Wreckfish  (Polyprion americanus)

The wreckfish is classified as Data Deficient (DD) on the IUCN Red List (1). The Brazilian subpopulation is classified as Critically Endangered (CR) on the IUCN Red List (1).

The wreckfish (Polyprion americanus), named for the tendency of juveniles to associate with floating ocean wreckage (3), is a large bluish-grey fish, with a paler, silvery underside and blackish-brown fins (2). The rough, scaly body is flattened sideways and the caudal, or tail, fin is gently rounded and edged with white. The wreckfish has a large mouth, with the lower jaw projecting considerably beyond the upper jaw (3), and a bony ridge protrudes across the upper part of the gill cover (2). Juvenile wreckfish bear black blotches on the head and body (2).

The wreckfish has an incredibly large distribution, primarily occurring in the Atlantic Ocean but also ranging into the Mediterranean, southern Indian Ocean and south-western Pacific Ocean (1).

Wreckfish are found in temperate and subtropical waters over continental and island slopes (4). Juvenile wreckfish inhabit the open ocean and are often associated with floating seaweeds and wreckage, as the name implies (3) (5). As adults, wreckfish are demersal, inhabiting the seabed at depths from 40 to 1,000 metres (5),

This long-lived fish has two distinct stages in its life history. Juvenile wreckfish inhabit the open ocean, where they feed on bony fishes, particularly Trachurus species (jack mackerels) (1). They live for more than two years at the sea surface before settling on the ocean bottom at great depths (4) (5).

Adult wreckfish continue to feed on fish, but also consume squid found in their deep water habitat (1). During spawning, which takes place between late July and early October, wreckfish come together in aggregations and females release their eggs into the deep ocean water (4). Being a multiple spawner, wreckfish release multiple batches of eggs during the spawning season (4). The oldest known wreckfish was a male, found to be 81 years old; the oldest known female was 64 years old (1).

The single, greatest threat to the wreckfish is from overfishing (1). Since the 1970s, fisheries specifically targeting wreckfish have existed (1), with the large size, quality flesh and high market price of the wreckfish attracting a lot of interest (5). Despite a lack of data on some wreckfish populations, it is believed that global wreckfish stocks may now be in decline (1). This assumption is based on the fact that wreckfish are slow to reproduce, which makes it susceptible to overexploitation, and due to signs that populations are being overexploited in some areas (1). For example, wreckfish fisheries in Brazil, Bermuda and Portugal began to decline within five years of their commencement (1). In addition, the habit of wreckfish to form aggregations when spawning increases its vulnerability to overfishing, as large groups are an easy target for fisheries (1).

Fishing regulations, which may help conserve stocks of wreckfish, are only in place in the USA and New Zealand (1). In the USA, commercial fishers must have permits, quotas are in place, and wreckfish are not allowed to be caught during the spawning season. The commercial fishery in New Zealand also has quotas in place (1). Elsewhere, particularly in Brazil, conservation measures for the wreckfish are worryingly absent (1).

View information on this species at the UNEP World Conservation Monitoring Centre.

For further information on the wreckfish: 

• IUCN Red List:
  www.iucnredlist.org