|Scientific Name:||Lopholatilus chamaeleonticeps Goode & Bean, 1879|
|Taxonomic Source(s):||Eschmeyer, W.N. and Fricke, R. (eds). 2015. Catalog of Fishes: genera, species, references. Updated 1 October 2015. Available at: http://researcharchive.calacademy.org/research/ichthyology/catalog/fishcatmain.asp. (Accessed: 1 October 2015).|
|Red List Category & Criteria:||Endangered A2bd ver 3.1|
|Assessor(s):||Aiken, K.A., Collette, B., Dooley, J., Kishore, R., Marechal, J., Pina Amargos, F. & Singh-Renton, S.|
This deep-living species is widely distributed and constructs burrows in deeper areas on soft substrate often near submarine canyons. It has an estimated generation length of 16 years. It is highly-valued by both commercial and recreational fishers. Long-lived, slow-growing species such as this tend to be particularly susceptible to overfishing, even with low fishing intensity or inefficient fishing methods. This species has been overfished in previous years and has undergone a 20 to 25 year cycle of increased and decreasing catches.
The main fishery and centre of abundance occurs almost exclusively in U.S. waters and is managed as three separate units: the Mid-Atlantic, the South Atlantic, and the Gulf of Mexico. The Mid-Atlantic was declared overfished in 1998, but is now considered rebuilt; the South Atlantic is not considered overfished; and despite declines in abundance since the 1980s, the Gulf of Mexico stock is also not considered overfished. However, it should be noted that the stock assessments for this species are generally data-poor, and as a result, contain a considerable amount of uncertainty. Biomass estimates show an increasing trend over at least the past decade in the Mid-Atlantic and South Atlantic; however, the species has been declining since 2005 in the Gulf of Mexico. Combined weighted spawning stock biomass for all three areas declined by 66% over the past three generations (48 years). Each stock is strictly regulated and monitored under U.S. federal law. The cause of this population decline is understood and reversible; however, is not considered to have ceased due to the declining trend in biomass in its exploited population in the Gulf of Mexico. Therefore, this species is globally listed as Endangered under criterion A2bd.
|Range Description:||Lopholatilus chamaeleonticeps is distributed in the western Atlantic Ocean from Nova Scotia (Canada) south along the U.S., in the Gulf of Mexico from the Florida Keys, Tampa (Florida) to the Texas/Mexico border, and off Mexico from Tabasco to the Yucatan Peninsula, and along South America from the Gulf of Cariaco (Venezuela) to Suriname (R. Robertson and J. Dooley pers. comm. 2013). Its depth range is 80-540 m, but is usually found between 100-200 m (Dooley 2002).|
Native:Canada; Guyana; Mexico; Suriname; Trinidad and Tobago; United States; Venezuela, Bolivarian Republic of
|FAO Marine Fishing Areas:|
Atlantic – western central; Atlantic – northwest
|Range Map:||Click here to open the map viewer and explore range.|
The U.S. and Canadian tilefish fishery began in 1879 and collapsed shortly thereafter with a mass mortality event caused by cold water intrusion in 1882 (Fisher et al. 2014). It began to recover in the late 1890s with an abundance of young fish (Bumpus 1899), and by 1915 the species was again being fished. The reported fishery landings have been highly variable, with peaks in 1914-1915, the late 1920s, mid-1950s, and mid-1970s (Freeman and Turner 1977) and low but relatively stable since 1984 (Shepherd 1998). Shepherd (1998) notes low landings and a significant decline in catch per unit effort (CPUE) of the north stock since about 1981 as evidence of over-exploitation. Turner (1986) reported that the effects of fishing have been drastic and stock size has been reduced by half to two-thirds, a level that continued into the mid-1990s (Shepherd 1998). High fishing mortality has truncated the size structure of the population; fewer larger fish greater than 70 cm have been landed (Grimes et al. 1980, Turner et al. 1983). The resurgence of this offshore fishery in the early 1970s partly as a recreational fishery may be a response to the decline of inshore fisheries because of habitat degradation and overfishing (McHugh 1977). However, a recent study found that changes in water temperature off New England due to anomalous cold water intrusions in the 1970s likely decreased survivability and overall reproductive success. This environmental stress combined with increased exploitation contributed to the significant population declines during this period (Fisher et al. 2014). Barans and Stender (1993) reported similar declines in stock size and mean individual size as the South Atlantic Bight fishery developed, and harvests have also declined since the late 1980s (Parker and Mays 1998).
