Projecting future climate change impacts on the distribution of pelagic squid in the Southern Ocean

This study examines how climate change may alter the distribution of pelagic squid in the Southern Ocean. Using species distribution models (SDMs), the authors projected the future habitat suitability for 15 squid species under two climate scenarios (SSP1-2.6 and SSP5-8.5) for the years 2050 and 2100.

The models indicate that increasing sea surface temperatures and retreating sea ice (key aspects of ocean warming) are major drivers of changing habitat conditions. Other factors, like chlorophyll concentration (a proxy for primary productivity), also play an important role.

The species-specific responses include potential winners and losers:

Potential Winners: Subtropical and cosmopolitan squid species (e.g., Histioteuthis atlantica, Teuthowenia pellucida, Todarodes filippovae, and Bathyteuthis abyssicola) may gain suitable habitat, particularly at higher latitudes (Figure 1).

Figure 1 – Habitat distribution changes of subtropical species in 2050 SSP5-8.5 and 2100 SSP5-8.5 relative to present, and latitudinal gradient of habitat suitability of present versus future scenarios. In the trend graph, grey vertical line is the threshold for the presence of species

Potential Losers: In contrast, Antarctic and many subantarctic species (such as Onykia ingens, Onykia robsoni, Martialia hyadesi, Gonatus antarcticus, Histioteuthis eltaninae, Slosarczykovia circumantarctica, Mesonychoteuthis hamiltoni, Alluroteuthis antarcticus, Galiteuthis glacialis, Psychroteuthis glacialis, and especially Moroteuthopsis longimana) are projected to lose a significant portion of their current habitat (Figure 2).

Figure 2 – Habitat distribution changes of Antarctic species in 2050 SSP5-8.5 and 2100 SSP5-8.5 relative to present, and latitudinal gradient of habitat suitability of present versus future scenarios. In the trend graph, the grey vertical line is the threshold for presence of species.

Additionally, the study found that the northern limits of squid distributions are expected to move southward over time, with a reduction in biodiversity hotspots, which may alter the structure of the pelagic ecosystem. Changes in squid distribution could have cascading effects throughout the Southern Ocean food web, impacting predators such as seabirds, seals, and cetaceans that rely on squid as a major food source.

The authors note uncertainties related to the resolution of environmental data, the lack of trophic interactions in the models, and limited sampling in remote areas. They suggest that future studies incorporate finer-scale data (including depth as a third dimension) and more comprehensive biological information to better inform conservation and marine spatial planning.

Overall, the paper provides essential projections for understanding potential shifts in marine biodiversity due to climate change and highlights the importance of considering these changes in conservation strategies for the Southern Ocean.

Source: Guerreiro, M., Santos, C. P., Borges, F., Santos, C., Xavier, J. C., & Rosa, R. (2025). Projecting future climate change impacts on the distribution of pelagic squid in the Southern Ocean. Marine Ecology Progress Series, 757

Author: Sara Santos

Share