated under the cages can be removed by a submersible pump. # Oysters The image has a collection of images. The text in the image reads: - Rafts used to suspend oysters in baskets. - Harvesting a rope of oysters. - Oyster bed on ocean floor. - Raking oysters from bed. # Oysters The image depicts a man standing in a body of water, harvesting oysters from long strands.