| Summary | Patagonian squid (Loligo gahi) is also sometimes called Doryteuthis gahi or Loligo patagonica or Falkland calamari |
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| Project | SESMAD |
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| Subtype | Natural Resource Unit |
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| Sector | Fisheries (Stock-specific) |
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| Biotic | Yes |
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| Explanation | |
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| Commons Aggregation | Population |
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| Explanation | L. gahi are found mostly within Falkland Islands and off of Chile and Argentina. This stock is considered one species, but is divided into two cohorts (an autumn-spawning cohort and a spring-spawning cohort). |
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| Commons Boundaries | Somewhat unclear boundaries (2) |
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| Explanation | Generally known to be found on the Falkland Shelf, L. gahi is closely associated with the “Transient Zone” of mixed Shelf Waters with the Sub-Antarctic Superficial Water Mass of the Falkland Current (Arkhipkin et al. 2013a). Juveniles are found in shallow inshore waters <100m depth, while adults feed on the shelf edge (150-300m) (Arkhipkin et al. 2008). Females are found deeper than males (Arkhipkin et al. 2008). While general area, water conditions, and depths are known, boundaries remain unsure at any given time. |
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| Commons Indicator | [""] |
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| Explanation | No - cannot be used since population is so variable |
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| Commons Unit Size | Small (2) |
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| Explanation | Max. mantle length is 13-17 cm (Arkhipkin et al. 2013a) |
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| Environmental Medium | Oceanic |
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| Explanation | A neritic species occurring from the surface to 350 m depth but usually only to 285 m (FAO 2016) |
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| Inter Annual Predictability | Low (1) |
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| Explanation | Predicting the stock status from year to year is very difficult since there is a very weak stock-recruitment relationship. The annual life cycle of D. gahi, together with high interannual variation in the abundance of the two cohorts (ASC and SSC), makes it difficult to use methods of stock assessment and fishery management developed for long-living fish species (Rosenberg et al., 1990) (Arkhipkin et al. 2013a). Weak stock–recruitment relationships make even short-term population forecasts difficult as these depend not only on abundance of spawners but also on the fluctuating environment (Agnew et al., 2000, 2002) (Arkhipkin et al. 2013b). |
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| Intra Annual Predictability | Moderate (2) |
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| Explanation | The fishery is managed according to real time assessment of stock size. Data is collected from fishery participants. While not perfect, a number of models and environmental monitoring have been successful in maintaing spawner escapement. In-season monitoring continues because environmental conditions and other factors (e.g. new predators) changes availability. |
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| Commons Renewability | Renewable (1) |
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| Explanation | Reflective of environmental conditions. Reproduces quickly. |
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| Productivity | Very productive (3) |
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| Explanation | Reproduce twice a year (debated third). Contributes to ecosystem as common prey (consumed by hake, tooth fish, red cod, penguins, marine mammals). Can withstand moderate level of human extraction and use; can be overfished, but also can be harvested at high levels without impeding future generations. Not as high in energy as other fish consumed by predators. |
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| Commons Accessibility | Very accessible (3) |
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| Explanation | Without regulations, squid could be overfished by trawlers (without available technologies, very difficult to catch). Accessibility can still change based on conditions. |
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| Commons Heterogeneity | Moderate (2) |
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| Explanation | Within the Loligo Box, there are years where one area has higher reported catches than others. However, the entire box has reported catches, thus the resource is not patchy over a season. However, over a season fish are sometimes found in high numbers in certain areas and none in others. Also Loligo are found outside the box as well. |
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| Commons Mobility | Medium (2) |
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| Explanation | L. gahi do migrate, but remains primarily within the same region and at known depths.
The Patagonian longfin squid Loligo gahi undertakes spatial ontogenetic migrations on the Falkland shelf: juveniles move from spawning grounds located in shallow, inshore waters (20-50 m depths) to feeding grounds near the shelf edge (200-350 m depths). Immature squid feed and grow in these offshore feeding grounds and, upon maturation, migrate back to inshore waters to spawn (Arkhipkin et al. 2004). |
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| Commons Spatial Extent | 1429941 |
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| Explanation | 1429941 square kilometers (based on FAO total species distribution) In the Southwest Atlantic, D. gahi is widely distributed on the whole Patagonian Shelf, and found within waters of the Falkland (Malvinas) Current up to 38-40°S on the Argentinean Shelf. The squid is most abundant to the south, south-east and north-east of the Falkland Islands” (Arkhipkin et al. 2013a). Lives on shelves around southern tip of South America and in the Falkland Islands- most abundant in the Falkland Islands (Arkhipkin et al. 2013a). |
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| Technical Substitute | No |
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| Explanation | No technological substitute |
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