The haddock, Melanogrammus aeglefinus,
is a commercially-exploited groundfish found in the northwest
and northeast Atlantic Ocean. This demersal gadoid species is
distributed from Cape May, New Jersey to the Strait of Belle Isle,
Newfoundland in the northwest Atlantic (Collette and Klein-MacPhee
2002), where a total of six distinct haddock stocks have been
identified (Begg 1998). Two of these haddock stocks are found
in U.S. waters: Georges Bank and Gulf of Maine (Brodziak 2005).
The Georges Bank haddock stock is found in the shallow productive
waters of Georges Bank while the Gulf of Maine stock inhabits
waters of the southwestern Gulf of Maine (Figure
2.1). Both stocks support important commercial fisheries (Clark
et al. 1982, Brown and Munroe 2000, Brodziak et al. 2002,
Brodziak et al. 2006). Commercial fishing for haddock
occurs year round in U.S. waters. Otter trawl fishing gear produces
the majority of haddock landings, while the remainder of the catch
is taken with longlines or gill nets.
Recreational catches are relatively minor and amount to roughly
1%-2% of commercial catches in recent years. Most of the recreational
haddock catch is taken with hook and line gear in the Gulf of
Maine region during spring to late-autumn.
Adult haddock range in length
from 30 cm to up to a maximum size of about 1 meter. The largest
haddock captured in U.S. waters weighed 13.6 kg (Collette and Klein-MacPhee
2002). The oldest recorded haddock in the U.S. waters was a 17 year
old fish captured during a 1980 NEFSC research survey. Most of the
U.S. commercial haddock catch comprises age-3 to age-7 fish weighing
between 1 to 3 kg. Haddock reach sexual maturity between ages 1
to 4. In recent years, the median age of maturity for females has
been 1.8 years. Haddock spawning occurs from January to June and
peaks during February to early-April on Georges Bank, the primary
spawning area (Brodziak 2005). Haddock are primarily an offshore
groundfish and are commonly found at depths of 40 to 150 m (23 to
82 fathoms). Adult haddock can be found at temperatures of 0-13°C
but generally prefer temperatures of 2° to 9°C (36°
to 48°F). Juvenile haddock tend to occupy shallower water on
bank and shoal areas, while large adults are more commonly found
in deeper water. Adult haddock undertake seasonal movements in the
western Gulf of Maine, the Great South Channel and on the northeast
peak of Georges Bank, spending much of winter in deeper waters and
moving to shoaler waters in spring to spawn.
Adult haddock are benthic feeders.
They have a diverse diet that includes gastropod and bivalve
mollusks, polychaete worms, amphipods, crabs, shrimps, sea stars,
sea urchins, sand dollars, brittle stars, and occasional fish
eggs (Brodziak 2005). Adult haddock will sometimes consume small
fishes, especially herring. Pelagic larvae and small juvenile
haddock feed on phytoplankton, copepods, and invertebrate eggs
in the upper part of the water column. Juvenile haddock eat small
crustaceans, primarily copepods and euphausiids, as well as polychaetes
and small fishes. Juveniles make a transition from pelagic to
demersal habitat at ages from 3 to 5 months. Juvenile haddock
are eaten by elasmobranchs (spiny dogfish and skates) and many
groundfish species (cod, pollock, cusk, white hake, red hake,
silver hake, goosefish, halibut, and sea raven). Gray seals also
prey on haddock.
Growth rates of haddock have fluctuated
over the past 50 years. During the 1960s, an age-4 haddock averaged
48-50 cm (19-20 in.). During the 1980s and 1990s when stock sizes
were lower, size at age increased and an age-3 fish averaged about
48-50 cm in length. In recent years growth rates have slowed, with
haddock reaching 48 to 50 cm at age 4. On Georges Bank, haddock
growth appears to be density-dependent, with reductions in mean
lengths at age across age classes as stock size has increased in
recent years (Brodziak et al. 2006). Commercial fishery mean weights
at age of Georges Bank haddock during 2001-2004 were below their
long-term average for all age classes, with decreases ranging from
7% to 44%.
Haddock maturation rates have
also changed through time. During the early 1960s, all females of
age 4 and older were sexually mature and 75% of age-3 females were
mature. Size at maturity of Georges Bank haddock has declined in
recent years (O’Brien et al. 1993; Trippel et al. 1997). For
example, median length of maturity for females was about 40 cm during
1977-1983 but declined to about 34-36 cm in the early-1990s. Since
1998, virtually all age-3 females and 50% of age-2 females are mature
(Brodziak et al. 2006). Although earlier maturation will increase
spawning stock biomass, the actual reproductive success of first-spawning
haddock has not been documented.
