Golden Tilefish, Lopholatilus chamaeleonticeps,
are distributed in the Northeast Atlantic along the outer continental
shelf from Nova Scotia to South America, and are relatively abundant
in the Southern New England to Mid-Atlantic region at depths of
80 to 440 m (44 to 240 fathoms). Golden tilefish have a narrow
temperature preference of 9° to 14° C and generally occur
in and around submarine canyons where they occupy burrows in the
sedimentary substrates. Golden tilefish are relatively slow growing
and long-lived with a maximum observed age and length for females
of 46 years and 110 cm (43.3 in.), and 39 years and 112 cm (44.1
in.) for males. At lengths exceeding 70 cm (27.6 in.), the predorsal
adipose flap, characteristic of the species, is larger in males
and can be used to distinguish the sexes. Golden tilefish of both
sexes are mature at ages of 5 to 7 years (Grimeset al.
1988).
The Mid-Atlantic Fishery Management Council
implemented the Golden tilefish Fishery Management Plan (FMP)
in November of 2001. Rebuilding of the Golden tilefish stock to
Bmsy was based on a ten-year constant harvest quota
of 905 mt. The northern Golden tilefish unit stock is defined
as statistical areas north of Cape Hatteras to the Hague line
along the shelf break (Figure
21.1). The information provided herein reflects the results
of the most recent peer-reviewed assessments for the Golden tilefish
stock (NEFSC 2005)
The
Fishery
Total commercial landings (live
weight) increased from less than 125 mt during 1967-1972 to more
than 3,900 mt in 1979 and 1980(Figure
21.2[Fig
21.2 Data]). Landings stabilized at about 2,000 mt
during 1982-1986, increased to 3,200 mt in 1987 but declined to
450 mt in 1989. During 1988-2001, annual landings ranged between
454 and 1,838 mt. An annual quota of 905 mt was implemented in
November of 2001. Landings in 2003 and 2004 exceeded the quota
at 1,130 and 1,215 mt respectively (Table 21.1).
Since the 1980s, over 85% of the commercial landings of Golden
tilefish in the MA-SNE region have been taken in the longline
fishery. During the late 1970s and early 1980s Barnegat, NJ was
the principal Golden tilefish port; more recently Montauk, NY
has accounted for most of the landings.
Estimates of recruitment do
not exist. However, strong year classes (1993 and 1999 cohorts)
can be seen in the commercial length frequency distributions.
Most of the landings between 2002 and 2004 were from the strong
1999 year class (Figure
21.3[Fig
21.3 Data]).
CPUE Indices
A fishery independent index
of abundance does not exist for Golden tilefish. However, three
different time series of commercial longline catch per unit effort
(CPUE) indices are available. The first series was developed by
Turner (1986) who used a general linear modeling approach to standardize
tilefish effort during 1973-1982 obtained from logbooks of tilefish
fishermen. Two additional CPUE series were calculated from the
NEFSC weighout data (1979-1993) and vessel trip report data (VTR,
1995-2004). CPUE values declined from the mid-1970s to the early
1990s, briefly increased and declined in the late 1990s, and have
increased since 2000 (Figure
21.2
[Fig 21.2 Data]). The commercial landings at lengths suggests
that this recent increase in CPUE is due to the strong 1999 year
class.
Figure
21.2
Figure 21.3
Figure
21.4
Figure 21.5
Assessment
Results
A surplus production model (ASPIC) was used
in the 2005 Golden tilefish stock assessment (SARC 41). The
ratio F/Fmsy exceeded 1.0 during 1978-1988, fluctuated below
and above 1.0 during 1989-1998, and has since been below 1.0
(Figure
21.4[Fig
21.4 Data]). The ratio of B/Bmsy was above
1.0 in the 1970s. B/Bmsy was below 0.5 from 1988
through 2001, but increased to 0.72 in 2005.
Biological Reference Points
Biological reference points were last calculated
at SARC 41 (NEFSC 2005) and are presented in Table
21.2. The updated biological reference points in SARC 41
did not change greatly from the original estimates used for
the development of the Golden tilefish fishery management plan.
Both the age and length based YPR model estimated Fmax
at 0.14 (Figure
21.5[Fig
21.5 Data]).
Summary
The biomass of Golden tilefish has increased
and in 2005 the B/Bmsy ratio was 0.72. The F/Fmsy
ratio in 2004 was below 1.0 (0.87). Thus, the stock is not in
a overfished condition and overfishing is not occurring.
Grimes, C. B., C. F. Idelberger, K. W. Able,
and S. C. Turner. 1988. The reproductive biology of tilefish, Lopholatilus
chamaeleonticeps Goode and Bean, from the United States
Mid-Atlantic Bight, and the effects of fishing on the breeding
system. Fish. Bull., U.S. 86(4):745-776.
NEFSC [Northeast Fisheries Science Center].
1993. Report of the 16th Northeast Regional Stock Assessment
Workshop (16th SAW), Stock Assessment Review Committee (SARC)
consensus summary of assessments. Northeast Fish. Sci. Cent.
Ref. Doc. 93-18. 116 p.
Turner, S. C., C. B. Grimes, and K. W. Able.
1983. Growth, mortality, and age/size structure of the fisheries
for tilefish, Lopholatilus chamaeleonticeps, in
the Middle Atlantic-Southern New England region. Fish. Bull.,
U.S. 81(4):751-763.
Turner, S.C. 1986. Population dynamics of
and impact of fishing on tilefish, Lopholatilus chamaeleonticeps,
in the Middle Atlantic-Southern New England region during
the 1970s and early 1980s. New Brunswick, N.J.: Rutgers University.
Ph.D. dissertation.
Nitschke, P., G. Shepherd, and M. Terceiro.
1998. Assessment of tilefish in the Middle Atlantic-Southern
New England Region. Northeast Fish. Sci. Cent. Report to
the Science and Statistics committee.