Campaigners opposed to the construction of a third nuclear power plant on the coast of Suffolk have accused developers of triggering the annual "slaughter" of 28.5 million fish.

According to pressure group Together Against Sizewell C (TASC), over a 20-year period between 2035 and 2055, an estimated 560 million fish would be entrained through the water intake of the proposed plant and its operational neighbour, Sizewell B, and impinged against cooling system screens.

TASC furthermore accused the Government's Centre for Environment, Fisheries and Aquaculture Science (Cefas) of "turning a blind eye" to the "wholesale massacre" of protected species.

The group said its calculations were based on a development consent order document, produced by operator EDF, to illustrate the predicted annual impingement of fish at Sizewell B between 2009 and 2013.

TASC said its sums were calculated on the assumption that Sizewell C is approved and that regulatory approval is granted for the twenty year life extension of Sizewell B on the Suffolk coast near Leiston.

Campaigners claimed that the proposed twin reactor would be responsible for the entrainment and impingement of 2.5 times as many fish as its existing neighbour, including two million bass, along with other species subject to conservation measures, like shad, Blackwater herring, eel and lamprey.

Pete Wilkinson, TASC chairman, said: "This carnage is wholesale, inhumane and unacceptable, and flies in the face of the government’s so-called ‘green agenda’.

"We expect Cefas to condemn this level of impact at the inquiry stage of the Sizewell C development consent order.

East Anglian Daily Times: TASC chairman Pete WilkinsonTASC chairman Pete Wilkinson (Image: Archant)

"Cefas’ stated aim is ‘to help keep our seas, oceans and rivers healthy and productive, and our seafood safe and sustainable’. Instead, it seems that Cefas appears quite at ease with itself presiding over the deaths of millions of fish, and clearly feels the huge number of fish deaths is acceptable, in that the overall health of fish stocks will not be compromised."

Sizewell C said it did not recognise TASC's figures, adding: “Our assessments show that the fish impacted are mainly sprat and herring. The intake of these species by Sizewell C is 0.01% of the stock in the area.

"Fisheries scientists describe the impact of new nuclear power stations on the marine ecosystem as ‘insignificant’.

"We will use a fish returns system, just as we do at Sizewell B, to avoid the impact on fish as much as possible.

"The modern fish returns system installed at Sizewell C will also ensure higher survival rates. Those fish returned which do not survive are eaten by other sea life. “

Cefas said it was not within its scope to have voiced its concerns, but that its role in relation to Sizewell C was to ensure the marine evidence base was scientifically robust, to fully assess the potential marine impacts and, where feasible, to work with EDF engineers to reduce potential impacts by design optimisation.

"The proposed designs are assessed by the consenting authorities to determine their acceptability," it added.

"Our objective is to ensure that the adverse impacts of human activities don’t affect the long-term viability of communities, habitats, or populations of vulnerable and declining species.

"Where impacts do occur, such as the mortality of fish on power station intake screens, we assess these against other sources of mortality – natural and caused by human activity – and the ability of the population to withstand such losses.

"Compared to the natural population size, relatively few fish will be impacted, and we are confident that mortality rates caused by the new nuclear industry are sustainable and the impact on the wider marine ecosystem will be insignificant."

It added: "In undertaking this nationally important work for EDF to develop UK’s new nuclear capability, we avoid conflicts of interest by not providing advice to government regulators on new nuclear developments.

"In the consenting process, all assessment methodologies and survey data are provided to regulators for their independent scrutiny and decision making."