University of Tasmania
Browse

sorry, we can't preview this file

137241 - The endemic and endangered Maugean Skate (Zearaja maugeana).pdf (1.89 MB)

The endemic and endangered Maugean Skate (Zearaja maugeana) exhibits short-term severe hypoxia tolerance

Download (1.89 MB)
journal contribution
posted on 2023-05-20, 10:34 authored by Andrea Morash, Jeremy LyleJeremy Lyle, Currie, S, Bell, JD, Stehfest, KM, Jayson SemmensJayson Semmens

The endangered and range-restricted Maugean skate (Zearaja maugeana) is subjected to large environmental variability coupled with anthropogenic stressors in its endemic habitat, Macquarie Harbour, Tasmania. However, little is known about the basic biology/physiology of this skate, or how it may respond to future environmental challenges predicted from climate change and/or increases in human activities such as aquaculture. These skate live at a preferred depth of 5–15 m where the dissolved oxygen (DO) levels are moderate (~55% air saturation), but can be found in areas of the Harbour where DO can range from 100% saturation to anoxia. Given that the water at their preferred depth is already hypoxic, we sought to investigate their response to further decreases in DO that may arise from potential increases in anthropogenic stress. We measured oxygen consumption, haematological parameters, tissue–enzyme capacity and heat shock protein (HSP) levels in skate exposed to 55% dissolved O2 saturation (control) and 20% dissolved O2 saturation (hypoxic) for 48 h. We conclude that the Maugean skate appears to be an oxyconformer, with a decrease in the rate of O2 consumption with increasing hypoxia. Increases in blood glucose and lactate at 20% O2 suggest that skate are relying more on anaerobic metabolism to tolerate periods of very low oxygen. Despite these metabolic shifts, there was no difference in HSP70 levels between groups, suggesting this short-term exposure did not elicit a cellular stress response. The metabolic state of the skate suggests that low oxygen stress for longer periods of time (i.e. >48 h) may not be tolerable and could potentially result in loss of habitat or shifts in their preferred habitat. Given its endemic distribution and limited life-history information, it will be critical to understand its tolerance to environmental challenges to create robust conservation strategies.

Funding

Fisheries Research & Development Corporation

History

Publication title

Conservation Physiology

Volume

8

Article number

coz105

Number

coz105

Pagination

1-15

ISSN

2051-1434

Department/School

Institute for Marine and Antarctic Studies

Publisher

Oxford University Press

Place of publication

United Kingdom

Rights statement

Copyright 2020 The Authors. Licensed under Creative Commons Attribution 4.0 International (CC BY 4.0) https://creativecommons.org/licenses/by/4.0/

Repository Status

  • Open

Socio-economic Objectives

Fisheries - wild caught not elsewhere classified

Usage metrics

    University Of Tasmania

    Exports

    RefWorks
    BibTeX
    Ref. manager
    Endnote
    DataCite
    NLM
    DC