Posts By: David Muirhead
September 19, 2017
More About the Normanville Communication Cable
Further to my article “The 1875 Communication Cable from Normanville to Kangaroo Island”, whether the cable was installed in during the 1860s or the 1870s, has been a niggling doubt for the author. The few historical records I’d come across seemed to vary a bit as to key dates with regards to the draft project’s definitive government funding approval date, works commencement and completion dates, and even the official opening ceremony date. Several years ago, I read an old newspaper article, reprinted in one of several…
Posted in intertidal zone, Jetties, Maritime History | By David Muirhead
September 17, 2017
One Genus Two Species, Endless Entertainment
Encounters of the kind below are not what most of us expect when at the beach for a swim and a bit of relaxation on a nice summer day. Which adds a special touch, for me at least. You can wade bare-footed at knee to waist depth off almost any white sandy beach in Gulf St Vincent and Spencer Gulf and see several species of pipefish that specialize in hiding in and around the edges of those dark patches of seagrass detritus that are…
Posted in Bony fishes, Coastal species, Syngnathids | By David Muirhead
August 19, 2017
The Unique South
Seems like only yesterday that lovers of temperate southern Australian rocky reefs first heard and, in some cases, eagerly promulgated the term “The Unique South “. The term had instant appeal as a catchy descriptor with seemingly obvious educational value. I loved the term from the first encounter. I guess the term “Unique South ” struck so powerful an emotional chord within me because fate decreed the time had come. And because of the validation it bestowed on people who…
Posted in Creative writing | By David Muirhead
October 19, 2014
Harlequin Fish in peril in SA, still targeted
To the editor of The Sunday Mail, I note with dismay the anachronistic discrepancy of two items printed on page 69 in the Sunday Mail today (October 19, 2014). The first item, ‘Fishing Hot Spots with Jon Huie’ shows a trophy shot of a rare Harlequin Fish caught off Cape Jervis by an angler. The other item, ‘What’s On’ describes a planned beach cleanup and dolphin awareness activities under the heading: Sea Shepherd Adelaide Beach Activity Day at Brighton jetty and beach. The Harlequin Fish…
Posted in Bony fishes, Marine Protected Areas, Pollution | By David Muirhead
August 11, 2014
Opalescent Eye of Toadie – Reflecting on refracted light
Here’s why I rave about our toadies’ amazing eyes when seen via facemask in shallow, sandy, near-shore areas. I see them mainly late, in summer and autumn, when they are at their most prolific. They are found in very shallow areas almost anywhere in SA, except for the far west coast. The image below which features their green and blue ‘opal’ eyes is from knee-depth shallows of Lady Bay on a bright sunny day. Despite the camera data stating ‘flash used: yes’, I assure you…
Posted in Bony fishes | By David Muirhead
July 26, 2014
The Southern Rock Lobsters at Margaret Brock Reef
The sanctuary zone at Margaret Brock Reef is the only place I’ve dived in SA where I’ve seen large numbers of huge rock lobsters (along with prolific juveniles and all between). Until then, I’d wrongly believed the (with hindsight, small to medium) lobsters (up to approx. 3-4 Kg with regard to the few we ate each Xmas!) that I and my various dive buddies were seeing everywhere else in SA were actually big, quite mature lobsters. We were in fact…
Posted in Crustaceans, Marine Protected Areas | By David Muirhead
February 28, 2004
Testing a Shark Shield while snorkeling at Marino
Having used a scuba-model Shark Shield for many years, I recently had the privilege of testing the new snorkeling version which Mike Wescombe-Down of the Coastal Waters Dive Club kindly loaned me in readiness for the West Coast Blue Groper Survey (See next Newsletter?). I never actually used it on that trip as I only snorkeled in ‘safe’ inshore areas such as gutters, channels and pools largely protected from the open sea, and when photographing on SCUBA in open water…
Posted in Dive Reports, Equipment | By David Muirhead
August 30, 2002
Tumby Bay Jetty Dive
Jenni and I had a few days R and R at Port Lincoln this week so I took my gear, hoping to get a few dives. The shore/jetty dive prospects and viz at Whyalla, Cowell, Port Neill and Arno Bay varied from poor to “possibly just o.k. but let’s try the next town.” Finally at Tumby Bay, the last town before Port Lincoln, both the viz and the jetty access looked adequate so in I went, complete with a ‘Seachange’…
Posted in Dive Reports, Jetties, Syngnathids | By David Muirhead
July 30, 1997
Dory Diary
Whilst diving with Paul and Leona Fitzgerald on the Noarlunga Tyre Reef on 30/1/97 I chanced upon a very distinctively shaped fish lurking close to a tyre pyramid. Though I cannot recall ever sighting one during my years of diving in SA waters, I was quite sure this was a Dory. I hoped that it would oblige me by either being approachable or, at least,seeking refuge within a pyramid (as other species on tyre reefs often do, notably Bullseyes, Black-spotted…
Posted in Dive Reports | By David Muirhead
May 30, 1997
Growing A Mineral Base For Coral Growth
The January 17 issue of “Australian Doctor” told of the use of electricity to create a base that coral could grow on. Dr Karl Kruszenelnicki’s “Wierd Science” column tells how magnesium and calcium-based minerals build up when electricity is passed through sea water. A layer of minerals 20cm thick took three years to build up. These acted as a base for corals and other animals to attach to. This mineral accumulation works on old cars, seals off potential toxins and…
Posted in Coral | By David Muirhead