Haddock are highly fecund broadcast
spawners that spawn over rock, gravel, sand, or mud bottom. An average-sized
female (55 cm, 22-in.) produces approximately 850,000 eggs. Larger
females are capable of producing up to 3 million eggs annually.
Haddock spawning is concentrated on the northeast peak of Georges
Bank. The western edge of Georges Bank also supports a smaller spawning
concentration (Walford 1938). The two spawning components are persistent
and exhibit phenotypic differences in otolith morphometrics (Begg
et al. 2000). Spawning concentrations also occurred historically
along the Maine coast. Females release eggs near the ocean bottom
in batches where they are fertilized by a courting male. After fertilization,
haddock eggs become buoyant and rise to the surface water layer
where they drift with ocean currents. Juvenile haddock are pelagic
for 3-5 months after hatching and settle to the bottom at a size
of roughly 10 cm.
The U.S. fishery for haddock is
managed by the New England Fishery Management Council under the
Northeast Multispecies Fishery Management Plan (FMP). Haddock are
jointly managed with a complex of 15 groundfish species under this
FMP (NEFMC 2003). Management measures have included fishing area
closures, gear restrictions, trip limits, and minimum size limits.
Since 1994, direct fishing effort controls have been in place including
a moratorium on permits and days-at-sea restrictions under Amendments
5 and 7 to the FMP. Amendment 9 to the FMP established initial biomass
rebuilding targets and a harvest control rule to specify target
fishing mortality rates. In May 2004, Amendment 13 to the FMP was
implemented. Amendment 13 implemented formal rebuilding plans for
New England groundfish stocks, including haddock, based on revised
biomass and fishing mortality targets derived by the Working Group
on Re-evaluation of Biological Reference Points for New England
Groundfish (NEFSC 2002). The overall goal of Amendment 13 is to
reduce fishing mortality to rebuild depleted groundfish stocks to
target biomasses. In addition, a formal quota sharing agreement
between Canada and the U.S. was implemented in 2004 to share the
harvest of haddock in the transboundary eastern Georges Bank haddock
management unit. This agreement includes total allowable catch quotas
for each country as well as in-season monitoring of the U.S. catch
of haddock on eastern Georges Bank. The Canadian fishery on Georges
Bank is managed under an individual quota system.
Total commercial haddock landings
(U.S. and Canada) from the Georges Bank and Gulf of Maine stocks
increased to 22,032 mt in 2005, a 18% increase from 18,604 mt in
2004. The 2005 haddock catch is the highest total catch since 1983
(19,606 mt) and almost 9-fold greater than the record low of 2,533
mt in 1995. U.S. commercial haddock landings decreased to 7,542
mt in 2005, down 14% from 8,766 mt in 2004. Despite recent increases
in haddock yields, current landings are less than 1/3 of the long-term
potential yield of the combined Gulf of Maine and Georges Bank haddock
stocks. The information provided herein reflects the results of
the most recent peer-reviewed assessments for the Gulf of Maine
and Georges Bank haddock stocks (Brodziak and Traver 2005, Brodziak
et al. 2006).
GULF OF MAINE HADDOCK
The total commercial fishery landings
of Gulf of Maine haddock were 1,435 mt in 2005, a 41% increase from
1,021 mt in 2004 (Table 2.1, Figure
2.2 Data]). Annual commercial landings averaged 1,200 mt during
2001-2005; this was the highest 4-year average since the mid-1980s.
Although commercial landings of Gulf of Maine haddock have increased
since the mid-1990s, they are less than one-quarter of the long-term
potential yield (5,100 mt) (NEFSC 2002) and below historic yields
realized during the 1950s-1960s and early-1980s (Figure
Recreational fishery landings
of Gulf of Maine haddock totaled 240 mt in 2005, a 2% increase from
235 mt in 2004 (Table 2.1). Prior to 2000,
recreational landings were a relatively minor component of the Gulf
of Maine haddock yield. Since 2001, recreational fishery catches
have increased to average 204 mt per year and have ranged from 12%
to 19% of the total annual yield.
