Chill Out: Preventing Scrombrotoxin Poisoning

Two primary species of mackerel are harvested in Florida waters. The King mackerel (Scomberomorus cavalla) and Spanish mackerel (Scomberomorous maculatus) are two of the most important fishery species in the state. In 2011, both species were among the state’s top 10 commercial finfish species for landings and dockside value, worth more than $10 million combined.

As any south Florida angler knows mackerel are also among the most popular recreational fishes. They’re fairly common, put on a good fight, and taste good too. Sixty-eight percent of the total allowable catch is allocated to the recreational fishery and King and Spanish mackerel are both among the top five recreationally harvested species in the state (by weight).

King and Spanish mackerel are healthy sources of protein, Omega-3s, selenium, and B vitamins. However, it is essential that they are handled properly once landed as they have been identified by the U.S. Food and Drug Administration (FDA) as being capable of causing scombrotoxin poisoning. Other potential fish include:

What is scombrotoxin poisoning?

Scombrotoxin or histamine poisoning occurs when histamine and other biogenic amines are permitted to build up as a result of bacterial spoilage associated with time/temperature abuse. In the U.S. it is one of the most common illnesses caused by seafood, but it may also be prevented with proper handling and cooling. Biogenic amines, including histamine, are natural chemicals that can form in fish anytime during harvest, preparation and storage, though growth is more rapid at high temperatures. These amines may begin to develop after the fish dies, and will increase if the fish is left in the water too long after death, or if it is not adequately chilled immediately after it is brought on board.

Symptoms

Once histamine is formed it does not go away and cannot be eliminated by washing, cooking or freezing. Therefore, prevention is the only way to assure that histamine is not present in fish. Any fish that is showing signs of spoilage should be discarded, however even if a fish smells or looks good histamine may still be present and illness is possible. In most cases, the illness occurs very quickly and is relatively short-lived. While severe reactions are rare, symptoms are very uncomfortable and include flushing of the face and neck, tingling sensation of the tongue, headaches or dizziness, vomiting and/or diarrhea.

Prevention

Rapid chilling of fish immediately after death is the most important strategy for preventing the formation of scombrotoxin. Formation of biogenic amines is drastically reduced by cooling fish to 40° F (internal) and fish should be packed in ice, ice slush, chilled seawater or chilled brine as quickly as possible. Since larger fish take longer to cool than smaller fish evisceration (removal of the guts) of larger fish is a good way to help remove the bacteria that causes formation of biogenic amines. Evisceration must be done carefully and the gut cavity should be filled with ice or cooling media to quicken internal chilling.

References

1. Fish and Fishery Products Hazards and Controls Guidance (FDA Hazards Guide)(4th Edition).

2. FDA Bad Bug Book: http://www.fda.gov/downloads/Food/FoodSafety/FoodborneIllness/

Great Goliath Grouper Count: 2012 Collier Results

Well the good news is that my colleagues and I were able to complete a third year of surveys for the Great Goliath Grouper Count (GGGC). The bad news is the weather wasn’t cooperative, and we weren’t able to survey as many sites as in the past two years. In addition, the number of grouper we counted was much lower than in past years, which could be in part to the poor visibility we had to deal with this year.

The GGGC  is a collaborative outreach project between Florida Sea Grant and the Florida Fish and Wildlife Conservation Commission  to provide a regional “snapshot “ of goliath grouper presence and minimum abundance on artificial reefs throughout  the region in a relatively short time frame (ideally one week). The concept came from the National Christmas Bird Count done through the Audubon Society.  Volunteers  collect fundamental fisheries information  that help researchers characterize the size structure of goliath grouper within the study area and compare  abundance and size distribution to habitat features, depth and region.  Besides Collier County, surveys are conducted from Lee through Pinellas Counties in Southwest Florida, and off Taylor and Bay Counties in the Big Bend and Panhandle region. Beginning in 2011, we also had survey teams off the east coast of Florida near Palm Beach County.  I am always quick to point out that this project is by no means a substitute for a formal stock assessment, as it is not comprehensive enough in scope, but it certainly can help provide managers and researchers with additional information they can use when assessing the health of the recovering goliath grouper population in Florida.

Highlights of this year’s GGGC in Collier County

·          Nine divers and two boats only surveyed  seven of the twelve designated Collier sites  due to rough weather conditions

·         Because of the weather the surveys were spread out over a week’s time period instead of the normal two day time frame.

·         The depths of the sites surveyed ranged from 30 to 80 feet

·         Four of the sites sampled were ship wrecks, two were radio towers, and one was a rubble pile

·         The number of goliath grouper present at each site ranged from one to twelve.