Hightower and Grossman (1989) determined fishing mortality of the southeast U.S. population to range from 0.10 (M - 0.10) to 0.48 (M = 0.25) which results in sustainable yields of 40 (M - 0.10) to 82 t (M = 0.25) per year. They obtained higher estimates of virgin population density (883-1,710 per km²) when research CPUE data were used and determined sustained yield estimates also were higher, ranging from 55 (M - 0.10) to 148 t (M = 0.25) per year. Observed yields in the developing fishery exceeded 100 t in 1981-1984 and in 1986; however, current observations indicate that fishing effort has declined to a low level in response to reduced catches. They recommend that the annual harvest not exceed about 50 t, which should result in a stock biomass of about 400 t to 800 t.
According to the Mid-Atlantic (SARC58 2014) stock assessment, predicted total spawning stock biomass declined by 76% over the past 42 years (1971-2012; Table B26 page 416). This decline was calculated by taking the endpoints of the time series. According to the South Atlantic (SEDAR25 2011) stock assessment, predicted spawning stock biomass declined by 50% over the past 47 years (1962-2010; Table 5.3 page 24). This decline was calculated by taking the endpoints of the time series. Point estimates from the base model indicate that the U.S. southeast stock of Lopholatilus chamaeleonticeps is currently not overfished and overfishing is not occurring. However, the estimated time series of F/FMSY calculated by SEDAR suggests that the populations had been overfished during the assessment period (SEDAR25 2011). Hightower and Grossman (1988) determined adult population density prior to fishing ranged from 603 to 950 per km² and stock biomass ranged from 1,130 to 1,570 tonnes (t). They obtained higher estimates of virgin population density (883-1,710 per km²) when research CPUE data were used. Although total landings vary greatly, CPUE data showed continuous decline prior to 1999 in the mid-Atlantic. Although total landings vary greatly, CPUE data show continuous decline. Steimle et al. (1999) report declines in CPUE (Georges Bank - Middle Atlantic) from 1970 to 1995 from over 6 mt/day to 1 mt/day, which represents an approximate decline of 78% over 24 years and represents an average decline in CPUE of 3.25% per year. Future declines in CPUE are probable.
Gulf of Mexico
Total biomass and spawning biomass in the eastern Gulf of Mexico declined steadily beginning in the early 1980s; in the western Gulf of Mexico it declined until 1990, then increased from 1996 to 2000 and remain relatively constant from 2000 onward (SEDAR22 2011). Mean age of females in 1965 was 6 years, declined to 2 years in 1997, and increased to a mean age of 4 years in 2009. According to the Gulf of Mexico (SEDAR22 2011) stock assessment, predicted spawning stock biomass declined by 41% and total biomass by 68% over the past 45 years (1965-2009; Table 3 page 32). This decline was calculated by taking the endpoints of the time series generated using the SS3 central realization/SS run 1. The SS3 Central/SS run 1 realization stood out to the SEDAR22 working group as the most pragmatic choice to visualized trends abundance, biomass and exploitation of this species. The following information reflects this choice, however the working group recognized that this is only one of many equally plausible runs (SEDAR22 2011). It was concluded that overfishing of the Gulf of Mexico tilefish stock was not occurring and the stock was not overfished in 2009 (SEDAR22 2011).
