|Scientific Name:||Squatina californica Ayres, 1859|
|Taxonomic Source(s):||Ayres, W. O. 1859. On new fishes of the Californian coast. Proceedings of the California Academy of Sciences (Series 1) 2: 25-32.|
|Red List Category & Criteria:||Near Threatened ver 3.1|
|Assessor(s):||Cailliet, G.M., Chabot, C.L., Nehmens, M.C. & Carlisle, A.B.|
|Reviewer(s):||Barry, S.N. & Lawson, J.|
|Contributor(s):||Sosa-Nishizaki, O., Castillo Géniz, J.L., Galvan-Magana, F., Ramírez Amaro, S.R. & Sandoval-Castillo, J.|
|Facilitator/Compiler(s):||Kyne, P.M., Walls, R.H.L., Ebert, D.A. & Dulvy, N.K.|
The Pacific Angel Shark (Squatina californica) occurs off the coast of North America from Alaska to Baja California, Mexico (including the Gulf of California), where it is associated with soft bottom habitats. It grows slowly and matures late in life (8-13 years), has an estimated generation length of 11.7-17.0 years, and produces an average of six pups per year. Based on these life history characteristics and the potential for isolation due to patchy habitat distributions and restricted movement patterns, resident stocks of Pacific Angel Shark may be vulnerable to heavy localized fishing pressure.
This species was commercially harvested in California beginning in the late 1970s. In response to a decline in landings, management measures (including a ban on nearshore gillnets and minimum size limits) significantly reduced the landings in California and these landings have stabilized at low levels over the past decade (2005-2014). In Mexico this species is still fished, and logbooks have been required in targeted shark fisheries since 2006. The population trend remains unknown, but reported landings data (2003-2015) from Baja California suggest that landings declines of >99% may occur within three generations if current trends continue. While landings data cannot be equated with population declines, fishing pressure in Mexico has likely remained relatively stable over time. Given that this species is taken in targeted elasmobranch fisheries in Mexico, and that landings have declined under stable fishing pressure, this species is globally assessed as Near Threatened, with a suspected population decline approaching 30% over three generations. In the United States, however, this species is considered Least Concern, as the threat of targeted commercial fishing has ceased, and ground fisheries along the west coast of the United States are managed.
|Previously published Red List assessments:|
|Range Description:||The Pacific Angel Shark occurs off the coast of North America from Alaska to the tip of Baja California, Mexico (including the Gulf of California), and is particularly abundant in central and southern California (United States) waters, especially off the coast of Santa Barbara (Natanson and Cailliet 1986, 1990; Leet et al. 1992, 2001) and off El Barril, Baja California (Castro 2005). It was previously reported that the South Pacific Angel Shark (Squatina armata) was a possible synonym of this species, but this has largely been confirmed to be a separate species (Stelbrink et al. 2010). Further evidence to support that Pacific Angel Shark does not occur in Chile was provided in a recent checklist for elasmobranchs in Chilean waters, where South Pacific Angel Shark but not Pacific Angel Shark was reported to occur (Bustamante et al. 2014).|
Native:Canada (British Columbia); Mexico (Baja California); United States (Alaska, California, Oregon, Washington)
|FAO Marine Fishing Areas:|
Pacific – southeast; Pacific – northeast; Pacific – eastern central
|Range Map:||Click here to open the map viewer and explore range.|
|Population:||No information on stock size or structure has been documented for the species. However, three genetically distinct populations have been described off of the west coast of the United States within the California Channel Islands (Northern Channel Islands, Southern Channel Island, and along the mainland) that are most likely separated by deepwater channels (Gaida 1997). It has also been suggested that populations on the Pacific side of Baja California are distinct from that of the Gulf of California (Ebert 2003). Currently, support for these possibly divergent lineages has not been provided and the existence of distinct genetic subpopulations from throughout the eastern Pacific distribution of the species has not been assessed. Because of its rather limited geographical range and evidence of only limited exchange among regional stocks within this range, resident stocks near large population centres may be particularly vulnerable to heavy localized fishing pressure.|
This species was commercially fished in California beginning in the late 1970s. In 1977 landings totalled 0.15 metric tones (mt), and during the expansion phase of the commercial fishery for this species, landings rose dramatically to 117 mt in 1981, and to 277 mt in 1984. Landings peaked and began to decline from 426 mt in 1987 to 112 mt in 1990. While declines were observed around this time, these declines were not strictly a reflection of population declines, as a minimum size limit was proposed in 1987 and became law in 1989 (Leet et al. 2001). In 1991, a 50% decline in effort occurred in response to bans on gill and trammel nets in California. This also had a dramatic effect on the landings, which dropped to 8.62 mt in 1995 and 8.16 mt in 1997, but then increased to 15 and 24 mt in 1997 and 1999, respectively. At the same time that landings were dropping in California, a Mexican gillnet fishery began targeting Pacific Angel Shark in 1997, with estimated landings of close to 163 mt in 1999 (Leet et al. 2001). More recently, landings in California have stabilized at around 6.81 to 4.04 mt from 2005 to 2014 (California Department of Fish and Wildlife 2000-2014).
