Galeorhinus galeus, Tope

• Main Authors: Walker, T. I., Rigby, C. L., Pacoureau, N., Ellis, J., Kulka, D. W., Chiaramonte, Gustavo Enrique, Herman, K.
• Format: Article in Journal/Newspaper
• Language: English
• Published: International Union for Conservation of Nature
• Subjects: Chondrichthyes; Carcharhiniformes; Triakidae; Tope shark; Soupfin shark; School Shark; Cazon; Trompa de cristal; https://purl.org/becyt/ford/1.6; https://purl.org/becyt/ford/1; Pacific; Indian; New Zealand; Northeast Atlantic
• Online Access: http://hdl.handle.net/11336/145926

Tope (Galeorhinus galeus) is a medium-sized (to 200 cm total length) bentho-pelagic shark, widespread in temperate waters in most oceans. It is present across the Northeast, Eastern Central, Southwest, and Southeast Atlantic, the Mediterranean Sea, the Eastern Indian, and across all of the Pacific, except in the Northwest Pacific. It occurs on continental shelves and upper to mid slopes from shallow inshore to well offshore to depths of 826 m, though most frequently to depths of 200 m. Genetic and tagging data support up to six separate subpopulations of Tope and while the species makes extensive movements within each of the subpopulations, there is no evidence of mixing between them. Tope has a particularly low biological productivity with a late age-at-maturity and triennial reproductive cycle. It is caught globally as target and bycatch in industrial and small-scale demersal and pelagic gillnet and longline fisheries, and to a lesser extent in trawl and hook-and-line fisheries. Tope is often retained for the meat and fins but is discarded or released in some areas, in line with regional management measures. Steep subpopulation and stock reductions of >80% over the past three generation lengths (79 years) have occurred in the Southwest Atlantic, southern Africa, and Australia. In the Northeast Atlantic, the subpopulation is estimated to have undergone a reduction of 76% over the past three generation lengths (79 years). The New Zealand stock is estimated to have undergone a reduction of 30?49% over the past three generation lengths (79 years). In the Northeast Pacific, a dramatic decline in the subpopulation occurred in the early 1940s, with no recovery until 1997?2004 when localized management led to a localized increase in abundance. The consistent steep subpopulation reductions across most of the analyzed subpopulations and stocks together with the lack of movement between the subpopulations are cause for serious concern. Management in Australia, probably aided by the immigration of large mature animals ...