ABSTRACT

Microplastic (MP) particles (<5000 µm) pose a risk to many marine organisms. Globally, sponges are important suspension-feeding organisms that may be particularly vulnerable to MPs since many of these particles fall within their food size range. However, there has been little research on spatial variation in MP abundance in sponges. Here we examined MP abundance and spatial variation in sponges from Aotearoa New Zealand (NZ). We aimed to confirm the presence of potential microplastics (PMPs) in samples from 45 sponge samples across six species and three sites in the Wellington Harbour. Samples were digested with bleach, filtered, and analysed using fluorescent microscopy to quantify and measure PMPs. PMPs were present in every sponge sample with abundances between 207 ± 131 and 1893 ± 396 PMP particles g^-1 (dry sponge weight). There were significant differences in PMP abundance between sites and between some species, but most of the variation was explained by site (40–53% vs. 4–24% of the variance). Our results suggest that PMP abundance in sponges is mainly explained by spatial variation in microplastic abundance rather than species identity.

摘要

微塑料 (MP) 颗粒（<5000 µm）对许多海洋生物构成威胁。在全球范围内，海绵是重要的以悬浮液为食的生物，可能特别容易受到 MP 的影响，因为其中许多颗粒都在它们的食物大小范围内。然而，关于海绵中 MP 丰度空间变化的研究很少。在这里，我们检查了来自新西兰 (NZ) 的海绵中的 MP 丰度和空间变化。我们的目的是确认来自惠灵顿港三个地点的六个物种的 45 个海绵样本的样本中是否存在潜在的微塑料 (PMP)。样品用漂白剂消化、过滤，并使用荧光显微镜进行分析以量化和测量 PMP。PMP 存在于每个海绵样品中，丰度在 207 ± 131 和 1893 ± 396 PMP 颗粒 g ^-1之间（干海绵重量）。不同地点之间和某些物种之间的 PMP 丰度存在显着差异，但大部分变异是由地点解释的（40-53% 对 4-24% 的方差）。我们的结果表明，海绵中 PMP 的丰度主要是由微塑料丰度的空间变化而不是物种特性来解释的。