|Scientific Name:||Nasolamia velox|
|Species Authority:||(Gilbert, 1898)|
Carcharhinus velox Gilbert, 1898
|Taxonomic Notes:||Original description by Gilbert, published in Jordan, D.S. and Evermann, B.W. 1898. The fishes of North and Middle America: a descriptive catalogue of the species of fish-like vertebrates found in the waters of North America north of the Isthmus of Panama. Part III. Bulletin of the United States National Museum No. 47: i-xxiv+2183a-3136.|
|Red List Category & Criteria:||Data Deficient ver 3.1|
|Assessor/s:||Ruiz, C., Arauz, R., Pérez-Jiménez, J.C., Castillo-Geniz, J.L.& Soriano-Velásquez, S.|
|Reviewer/s:||Valenti, S.V. & Kyne, P.M. (Shark Red List Authority)|
The Whitenose Shark (Nasolamia velox) is an uncommon to rare shark of the eastern Pacific found from Mexico, through Central America to Colombia, Ecuador and Peru in South America. Primarily it is an inshore species at depths of less than 24 m, but also found offshore to depths of 192 m. This species is taken by longline and gillnets in inshore fisheries and in some regions directed shark fishing is increasing. Destructive trawling practices, water pollution and coastal sedimentation may also threaten the coastal nursery grounds of this species. No data are available on population trends and little is known of the life-history of this species (although fecundity is low: 5?6 pups per litter). It is assessed as Data Deficient as a result of insufficient information and research is required on biology, population trends and capture in fisheries.
|Range Description:||Eastern central and southeast Pacific: from Mexico to Peru including Central America (Guatemala, El Salvador, Nicaragua, Costa Rica), Colombia, Ecuador (including the Galápagos Islands; Grove and Lavenberg 1997). In Mexico is found in the Gulf of Tehuantepec, Baja California, and the Gulf of California in Sinaloa (Compagno 1984, Ocampo-Torres 2001).|
Native:Colombia; Costa Rica; Ecuador; El Salvador; Guatemala; Mexico; Nicaragua; Panama; Peru
|FAO Marine Fishing Areas:||
Pacific – eastern central; Pacific – southeast
|Range Map:||Click here to open the map viewer and explore range.|
|Population:||Formerly uncommon to rare where it occurs (Compagno 1984), although it has been recorded in unusually large numbers in the artisanal shark fishery of Puerto Madero, Chiapas, Mexico. No time series of CPUE exist for this species, and it is not possible to deduce population trends. Little is known of the population structure, but nursery grounds are thought to exist in shallow waters close to the coast, and in bays and estuaries.|
|Habitat and Ecology:||
A tropical inshore and offshore shark, normally found over the continental shelves in shallow coastal waters (Compagno 1984, Fischer 1995). It is usually found at depths of 15?24 m, but occasionally can be found down to 192 m depth (Compagno 1984). In Guatemala it has been reported 20?60 miles from the coastline on the continental slope (Ruiz and Lopez 1999). In Mexico, it was also observed close to fresh water river mouths (Hernandez 1971); a few individuals have been observed in the Mexican Central Pacific (Pérez-Jiménez 2005). In Costa Rica they are found in the catches registered at 50?75 miles from the coast, and in demersal fisheries operating on the slopes of the continental shelf (Vargas and Arauz 2001).
Reproduction is viviparous, with a yolk-sac placenta, and five to six young in a litter (Compagno 1984, Ruiz and Lopez 1998). It feeds on small bony fishes, including anchovies, and crabs. They reach a maximum size of 165 cm total length (TL) (Ruiz et al. 2000). Size at birth is about 53 cm TL; males are immature at 92?106 cm but adult at 140 cm (Compagno 1984). Reproduction (mating and birth) may occur in the months of May through July, as recently born individuals have been observed towards the end of March (Ruiz and Mijangos 1998).
This species is captured as bycatch of gill nets and surface long lines in inshore fisheries and in some areas directed shark fishing is increasing (Soriano-Velásquez et al. 2004). This species is reported in the commercial landings of some Central America countries, Mexico, Ecuador and Colombia, but it is not reported in the catches of El Salvador and Panama. In Costa Rica, it is caught by pelagic and demersal long-liners. Adult sharks taken in Costa Rica?s demersal longline fishery are used for local consumption and fins may be exported to Hong Kong. Observations on board one fishing trip that included six sets and 3,400 hooks resulted in the capture of 35 whitenose sharks, constituting 12.1% of the total catch (CPUE = 10.3 individuals/1,000 hooks). It is assumed that in Costa Rica effort is increasing in the directed shark demersal longline fishery that catches this species along the continental shelf, however specific data and fisheries information is scarce (R. Arauz pers. obs.). Pups are incidentally captured on nursery grounds close to the coastal shallow waters, by fisheries operating with drift gill nets.
In the artisanal shark fishery of Puerto Madero, Chiapas (Gulf of Tehuantepec, México) this is the fifth most important shark species by number (Soriano-Velásquez et al. 2004). During the period June 1996 to May 2001, a total of 1,149 individuals were recorded from the shark landings (529 females, 620 males) (Soriano-Velásquez et al. 2004). A preliminary CPUE series indicated a stable trend during the study period (1996?2001), with an average CPUE of 1.74 individuals per trip. The highest average was 15 individuals per trip calculated for July 1998 (Soriano-Velásquez et al. 2004). This unusually high CPUE was perhaps associated with the ENSO in 1998, which affected the oceanography of the Gulf of Tehuantepec, increasing the average seawater temperature, and possibly prompting the migration of a larger number of sharks to GOT (Soriano-Velásquez et al. 2004).
Artisanal net fisheries operate across the species? South American range, and although species-specific data are not available, the whitenose shark is likely captured by inshore fisheries in Colombia, Ecuador and Peru. In Peru, pressure on inshore shark species is high, particularly houndsharks, but it is likely that N. velox is also a component of landings there.
The impact of trawl fisheries on this species should be evaluated. Although the species is less likely captured by trawl fishing gear than gillnets and longlines, this species? coastal nursery grounds are probably affected by habitat degradation through destructive trawling practices. Water pollution and coastal sedimentation may also threaten nursery grounds through habitat degradation.
There are no specific conservation or management measures in place for this species. In Nicaragua, finning is regulated for all shark species. In Mexico, shark fisheries are controlled through a permit program. In Ecuador, finning, as well as fishing in the protected zone of the Galapagos Marine Resources Reserve is prohibited but illegal fishing occurs. Ecuador also requires that fishermen record information on fishing trips.
Recommendations for conservation actions may include:
- Coastal zone management plans
- Analyze and update laws and regulatory frameworks
- Establish cooperative agreements between and among countries that may be sharing the same population (e.g., Mexico -Chiapas- and Guatemala)
- Regular monitoring of all commercial artisanal and industrial landings
- Continue monitoring on the biology of the species (morphometric measurements and biological information is needed)
- Harmonization of regulatory frameworks and standardization of conservation strategies between and among countries of the same region
- Long-term conservation actions may include buying of fishing rights.
There is also a requirement to obtain information on catches where little or no data are available (i.e., South America).
|Citation:||Ruiz, C., Arauz, R., Pérez-Jiménez, J.C., Castillo-Geniz, J.L.& Soriano-Velásquez, S. 2009. Nasolamia velox. In: IUCN 2012. IUCN Red List of Threatened Species. Version 2012.2. <www.iucnredlist.org>. Downloaded on 20 May 2013.|
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