Salinity-temperature interaction drives metabolic and energetic changes in an Arctic crustacean

The Arctic is shifting towards a prevalence of warm and more saline Atlantic-like waters. These changes in the marine environment pose significant challenges for the eco-physiology of marine invertebrates. Here we measured the metabolic enzyme activity of citrate synthase and lactate dehydrogenase, as well as the energy content and level of oxidative damage in 71 individuals (~ 10/station) of Thysanoessa inermis collected in six fjords in Svalbard that were characterized by different levels of influence of Atlantic water and, thus, temperature and salinity variability in the water column. T. inermis inhabiting fjords with strong influence of Atlantic water masses had lower lipid and protein content, and higher anaerobic metabolism compared to those from more Arctic fjord types. Moreover, T. inermis collected in fjords with high variability in both temperature and salinity had 0.8-fold lower lipid content than station with more stable temperature and salinity. Our results suggest that T...., Sampling
At each station, measurements of temperature, salinity and fluorescence were obtained by a ship-board conductivity, temperature, and depth (CTD) profiler (SBE911plus, SeaBird Electronics) with a SeaPoint fluorometer attached. The latitude and longitude of sampling locations are given in Table 1 as well as the average temperature and salinity of the sampling location from the bottom to 5m depth. We have also calculated the variation (i.e., delta = maximum value minus minimum value recorded) of both salinity and temperature from the bottom to 5 m depth to estimate how much variation in these variables euphausiids will encounter during their diel vertical migrations. These delta values were used in the statistical analyses.
To estimate chlorophyll a concentration at surface (5 m), seawater samples of 100 mL were filtered through 25 mm GF/F filters (Whatman) in triplicate, extracted in 100% methanol for 24h at 4°C, and measured fluorometrically with an AU10 Turner Fluorometer (Turn..., , # Salinity-temperature interaction drives metabolic and energetic changes in an Arctic crustacean

[https://doi.org/10.5061/dryad.44j0zpcr4](https://doi.org/10.5061/dryad.44j0zpcr4)

## Description of the data and file structure

### Files and variables

#### File: R_dataset_Ecosphere.csv

**Description:** This dataset contains all the environmental variables collected during the Svalbard cruise and the results from each biomarker. The dataset is semicolon-delimited with commas as the decimal. n/a values indicate \"not available\" data (not enough sample for performing the assay).

##### Variables

* Station (location where krill were sampled): Rijpfjorden, Storfjorden, Kongsfjorden, Isfjorden, WaF (Wahlenbergfjorden), Hinlopen;

* Fjord type (type of fjord classification based on previous and current data present in the study): Arctic, Mixed, Atlantic;

* Station number (number of the location): 1-6;

* Krill (name of each krill individual);

* mass: mass of each krill in mg

* len...,