Publications | gillanders-lab

2025 Publications (links to each paper available at read more)

Microplastic presence in dried and fresh fish from seafood markets in Sri Lanka

Wootton, Nina, Vinuri Silva, Danielle Giuretis, Patrick Reis-Santos, Bronwyn M. Gillanders. 2025. Marine and Freshwater Research.

Context. Microplastics have been found in aquatic ecosystems globally, including in many marine organisms. Despite this, understanding the occurrence of microplastics in seafood products prepared for human consumption has received less attention. Aims. This study aims to determine the abundance and type of microplastic in dried and fresh fish purchased from seafood markets. Methods. Four locally harvested species of anchovies and sardines were sampled from seafood markets across Sri Lanka. These pelagic species are popular seafood items and are commonly consumed whole. We analysed fresh (gastrointestinal tracts, and whole body) and dried fish (whole body) under the microscope for microplastic presence (>38 μm, < 5mm), followed by polymer validation. Key results. Across all fish sampled (N=215), 82.3% had microplastic (3.64  0.26 MPs/ind), with fibre shaped pieces making up more than 95% of all microplastic particles. Overall, contamination was higher in fresh fish compared to whole dried fish. And, acrylic resin was the most common polymer. Conclusions. Microplastics were found in nearly all fresh fish and almost half the dry fish from Sri Lanka, confirming the pervasive nature of microplastic contamination. Implications. Differences in contamination levels in popular seafood products demonstrate how preparation and consumption habits can influence microplastic intake.

Local and regional-scale climate variability drives complex patterns of growth synchrony and asynchrony in deep-sea snappers across the Indo-Pacific

Widdrington, JB, P Reis-Santos, JI MacDonald, BR Moore, SJ Nicol, JR Morrongiello, BM Gillanders 2025. Global Change Biology

Climatic variation can play a critical role in driving synchronous and asynchronous patterns in the expression of life history characteristics across vast spatiotemporal scales. The synchronisation of traits, such as an individual’s growth rate, under environmental stress may indicate a loss of phenotypic diversity and thus increased population vulnerability to stochastic deleterious events. In contrast, synchronous growth under favourable ecological conditions and asynchrony during unfavourable conditions may help population resilience and buffer against the negative implications of future environmental variability. Despite the significant implications of growth synchrony and asynchrony to population productivity and persistence, little is known about its causes and consequences either within or among fish populations. This is especially true for long-lived deep-sea species that inhabit environments characterised by large-scale interannual and decadal changes, which could propagate growth synchrony across vast distances. We developed otolith growth chronologies for three deep-sea fishes (Etelis spp.) over 90˚ of longitude and 20˚ of latitude across the Indo-Pacific region. Using reconstructed time series of interannual growth from six distinct Exclusive Economic Zones (EEZs), we assessed the level of spatial synchrony at the individual-, population- and species-scale. Across five decades of data, complex patterns of synchronous and asynchronous growth were apparent for adult populations within and among EEZs of the Pacific Ocean, mediated by shifts in oceanographic phenomena such as the Pacific Decadal Oscillation (PDO). Overall, our results indicate that the degree of synchrony in biological traits at depth depends on life history stage, spatiotemporal scales of environmental variability, and the influence of ecological factors such as competition and dispersal. By determining the magnitude and timing of spatially synchronous growth at depth and its links to environmental variability, we can better understand fluctuations in deep-sea productivity and its vulnerability to future environmental stressors, which are key considerations for sustainability.