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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Close to Home: What Drives the Distribution of Intertidal Rockpool Fishes?

Read below for a great summary by Kai Paijmans on his research examining the distribution of rockpool fishes. Kai’s project was for a 3rd year UOW research subject, where he was supervised by Dr. Marian Wong and Ben Gooden.

Close to Home: What Drives the Distribution of Intertidal Rockpool Fishes?

Rocky intertidal shores are right on the edge of our home – between the known of the shores and the vast unknown of the world’s oceans. Although regularly overstepped by many of us, rockpool life is largely overlooked in favor of large charismatic and untouchable creatures of the open and comparatively inaccessible ocean. It is important to understand the ecological processes occurring on rocky shores as they are right on our doorstep; heavily used for, and potentially impacted upon by recreation. Continue reading

Fish Thinkers Research Group Youtube channel now online!

Follow the link below to watch our first youtube video! Make sure to watch in HD. It’s a short edit of my trip to Lord Howe Island to survey the marine parks fish populations using baited remote underwater video systems. More videos coming soon so stay tuned!

Urbanisation impacts abundance (but not richness) of salt marsh molluscs

Matt Rees:

A great summary by Ben Gooden on Geoff Clarke’s research examining the impact of urbanisation on salt marsh snails. It was a lot of fun hanging out counting snails in the mud, especially along the shores of Lake Illawarra (we saw some weird things). Make sure you head over to Ben’s blog for more interesting ecological posts!

Originally posted on Ben Gooden - Ecological Research:

salt marsh impactThe preliminary results are now in: urbanisation at the landward boundary of coastal salt marshes is associated with a two-fold reduction in the density of molluscs inhabiting adjacent coastal salt marsh. Our results found, however, that despite this reduction in overall molluscan abundance, urbanisation had no effect on the number of different mollusc species (i.e. richness) present in adjacent salt marshes.

The overall aim of this project was to examine effects of shoreline urbanisation on the unique molluscan fauna within endangered salt marsh of south-eastern Australia. My student, Geoff Clarke did a stellar job with this project, counting and identifying over 7,500 individual snails from six species, most of which are restricted to salt marsh or similar vegetation that borders estuaries and coastal embayments.

Geoff surveyed 9 ‘urbanised’ and 9 ‘forested’ (which he termed natural) reference sites across three embayments (see accompanying satellite images). Each site consisted of a…

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Surrogates for temperate reef biodiversity and their use in conservation

Earlier this year my co-authors and I published a paper in Diversity and Distributions that examined a cost-effective way of predicting reef biodiversity for conservation purposes. Here is some background on the issues surrounding the design of Marine Protected Areas (MPAs) and a brief summary of our research findings.

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Western Australian Shark Hazard Mitigation Drum Line Program

Lachlan Fetterplace:

 

Marty over at SQUIDDLED THOUGHTS posted today on where to go to make a submission on the proposed WA Shark Hazard Mitigation Drum Line Program 2014 – 2017. If its something you are interested in or care about then its worth taking a look.

Originally posted on Squiddled thoughts:

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The Environmental Protection Agency in Western Australian are now accepting submissions for public comment on the proposed WA Shark Hazard Mitigation Drum Line Program 2014 – 2017.

I would urge people to have a look at the documentation here and to make a submission here. On the face of it, I am personally opposed to the idea for the following reasons:

  1. I like sharks.
  2. Many species of non-target sharks are captured on drum lines.
  3. Other forms of marine life such as whales and turtles could become entangled.
  4. Great White Sharks, one of the “target” species, are listed as vulnerable under Western Australia’s legislation (Wildlife Conservation Act 1950 (Western Australia)). Great White Sharks are also listed as vulnerable under national legislation (Environment Protection and Biodiversity Conservation Act 1999). 
  5. Shark control programs such as those implemented in NSW and Qld have not significantly reduced shark attacks.
  6. Many, many more people die…

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Special marine ecology edition of the ESA bulletin is now online!

The latest Ecological Society of Australia bulletin, which I co-edited alongside Ben Gooden, is now up online! It has been such a great experience to invite some of Australia’s premier marine scientists to showcase their research in this special marine ecology issue. In this edition we have contributions by Emma JohnstonMelanie BishopRob HarcourtLuciana Möller and Guido Para, along with student contributions by Paul CarnellJulia Santana Garcon and our very own Lachlan Fetterplace. The bulletin covers a diverse range of current marine ecological research, from kelp forest dynamics to marine predators, ecotoxicology to cetacean behaviour and mudflat ecology to surveying fish with underwater cameras – so there is something for everyone!

You can read or download the bulletin here!

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