Evaluating intra- and inter-life stage density-dependent dynamics for management of perennial amphidromous fish.

Compensatory density-dependent (DD) processes play an integral role in fisheries management by underpinning fundamental population demographics. However, DD processes are often assessed only for specific life stages, likely resulting in misleading evaluations of population limitations. Here, we assessed the relative roles of intra- and inter-life stage DD interactions in shaping the population dynamics of perennial freshwater fish with demographically open populations.

Predicting biomass of resident kōkopu (Galaxias) populations using local habitat characteristics.

With the global decline of freshwater fishes, quantifying the body size-specific habitat use of vulnerable species is crucial for accurately evaluating population health, identifying the effects of anthropogenic stressors, and directing effective habitat restoration. Populations of New Zealand's endemic kōkopu species (Galaxias fasciatus, G. argenteus, and G.

Interacting effects of density and temperature on fish growth rates in freshwater protected populations.

Despite the demonstrated benefits of marine protected areas, there has been relatively little dialogue about freshwater protected areas (FPAs) even though some have been established to protect freshwater species from recreational and commercial fishers. After populations recover from fishing pressure, abundances and densities of formerly fished species increase, and we should therefore expect changes in demographic traits compared to those in exploited populations. To test this, we used capture-mark-recapture data for 10 populations across a density gradient mediated by different degrees of fishery closure.

Synergistic interactions within disturbed habitats between temperature, relative humidity and UVB radiation on egg survival in a diadromous fish.

Anthropogenic impacts, including urbanization, deforestation, farming, and livestock grazing have altered riparian margins worldwide. One effect of changes to riparian vegetation is that the ground-level light, temperature, and humidity environment has also been altered. Galaxias maculatus, one of the most widely distributed fishes of the southern hemisphere, lays eggs almost exclusively beneath riparian vegetation in tidally influenced reaches of rivers.

Population sinks resulting from degraded habitats of an obligate life-history pathway.

Many species traverse multiple habitats across ecosystems to complete their life histories. Degradation of critical, life stage-specific habitats can therefore lead to population bottlenecks and demographic deficits in sub-populations. The riparian zone of waterways is one of the most impacted areas of the coastal zone because of urbanisation, deforestation, farming and livestock grazing.