UNIT 2: NORTHEAST PELAGIC FISHERIES

INTRODUCTION

	Northeast pelagic or mid-water fisheries are highly seasonal,
reflecting the migratory patterns of schooling fishes including
Atlantic herring, Atlantic mackerel, butterfish, bluefish, and two
species of squids. All of these species winter on the Middle
Atlantic shelf and undergo northward and inshore migrations in the
spring and summer. Landings are derived with a variety of fishing
gears including off-bottom and bottom trawls, gill nets, and
seines. Commercial landings of pelagic fishes off the U.S.
northeast coast have averaged 142,000 t since 1990, while
recreational landings (primarily bluefish and mackerel) in 1992
were about 17,000 t. In 1992, the commercial landings produced
about $49 million in dockside revenue, of which the squids
accounted for the greatest proportion ($33 million). Bluefish and
mackerel are important to recreational fisheries of the region:
Approximately $345 million is spent annually to fish for bluefish
alone.
	Most of the northeast pelagic resources were heavily exploited by
foreign fleets during the 1970's, in most cases resulting in rapid
declines in stock sizes and yields. Subsequently, however, there
has been little U.S. interest in stocks such as mackerel, resulting
in rapidly increasing abundance. The pelagic stocks are managed
under two Federal FMP's of the Mid-Atlantic Council: the Mackerel,
Squid, and Butterfish FMP and the Atlantic Bluefish FMP. Atlantic
herring are managed under the auspices of the Atlantic States
Marine Fisheries Commission.

SPECIES AND STATUS

	The U.S. northeast midwater fisheries are dominated by six species:
Atlantic mackerel, Atlantic herring, butterfish, bluefish, and two
squids: Long-finned (Loligo) and short-finned (Illex). Four of the
stocks are considered underfished (mackerel, herring, Illex squid,
and butterfish). 
	The long-term population trends for herring and mackerel, the
principal pelagic species, have fluctuated considerably during the
last 25 years (Fig. 2-1). The abundance index reached minimal
levels in the mid-1970's, reflecting pronounced declines for both
species (as well as the collapse of the Georges Bank herring
resource). Both species have been increasing in recent years.
Atlantic mackerel recovered during the 1980's, and stock
assessments indicate a total stock in excess of 2.5 million t.
Mackerel landings in 1992 were very low only 38,300 t. Although
precise estimates of the size of the mackerel stock are not
available, clearly the catch could increase several-fold. Growth,
maturity rates, and productivity have declined as the stock has
grown.
	The total Atlantic herring resource off the northeast U.S. is
considered underutilized. Total landings from the coastwide
Atlantic herring complex of stocks was 91,700 t (U.S. landings were
59,200 t), representing a substantial increase from the 1983 level
(36,400 t total by both countries). The coastal stock
complex comprises two major stock groups in U.S. waters: Gulf of
Maine and Georges Bank. Canadian catches in New Brunswick are also
included in the combined stock analysis, since these fish mix with
U.S. origin herring during portions of the year. The Georges Bank
herring stock was virtually extirpated, following landings of over
370,000 t (1967) and nonsustainable landings levels throughout that
period. There is some indication of a recovery of the Georges Bank
herring stock, based on U.S. and Canadian bottom trawl surveys and
ichthyoplankton investigations and bottom trawl surveys in the
region. The entire stock complex is considered to be increasing in
abundance.
	Of the two squid species, long-finned squid is the most important,
due to the significant international export market (primarily to
Italy and Spain). Recent research indicates that both squid species
have short life spans of roughly one year. Current estimates of
long-term potential yields for these species were based upon a
longer life span and are being reevaluated. At present, Loligo
stock biomass is below its long-term average while Illex stock
biomass is at its long-term average based upon research vessel
surveys. Fishing effort for both species has increased in recent
years. The availability of both species to fishermen, especially
the short-finned squid, changes seasonally.
	Butterfish are likewise considered underexploited, based on current
research survey results and historic landings patterns. Landings of
butterfish have declined significantly in recent years, primarily
due to reduced export demand. The stock is currently being fished
well below its LTPY (Table 2-1).
	Bluefish landings peaked in 1980 at 72,600 t, and have since
declined to an average of 25,300 t in recent years (Table 2-1). The
majority of total landings (over 80%) are by recreational
fishermen. The recent downward trends in recreational and
commercial catches, and the continuing decline in the index of
abundance based on recreational catch per bluefish trip, suggest
that bluefish abundance decreased during the 1980's, and that the
stock is fully exploited.

ISSUES

Scientific Advice and Adequacy of Assessments

	Although historical data on catches and fishing effort are adequate
for assessment purposes, stock assessments for northeast pelagic
resources are relatively imprecise, owing to the highly variable
trawl survey indices of relative abundance used for calibrating
cohort models, to the short life span of some stocks (squids and
butterfish), and to low exploitation rates of some species. More
precise assessments will require the development of hydroacoustic
sampling of pelagic fish stocks, combined with trawling surveys to
separate the different species components. More precise assessments
for short-lived stocks will depend on the availability of more
appropriate survey and commercial performance data.

Underutilized Species

	All of the pelagic stocks except bluefish are considered
underutilized. Recent average yields could be more than doubled and
still not reach the long-term potentials. Current potential yields
are nearly four times the recent average yields (Table 2.1).
Current stock sizes of these underutilized stocks are somewhat
uncertain (see above), but nevertheless potential yields
substantially exceed current landings, even if conservative
stock-size calculations are assumed. 

Bycatch and Multispecies Interactions

	Concentrations of schooling fish such as the northeast pelagics are
utilized by an array of predatory fishes, marine mammals, and
birds. In winter months, fisheries targeted at Atlantic mackerel,
herring, and squids take some marine mammals including pilot whales
and common dolphins. Intensification of these pelagic fisheries to
take advantage of these underutilized resources could result in
greater marine mammal kills. Current large stock sizes of these
pelagic resources may be resulting in increased predation mortality
of larval fishes, particularly due to mackerel predation on Georges
Bank and in southern New England in late winter and spring.