What are forage fish?
Forage fish are small to medium-sized schooling fishes that typically mature early and have short life spans. Sardines, anchovies, and menhaden are classic examples, but many other species like goggle eyes, mullet, pinfish, and ballyhoo also have similar life cycles.
Why do forage fish matter?
Forage fish represent the first vertebrate link in marine food webs. They feed predominantly on small plant and animal matter and, in turn, transfer this energy to higher trophic levels where they are subsequently preyed on by larger, predatory fish such as redfish, snook and sailfish. Therefore, fisheries managers need to determine how many forage fish can be harvested and how many need to be left in the ocean in order to properly fulfill their role as food for larger fish species and animals.
How are forage fish harvested?
Globally, forage fish account for nearly one-third of all marine fish that are harvested annually. The majority (90%) are processed for aquaculture, feed for poultry and livestock, and nutritional supplements for people. In Florida, forage fish constitute 20% of all commercial catches.
Meet some of Florida’s important forage fish species
Scaled sardine or pilchard (Harengula jaguana)
Most people in Florida refer to scaled sardines as pilchards. Pilchards are common inshore and nearshore along both coasts of Florida. They have a maximum size of approximately 15 cm, rarely live more than a year, and are often misidentified with their close relative, the false herring (Harengula clupeola). One study reported that pilchards are heavily preyed upon by king and spanish mackerels, little tunny, gag grouper, bluefish, crevalle jack, yellowfin tuna, and dolphin. Total statewide landings of scaled sardine in 2012 were 29,365 pounds. No formal stock assessment exists for this species.
Atlantic thread herring (Opisthonema oglinum)
Thread herring are common in Florida and occur from the Gulf of Maine on the east coast throughout the Gulf of Mexico and the Caribbean southward to Brazil. They can be readily identified by their last dorsal fin ray, which is long and filamentous.Thread herring have a lifespan of at least three years and become reproductively mature at between 4.7 and 5.7 cm in fork length at roughly age one or two. Spawning takes place in nearshore waters from March through July. The 2013 landings for threadfin were 1.7 million pounds. No formal stock assessment exists for this species.
Pinfish (Lagodon rhomboides)
This well-known species of forage fish is a ubiquitous resident of Florida’s extensive sea grass beds. Pinfish may live as long as seven years and a two year old fish averages five inches in length. They mature by age one or two when they are approximately 4.3 inches in length. Pinfish exhibit seasonal migrations where they move to offshore habitats during the fall, where they reside and spawn through the spring. They are an important prey item for many species of fish including redfish, seatrout, and even gag grouper during winter months. Pinfish feed on a variety of invertebrates but as they grow, the shape of their teeth change and their intestines increase in length as they graze on more plant material. The 2013 landings for pinfish were 45,852 pounds. No formal stock assessment exists for this species.
Spanish sardine (Sardinella aurita)
Spanish sardines can be encountered in Florida from the shoreline out to depths of 100 feet, but the highest concentrations occur at depths less than 65 feet. They exhibit diurnal vertical migrations where schools spend more time near the bottom during the day and utilize more of the water column at night. Spawning evidence is conflicting but is thought to occur year-round primarily along the Gulf coast shelf. After spawning, adults undertake migrations to nearshore feeding areas. Spanish sardines have a lifespan of only 4 years and can reach 7.5 inches in fork length. Females become sexually mature by their second year when they are approximately 5.3 inches in length. Females grow faster and larger than males. Key predators of Spanish sardines include grouper, bluefish, crevalle jack, spanish and king mackerel, and yellowfin tuna. Spanish sardines are harvested in Florida primarily with purse seine nets and 2012 landings were just under one million pounds.
Striped mullet (Mugil cephalus)
Striped mullet are found worldwide and occur throughout Florida. They have somewhat of a catadromous lifecycle where they inhabit fresh and brackish water habitats but spawn in the sea. Unlike other forage fish, striped mullet are fairly long-lived and may reach nine to 13 years in age. They can grow to 20 inches in total length and become sexually mature at two to three years of age when they are approximately 11.5 inches in fork length. Spawning occurs in the outer continental shelf at depths over 5,000 feet during November through January. Striped mullet feed primarily on benthic microalgae, detritus, and sediment particles. They are important forage for common snook, spotted seatrout, red drum, southern flounder, and a variety of birds. Striped mullet have been regulated in Florida since 1989 and harvest was substantially reduced by the 1995 constitutional amendment that banned the use of entangling nets in Florida waters. The last stock assessment was conducted in 2008 and indicated that striped mullet are well-managed and are not overfished or experiencing overfishing. The next stock assessment is due at the end of 2014. Total landings in 2012 were 9,599,144.