Research Vessel Survey
The NEFSC autumn bottom trawl
biomass index is used to track the relative abundance of the Gulf
of Maine haddock stock (Figure
2.3 Data]). The NEFSC spring survey biomass index exhibits similar
trends but is less responsive to changes in haddock abundance in
the Gulf of Maine region. The relative abundance of Gulf of Maine
haddock decreased from the late-1970s through early-1990s. The NEFSC
autumn survey biomass index declined from 1978 to a record low in
1992 (0.1 kg per tow). Biomass increased to a peak of 14.0 kg/tow
in 2000 and has declined to about half that level in 2004 (Figure
2.3 Data]). The 2005 biomass index (3.9 kg/tow) is roughly 1/5
of the target biomass of 22.2 kg/tow..
NEFSC autumn survey number
per tow at age indices track changes in the age composition of the
Gulf of Maine haddock stock through time (Figure
2.4 Data]). Relative abundance was high in the 1960s, in part
due to the strong 1962 and 1963 year classes. Relative abundance
declined in the early 1970s as the stock was overfished and recruitment
declined. Stock size at age increased briefly in the late-1970s
due to improved recruitment, particularly the strong 1975 and 1976
year classes. Relative abundance at age declined again in the early-1980s
and reached a record low in 1991. Since then, recruitment has improved
and relative abundance has increased, in part due to the recruitment
of the strong 1998 year class. In 2000, the total autumn survey
number per tow index (16.6 fish per tow) was at the highest level
observed since 1965. While the total number per tow index has since
declined to 5.7 fish per tow in 2004, the current relative abundance
at age indices are 10-fold higher than when the stock collapsed
in the early-1990s.
The status of the Gulf of Maine haddock
stock is assessed based on research vessel survey indices and
commercial landings (Brodziak and Traver 2005). Overfishing status
is evaluated using a fishing mortality rate index calculated as
the ratio of annual commercial landings (in weight) to the 3-year
average of the NEFSC autumn survey biomass index (NEFSC 2002).
Overfishing occurs when the fishing mortality index exceeds FMSY=0.23.
Fishing mortality (F) on Gulf of Maine haddock fluctuated between
0.08 and 0.34 during 1963-1976 (Figure
2.5 Data]). F subsequently increased to a peak of 1.22 in
1983 and then declined to a low of 0.17 in 1989. F increased again
to over 0.85 during 1991-1994 but has since decreased and has
remained lower than FMSY since 2000. In 2004, the fishing
mortality index was F=0.18.
The Gulf of Maine haddock stock is classified
as overfished when the 3-year average NEFSC autumn biomass index
falls below 11.1 kg per tow, which is one-half of the BMSY
proxy of 22.2 kg per tow (Brodziak and Traver 2005). Stock biomass
was above the overfished threshold in the 1960s but eventually
declined in the late-1960s and the stock was in an overfished
condition in 1971 (Figure
2.6 Data]). The stock remained overfished until 1978 when
the strong 1975-1976 year classes recruited to the fishery. Stock
biomass remained above the overfished threshold for 2 years and
subsequently declined. The stock has been in an overfished condition
since 1981. In 2004, the biomass index was 5.8 kg per tow, roughly
26% of the BMSY target.
of Gulf of Maine haddock, as indexed by the NEFSC autumn survey,
has been intermittent since the 1960s (Figure
2.6 Data]). Two strong year classes were produced in the early-1960s
(the 1962 and 1963 year classes). Recruitment then declined and
remained low until the 1970s when several strong year classes appeared.
Recruitment declined again in the 1980s and remained low until the
late-1990s when the strong 1998 year class was produced. Since 2000,
recruitment has again decreased to low levels. In particular, the
abundance of the 2003 year class of Gulf of Maine haddock appears
to be average, in contrast to the exceptional abundance of the 2003
year class of Georges Bank haddock.
Biological Reference Points
Biological reference points for
the Gulf of Maine haddock stock were determined by the Working Group
on Re-evaluation of Biological Reference Points for New England
Groundfish (NEFSC 2002). The Working Group used catch and survey
data from the 2001 assessment to estimate survey-based proxies for
MSY-based reference points (Table 2.2). These
estimates were: MSY=5,100 mt, BMSY=22.2 kg per tow using
the 3-year average of the NEFSC autumn survey biomass index, and
FMSY=0.23 thousand mt/kg per tow using the 3-year average
of the NEFSC autumn survey biomass index.
