The feeding ecology of invasive pink salmon Juveniles in northern Norwegian rivers and their role as prey to native Salmonids

Increasing numbers of invasive Pacific pink salmon (Oncorhynchus gorbuscha) are spawning in northern Norwegian rivers, leading to large numbers of juveniles migrating to coastal waters. This raises concerns about food competition in rivers with native salmonids, although details about the timing and intensity of pink salmon feeding and the characteristics of their freshwater diet remain unclear. Some evidence indicates that pink salmon can also serve as a food source for native salmonids, as do the carcasses of spawned adults, eggs and juveniles. This study investigated largely unexplored aspects of the emergence timing and feeding behaviour of juvenile pink salmon. The prevalence, timing and impact of fish size on freshwater feeding was examined across 10 rivers in northern Norway, using stomach content and stable isotope (δ13C and δ15N) analyses to assess diet composition. Similar methods were applied to assess whether native juvenile salmonids feed on pink salmon tissue, such as juve..., , # Data from: The feeding ecology of invasive pink salmon Juveniles in northern Norwegian rivers and their role as prey to native Salmonids

Dataset DOI: [10.5061/dryad.n02v6wxch](https://doi.org/10.5061/dryad.n02v6wxch)

## Description of the data and file structure

Pink salmon, Atlantic salmon and brown trout juveniles were sampled from 10 northern Norwegian rivers. Fish were weighed, measured for total length and stomach contents were examined. Stable isotope analysis was run on some individuals to examine changes in reliance on marine derived nutrients and energy from pink salmon eggs or carcasses vs freshwater invertebrates. 
### Files and variables

#### File: Pink-salmon-master-file.csv

**Description:** 

##### Variables

* Label_ID: Unique identification code for each individual 
* Day:
* Month:
* Year:
* Date: dd.mm.yyyy
* River: Sample origin river
* River_Section: Sample river section origin (Lower or Middle)
* Species: Pink salmon, atlantic salmon or brown trout
* Sampling_..., ,