The rollout of fishing vessel cameras has come with more vigilant reporting of ocean wildlife deaths.

MPI data from its 127 vessels with monitoring cameras suggests deaths were under-reported before their use.

Reports of dolphin captures have risen nearly seven-fold since cameras were introduced, compared with 2018, and volumes of discarded fish are up nearly 50 percent.

Forest and Bird's Geoff Keey says these findings weren't unexpected, given data from other countries.

"We saw similar numbers in Australia, when Australia put cameras on boats. We actually went and did the math and found that in-shore boats were between 5 and 9 times more likely to report- if there was an observer on board."

Seafood NZ Chief Executive Jeremy Helson says fishers have been paying more attention.

"There's a lot going on on a fishing vessel, there's catch coming on board, there's fish to sort and different priorities at different times. Most fishers, I do believe, do the right thing, they want to do the right thing."

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