Murray Duncan

Murray Duncan
Stanford University | SU

PhD - Fisheries Science

About

20
Publications
5,507
Reads
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260
Citations
Introduction
I am a marine fisheries scientist specializing in applied research aiming to enhance commercial fisheries sustainability. This is primarily done by taking an eco-physiological approach to quantify the influence of climate and exploitation drivers on aspects of fish stock productivity. My broader research interests include the effect of environmental variability on population dynamics, fish life-histories, Marine Protected Areas and incorporating climate data into fish stock assessment modelling. I am based at the South African Institute for Aquatic Biodiversity and the Department of Ichthyology and Fisheries Science, Rhodes University where I lecture, co-supervise postgraduate students and help run multiple research projects across southern Africa.
Additional affiliations
January 2019 - December 2020
Rhodes University
Position
  • PostDoc Position
Description
  • Researching eco-physiological aspects of fish populations in Southern Africa
Education
May 2015 - March 2019
Rhodes University
Field of study
  • Fisheries Science

Publications

Publications (20)
Article
Full-text available
The Republic of Seychelles is one of six African Small Island Developing States (SIDS) and has a marine-based economy reliant on fisheries and international tourism. Seychelles has been flagged by the United Nations as highly vulnerable to climate change. Climatic threats are compounded with population declines of key fishery species. A progressive...
Article
Full-text available
Climate change not only drives increases in global mean ocean temperatures, but also in the intensity and duration of marine heatwaves (MHWs), with potentially deleterious effects on local fishes. A first step to assess the vulnerability of fishes to MHWs is to quantify their upper thermal thresholds and contrast these limits against current and fu...
Article
Anthropogenic induced climate change is predicted to increase the thermal variability in coastal waters, which can have strong physiological effects on individuals and populations of marine ectotherms. The magnitude and direction of these thermal effects varies depending on species, life stage, biogeography, habitat and season. This study aimed to...
Article
Sagittal otolith pairs were extracted from two-hundred-and-twenty-six giant African threadfin Polydactylus quadrifilis collected from the Kwanza Estuary in Angola between 2016 and 2018 ranging in size from 160 to 1360 mm fork-length (FL) and from one to 23 years of age (26 juvenile, 170 male, nine intersex and 27 female). An additional 85 otolith p...
Article
Full-text available
The distributions of ectothermic marine organisms are limited to temperature ranges and oxygen conditions that support aerobic respiration, quantified within the metabolic index (ϕ) as the ratio of oxygen supply to metabolic oxygen demand. However, the utility of ϕ at local scales and across heterogenous environments is unknown; yet, these scales a...
Article
Linefish' is a uniquely South African term used to describe marine fishes that are captured using hook and line. The South African linefishery is a complex socio-ecological system that has a considerable impact on the coastal marine environment while generating social and economic benefits for commercial, small-scale and recreational fishers. Like...
Article
Full-text available
Foreign fishing tourism (FFT) is becoming increasingly popular in the developing world, where it often coexists alongside other important sectors involving domestic recreational anglers and dependant artisanal and subsistence fishing communities. Therefore, it is important that FFT operations use effective catch‐and‐release (C&R) angling to minimis...
Article
Catch-and-release (C&R) angling has increased in popularity through its mandatory and voluntary use in fisheries conservation and management. However, research has shown that fish can experience considerable stress during a C&R event. The physiological response of fishes is typically assessed by measuring the concentrations of blood-plasma cortisol...
Article
Full-text available
There is widespread consensus among climate scientists today that global climate change is real and has anthropogenic roots. Marine species, for example, are exposed to a large array of abiotic stressors, such as warming and ocean acidification, that are linked directly to anthropogenic climate change. The general view on whether natural population...
Article
Full-text available
Quantifying how the heart rate of ectothermic organisms responds to environmental conditions (e.g. water temperature) is important information to quantify their sensitivity to environmental change. Heart rate studies have typically been conducted in lab environments where fish are confined. However, commercially available implantable heart rate bio...
Article
As marine environments are influenced by global warming there is a need to thoroughly understand the relationship between physiological limits and temperature in fish. One quick screening method of a physiological thermal tipping point is the temperature at which maximum heart rate (ƒHmax) can no longer scale predictably with warming and is referre...
Book
Full-text available
The Southern African Marine Linefish Symposium is an event where scientists come together and present any contemporary research relating to linefisheries in the region. The symposium occurs every 4 - 7 years depending on circumstances and the research presented at each event is summarized and published in the form of a proceedings document. The lat...
Article
Full-text available
The El Niño–Southern Oscillation (ENSO) phase state is reported to drive interannual variability in sea temperatures along South Africa’s south coast through its influence on wind-induced upwelling processes. Whether ENSO drives the intensity of localised, abrupt, intermittent upwelling is less well known. To explore this relationship, we used an i...
Article
Full-text available
While otoliths are considered the most reliable structure to accurately age fish, a variety of otolith preparation techniques are available, which have consequences on the otolith's optical properties and therefore interpretation of growth bands. Recently, numerous studies from a variety of authors have criticised the use of whole otoliths in agein...
Article
Full-text available
Physiological rates and processes underpin the relationships between ectothermic organisms, such as fish, and their environment. The response and persistence of fish populations in an increasingly variable ocean is dependent on the distribution and diversity of physiological phenotypes. Growing evidence suggests that fisheries exploitation can sele...
Article
Full-text available
Restricting human activities through Marine Protected Areas (MPAs) is assumed to create more resilient biological communities with a greater capacity to resist and recover following climate events. Here we review the evidence linking protection from local pressures (e.g., fishing and habitat destruction) with increased resilience. Despite strong th...
Article
Full-text available
Ecologists must understand how marine life responds to changing local conditions, rather than to overall global temperature rise, say Amanda E. Bates and 16 colleagues. Ecologists must understand how marine life responds to changing local conditions, rather than to overall global temperature rise.
Article
The slinger, Chrysoblephus puniceus, a seabream of the family Sparidae, is an important commercial linefish species in South Africa and Mozambique. Despites its fisheries importance little is known about the population structure of the species and it is currently managed separately by both countries. The genetic connectivity between localities thro...

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Projects

Project (1)
Project
Examine the impacts of ocean warming in Namibia and more specifically to examine the impact of hybridisation on the thermal physiology of Argyrosomus species.