Tag Archives: Marine Research

Fish Thinkers online: 2015 in review

 

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Photo credit: Top centre Aussie Fly fisher, top right John Harding & all others Fish Thinkers.

I was reading one of the bigger ecology blogs that I find myself returning to fairly regularly and they posted a review of their blog year, mostly for themselves to reference.  I found it interesting so went to have a look at our own blog and social media stats. I thought  I’d post a fish thinkers summary mainly as a record for myself but also on the odd chance anyone else is vaguely interested (its also a sneaky way to kick off a year in which I plan to post on here more regularly). Continue reading

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Make your assignment marker happy

While I am reblogging things; I have been meaning to reblog this post of Martins for a while. He has written a useful little document (that you can download) outlining many of the basic grammar and formatting mistakes that students make in their reports (and that apparently make him miserable haha). Lets be honest, I made a few of the mistakes as well so I found it quite useful myself but perhaps its best use is being passed onto undergrads when you are going mark their work ;). I’ll let Martin do the rest of the talking…

Squiddled thoughts

The dreaded red pen. The dreaded red pen. An example of a very frustrated marker. I hope my feedback was a little less personal (this is NOT a picture of my marking). 

Recently I’ve been marking for some second and third year biology classes. I’ve been a little shocked at the quality of the work the students have been presenting. I found myself wondering whether I was marking them too hard? However, I soon came to the conclusion that this was not the case.

One of the classes is a third year class and some of these students are on the cusp of completing a Bachelor of Science without knowing whether to use “two”, “to” or “too”. It’s a scary thought. I would like to think that these students wouldn’t be able to complete their degrees with such appalling spelling and grammar, but let’s face it, they’ve made it through to the final semester of their undergraduate degrees…

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Ocean Acidification – The Ocean’s other problem with CO2

This guest post is from Elliot Scanes, a PhD candidate from Western Sydney University who runs cool experiments to understand the impact of climate change on our molluscs. Elliot has a great Instagram research account with Dr Vicky Cole called seao2, so give them a follow to keep up to date with their work.


Ocean Acidification – The Ocean’s other problem with CO2 

by Elliot Scanes

Humans are currently emitting CO2 faster than has occurred on Earth for millions of years. Currently, atmospheric CO2 concentrations are at their highest point in 800,000 years and don’t look like slowing any time soon. Inevitable global warming as a consequence of the excess CO2 and other pollutants causing the “greenhouse effect” is well established among scientists (despite what politicians might say). This warming of the earth will eventually also cause warming of the oceans, most notably affecting species ranges. But this is not the only way excess CO2 is going to change the world’s oceans. The oceans have already absorbed 40% of the CO2 emitted by humans, and will keep continuing to do so. As CO2 dissolves in seawater, it forms carbonic acid, which, in turn causes the oceans to acidify. So far, oceanic pH (the measure of acidity) has fallen 0.1 units, and is predicted to fall 0.3 – 0.4 pH units by 2100 unless drastic global action is taken to curb emissions.

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Collecting Sydney rock oysters (Saccostrea glomerata) for experiments in Port Stephens.

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Opening flat oysters (Ostrea angasai).

 

 

 

 

 

 

 

 

This small decrease in pH may seem insignificant, however pH is measured on a natural logarithmic scale (for those mathematicians) which means that each unit is an order of magnitude larger than the previous. A 0.3 unit drop in pH means that calcium carbonate, the mineral that all shelled animals shells are composed of, is now soluble in seawater. Predictably, scientists are most concerned about the shelled animals of the ocean like molluscs, crustaceans and cnidarian (corals). Investigations by our lab at Western Sydney University have shown that under these scenarios Sydney rock oysters will have difficulty forming their shell, especially in their juvenile stages. These difficulties waste vital energy, which is especially important in an environment where you always need an edge on your competitor. Similar studies have found comparable effects in sea urchins, corals, scallops and almost every shelled animal in the ocean that you can think of. Continue reading

The global tracking map: your key to discovering how the marine world moves.

VEMCO researchers map

VEMCOs researchers map: ‘Help us help you collaborate with the best researchers in the world and let us “Put You on the Map”! Red pins represent studies using VEMCO products, the dark pins represent institutes’.

For those that have an interest in animal movement in the oceans, I’d like to draw your attention to a handy and interesting tool on the VEMCO website; the global tracking map. This tool 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.

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

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