Little is known about the effect of fisheries on the population of the Pacific Angel Shark in Mexico, but landings in some areas have declined and researchers have detected changes in size composition. Fisher interviews conducted along the coast of Baja California also suggest that catches have declined over time (Sergio Ramirez, pers. comm., 2 December 2016). Logbook data from the demersal trawl fleet in San Felipe, Baja California report catches of 663 to 6,375 kg from 2009-2013. Data on landed weight of the Pacific Angel Shark from Baja California reported to Bahia de Los Angeles are available over twelve years (2003-2015; CONAPESCA). These data suggest that landings have declined steadily from a peak of 83,778 kg in 2012 to 16,173 kg in 2015, representing a decline in landings of >99% over three generations (2003-2057) if fishing continues at the same rate (CONAPESCA). Changes in Mexican fishing effort are difficult to detect, but effort is estimated to be relatively stable. Species-specific landings data are also available for Sonora state, but no trends in landings are yet clear (CONAPESCA).
A survey of landings of artisanal fishers targeting elasmobranchs was conducted in Sonora, Mexico (Gulf of California) from 1998-1999. Pacific Angel Shark constituted 1.3% of the total chondrichthyan landings, increasing to 3.3% in winter, which was considered "a notable contribution" by the authors (Bizzarro et al. 2009a). Surveys were also conducted on the Gulf of California side of the Baja peninsular and found Pacific Angel Shark to constitute 11.6% of the total chondrichthyan landings (Bizzarro et al. 2009b). Along the Pacific coast of the Baja peninsula, an artisanal fishing community survey conducted between 2006 and 2008, determined that this species made up 1.86% of the total elasmobranch landings (Cartamil et al. 2011). In a survey focusing on the Pacific coast of Baja California Sur, this species was found to make up 5.6% of the elasmobranch catch (a catch-per-unit-effort of 1.82 individuals per vessel per trip; Ramirez-Amaro et al. 2013).
|Current Population Trend:||Decreasing|
|Habitat and Ecology:||Pacific Angel Shark are relatively small, benthic elasmobranchs, that are commonly found in soft bottom habitats, including shallow bays and estuaries, as well as around rocky reefs and kelp forests (Feder et al. 1974, Ebert 2003). It lives in relatively shallow waters to depths of 100 m, but it is much more abundant in nearshore, coastal waters (Eschmeyer et al. 1983). They are fairly residential, restricting their movements to a small geographic area, possibly on the order of 150 ha or 375 acres, with the potential to make longer distance movements (Ebert 2003, Love 2011). For example, one Pacific Angel Shark tagged in Catalina Island was recaptured three and a half years later at Santa Cruz Island, a distance of approximately 100 km (Leet et al. 2001). They are generally quiescent during the day, often remaining buried in the sediment, but become quite active and hunt during the night (Pittenger 1984, Leet et al. 1992, 2001; Castro 2011). They appear to exhibit a high degree of site fidelity, with reports of sharks having preferred foraging and resting locations (Standora and Nelson 1977, Love 2011).|
Numerous techniques of ageing and age verification have been used on Pacific Angel Shark, but none except tag-recapture have been successful at estimating their growth rates or age-specific processes (Natanson and Cailliet 1990, Cailliet et al. 1992). These tag-recapture data, however, allowed an estimate of von Bertalanffy growth and demography parameters that predicted relatively slow growth and moderate fecundity, with maturity occurring relatively late in life. Off California, males and females begin to mature between 90-100 cm total length (TL), with an average reproductive age of 8-13 years (Cailliet et al. 1992, Cortes 2002, H. Mollet unpublished data 2005). All males and females larger than 103 cm and 112 cm, respectively, are mature (Natanson and Cailliet 1986). In the Gulf of