KZN Sharks Board
In order to protect swimmers we need to
reduce the environmental impact of nets. Sharks play an important role as apex
predators in regulating the numbers of animals on which they prey. Nets are not
only harmful to sharks but also catch Rays, Dolphins, Turtles and other sea
life. The Sharks Board has worked for some time on solutions to reduce the
number of nets, including drumlines, a research project with the Endangered
Wildlife Trust to determine the efficacy of dolphin deterrent devices and
discretionary bathing. This discretionary bathing has allowed them to keep nets
out of the water for as long as two months, minimizing the chances of
large-scale mortalities especially during the annual Sardine Run. In a more
recent project they are investigating using its patented waveform in a shark
repellent cable that would surround a bathing area with an electrical field.
Physicists and electrical engineers were contracted for this research in 2010
which has since commenced.
Wideside Magazine, 1 of 4, 2012
Further information: Tel 031 566 0400
Fish conditioning lead to later danger?
As the controversy over chumming for sharks
and cage diving rages on there is always a nagging doubt that we are supporting
something that could lead to later danger. It is rare for a diver to be
attacked by a shark unless: they are in a bait ball, in the wrong place at the
wrong time or acting foolishly and dive operators who offer these extreme
experiences say they have never felt in any danger. Theoretically, anything
that changes the behaviour of a creature in its natural habitat is unwarranted
interference, however the test of stress in a creature is whether it continues
to live, eat and breed in the area and the evidence of stress-free fish is
everywhere. So is it a bad thing for fish to become conditioned to the presence
of divers in their private domain? Maybe as we learn about them, they learn
about us and judging by behaviour once they know us, they don’t seem to mind
us.
Divestyle Magazine, Nov/Dec, 2012
Further information: divestyle.co.za
Article by: Jill Holloway
Dune forest rehab in Richards Bay
Richards Bay Minerals (RBM) mines mineral
sands on sensitive sub-tropical remnant coastal dunes. High standards of
rehabilitation have always been a top priority for the company and restoration
began when mining began on mostly bare, degraded dunes in 1977.The objective
was to restore natural forest values to mined dunes. Although it takes between
18 and 24 years to re-establish the same sort of vegetation evident in the surviving
forest remnants nearby, results in Richards Bay to date have been outstanding.
Restoration was achieved in a 3 stage successional development. First ground
cover and grasses were established on reshaped dunes, then acacia forest moved
in and finally mature forest species appeared .As predicted native fauna also
re-established overtime. The plant and animal life found there now form a dune
forest similar to other indigenous forests along the coast. The Richards Bay
experience is an object lesson – particularly the benefits that flow from
progressive rehabilitation and the value of long term monitoring and research.
Truly understanding and re-establishing a complex local ecosystem is a journey,
it takes experience, commitment and time.
Wildside Magazine, 3 of 4, 20012
Further information: www.rbm.co.za
Email: communication@rbm.co.za
Thanks Megan for your industry news this week. Reading the article on the Dune Forest rehab in Richards Bay, the question came up of how they could possibly think to rehabilitate a coastal forest that has taken 700- 800 years to get to the point it was before man stepped in. Doing some research on the matter i found some interesting facts on this topic. The analyses done on the rehabilitation point to a relatively speedy recovery Probably the largest, in terms of sheer biomass, and arguably the most important component of a forest, is its trees. Their analyses done showed that the tree assemblage (the collection of species that occur together in a particular place) will recover the same tree diversity and species composition of an undisturbed dune forest in about 40 to 45 years after the initial rehabilitation of an area. They also calculated that the bird, small mammal, millipede, dung beetle and herb assemblages should all recover in less than 40 years. Although there is a measure of uncertainty in these predictions (as with all scientific analyses), it is unlikely that it will take much longer than 90 years they predict. Almost seems impossible, but very impressive if they were to be accurate on these predictions!!
ReplyDeleteFor more information go to the CERU (Conservation Ecology Research Unit) website and read all about it!
http://www.ceru.up.ac.za/restoration/faqs.php