Thanks. Here an extract from Meredith's article. I should have put some of these numbers in my piece.
In considering this level of fish larvae mortality we might note that the average American Shad lays in the region of 30,000 eggs a year and a salmon 2,000 to 5,000 eggs. Fish eggs and larva have extremely high mortality because they're food for other fish. Fish lay thousands of eggs because most don't survive and become adult fish.
People like the NRDC say that once-through kills millions of fish per plant per year? Is this true? What trade-off should we accept between fish deaths and efficiency?
Any tradeoff should be based on the impact on the adult populations. Once you determine the effect on the adult popualtion, that change can be part of yr cost/benefit calculus. As the piece points out, most fish populations are density driven. Female fish lay thousands of eggs per year of which 1 or 2 survive to adulthood. Th e actual number that survive depends on the adult popualtion that the environment can support.
This was an issue in shutting down Indian Point in 2020 and 2021. The Riverkeepers claimed the plant was killing a billion larvae per year. But IP2 and IP3 began ops in 1975 and 1976. So plants that had been killing billions per year sicne 1976 were still killing a billion per year 45 years later. Clearly, the plants were not having much effect on the egg laying population.
This is so true. Thank you for writing this.
I wrote an article about this several years ago. Fiish eat fish eggs. That is the main cause of fish egg mortality. It's not about cooling towers.
The whole cooling tower thing is just a way to atack nuclear plants. (Please also look at the inset about Turkey Point.) https://www.neimagazine.com/features/featurekeeping-cool-under-pressure-4888411/
Meredith,
Thanks. Here an extract from Meredith's article. I should have put some of these numbers in my piece.
In considering this level of fish larvae mortality we might note that the average American Shad lays in the region of 30,000 eggs a year and a salmon 2,000 to 5,000 eggs. Fish eggs and larva have extremely high mortality because they're food for other fish. Fish lay thousands of eggs because most don't survive and become adult fish.
People like the NRDC say that once-through kills millions of fish per plant per year? Is this true? What trade-off should we accept between fish deaths and efficiency?
Ben,
Any tradeoff should be based on the impact on the adult populations. Once you determine the effect on the adult popualtion, that change can be part of yr cost/benefit calculus. As the piece points out, most fish populations are density driven. Female fish lay thousands of eggs per year of which 1 or 2 survive to adulthood. Th e actual number that survive depends on the adult popualtion that the environment can support.
This was an issue in shutting down Indian Point in 2020 and 2021. The Riverkeepers claimed the plant was killing a billion larvae per year. But IP2 and IP3 began ops in 1975 and 1976. So plants that had been killing billions per year sicne 1976 were still killing a billion per year 45 years later. Clearly, the plants were not having much effect on the egg laying population.