Pelagic fish Ireland

Main ImageIn Ireland, there are 22 vessels which target only pelagic fish, with a further dozen or so vessels that target pelagic fish at certain times of the year. The dedicated pelagic vessels are called Refrigerated Sea Water vessels or RSW vessels for short and are only active for about 5 months of the year targeting a single species at a time.

RSW Vessels

The RSW vessels have tanks onboard which are filled with sea water. The water is cooled by a refrigeration plant to bring the temperature down to 0°C before the first fish are pumped into the tanks.

The water in each tank of fish is circulated by drawing it from the top of the tank, passing it through a shell and tube heat exchanger, and returning it to the bottom of the tank, thus forcing it up through the mass of fish to promote rapid and uniform cooling.

Pelagic Nets

A typical Irish RSW vessel uses pair pelagic trawls for targeting pelagic species. Pelagic trawls are much larger than trawls which catch whitefish. The trawls are normally towed between two vessels, at around 4.5 knots.

Pelagic trawls are towed at the appropriate level in the water column to intercept target shoals, with gear depth being controlled by altering towing speed and/or warp length. As a result, there is no impact on bottom habitats and bottom structures.

Sophisticated sensors on the net can tell the skipper how much fish is in the net, allowing the skipper to have control over how much fish can be caught at a time. This is important as each vessel has its own quota for each species and if they are coming close to the amount they can take, they can set the sensors to only catch the remaining amount they are allowed.


2010 El Niño Reveals Marine Life Reductions

2010-03-04 23:34:48 by tarlipps

The ongoing El Niño of 2010 is affecting north Pacific Ocean ecosystems in ways that could affect the West Coast fishing industry, according to scientists at NOAA and Scripps Institution of Oceanography, UC San Diego.
Researchers with the California Cooperative Oceanic Fisheries Investigations (CalCOFI) at Scripps and NOAA's Southwest Fisheries Science Center report a stronger than normal northward movement of warm water up the Southern California coast, a high sea-level event in January and low abundances of plankton and pelagic fish -- all conditions consistent with El Niño.
Sea surface temperatures along the entire West Coast are 0


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