Scientific Research Vessels 'José Olaya Balandra', and 'Humboldt' Photo: Stockfile/FIS

IMARPE: Report on the 'Giant Squid (Dosidicus gigas) Research Cruise'

PERU
Friday, March 14, 2025, 00:10 (GMT + 9)

The technical report "Giant Squid (Dosidicus gigas) Research Cruise December 2024 - February 2025" presents the results of the research cruises conducted in the Peruvian sea" presents the results of the research cruises conducted in the Peruvian sea.

Introduction 

The giant squid is the second most economically important fishing resource in the country, contributing to food security, job creation, and foreign currency income. Currently, it is harvested exclusively by the artisanal fleet (Guevara et al., 2018). It is a predatory and voracious species, fast-growing and with high energy demands, which reaches its maximum development on average at one year of age. This species is associated with highly productive water bodies, such as upwelling systems, and thrives when prey concentrations are abundant, preferring mesopelagic species that are an important part of its diet (Alegre et al., 2014b; Ehrhardt et al., 1983; Markaida, 2006a; Nigmatullin et al., 2001; Roper et al., 1984; Rosas, 2007). The highest concentrations are associated with the upwelling systems of the north-central zone of the CHS and the California Current System (CCS) (Anderson and Rodhouse, 2001; Nigmatullin et al., 2001). There are individuals that can exceed the life span of up to two years, reaching a mantle length of up to 1.2 meters and a total weight of up to 65 kilograms (Csirke et al., 2018); However, in recent years, smaller sizes have been observed, with individuals classified as medium and small. Furthermore, the species exhibits sexual dimorphism, and up to three size ranges/groups (or morphotypes) are recognized (small, medium, and large), depending on their sex and maturity (Nigmatullin et al., 2001).

In Peru, giant squid is characterized by significant fluctuations in abundance and availability due to environmental variability. This is reflected in the landing volumes recorded between 1991 and 2019, with peak values ​​of approximately 210,000 tons in 1994, with the participation of a foreign-flagged industrial squid fleet, and catches exceeding 500,000 tons in 2008 and 2014, with the participation of a national artisanal fleet. However, under more intense and prolonged warm weather conditions, as occurred during the 1997-1998 El Niño event, the resource was less available to the fleet, with catches falling below 16,000 tons. In recent years, dramatic changes in landings have again been observed: 621,925 tons were landed in 2023, and 188,345 tons in 2024, representing a 70% drop. So far this year, preliminary landings have reached 9,182 tons, much lower than those reported for the same period in the last five years. The marked dynamism of the resource demands the constant development of research aimed at estimating abundance indices, determining biological status, and describing population structure, among other aspects. In this context, this report presents the results of the Giant Squid research cruises carried out in December 2024 and January-February 2025.

These cruises were carried out aboard the Scientific Research Vessels "José Olaya Balandra" and "Humboldt" between December 2024 and February 2025.

Chart of oceanographic stations (a) and fishing routes and operations (b) of the Giant Squid Research Center, Center 2412 - 2501-02, BICs "José Olaya Balandra" and "Humboldt." (Click on the image to enlarge)

What was studied and how?

Researchers studied giant squid in different areas of the Peruvian sea. To do so, they conducted research cruises that covered the northern and southern reaches of Peru, from Punta Sal to Ilo. The cruises ventured out to sea from 50 to 190 nautical miles off the coast.

During the cruises, the scientists collected different types of information. They measured ocean conditions, such as temperature, salinity, oxygen, and pH. They also recorded weather data, such as air temperature, pressure, and wind.

To study the giant squid, they used special equipment called echo sounders, which allow them to detect and measure the number of squid in the water. In addition, they captured squid using trawls and handlines. These captured squid were studied in detail to determine their size, reproductive status, and genetics. Samples of zooplankton, tiny animals that live in the water and serve as food for giant squid, were also analyzed.

What was found?

The researchers found that ocean conditions varied in the different areas studied. In the central zone, conditions were fairly stable, but in other areas, there were changes in water temperature.

Giant squid were found in many areas, but there were more squid in the central zone. A total of 1,110.9 kg of giant squid were caught. Most of the squid were caught using handlines. The areas where the most squid were caught were those between 80 and 120 nautical miles from the coast.

Distribution of Giant Squid Cr. 2412 and Cr. 2501-02 Giant Squid. BIC José Olaya and BIC Humboldt. (click on the image to enlarge)

The caught squid were of different sizes, depending on the area and the way they were caught. Scientists also studied other aspects of giant squid biology, such as its reproduction and its relationship between size and weight.

In addition to giant squid, researchers found many other species of fish and invertebrates in the sea. They identified 84 different species. The most common species caught was a type of crustacean called Grimothea monodon. They also found 15 species of cephalopods, including giant squid and argonaut.

What does all this mean?

The results of this study show that the giant squid is an animal found in many areas of the Peruvian sea. The number of squid and their size vary depending on the ocean conditions and the area.

The study also shows that the ocean is a very diverse place, with many different species of animals.

This report is important because it helps us better understand the giant squid and its role in the marine ecosystem. This information is useful for making decisions about how to manage and protect this fishery resource.

[email protected]
www.seafood.media

Print