Wide geographic separation and evidence of limited movements may necessitate management as separate south Atlantic and Gulf of Mexico stocks. For this reason, it is assumed that there is little emigration or immigration of this species in or out of the Gulf. The majority of its population in the Gulf of Mexico may be present in the northern Gulf of Mexico, as this species is mostly associated with compacted mud habitat. Given its habitat preference, we estimate that at least 70% of its Gulf of Mexico population occurs in the northern Gulf in U.S. waters. In Mexico, all tilefishes are recorded in mixed catches of either Blanquillo camelo or Conejo Amarillo and there are no species-specific statistics collected. It may be known as Corvinato. There are no specific management measures for tilefishes in Mexico. They are not very common in markets, and may be seasonal catches. This species also occurs as by-catch in the Mexican Red Grouper fishery.
Biomass estimates show an increasing trend over at least the past decade for the Mid-Atlantic and South Atlantic stocks, however, it has been declining since 2005 in the Gulf of Mexico. Population declines estimated from the spawning stock biomass in the three assessment areas (Mid-Atlantic, Gulf of Mexico, and South Atlantic) were weighted based on the proportion of recruits occurring in each area in 1971 (the earliest year of available data for the Mid Atlantic). The proportion of recruits was estimated to be 64% in the Mid-Atlantic, 26% in the South Atlantic, and 10% in the Gulf of Mexico. Percent declines were estimated using the endpoints of the available data and resulted in different starting and ending years for each area (Mid-Atlantic: 41 years; Gulf of Mexico: 44 years; South Atlantic: 48 years). Based on the shape of the time series of spawning stock biomass, we suspect that these endpoints are a reasonable representation of the state of the population now and three generation lengths ago. Therefore, the weighted overall spawning stock biomass decline of 66% was assumed to have occurred over the past three generations (48 years).
|Current Population Trend:||Decreasing|
|Habitat and Ecology:||This bottom dwelling species occurs mostly on silt-clay substrate and is more common where there is suitable substrate for burrow construction, such as scour depressions around boulders or rubble piles; also often near submarine canyons (Valentine et al. 1980, Able et al. 1982, Low and Ulrich 1983, Grossman et al. 1985). It prefers temperatures of 8°C to 17°C. Off the coast of New England, USA, it is restricted to the normally warm-water, upper continental shelf/slope and has suffered mass mortality in the past due to intrusion by cold Subarctic water. Such changes in water temperature also affects its reproductive success (Fisher et al. 2014). Adults usually live in groups and feed on shrimps, crabs, fish, squid, bivalves and holothurians (Steimle et al. 1999, Dooley 2002). Its main predator is goosefish (Steimle et al. 1999, NOAA Tech Memo NMFS-NE-152).|
This is the largest species of tilefish; it can reach 110 cm standard length, 125 cm total length (24.9 kg), and is commonly found to 60 cm (5-7 kg). This species grows slowly and is suspected to be a protogynous hermaphrodite. Males are larger than females. The otoliths of this species are considerably difficult to age (SEDAR4 2004). According to a study conducted in the Mid-Atlantic/New England region, females can live up to 46 years and males to 39 years (Turner 1986). SEDAR25 (2011) agreed upon a maximum age of 40 years according to a study conducted by Palmer et al. (2004) in the southeastern Atlantic. A recent study concluded that the longevity of this species off Florida in the Atlantic is estimated at 26 years using a lead-radium dating technique (Lombardi-Carlson and Andrews 2015). Size and age at 50% maturity is 344 mm total length (TL) at age two (SEDAR 2011). Females mature between five to seven years of age at a fork length (FL) of 50 cm and can release between 2-8 million eggs per spawning event. Males generally mature at about five years and 50 cm FL; however, some males delay participation in spawning. Virtually all males develop ripe testes by six to seven years of age and 65 cm to 70 cm FL (Grimes and Turner 1999). Spawning in the Mid-Atlantic and South Atlantic occurs between March to November and in the Gulf of Mexico from January to June.
Generation length = Age of first reproduction + (z * Length of the reproductive period) (IUCN Standards and Petitions Subcommittee 2014). Length of the reproductive period = Longevity - Age of first reproduction; z = 0.5; Longevity = 26 years; Age of first reproduction= (5+7)/2 = 6 years. Therefore, generation length = 16 years [6+(0.5*(26-6))].
