Fishermen's News - The Advocate for the Commercial Fisherman

Vessel Sanitation


July 1, 2019

This is the second in a three-part series designed to address bacteria, sanitation and temperature as they work together to protect or decrease shelf life at harvest and transport to the processing facility.

A clean fishing vessel inhibits bacteria growth and improves shelf life of seafood. Every fishing vessel should be deep cleaned before the season with a strong cleaning program after each delivery and another deep thorough cleaning post fishing season. Annual vessel cleanliness includes evaluating fish contact surfaces, cleaning, sanitizing and inspecting and creating a program to keep surfaces bacteria free.

At the beginning of every season a complete evaluation should be done of the fishing vessel. Diesel, lubricant and other chemicals storage and usage should be evaluated to make sure all precautions have been taken to prevent contamination. Animals, if allowed on board by the processor (many processors have a no pets aboard policy) must be kept away from all fish contact surfaces. The evaluation should also take into account areas of direct and indirect contact with the fish for ease of cleanliness and sanitizing.

Fish contact surfaces include the hold and deck but can also include nets, tables, and mats. Any surface that can come in contact with the product should be evaluated for bacteria harborage.

Porous surfaces such as untreated wood, fiber, and pitted metal or rubber are prime breeding grounds for most bacteria.

In creating a sanitation program, it is important to remember that cleaning and sanitizing are two separate operations.

Cleaning is the process of removing food and other types of soil from a surface. This is accomplished by first removing large pieces of protein, dirt or rust by hand and then using a cleaning agent that removes food, soil, rust stains, minerals, or other deposits. The right cleaning agent must be selected to make cleaning easy. Cleaning agents are divided into four categories, not all of which should be used on board a fishing vessel:

Detergents – All detergents contain surfactants that reduce surface tensions between the soil and the surface, so the detergent can penetrate quickly and soften the soil.

Solvent cleaners – Often called degreasers, solvent cleaners are alkaline detergents that contain a grease-dissolving agent.

Acid cleaners – Use on mineral deposits and other soils alkaline cleaners cannot remove, these cleaners are often used to remove scale.

Abrasive cleaners – Use these cleaners to remove heavy accumulations of soil often found in small areas. The abrasive action is provided by small mineral or metal particles, fine steel wool, copper, or nylon particles. Some abrasive cleaners also disinfect.

Chemicals with strong smells or added scent should never be used on fish contact surfaces. These include all phenol based cleaners such as Lysol or Pine-sol.

Sanitizing is the process of reducing the number of microorganisms that are on a properly cleaned surface to a safe level. A safe level is defined as a 99.999% reduction of the number of disease microorganisms that are of public health importance. Sanitizing is accomplished by using either heat, radiation, or chemicals. Unless the item to be sanitized is effectively cleaned, it is impossible to obtain close contact between the sanitizer and the surface to the sanitized. Also, some chemical sanitizers, such as chlorine and iodine, react with organic matter and so will be less effective when the surface is not properly cleaned.

Sanitizing Methods:

Heat: There are three methods of using heat to sanitize surfaces. The first is exposing the surface to steam using one of the following time temperature schedules – 170 degrees F for 15 minutes or 200 degrees F for 5 minutes. A second method is hot water, which is the most common method. The higher the temperature, the less time that is needed to kill microorganisms. The final method of using heat is hot air that is applied at 180 degrees F for 20 minutes.

Radiation: Ultraviolet radiation can be used to sanitize but is not practical or available for use on fishing vessels. Its major application is in the packaging areas of food processing facilities. The contact time should be at least 2 minutes. It only destroys those microorganisms that are in direct contact with the rays of light.

Chemicals: The chemicals that have been proven to be effective at the proper concentration include chlorine, iodine, and quaternary ammonium. Different factors influence the effectiveness of chemical sanitizers. The three factors that must be considered are:

• Concentration – The presence of an insufficient amount of a sanitizing agent will result in an inadequate reduction of microorganisms. Too much can be toxic.

• Temperature – Generally chemical sanitizers work best at temperatures between 55 degrees F (13 degrees C) and 120 degrees F (49 degrees C).

• Contact time – In order for the sanitizer to kill microorganisms, the cleaned item must be in contact with the sanitizer (either heat or approved chemical) for the recommended length of time.

Sanitizing methods and effectiveness vary in ease of use and cost. The following are general guidelines for use of the three basic sanitizers. Labels should always be followed for adequate and proper usage.

Chlorine – 50 ppm in water between 75-100 degrees F (7 seconds).

Chlorine has the advantage of being effective on a wide variety of bacteria and is generally inexpensive. It can be found in both the powdered and liquid form. Chlorine can be corrosive and irritating to the skin; effectiveness decreases with increasing pH of solution; deteriorates during storage and when exposed to light; dissipates rapidly; loses activity in the presence of organic matter. Chlorine is under intense scrutiny from many water quality agencies and it is not recommended for discharge into water bodies.

Iodine – 12.5-25 ppm in water at least 75 degrees F (30 seconds).

The advantage of iodine is that it forms a brown color that is indicative of the germicidal strength and is less irritating to the skin than is chlorine. However, it is expensive, hard to find and may discolor equipment and surfaces.

Quaternary Ammonium Compounds – up to 200 ppm in water at least 75 degrees F (30 seconds).

“Quat” is the choice of most seafood processing facilities because it is nontoxic, odorless, colorless, noncorrosive, nonirritating; stable to heat and relatively stable in the presence of organic matter; active over a wide pH range; and quite active against thermoduric organisms. It can come in powder and liquid form.

Chemicals for cleaning and sanitizing may be hard to source for vessel owners. Chemicals may be purchased in bulk from a chemical supply company or you may be able to source them directly from a processing plant at little or no cost.

All good sanitation programs involve testing surfaces for residual dirt and bacteria. At minimum fish contact surfaces should be tested before the season and after end of the season clean up. There are many options for instant read surface swabs that test for the presence of e coli and non-speciated listeria.

Following a clear vessel sanitation program will go a long way in increasing the quality of the catch by slowing the bacterial growth that impacts shelf life.

Brandii (O’Reagan) Holmdahl is the Director of Quality and Regulatory Compliance with Bornstein Seafoods. Over the last 28 years she has worked in seafood production in every major region and handling most species of seafood harvested in Alaska. She has also fished on long liners, gill netters and worked on tenders. She recently spent 2 years in global seafood exports and imports on the East Coast and has returned to the Pacific Northwest to follow her passion for helping fishermen deliver the highest quality seafood available.


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