Although Gulf of Maine haddock
abundance has increased since the mid-1990s, stock biomass remains
low in comparison to BMSY. Fishing mortality on Gulf
of Maine haddock has remained below FMSY since 2000 although
F increased in 2003-2004. Overall, the Gulf of Maine haddock stock
remains in an overfished condition although overfishing is not currently
The Georges Bank haddock stock
has been commercially exploited since the 19th century with reliable
landings statistics available beginning in 1904 (Figure
2.7 Data]). Since then, the fishery for Georges Bank
haddock has gone through seven periods: (1) the initial expansion
from 1904-1923 when annual landings averaged 17,400 mt; (2) the
rapid expansion and decline during 1924-1930 when landings averaged
73,200 mt; (3) the thirty-year period of fishery stability during
1931-1960 when annual landings averaged 46,300 mt; (4) the rapid
expansion and decline during 1961-1968 when landings averaged 73,000
mt and foreign distant water fleets began to harvest the resource;
(5) the pre-Hague line fishery during 1969-1984 when landings averaged
about 13,500 mt; (6) the fishery nadir during 1985-2000 when landings
averaged only 5,600 mt (Table 2.3); and (7)
the nascent recovery from 2001-2005 when annual landings have increased
to average 15,000 mt per year (Table 2.3).
Landings have generally increased each year since 1995 as the stock
has been rebuilding under restrictive management measures. In 2005
total commercial landings were 20,597 mt, almost 9-fold larger than
the lowest recorded landings in 1995. U.S. landings in 2005 were
6,107 mt, a 21% decrease from 7,746 mt in 2004. The U.S. fishery
accounted for approximately 30% of the total Georges Bank haddock
landings in 2005.
The commercial fishery landings
of Georges Bank haddock has been primarily composed of age-3 and
older fish (Figure
2.8 Data]). During the 1960s, the exceptional 1963 and
strong 1962 year classes dominated the commercial fishery while
the strong 1975 and 1978 year classes dominated catches in the late-1970s
to early-1980s. In recent years, the strong 1998 and 2000 year classes
have produced the majority of the fishery yield in each subarea
of Georges Bank (Figure
Research Vessel Survey Indices
survey data provide relative abundance indices for the Georges Bank
haddock stock from the 1960s to the present. The NEFSC spring and
autumn biomass indices exhibit similar trends through time (Figure
2.9 Data]). Both indices show the long-term decline in
stock biomass that has occurred since the 1960s. Both spring and
autumn indices both increased in the mid-1970s due to the strong
1975 and 1978 year classes and then declined in the early 1980s.
Autumn indices declined from record highs in the 1960s to low levels
in the early-1970s. The NEFSC autumn survey index series averaged
53 kg/tow during 1963-1968, declined to15 kg/tow during 1969-1984,
and declined further to 6 kg/tow during 1985-2000. Similarly, the
NEFSC spring survey index series averaged 19 kg/tow during 1968-1984
and then declined by more than 50% to an average of 8 kg/tow during
1985-2000. Both spring and autumn survey indices have increased
in recent years as stock biomass has begun to rebuild. Since 2001,
the autumn survey index has averaged 35 kg/tow while the spring
index has averaged 21 kg/tow.
The NEFSC autumn catch per tow at
age shows how the age composition of the Georges Bank haddock
stock has changed since 1963 (Figure
2.10 Data]). In the mid-1960s, the age structure
included a full range of age groups and was dominated by the 1963
year class. In the late-1960s to early-1970s the stock collapsed
due to overfishing which led to an absence of older fish and low
2.10 Data]). The stock rebounded in the late-1970s
due to the recruitment of the strong 1975 and 1978 year classes.
Subsequently stock abundance declined and recruitment decreased
in the 1980s. By the early-1990s, the age structure of the stock
was truncated and included few fish of age-4 and older. In the
late-1990s, stock size began to increase at low fishing mortality.
Since then, the stock has been rebuilding and the current age
composition is dominated by the exceptional 2003 year class (Figure
Fishing mortality on Georges Bank haddock
has changed substantially since the 1970s (Brodziak et al.
2006). Fishing mortality fluctuated around 0.4 during the early-1970s
2.11 Data]). F declined to less than
F=0.13 during 1974-1976 but increased again in the mid-1970s.
and remained above the overfishing threshold FMSY=0.26
during 1979-1994. F increased over 5-fold in the mid-1980s and
averaged 0.35 during 1985-1994. F declined to one-half FMSY
in 1995 coincident with the imposition of restrictive fishery
management measures. Since 1995, fishing mortality has remained
below the overfishing threshold although F has increased 33%
from F=0.18 in 2001 to F=0.24 in 2004.
Georges Bank haddock spawning biomass
also changed substantially over the past several
2.12 Data]). Spawning
biomass peaked in the 1960s averaging 132 kt during
1963-1968, declined to a near-record low of 15 kt
in 1973, and averaged only 27 kt during 1969-1974.
