“The continuing consolidation of seed and pesticide companies essentially creates a monopoly of toxicity in control of the world’s seed market and food supply. These agrichemical giants threaten the availability and genetic diversity of seeds that are critical to a sustainable food system and to our ability to respond to the impacts of climate change,” Andrew Kimbrell, executive director of Center for Food Safety, said Tuesday.

The petitions signed by over 700,000 people were delivered by nine consumer advocacy and environmental groups—including Food & Water Watch, Sierra Club, Pesticide Action Network, Friends of the Earth, and Center for Food Safety, among others—as the U.S. Senate Judiciary Committee met Tuesday to examine the wave of consolidation in the biotech and agrochemical industry.

“I’m afraid this consolidation wave has become a tsunami,” said Iowa Sen. Charles Grassley, the Republican chairman of the Senate Judiciary Committee, as the hearing opened.

“Just six corporations already dominate worldwide seed and pesticide markets,” commented Marcia Ishii-Eiteman, senior scientist with Pesticide Action Network, in a statement released by the groups. “Additional consolidation will increase prices and further limit choices for farmers, while allowing Monsanto and friends to continue pushing a model of agriculture that has given us superweeds, superbugs, and health-harming pesticides. Instead, we need to invest in agroecological, resilient, and productive farming.”

Kiki Hubbard, director of advocacy for Organic Seed Alliance, noted that all farmers “experience the negative consequences of seed consolidation. Organic farmers in particular are already underserved by the industry because the dominant players only invest in seed technologies and chemical production systems that are in conflict with organic farming practices.”

“The last thing that U.S. agriculture needs now is more concentration,” added Michael Sligh of the Rural Advancement Foundation International. “What farmers need is more regionally and locally-adapted seeds choices and more biodiversity. Concentration lead to higher seed prices for farmers and lower take home pay.”

“The shocking consolidation in the biotech seed and agrochemical industry turns our food system over to a cabal of chemical companies, undermining family farmers and consumers,” noted Food & Water Watch Executive Director Wenonah Hauter. “We urge federal regulators to block these pending mergers to prevent further corporate control of our food system.”