fish aggregating device造句

• Fish aggregating devices and navigational aids were located at various strategic points.
• When fishermen use such objects, they are called fish aggregating devices ( FADs ).
• In sheltered coastal waters, anchored or drifting rafts can become effective fish aggregating devices.
• Data on fish aggregating devices, known as FADs, is currently sparse in many ocean regions.
• Typical vertical behaviour of bigeye tuna shifts when fish associate with seamounts, buoys and fish aggregating devices, with individuals remaining in surface waters.
• Fish aggregating devices were installed in the municipal waters of La Union, Ilocos Sur and Ilocos Norte to ensure the livelihoods of affected Filipino fishermen.
• When used to catch fish that shoal together with other species, or when used in parallel with fish aggregating devices, the percentage of by-catch greatly increases.
• Several studies have shown the species congregates around floating buoy-like fish aggregating devices ( FADs ), both in shallower waters, as well as in extremely deep ( 2500 m ) waters, indicating the species may move around pelagically.
• Tuna are captured by several methods : pole and line vessels which use poles baited with other smaller pelagic fish as baitfish, and rafts called fish aggregating devices are set up, because tuna, as well as some other pelagic fish, tend to congregate under floating objects.
• Association with objects has been observed to occur over periods of approximately 10 30 days . This associative behaviour of bigeye tuna ( and also other species of tuna ) is taken advantage of by fisheries with approximately 27 % of all catches of tunas by purse seine vessels in the western and central Pacific Ocean derived from fish aggregating devices.