You and Your CourseOpportunities
Research and Teaching
Our ResearchResearch Degrees
Partners and Community
Partner with JCU
- About JCUPartner with JCU
- Careers and Employability
- College of Arts, Society and Education
- College of Healthcare Sciences
- College of Medicine and Dentistry
- Division of Tropical Environments and Societies
- International Students
- JCU Eduquarium
- Open Day
- Parents and Partners
- Pathways to University
- JCU Connect
- Scholarships @ JCU
- Media & Comms
- Australian Institute of Tropical Health & Medicine
- About JCU
Featured News Naïve fish easy targets for spear fishers
Naive fish easy target for spear fishers
Nov 13, 2012: - Big fish that have grown up in marine reserves do not seem to know enough to avoid fishers armed with spear guns waiting outside the reserve.
The latest research by an Australian team working in the Philippines into the effects of marine reserves has found there is an unexpected windfall awaiting fishers who obey the rules and respect reserve boundaries – in the form of big, innocent fish wandering out of the reserve.
“There are plenty of reports of fish, both adults and juveniles, moving out of reserves and into the surrounding sea. Having grown up in an area where they were protected from hunting, we wondered how naïve they would be with regard to avoiding danger from humans,” says Fraser Januchowski-Hartley of the ARC Centre of Excellence for Coral Reef Studies at James Cook University.
The answer is: pretty naïve.
“Educated fish normally turn tail and flee when a diver armed with a spear gun approaches within firing range of them. The typical flight distance is usually just over four metres,” he explains.
“However in our studies of marine reserves in the Philippines, Vanuatu and Papua New Guinea, where spearfishing remains a major way of harvesting table fish, we discovered that reserve-reared fish were much less wary and allowed people to get much closer.
“The fish are literally more catchable.”
The team studied fish across the boundaries of marine reserves from 200m inside the protected areas to 200m into the fished areas. They used underwater markers and measuring tapes to measure the ‘flight initiation distance’ of fish targeted locally by spear fishers. This indicates how close a skin diver can approach to a large fish before it decides to turn and flee.
They found that target fish living in fished areas were typically much warier of divers, and took flight at distances a metre or two further away, than ones living within the reserve.
They also established that the ‘naivete radius’, whereby more catchable fishes spill out of the marine reserves extended for at least 150 metres from the boundary.
The team’s findings suggest that fishers are more likely to catch fish that stray out of the reserve, and so improve the local fish harvest. This may help fishers become more supportive of marine reserves.
JCU’s Dr Nick Graham, a co-author on the study said that in these parts of the oceans, spear fishing was still very much about survival for humans and putting food on the family table.
“So it is important that local fishers feel they are deriving some benefit from having a local area that is closed to fishing, or they may not respect it,” Dr Graham said.
“This information is also useful in traditional reserves where fishing is taboo most of the time, but then they are opened for fishing by village elders just a few days a year.”
Mr Januchowski-Hartley said that on the face of it, this work suggests that marine reserves can play an important role in putting more fish on the table of local communities in these tropical locations – as well as conserving overall fish stocks and replenishing those outside the reserve.
The team’s paper ‘Spillover of fish naïveté from marine reserves’ by Fraser A. Januchowski-Hartley, Nicholas A. J. Graham, Joshua E. Cinner and Garry R. Russ appears in the latest issue of the scientific journal Ecology Letters. http://doi.wiley.com/10.1111/ele.12028
Nick Graham, JCU and CoECRS, ph +61 (0)7 4781 6291 or 0466432188
Fraser Januchowski-Hartley, CoECRS, ph +1 608 807 1202
Jenny Lappin, CoECRS, +61 (0)7 4781 4222
JimO’Brien, James Cook University Media Office, +61 (0)7 4781 4822 or 0418 892449
Issued: November 13, 2012
- James Cook University
- Bachelor of Advanced Science
- Bachelor of Arts
- Bachelor of Biomedical Sciences
- Bachelor of Business
- Bachelor of Business / Laws
- Bachelor of Business & Environmental Science
- Bachelor of Dental Surgery
- Bachelor of Early Childhood Education
- Bachelor of Primary Education
- Bachelor of Secondary Education
- Bachelor of Environmental Practice
- Bachelor of Geology
- Bachelor of Information Technology
- Bachelor of Laws
- Bachelor of Nursing Science (External)
- Bachelor of Midwifery
- Bachelor of Pharmacy
- Bachelor of Physiotherapy
- Bachelor of Planning
- Bachelor of Psychological Science
- Bachelor of Science
- Bachelor of Social Work
- Bachelor of Speech Pathology
- Bachelor of Sport & Exercise Science
- Bachelor of Veterinary Science
- Bachelor of Clinical Sciences (Honours)
- Bachelor of Engineering (Honours)
- Bachelor of Engineering / Science (Honours) MBA in Tourism
- Master of Public Health and Tropical Medicine
- Master of Data Science
- Bachelor of Sports Psychology
- Bachelor of Marine Science
- Bachelor of Medicine / Surgery
- Bachelor of Nursing Science [Pre-Registration]
- Bachelor of Medical Laboratory Science (Honours)
- Bachelor of Occupational Therapy (Honours)
- Bachelor of Psychology
- Master of Conflict Management & Resolution
- Graduate Certificate of Conflict Management & Resolution
- Master of Global Development
- Master of International Tourism & Hospitality Management
- Bachelor of Technology and Innovation
- Bachelor of Science & Bachelor of Laws
- Diploma of Higher Education
- Diploma of Higher Education (Business)
- Diploma of Higher Education Majoring in Business Studies
- Diploma of Higher Education Majoring in Engineering and Applied Science
- Diploma of Higher Education Majoring in General Studies
- Diploma of Higher Education Majoring in Health
- Diploma of Higher Education Majoring in Information Technology
- Diploma of Higher Education Majoring in Science
- Diploma of Higher Education, Majoring in Society and Culture