California, Pacific Angel Shark mature at a smaller size, 75.6 cm for males and 77.7 cm for females (Romero-Caicedo et al. 2016). Age at maturity of the Pacific Angel Shark in California is around 10 years, but ranges from 8 to 13 years (Natanson and Cailliet 1986, Cailliet et al. 1992). The reproductive mode of this angelshark is aplacental viviparity. Females give birth to 1-13 pups (average six) after a 10 month gestation with pupping occurring between March and June (Natanson and Cailliet 1986, Ebert 2003). Size at birth is approximately 25 cm TL (Natanson and Cailliet 1986). Maximum reported length is 152 cm TL for females and 118 cm for males (Natanson 1984), and maximum length in the Gulf of California was estimated at 99 cm TL (Romero-Caicedo et al. 2016). Maximum age is around 22-35 years (Natanson 1984, Cailliet et al. 1992, Cortes 2002, H. Mollet unpub. data 2005). Generation length is estimated to be 11.7-17.0 years (Cailliet et al. 1992, Cortes 2002, H. Mollet unpub. data 2005).
|Generation Length (years):||11.7-17.0|
|Use and Trade:||This species is valued for its meat.|
Historically, the Pacific Angel Shark was discarded at sea or used as bait, but in the 1970s a commercial fishery in California began targeting this species. A rapid increase in Pacific Angel Shark landings between 1983-1986 occurred in California (Richards 1987), leading to concern that stocks could be overexploited. Even though a minimum size was proposed for the gillnet fishery targeting both California Halibut (Paralichthys californicus) and Pacific Angel Shark, this measure proved not to be effective at reversing the declining population levels along the Santa Barbara/Ventura coast and Channel Islands areas, California (Richards 1987, Cailliet et al. 1993). Additionally, it was observed that declines in landings were occurring prior to the implementation of these management strategies indicating the over-exploitation of the species within the region (Leet et al. 2001).
In Mexico this species is caught in fisheries targeting elasmobranchs. Fishing effort in Mexico is challenging to quantify, as some fishers hold licenses but are inactive, while others may share a single license among multiple vessels (Sosa-Nishizaki, pers. comm. 2016). This species is now absent from regions in Baja California Sur where it was historically found in catches (Laguna San Ignacio and Bahia Magdalena), and there is also evidence for depensation in this region (Ramirez-Amaro et al. 2013).
The northeast Pacific population of the Pacific Angel Shark appears to have stabilized, at least in the waters of California. A ban on gillnet fisheries that targeted the California Halibut (Paralichthys californicus) was voted into law by Californians in 1990 (Proposition 132). Through this ban, the fishery is indirectly regulated (Cailliet et al. 1992, Leet et al. 1992). Additionally, a minimum retention size limit became law in 1989, which decreased the juvenile catch and overall harvest on exploited stocks. Drift gillnet fisheries are also prohibited off the coast of Washington state.
Further north, along the United States west coast (Washington, Oregon and California), ground fisheries are managed by a federal Groundfish Fishery Management Plan. Although this species is not a focal species of the plan, and no species-specific data on the Pacific Angel Shark will be collected, other chondrichthyans are being managed under this program.
In Mexico, some fisheries are required to record species-specific data under the category of "angelito" (Pacific Angel Shark) in logbooks. While not all fisheries have established a logbook system, in fisheries targeted sharks they have been required since 2006. Additionally, in 2012 Mexico implemented a seasonal fishing closure from May 31 to July 31 for fisheries targeting elasmobranchs on the Pacific Coast.
|Citation:||Cailliet, G.M., Chabot, C.L., Nehmens, M.C. & Carlisle, A.B. 2016. Squatina californica. The IUCN Red List of Threatened Species 2016: e.T39328A80671059.Downloaded on 13 December 2017.|