Economic impacts of Papahānaumokuākea Marine National Monument expansion on the Hawaii longline fishery

Fishing trip cost modeling using generalized linear model and machine learning methods – A case study with longline fisheries in the Pacific and an application in Regulatory Impact Analysis

“…For trips that were taken by the affected vessels during the WCPO closures (type 4), their travel distances and fishing days were significantly longer than the regular trips that fished exclusively in the WCPO (type 1), the area where vessels were most likely to fish without the WCPO closures. The behavior of increasing fishing effort during the WCPO closures was consistent with Chan [ 53 ] and Mangi et al [ 54 ] in the way that vessels used to fish inside the closed areas had increased their fishing effort after the marine protected area closures. On the other hand, for vessels that were affected during the EPO closures (type 5), their trips had the shortest travel distances and longest fishing days.…”

Reply to “Catch rate composition affects assessment of protected area impacts”

“…The horizontal blue and yellow lines show that revenue-per-unit-effort has generally increased since the expansions began in 2014 and the blue-dashed and yellow-dashed lines show that revenue-per-unit-effort further increased for the 16 months following the Papahānaumokuākea monument expansion (the time period that our study focused on). This directly contradicts Dr. Chan’s study 2 which, looking at the exact same 16-month period, claimed that the Papahānaumokuākea monument expansion caused a 9% decrease in revenue-per-unit-effort.…”

Catch rate composition affects assessment of protected area impacts

“…1a , dashed lines). The decline in aggregate commercial CPUE corresponds to the declines documented by Chan 2 , who also used a measure of aggregate commercial catch rate and revenue. It is also noted that the increase in Bigeye + Yellowfin CPUE documented by Lynham et al 1 in 2017 quickly dissipates when data from 2018 and 2019 were included, whereas aggregate commercial CPUE continues to decline in those years.…”

“…Lynham et al 1 assess the impact of marine national monument expansion on catch rates in Hawaii’s longline fishery, finding little, if any negative impact. Another paper, recently published by Chan 2 , also assesses the impact of Papahānaumokuākea Marine National Monument (PMNM) expansion, but finds, for vessels with a history of fishing in PMNM, expansion decreased catch rates by 7% and revenues by 9%. I examine the source of this discrepancy and find catch rate composition to critically affect the underlying trends in data with which models are fit and are likely the source of the conflicting findings.…”