Fisheries FAQ

In Tampa Bay most species of fish are edible. Puffers and barracuda should not be eaten. There are some consumption warnings for a few species of fish for mercury content and ciguatera toxin. Some edible species of fish are not eaten because of a variety of factors including off taste, high number of bones, and little available meat.

Yes! In fact, we do not even need that much biological tissue (muscle tissue, fin clips, etc); we can identify species by a scale or fin clip.

Fish have three ear bones called otoliths. Otoliths are hard, calcareous stones that serve some of the same basic purposes for fish, as do our own inner ear bones. For example, otoliths help fish keep their balance, and human inner ear bones help people stay balanced. The otoliths grow by putting on daily growth layers similar to the rings of trees as they grow. In the early 1960s, scientists determined that the growth rings are actually synchronized to time. They showed that by removing the fish's ear bone, cutting a thin slice of it, and looking at the rings under a microscope, the fish's age could be determined. The daily growth rings become less clear as fishes grow, but as in trees, annual growth patterns can be seen if the otolith is properly prepared. In regions of the country where there is a distinct seasonal variation, the rings are generally more apparent. In tropical areas that have a more uniform year round growth rate, the rings may become more difficult to read.

Tarpon have a swim bladder, which is adapted for air breathing. The swim bladder is highly vascularized, which means it has a rich supply of blood vessels, and it connects to the throat of the fish. When a tarpon is rolling on the water surface, it is taking a breath of air. Its mouth opens as it surfaces; air is taken into the mouth. As the tarpon rolls back into the water, its mouth closes, and air is forced back into the swim bladder. Oxygen then passes from the swim bladder into the blood stream. Tarpon also use their gills for oxygen uptake. Air breathing frequency depends on oxygen content and temperature of the water.

Game fish are species that are normally caught for sport because they are considered excellent fighters. However, some, like snook, are prized for their flesh. Most game fish are protected from commercial harvest. Common Florida inshore game fish studied at the Fish and Wildlife Research Institute include tarpon, snook, red drum, and bonefish. Game fish research at FWRI is funded by Wallop-Breaux sport fish restoration money.

There are more than 1000 different species of fish in Florida's inshore waters. Florida's largest estuary, Tampa Bay, covers 440 square miles and has over 300 species of inshore fish.

Otoliths, commonly known as "ear stones," are hard, bone-like structures located directly behind the brain of bony fishes. These structures aid fish in balance and hearing. Cartilaginous fishes, which include sharks, skates, and rays, do not have otoliths.

For scientists, otoliths are important to age and growth studies. Once the otoliths are removed from the fish, they are cleaned, dried, and cut into thin cross sections. The age of the fish is determined by counting the visible rings on the thin sections, as one would count rings on a tree. This information, combined with other data, allows scientists to determine growth rates, age at reproduction, and to predict the number of fish in future generations.

Baitfish are small schooling fish, typically herring, which are located in bays and open waters. Not only do they serve as food for larger fish in the natural setting, but they are primarily used by humans as a means of obtaining larger fish through recreational harvest.

Baitfish common to Florida waters include Atlantic thread herring, scaled sardines, Spanish sardines, round scad, and several species of menhaden and anchovies.

No one has been able to ask a mullet why it jumps. In waters with low dissolved oxygen, mullet may jump more frequently, which might indicate a greater need for oxygen. Some biologists feel that jumping aides mullet in removing parasites; others believe it may be part of schooling behavior in mullet. An intriguing notion is that maybe they just like to jump.

Biologists sample fish for a variety of reasons: abundance, species composition, size structure, age structure, genetic structure of populations, maturity, reproductive condition, and parasites and diseases. The Florida Fish and Wildlife Conservation Commission's Fish and Wildlife Research Institute gains this information through several research programs including Fisheries Independent Management, Fish Biology, Fisheries Dependent Management, Fish Health, Stock Assessment and Modeling, and Genetics. Researchers gather information from recreational anglers and commercial fishers as well as employ scientific fishing gear to gather data about fish populations independent of the harvest. Research gear allows biologists to examine aspects of the fish populations that are more representative of populations in the wild, information which cannot be assessed by looking at anglers' catches.

The geographic origin of an individual fish can almost never be determined through genetic analysis; however, there is research that indicates that analyzing elemental concentrations in fish may help determine where a fish spent most of its life. Many fish are genetically similar across geographic regions, so it may not be easy to determine where a fish originated.