·         A minimum of 49 goliath grouper were counted at the seven sites (Avg 7).  As a comparison, last year we counted a minimum of 128 grouper on 10 sites (Avg 12.8).

·         Of the 49 grouper that were counted, one was estimated to be less than three feet, 28 were estimated to be between three and five feet, and 20 were estimated to be greater than five feet.

I will be sure to share the results from the rest of the project as soon as I get them.

Florida Scallop Fishery Webinar Recording

Did you know…

Bay scallops in Florida only live about a year? There is a commercial fishery for calico scallops in Florida? Want to know more?

I invite you to watch a recording of a webinar my Sea Grant colleague Dr. Lisa Krimsky and I gave on Florida’s scallop fishery. The presentation is part of our Florida Seafood Brown Bag Webinar Series. The series is intended for seafood lovers and educators who are interested in learning more about the safety and sustainability associated with Florida’s fisheries and seafood industry. The goals of the scallop presentation are:

1. Increase your knowledge of basic scallop biology and ecology
2. Enhance your understanding of the trends, importance, and management of Florida’s scallop populations and fisheries
3. Make you more informed about the purchasing, storing, and handling of scallops

 To view the recording, click HERE

We want to hear from you!
 We would love to get your feedback about the presentation by completing a short evaluation. Your input helps us plan for future educational programs. To access the evaluation click HERE.

Recordings of Past Webinar in the Series

Click HERE if you would like to view the recordings of past webinars from this series.

Additional Scallop Resources 

Florida Sea Grant: Recreational Scalloping in Florida

ISSC:Interstate Shellfish Sanitation Conference – Scallop handling and safety

FWC:Recreational Scalloping Survey

FDACS:Scallop Recipes

 

 

Don't Let Your Catch Spoil the Day

As the fishing action heats up this summer, so inevitably do temperatures, which can spell trouble for an angler if he/she isn’t careful.  Fish are highly perishable, and the methods by which anglers handle their catch from the time it is hooked until it is cooked can impact the quality of their meal.

Once a fish dies, irreversible spoilage begins. Enzymes and bacteria are responsible for this process. Enzymes that normally regulate a fish’s metabolism are left unchecked and start breaking down body cells. Fish caught while feeding may experience quicker rates of spoilage because digestive enzymes will already be active.  A softening of flesh around the gut is often an indication of this process as enzymes quickly digest these tissues.

Bacterial growth in the body will accelerate as the fish decomposes. Fish may also become more susceptible to bacteria from the environment as the fish’s natural defenses are broken down. Exposure to the sun and Florida temperatures can quickly accelerate this process. One bacterium on a fish’s body can multiply into millions of bacteria within hours if conditions are right. This bacterial activity will contribute to the deterioration of the flesh. In fact, fresh fish flesh is practically odorless, but fishy odors associated with spoilage are the result of bacteria hard at work.

While it is impossible to completely prevent spoilage, anglers can reduce this process by properly chilling their catch. This also reduces health risks associated with warmer temperatures.

One of the most recommended chilling methods for recreational anglers is the use of a brine slush-ice mixture. This is accomplished by combining at least two parts ice to one part clean seawater in an insulated cooler. Fish will chill four to five times quicker in slush ice because it will be surrounded by 32°F slush water.

To maximize the chilling process, seafood specialists recommend using at least one pound of ice per pound of fish. Cover the bottom of a cooler with several inches of ice and then surround the entire fish with another layer of ice.  When deciding on how much ice to bring, anglers should also take into account the length of their trip, the surrounding air and water temperature, and if possible, the type and size of fish being targeted.  Crushed or flaked ice is recommended because of the greater amount of surface area in contact with the fish, which will result in quicker chilling rates. Larger pieces can tear or bruise the skin more easily, but is better than no ice at all.

As the ice melts, water will help wash bacteria away from the surface of the fish. Water should be drained periodically to help remove accumulated bacteria. Continue to add ice as needed to maintain the appropriate slush mix.



Bleeding and gutting a fish will also enhance the quality of fish destined for your plate. Bleeding a fish will improve muscle appearance and flavor, and can reduce the cooling time once a fish is put on ice.  Gutting a fish helps to remove sources of bacteria and enzymes that can increase spoilage rates. It will also reduce chilling time because a significant amount of body weight is removed.  Keep the entrails intact to avoid contamination with other parts of the body. Knives and cutting surfaces should be clean to minimize further contamination. Once the fish is gutted, rinse the cavity with clean water to remove any excess blood, slime or viscera and pack it in the ice.  Keep in mind that legally, fish must be landed whole with head and tail intact.