Institute of Marine Science, University of Auckland, Private Bag 92019, Auckland, New Zealand.
School of Chemical Sciences, University of Auckland, Private Bag 92019, Auckland, New Zealand.
Aquat Toxicol. 2020 Nov;228:105645. doi: 10.1016/j.aquatox.2020.105645. Epub 2020 Sep 24.
The toxicity of heavy metals commonly impacts the survival of crustacean and bivalve larvae in hatchery culture, and this has led to the widespread use of EDTA to decrease this toxicity. Since EDTA has a very poor biodegradability leading to potential persistent environmental effects, alternative methods to prevent heavy metal toxicity to shellfish larvae are needed. EDDS is a biodegradable potential alternative to EDTA for this application and was tested as a treatment of the seawater used for rearing aquaculture Greenshell™ mussel (Perna canaliculus) larval embryos in this study. Mussel embryos reared with EDTA or EDDS had significantly better survival than without. The concentrations and spatial distributions of heavy metals in D-veliger larvae as determined by Inductively Coupled Plasma Mass Spectrometry (ICP-MS) and X-ray Fluorescence Microscopy (XFM) suggested that chelating agents increased the levels of calcium in larvae while they reduced the concentration of zinc. In addition, where decreased accumulation of the other heavy metals was not observed, chelating agents affected their distribution within the larvae, especially for copper and arsenic. This is the first study to test the use of EDDS for aquaculture hatchery application and shows that EDDS is an effective biodegradable alternative to EDTA that can mitigate the effects of heavy metals for shellfish larval rearing.
重金属的毒性通常会影响孵化场养殖的甲壳类和双壳类幼虫的存活，这导致了 EDTA 的广泛使用，以降低这种毒性。由于 EDTA 的生物降解性很差，可能会对环境产生持久的影响，因此需要寻找替代方法来防止贝类幼虫受到重金属的毒性影响。EDDS 是一种可生物降解的 EDTA 替代品，在这项研究中被测试为一种处理海水的方法，用于养殖水产养殖绿贻贝（Perna canaliculus）幼虫胚胎。与没有 EDTA 或 EDDS 处理的贻贝胚胎相比，用 EDTA 或 EDDS 处理的贻贝胚胎的存活率显著提高。电感耦合等离子体质谱法（ICP-MS）和 X 射线荧光显微镜（XFM）测定 D 型幼体幼虫中重金属的浓度和空间分布表明，螯合剂增加了幼虫体内的钙含量，同时降低了锌的浓度。此外，在没有观察到其他重金属积累减少的情况下，螯合剂影响了它们在幼虫体内的分布，特别是铜和砷。这是首次测试 EDDS 在水产养殖孵化场应用的研究，表明 EDDS 是 EDTA 的一种有效可生物降解替代品，可减轻重金属对贝类幼虫养殖的影响。
