Freshwater eels of the Anguilla genus are experiencing global decline, largely driven by human activity. In Aotearoa‐New Zealand, tuna (both shortfin and longfin eels) are similarly affected, with habitat fragmentation and modification key drivers of their decline. We investigated the distribution and abundance of tuna across regional, catchment and reach‐level scales in an urban environment. We developed species distribution models (SDMs) across the Tāmaki Makaurau (Auckland) region to explore patterns in tuna distribution across an urbanisation gradient. Additionally, we conducted a field survey across an urban catchment in Tāmaki Makaurau to assess the local habitat features associated with tuna presence and abundance. The predictive power of our SDMs was limited, and the field survey revealed that tuna were broadly distributed throughout the urban catchment, displaying only weak associations with specific habitat features. These findings suggest that in the absence of movement barriers, tuna can occupy a wide range of habitats throughout urban streams. However, the presence of tuna may not indicate suitable habitat for survival and growth, as their robust and opportunistic nature allows them to persist even in suboptimal environments.
Whitelock et al. (Wed,) studied this question.