The northern shortfin squid, Illex illecebrosus, is a highly migratory, transboundary species that is distributed in the Northwest Atlantic Ocean from the Florida Straits to Newfoundland (Dawe and Hendrickson 1998). The northern component of the stock, extending from Newfoundland to the southern Scotian Shelf, is assessed annually and managed by the Northwest Atlantic Fisheries Organization (NAFO) based on a total allowable catch (TAC). The southern and U.S. stock component, extending from the Gulf of Maine to Florida (Figure 30.1), has been managed since 1977 by the Mid-Atlantic Fishery Management Council (MAFMC), based on an annual TAC, under the provisions of the Atlantic Mackerel, Squid, and Butterfish Fishery Management Plan (FMP).

The Fishery

The onset and duration of the Illex fisheries reflect the timing of squid migrations through the fishing grounds. During summer through fall, a bottom trawl fishery occurs on the U.S. shelf, primarily in the Mid-Atlantic Bight, and an inshore jig fishery occurs in Newfoundland waters. Prior to 2000, Illex was also caught on the Scotian Shelf in an international mixed-trawl fishery for squid, argentine and silver hake (Hendrickson and Showell 2006). Total stock landings increased rapidly during the 1970s, from 1,600 mt in 1969 to a peak of 179,300 mt in 1979, and were mostly from the northern stock component (Figure 30.2 [Fig 30.2 Data]). After reaching a peak of 162,100 mt in 1979, landings from the northern stock component declined rapidly to 400 mt in 1983 and have since remained at low levels. From 1982 onwards, landings from the U.S. domestic fishery have comprised the majority of the total stock landings and U.S. harvests have ranged between 2,800 mt and 31,500 mt.

During 1968-1982, U.S. EEZ landings of I. illecebrosus were taken primarily by international fleets and landings reached a peak of 24,900 mt in 1976 (Figure 30.3 [Fig 30.3 Data]).There has been no fishing allowed in U.S. waters by international fleets since 1987. Since 1982, U.S. EEZ landings have been taken primarily by the domestic fleet. Most domestic fishery landings are taken during June September, with a peak in July, by vessels using small-mesh bottom trawls fishing near the edge of the continental shelf. U.S. landings increased from 2,000 mt in 1988 to 18,400 mt in 1994. Landings of 23,600 mt were taken in 1998 (Table 30.1) and resulted in a fishery closure because the TAC (19,000 mt) was exceeded. After 1998, landings declined rapidly to 2,700 mt in 2002. In 2004, landings increased to a record high of 26,100 mt, but the fishery was closed again because the quota (24,000 mt) was surpassed. Landings in 2005 (12,000 mt) were less than half of the 2004 landings.

Illex discards occur in the offshore Loligo fishery during November through April (NEFSC 2006). Annual discards from the Illex and Loligo fisheries combined have ranged between 0.5% and 6.0% of the annual Illex landings by weight. Annual discards were highest during 1998 and 2004 when Illex landings were also highest.

Figure 30.2

Figure 30.3

Figure 30.4

I. illecebrosus was last assessed in November 2005 at SAW 42 (NEFSC 2006). An in-season stock assessment model was developed but the results were considered preliminary because seasonal data were needed to further test the model. As a result, stock status could not be determined because estimates of fishing mortality and stock biomass were not available.

Biological Reference Points

Amendment 8 (MAFMC 1998) of the FMP specifies B_MSY as 39,300 mt, MSY as 24,000 mt, and F_MSY as 1.22 per year (Table 30.2). However, these reference points were derived from a biomass dynamics model that does not account for the species semelparous life history or adequate spawning escapement, and therefore, should be treated with caution.

Summary

It was not possible to evaluate stock status in 2004 because reliable estimates of stock biomass and fishing mortality were not available (NEFSC 2006). Post-fishery, autumn relative abundance indices for Illex reached a record high in 2003, but declined sharply in 2004 and returned to the 2002 level. The record-high survey index was followed by the highest level of landings on record in 2004, 26,000 mt, but landings subsequently declined to 12,000 mt in 2005. Fishing effort in 2004 was twice as high as in 2003.

Table 30.1 Recreational and commercial landings of Illex illecebrosus (thousand metric tons).

Table 30.2 MSY-based reference points for the U.S. component of the Illex illecebrosus stock.