How the world’s most widely used insecticide led to a fishery collapse

Neonicotinoids disrupt aquatic food webs and decrease fishery yields

1. Masumi Yamamuro1,2,*, 
2. Takashi Komuro2, 
3. Hiroshi Kamiya3, 
4. Toshikuni Kato3, 
5. Hitomi Hasegawa4, 
6. Yutaka Kameda5

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Science  01 Nov 2019:
Vol. 366, Issue 6465, pp. 620-623
DOI: 10.1126/science.aax3442

(https://science.sciencemag.org/content/366/6465/620?fbclid=IwAR3EAGT-rGqgBSzpHTa4qIRSdntqeaGAkqTrfM7K2W3hjeyS7G5DVK5h-pI)

Abstract

Invertebrate declines are widespread in terrestrial ecosystems, and pesticide use is often cited as a causal factor. Here, we report that aquatic systems are threatened by the high toxicity and persistence of neonicotinoid insecticides. These effects cascade to higher trophic levels by altering food web structure and dynamics, affecting higher-level consumers. Using data on zooplankton, water quality, and annual fishery yields of eel and smelt, we show that neonicotinoid application to watersheds since 1993 coincided with an 83% decrease in average zooplankton biomass in spring, causing the smelt harvest to collapse from 240 to 22 tons in Lake Shinji, Shimane Prefecture, Japan. This disruption likely also occurs elsewhere, as neonicotinoids are currently the most widely used class of insecticides globally.

How the world’s most widely used insecticide led to a fishery collapse

Neonicotinoids wiped out plankton and fish in a Japanese lake, and are likely harming aquatic ecosystems worldwide, new research suggests.

In 1993, farmers in Shimane Prefecture, Japan began using

neonicotinoids in their rice paddies and agricultural fields.

Kilograms of neonicotinoids sold annually in Shimane Prefecture

May 1993

Start of neonicotinoid use

in Shimane Prefecture

Runoff containing neonicotinoids from fields and paddies was

linked to a dropoff of zooplankton biomass in Lake Shinji.

Monthly measurement of zooplankton in micrograms carbon per liter

present in water from Lake Shinji

May 1993

Start of neonicotinoid use

in Shimane Prefecture

Populations of commercial smelt and eel in Lake Shinji, which

were reliant on zooplankton and benthos as a source of food,

began to collapse.

Tons of smelt and eel, caught annually in Lake Shinji

SMELT

EEL

May 1993

Start of neonicotinoid use

in Shimane Prefecture

SMELT

EEL

JOHN KAPPLER, NG STAFF.

SOURCE: MASUMI YAMAMURO ET AL., SCIENCE, 2019