According to SEDAR4 (2004), the female generation time was estimated to be 23.6 years, while SEDAR25 (2011) reported it as 20 years. We used the generation length of 16 years based on new data on longevity using improved ageing methodology (Lombardi-Carlson and Andrews 2015), which were not available for earlier SEDAR reports.
|Generation Length (years):||16|
|Use and Trade:||Lopholatilus chamaeleonticeps supports important commercial and recreational fisheries and is marketed fresh or frozen for its high quality white flesh. The recreational fishery is much smaller than the commercial fishery, but may increase in the future as catches of the more highly valued snapper-grouper species are restricted. Most of the commercial harvest is landed by longline in the Mid-Atlantic region, with a smaller amount by otter trawl; longlines and handlines are utilized in the South Atlantic and Gulf of Mexico (Grimes et al. 1980). Off Mexico, tilefishes are captured using handlines and gillnet methods; it is also taken as bycatch in longline fisheries targeting groupers (SAGARPA 2012).|
|Major Threat(s):||This species is long-lived and does not range far from the nest/pueblo it builds; these characteristics along with the fact this species is highly valued by commercial and recreational fishers, makes it highly susceptible to overexploitation and rapid population declines. There is a clear 20 to 25 year cycle of increasing and declining catches of Lopholatilus chamaeleonticeps, which is most likely a result of overfishing (Grimes and Turner 1999). Fish are harvested well before their size of first maturity, which decreases the chance for successful recruitment (Hightower and Grossman 1989).|
The U.S. tilefish fishery is regulated through individual fishing quota programs, recreational aggregate bag limits (4 fish), gear restriction, bycatch reporting methodologies for logbooks and observer programs, moratoria/commercial fisheries closures when needed (SEDAR 2011). Conservation measures that effectively reduced catch by one-third were implemented in 2007 in order to recover South Atlantic populations that were overfished since the 1980s. In the Gulf of Mexico, tilefishes were added to the Fishery Management Plan for the reef fish fishery with the passing of Amendment 1 in 1990, under the authority of the Gulf of Mexico Fishery Management Council. Management is not species-specific. The tilefish fishery off the eastern United States (which covers multiple species) was originally an open-access fishery, however, a Fishery Management Plan was put in place on 1 November 2001 which applies to Virginia/North Carolina. Tilefish south of North Carolina are managed under the Southern Atlantic Fishery Management Council's FMP for the Snapper-Grouper Fishery. The key measures taken by the Fishery Management Plan included a 10-year stock rebuilding schedule; a commercial quota divided into full-time, part-time and incidental categories; a trip limit for the incidental category; and limited entry for the full-time and part-time categories. The tilefish FMP became experimental as it did not expect cooperation nor was there a consequence for lack of cooperation. The FMP originally qualified 51 vessels for tilefish fishing, however, this number has gradually declined to 30 vessels. An annual Total Allowable Landings quota was established as well as a limited access program which established three permit categories (Rountree et al. 2008). An individual fishing quota (IFQ) program was implemented for the grouper and tilefish fisheries in 2010 (Scott-Denton et al. 2011).
The South Atlantic Fishery Management Council designated eight marine protected areas between Cape Hatteras, North Carolina, USA and the Florida Keys to protect seven species of the deepwater snapper-grouper complex in February 2009. These consist of five species of grouper and two tilefishes, including Lopholatilus chamaeleonticeps and C. microps. Managers have closed four deep water canyons in the Mid-Atlantic to bottom-tending mobile gear (including otter trawls) in order to protect tilefish habitat.
Tilefishes are considered data-poor for stock assessment purposes, and therefore, have many research needs. Research priorities for the Gulf of Mexico stock include: improving abundance indices, stock definition and structure, and life history components (SEDAR 2011).
|Citation:||Aiken, K.A., Collette, B., Dooley, J., Kishore, R., Marechal, J., Pina Amargos, F. & Singh-Renton, S. 2015. Lopholatilus chamaeleonticeps. The IUCN Red List of Threatened Species 2015: e.T16545046A16546277.Downloaded on 21 September 2018.|
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