Analyses of tissue samples from Antarctic Rock-cod (Trematomus bernacchii) collected at sites around Davis station to determine wastewater exposure and sub-lethal impact

Brief description

This metadata record will contain the results of analyses of tissue samples from Antarctic Rock-cod (Trematomus bernacchii) collected at sites around Davis station to determine wastewater exposure and sub-lethal impact. AAS Project 4177. The results of metal analysis, stable isotope analysis and images of histological analysis of fish from Davis Station are in this dataset.


Sample sites and fish collection

Antarctic Rock-cod were collected at 6 sites from Prydz Bay near Davis Station East Antarctica, during the 2012/13 summer. Approximately twenty fish were collected from each site by line and in box traps from four sites along a (9 km) spatial gradient starting from the Davis Station wastewater outfall, southward 0km (within 250m of the point of discharge), 1km, 4km and 9km, in the direction of the predominant current. Additionally, two reference sites were sampled 9 km and 16 km north of the discharge point. Once collected, fish were immediately returned to the Davis Station laboratories and sacrificed individually by immersion in an Aqui-s solution (~15ml/L). Once no signs of life were present (approximately 5 min), fish length and weight were measured. Tissues were preserved in various ways for a number of analyses to be conducted at a later date.

Stable Isotope analysis.

Davis Station Laboratory
Dorsolateral muscle tissue from the left side of each individual was removed, placed in aluminium foil and frozen at -20 degrees C for later analysis.

Tissue processing
A section of frozen tissue was removed (approximately 1 x 1 cm cubed), placed into a clean, acid washed glass crucible and cut into small pieces. This was then dried at 80 degrees C for 48 h. Tissue from each fish was carefully removed and placed into separate 2 ml Eppendorf tubes, each containing an washed, dried stainless steel ball bearing and the lids closed tightly to ensure no moisture could enter. Tissue was crushed into a fine powder by shaking in a Tissue II Lyser. Ball bearings were removed from vials and crushed tissue samples were sent to Cornell University Stable Isotope laboratory for d13C (carbon stable isotope) and d15N (nitrogen stable isotope) analysis. Stable isotope ratios are expressed in parts per thousand units using the standard delta (d) notation d13C and d15N.

Data Set
This data set consists of an Excel spreadsheet containing raw data of Nitrogen and Carbon Stable Isotope analysis from 6 sites in the Prydz Bay area of East Antarctica. It includes site distance and direction from wastewater discharge point.

The file name code stable isotope analysis is;
Project number_Season_Taxa_analysis type
AAS_4177_12_13_Trematomus_Isotopes
Project number : AAS_4177
Season : 2012/13 season
Taxa: Trematomus
Analysis type: Stable Isotope

Metal analysis.

Davis Station Laboratory
Dorsolateral muscle tissue from the right side of each individual was removed, placed in a plastic zip lock bag and frozen at -20 degrees C for later analysis.

Tissue processing
10g of frozen muscle tissue was sent to Advanced Analytical Australia for metal analysis of a suite of metals (Cd, Cr, Cu, Hg, Mn, Zn, Al, Ni, Pb).

Data Set
This data set consists of an Excel spreadsheet containing raw data of metal analysis (mg/kg) from 6 sites in the Prydz Bay area of East Antarctica. It includes site distance and direction from wastewater discharge point.

The file name code stable isotope analysis is;
Project number_Season_Taxa_analysis type
AAS_4177_12_13_Trematomus_Metals
Project number : AAS_4177
Season : 2012/13 season
Taxa: Trematomus
Analysis type: Metal analysis

Histological analysis

Davis Station Laboratory
A small piece of a number of fish tissues (gill, liver, spleen, head kidney, gonad), were collected immediately after death of the fish to ensure no degradation of tissue and preserved in 10% seawater buffered formalin for later analysis

Tissue processing
Each piece of tissue was dehydrated in ascending grades of ethanol (30-100%), cleared in Histolene and embedded in paraffin wax. Tissue was sectioned using a HM 32 Micron microtome at 4 microns. Standard haematoxylin and eosin (H and E) stain was used to stain all tissue sections. Each section was examined blind (i.e. the examiner did not know the field location of the tissue samples) using a Zeiss AxioPlan microscope at 100-400 x magnification. Histological analysis is ongoing.

Data Set
This data set consists of a pdf file with images of normal and potential sub-lethal histological alterations.

The file name code stable isotope analysis is;
Project number_Season_Taxa_analysis type
AAS_4177_12_13_Trematomus_Histology
Project number : AAS_4177
Season : 2012/13 season
Taxa: Trematomus
Analysis type: Histopathology

Lineage

Progress Code: completed

Statement: The unmodified summary description and a fully described list of sampling locations is provided in the word document in the dataset download.