nerc.ac.uk

Navigating challenges in spatio-temporal modelling of Antarctic krill abundance: Addressing zero-inflated data and misaligned covariates

Amaral, André Victor Ribeiro ORCID: https://orcid.org/0000-0003-3748-6801; Sykulski, Adam M.; Fielding, Sophie ORCID: https://orcid.org/0000-0002-3152-4742; Cavan, Emma. 2025 Navigating challenges in spatio-temporal modelling of Antarctic krill abundance: Addressing zero-inflated data and misaligned covariates. Spatial Statistics, 70, 100937. 13, pp. 10.1016/j.spasta.2025.100937

Before downloading, please read NORA policies.
[thumbnail of Open Access]
Preview
Text (Open Access)
/© 2025 The Authors. Published by Elsevier B.V.
1-s2.0-S2211675325000594-main.pdf - Published Version
Available under License Creative Commons Attribution 4.0.

Download (3MB) | Preview

Abstract/Summary

Antarctic krill (Euphausia superba) are among the most abundant species on our planet and serve as a vital food source for many marine predators in the Southern Ocean. In this paper, we utilise statistical spatio-temporal methods to combine data from various sources and resolutions, aiming to model krill abundance. Our focus lies in fitting the model to a dataset comprising acoustic measurements of krill biomass. To achieve this, we integrate climate covariates obtained from satellite imagery and from drifting surface buoys (also known as drifters). Additionally, we use sparsely collected krill biomass data obtained from net fishing efforts (KRILLBASE) for validation. However, integrating these multiple heterogeneous data sources presents significant modelling challenges, including spatio-temporal misalignment and inflated zeros in the observed data. To address these challenges, we fit a Hurdle-Gamma model to jointly describe the occurrence of zeros and the krill biomass for the non-zero observations, while also accounting for misaligned and heterogeneous data sources, including drifters. Therefore, our work presents a comprehensive framework for analysing and predicting krill abundance in the Southern Ocean, leveraging information from various sources and formats. This is crucial due to the impact of krill fishing, as understanding their distribution is essential for informed management decisions and fishing regulations aimed at protecting the species.

Item Type: Publication - Article
Digital Object Identifier (DOI): 10.1016/j.spasta.2025.100937
ISSN: 22116753
Additional Keywords: Antarctic krill, Hurdle model, Misaligned data, Zero-inflated
Date made live: 29 Sep 2025 10:42 +0 (UTC)
URI: https://nora.nerc.ac.uk/id/eprint/540311

Actions (login required)

View Item View Item

Document Downloads

Downloads for past 30 days

Downloads per month over past year

More statistics for this item...