Improving Fish Quality On-board Fishing Vessels

Sustainable Marine Fisheries June 26, 2013 Print Friendly and PDF

The time-honored approach that many fishermen follow when taking care of their catch is: Ice, ice and more ice. Generally, this is excellent advice. However, subtleties with how fish are handled prior to icing, as well as what type of ice, how much and when, can make a significant impact on the bottom line. Hank Soule, general manager of the Portland Fish Exchange, says that “many vessels could improve their bottom line by 10-20 percent by improving quality alone.” It is inherent to the display auction that better quality equals higher price. Days at sea are limited, and prices for everything are on the rise: ice and fuel, not to mention berthing, insurance and equipment. Making the most of your catch is more important than ever.

New England groundfish fisherman.

Through a Buyer’s Eyes

For the fisherman to get the good price, the buyer has to be willing to pay a little extra. So, what does a fish buyer look for when determining quality and price? Maggie Terry, a seasoned buyer and agent for North Coast Sea Food and Sea Trade International, summed it up: “Eyes, gill color, smell and firmness.” Eyes should be clear and not cloudy, gills should be bright red (or removed when appropriate), the fish should have a sweet (not fishy) smell, and the flesh should be firm and not bruised. Terry finds that the lower quality fish she sees at the display auction result from improper gutting and icing.

Strategies

Between the time a fish is landed to the deck and the time it’s offloaded, there are some considerations and potential steps that fisherman can take to improve fish quality. Each fisherman will have to balance the costs versus the benefits in judging which steps to take.

Landing and Sorting

After fish are caught, bacteria, biochemical changes and chemical actions will deteriorate the quality of the fish, generally through physical and temperature damage. These processes cannot be stopped, but they can be slowed by controlling temperatures, handling fish carefully and preventing contamination. Some things to consider: While fishing, keep the deck as wet and cool as possible, especially in hot weather. Once landed, the catch should be sorted quickly, concentrating on smaller fish (which will heat up faster) and higher-value species. Shorter tows or fewer nets per string in high density areas can speed the sorting process.

Take care to limit physical damage such as through gaffing or throwing; damage of this kind will make it easier for bacteria to penetrate the flesh and reduce fillet quality. Avoid using a fish pick if at all possible. Picks provide an immediate entry for bacteria into a fish, hastening the decay process. Gloves will do the job just as well and prevent damage to kept and discarded fish alike. If the fishery dictates, fish should be gutted and gilled quickly. Gutting removes a source of bacteria and enzymes, and improves chilling by removing a significant amount of warm body weight. Using clean gloves or thoroughly cleaned hands and a sanitized fillet knife helps. A bucket with a bleach sanitizing solution is a handy way of keeping bacteria down.

Washing and Chilling

Washing is a fairly universal practice for fishermen, but washing while taking even a small step to chill the fish down can strongly benefit fish quality. Washing and chilling take the initial heat out of the fish and remove bacteria. When taking these steps, risks to quality include over-crowding washing bins and brine tanks, contamination of wash or brine water, and handling damage. The more the fish are handled, the greater the opportunity for physical damage to occur, so take care when transferring fish. Washing is pretty straightforward, but the practice of putting fish in a basket, running a hose in, and stepping on the fish to move them around is damaging to the catch – it is an instant source of scale loss, bruising and abrasion. It is more advisable to hose the fish down on the deck prior to sorting, and to have a small dip tank handy to wash the catch down when it’s in baskets ready for the hold. If using a chill tank, a bin (such as an insulated transport tank) filled with a slurry of ice and fresh seawater (2:1) can be used. The best temperature for a wash bin or brine tank is 32 to 38 degrees Fahrenheit. When noticeably discolored, the wash or brine water should be replaced with clean seawater and ice, if needed.

Transfer to Refrigerated Storage

In many situations, “refrigerated storage” may be no more than storing totes of iced fish below deck. No matter what the vessel’s capacity, several simple steps will help to improve overall quality. Keep in mind that potential risks at this stage of processing include temperature, physical damage to fish, and contamination while icing and crating fish. As with each prior step of the process, handle fish with care. To avoid contaminating fish, remember: Cleanliness is important. Use a Food and Drug Administration (FDA) approved sanitizing agent to clean totes and gloves before handling. The proper dilution ratio when making a bleach sanitizing solution is 1/2 ounce of bleach per one gallon of water.

Chlorine bleach is highly effective on a wide variety of bacteria, is not affected by water salts, and is generally inexpensive. However, chlorine is corrosive and can be irritating to the skin. Sanitizing agents that contain iodine compounds are also effective. Iodine is less irritating to the skin than chlorine and is less effective, but it is still active against a wide variety of bacteria. Iodine cleaner agents may not be appropriate for your vessel, however, since they can discolor equipment and surfaces. Quaternary ammonium compounds are nontoxic, odorless, colorless, noncorrosive and nonirritating. However, they are less effective and not appropriate for washing down boat decks and equipment. Fish should be packed neatly, belly-down on the bottom layer and belly-up thereafter. When possible, the ice should completely cover the fish at each level. Fish that are severely damaged (scale loss, bruising, etc.) should be rejected or stored separately with like quality fish, as “one bad apple will ruin the bunch.” Fish that are still bent in rigor mortis should not be straightened out. Straightening will lead to a separation of the muscle bands in the flesh, which will reduce the quality of the fillet. All totes should be equipped with drainage holes, especially if stacked. Iced fish are best held at an air temperature of 32 to 40 degrees Fahrenheit, where ice is able to melt and the resulting melt water can percolate through the stacked crates to wash fish and keep them moist. While in storage, fish core temperature should be kept around 34 degrees Fahrenheit.

Hazard Analysis for the Commercial Fishermen

For the fish wholesale and retail vendor, regulations require a Hazard Analysis and Critical Control Points (HACCP) plan in place for their operation. HACCP is a science-based system that examines each step in food processing, isolates possible hazards and sets limits, or critical control points, within which the food is safe and the quality has been maintained. Fish handling programs are specific to the individual business or operation. What is critical for quality and safety to the wholesaler is different than the concerns the retail operation must consider. The flexibility of the hazard analysis process offers an easily integrated program for the commercial fishermen. The goal of a HACCP plan should be to produce a consistent, high quality product that will build a reputation with the buyers and will result in a higher landed value.

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USDA / NIFA

This work is supported by the USDA National Institute of Food and Agriculture, New Technologies for Ag Extension project.