Category Archives: Fisheries

Why Salmon can’t be on the menu anymore

We as consumers, particularly in western countries, are pretty boring when it comes to our seafood. Given the diversity of fish in our oceans this seems pretty strange. It’s like our taste buds are only fond of a handful of species such as tuna, cod, salmon, flake etc. But our obsession for these fish (majority of which are apex predators), has resulted in many of their stocks becoming overfished and deterioration of the ecosystems in which they live in. So it’s time we started mixing things up in terms of what seafood we catch, order, buy and cook!! This leads me to today’s guest post by Lauren Yates of Ponytail Journal. Lauren runs a super successfully blog covering all things from fashion, food and travel. When it comes to cooking, Lauren is a huge advocate of using sustainable seafood, regularly encouraging her followers to steer clear of the ‘trendy’ species that are overexploited and explore more sustainable options. Read her post below on why salmon can’t be on the menu anymore… Continue reading

Rules of attraction: enticing pelagic fish to underwater cameras

One aspect of my PhD is to understand a little bit more about the ecology of pelagic fishes, specifically what habitats they prefer in coastal waters. But before I could do this I first had to determine the best way to sample these fishes and this is what todays post is on. Continue reading

Building Coral Trout Management

This guest post is by Jordan Matley, a PhD Candidate at James Cook University who has worked on various subjects ranging from the foraging ecology of seals, beluga whales and narwhals in the Arctic to the movement of fish on coral reefs in Tropical Australia.  At the recent Australian Society of Fish Biology conference we were talking about all things fishy but his work on coral trout was one of the highlights for me. Hence (when he had his guard down at the bar) I asked him to give us a run down on some of his coral trout behaviour work.


Building Coral Trout Management

By Jordan Matley


A tagged leopard coralgrouper (Plectropomus leopardus) ready for release.

Imagine you were opening a new hotel from scratch. Because you are in a rush (and without any prior experience) you decide to put an ad online – “Tradespeople needed to build hotel. First 100 qualified applicants will be hired on the spot”. True to your word, you hire the first century of people who have a diploma related to Trades and Services. See the problem with that? Well, chances are the workforce will consist of those with the most common experience, likely general labourers. However, to build a hotel, you need a plethora of highly skilled workers: electricians, builders, decorators, plumbers, and the list goes on. But you did not select for that, you just grouped all tradespeople together and the more abundant profession filled the ranks. Foolish? I’d say so. Continue reading

Positive response of Giant Mud Crabs to protected areas

The giant mud crab (Scylla serrata) is a beast of a crustacean, capable of reaching 3kg in weight but often caught around the 0.5-1kg range. In Australia, they are distributed in sheltered waters from southern NSW, up through QLD, across the NT and over to Broome, WA.

Giant mud crabs have a short life cycle (3-4 years) and are reproductive machines. Females can carry between 2 – 5 million eggs and migrate up to 95km offshore to release their eggs. The young crabs hatch as tiny planktonic larvae, where they can remain in this stage for several weeks at the mercy of ocean currents. This aspect of their biology gives giant mud crabs substantial capabilities for dispersal.

A giant mud crab (Scylla serrata) chillin next to some mangroves on Mali Island. Photo by Jürgen Freund. Check out more of his amazing wildlife photos here and on facebook at Jurgen Freund Photography – Australia.

Their prized meat and high numbers within estuaries make them a highly targeted recreationally and commercially harvested species. In NSW, annual commercial landings are approximately 100-120t and the annual recreational catch is estimated between 30-60t. The main method of capture by both commercial and recreational fishers are crab pots, however rec fishers also use hoop nets or dillies.

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Defining geographic boundaries for shark populations

by Dr Pascal T Geraghty

Declining fish stocks and increasing fishing capability worldwide have placed an ever growing emphasis on the need for responsible fishery and species management at appropriate spatial scales. To achieve this, delineating the discrete breeding groups (or populations) of a target species within a given geographical area is of utmost importance. This is particularly challenging in the marine realm, however, where population boundaries are dictated by cryptic barriers to dispersal, a species’ potential for travel and reproductive behavioural traits. Nevertheless, genetic techniques have become an invaluable tool for uncovering population structure in exploited marine creatures.


Demersal longline shark fishing in northern NSW waters as observed during 2008/09. Photo: Dr Geraghty.

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