Nearly half of New Zealand’s river network is partially or fully inaccessible to migratory fish, a new study shows. NIWA has conducted the first nationwide assessment of river fragmentation, looking for structures that can act as barriers to fish. These structures are often human-made and include dams, culverts, and weirs. Dr Paul Fraklin, NIWA Freshwater Ecologist joins Dom to share more on the study.See omnystudio.com/listener for privacy information.