Spawning biomass increased moderately to average
48 kt during 1975-1984 and then declined again, averaging
only 23 kt during 1985-1994, with a record low of
14.6 kt in 1993. During the mid-1990s, spawning biomass
increased. Since 2001 spawning biomass has approached
levels observed in the 1960s and averaged 115 kt
during 2001-2004. Spawning biomass increased by 22%
from 96 kt in 2001 to 117 kt in 2004.
Georges Bank haddock recruitment
(stock size at age 1) fluctuated substantially
during 1963-2005 ranging from a low of 0.3 million
age-1 fish in 1971 to a high of 789 million in
2.12 Data]). Recruitment
during 1963-1968 averaged 117 million fish and
was dominated by the exceptional 1963 year class
(462 million age-1 fish). Recruitment declined
to average only 8 million fish during 1969-1974,
but subsequently increased and averaged 26 million
fish during 1975-1984, primarily due to the strong
1975 (106 million) and 1978 (84 million) year classes.
Recruitment averaged only 8 million fish during
1985-1994, but increased to average 22 million
fish during 1995-2000. Since 2001, recruitment
has averaged 179 million fish. In particular, the
1998 (47 million) and 2000 (91 million) year classes
are strong, while the 2003 year class (789 million)
currently appears to be one of the largest observed.
Biological Reference Points
Yield and spawning biomass per recruit and
MSY-based reference points for Georges Bank haddock were last
derived by the Working Group on the Re-evaluation of biological
Reference Points for New England Groundfish (NEFSC 2002). These
reference points have used in all stock assessments since 2002
(Brodziak et al. 2002, Brodziak et al. 2006). The Working Group
used analytical results from the 2001 assessment to estimate
these reference points (Table 2.4, Figure
2.13 Data]). The yield and spawning
biomass per recruit estimates were: F0.1 = F40%
= 0.26, and FMAX>1. The MSY-based reference
points were: MSY = 52,900 mt, BMSY = 250,300 mt,
and FMSY = 0.26. For the purpose of stock status
determination, the overfished threshold for Georges Bank haddock
is BTHRESHOLD = ½ BMSY = 125,200
mt, while the overfishing threshold is FTHRESHOLD
= FMSY = 0.26.
Analyses of stock-recruitment data (Figure
2.14 Data]) indicate that spawning
stock size affects recruitment of Georges Bank haddock (Brodziak
and Legault 2005; Brodziak et al. 2001, NEFSC 2002). For example,
Brodziak et al. (2001) found that when spawning stock biomass
is above 82 kt, the odds of recruitment being above average
is 20 times greater than when biomass is below 82 kt and the
average year class size is 5-fold higher. Thus, recruitment
is higher, on average, when spawning biomass exceeds a threshold
value. The Working Group on the Re-evaluation of Reference Points
for New England Groundfish determined that an appropriate productivity
threshold for Georges Bank haddock was 75 kt of spawning biomass
2.14 Data]). Above this threshold,
average recruitment is 96 million age-1 fish while below this
threshold averagerecruitment is about 21 million fish. When
spawning biomass is above 75 kt, the odds of achieving recruitment
above the 1931-2005 median value are 23 times greater than when
spawning biomass is below 75kt.
Survival ratios of Georges Bank
haddock, as indexed by recruitment per spawning biomass, fluctuated
about an average of 0.72 recruits per kg (R/S) during 1931-2004
2.15 Data]). Survival ratios averaged 0.77 R/S during 1931-1960
when spawning biomass averaged 102 kt. Since then survival ratios
have declined 12% on average to 0.68 R/S with a standard error of
0.18 during 1961-2004 when spawning biomass averaged 64 kt. Since
1961, three strong year classes 1963, 1975, and 2003) have had survival
ratios of roughly 3 or higher (Figure
2.15 Data]). Each of these year classes experienced very high
survival during early life history stages, suggesting the influence
of favorable environmental conditions in inducing large recruitment
events. Spawning biomass also affects survival ratios as survival
ratios average 0.82 when spawning biomass is above 75 kt in comparison
to only 0.59 (-28%) when spawning biomass is below 75 kt.
The response of the Georges Bank
haddock to reductions in fishing mortality during the 1990s was
marked. Under persistent overfishing in the 1980s, spawning biomass
declined from 67,400 mt in 1980 to only 14,600 mt in 1993. Since
1994, spawning biomass has increased substantially as fishing mortality
has declined. However, even though stock size has increased substantially
in recent years, the Georges Bank haddock stock is still in an overfished
condition since spawning biomass in 2004 was only 116,800 mt (93%
of BTHRESHOLD), less than half of the rebuilding target.
Fishing mortality in 2004 was 0.24 (92% of FTHRESHOLD)
and as a result, overfishing is not occurring on the Georges Bank
Prospects remain positive for
continued high recruitment as spawning biomass is currently above
the 75 kt threshold. Recent U.S. and Canadian assessments and research
survey data suggest that the 2003 year class is exceptionally abundant.
This year class has the potential to rebuild the stock to BMSY
in a few years if fishing mortality remains below FMSY.
If the recent increases in recruitment and survival can be sustained,
it is possible that historic yields on the order of 50,000 mt per
year can be attained.
Begg, G.A. 1998. A review of
stock identification of haddock, Melanogrammus aeglefinus,
in the northwest Atlantic Ocean. Mar. Fish. Rev. 60: 1-15.
Begg, G.A., W.J. Overholtz, and
N.J. Munroe. 2000. The use of internal otolith morphometrics for
identification of haddock (Melanogrammus aeglefinus) stocks
on Georges Bank. Fish. Bull. (U.S.) 99: 1-14.
Brodziak, J. K. T., W. J. Overholtz,
and P. J. Rago. 2001. Does spawning stock affect recruitment of
New England groundfish? Can. J. of Fish. Aquat. Sci. 58:306-318.
Brodziak, J. 2005. Essential
fish habitat source document: Haddock, Melanogrammus aeglefinus,
life history and habitat characteristics, 2nd edition. NOAA Tech
Mem. NMFS-NE-196, 74 pp.
Brodziak, J. K. T., and C. Legault.
2005. Model averaging to estimate rebuilding targets for overfished
stocks. Can. J. Fish. Aquat. Sci. 62:544-562.
Brodziak, J. and M. Traver. 2005.
Gulf of Maine haddock. In: Northeast Fisheries Science Center. 2005.
Assessment of 19 Northeast groundfish stocks through 2004: a report
of the Groundfish Assessment Review Meeting (2005 GARM), Northeast
Fisheries Science Center, Woods Hole, Massachusetts, 15-19 August,
2005. Northeast Fisheries Science Center Ref. Doc. 05-13. p. 415-423.
Brodziak, J., M.Traver, L. Col,
and S. Sutherland. 2006. Stock assessment of Georges Bank haddock,
1931-2004. Northeast Fisheries Science Center Ref. Doc. 06-11, NEFSC,
Woods Hole, MA 02543.
Brown, R. W., and N. J. Munroe.
2000. Stock assessment of Georges Bank haddock, 1931-1999. Northeast
Fisheries Science Center Ref. Doc. 00-12, NEFSC, Woods Hole, MA
Clark, S. H., W. J. Overholtz,
and R. C. Hennemuth. 1982. Review and assessment of the Georges
Bank and Gulf of Maine haddock fishery. J. Northw. Atl. Fish. Sci.
B. B., and G. Klein-MacPhee (Editors). 2002. Bigelow and Schrodeder’s
Fishes of the Gulf of Maine. 3rd Edition. Smithsonian Institution
[NEFMC] New England Fishery Management
Council. 2003. Final amendment 13 to the Northeast Multispecies
Fishery Management Plan including a final supplemental environmental
impact statement and an initial regulatory flexibility analysis.
NEFMC. [Newburyport, MA] 1659 p.
NEFSC. 2002. Final report of the
working group on re-evaluation of biological reference points for
New England groundfish. Northeast Fisheries Science Center Ref.
Doc. 02-04. 249 p.
L., J. Burnett, and R.K. Mayo. 1993. Maturation of nineteen species
off the northeast coast of the United States, 1985 1990. NOAA Tech.
Rep. NMFS 113. 66 p.
Trippel, E.A., M.J. Morgan, A.
Frochet, C. Rollet, A. Sinclair, C. Annand, D. Beanlands, and L.
Brown. 1997. Changes in age and length at sexual maturity of northwest
Atlantic cod, haddock and pollock stocks, 1972-1995. Can. Tech.
Rep. Fish. Aquat. Sci. 2157. 120 p.
Walford, L.A. 1938. Effects of
currents on distribution and survival of the eggs and larvae of
the haddock (Melanogrammus aeglefinus) on Georges Bank.
Bull. U.S. Bur. Fish. 49(20): 1 73.