Bald reef gets seaweed transplant
High levels of sewage in Sydney in the 1970s and 80s caused a species of seaweed, called crayweed (Phyllospora comosa), to disappear along the coast. Despite improved water quality in the 1990s, the 70km gap of depleted crayweed forest was never able to recover. Now, marine ecologists have successfully restored this once thriving species by transplanting fertile specimens of crayweed to two barren reef sites where it once grew. The transplanted crayweed survived similarly to the natural populations and successfully reproduced.
New test for salmon DNA tracing
Scientists have developed a new, efficient DNA test that allows escaped farmed salmon to be traced back to the fish farm from which it escaped. The advantage of this system is that not all of the fish in the sea cage need to be DNA tested, only the parents (which is still around 30 to 40,000 fish!). By having the DNA of the parents, any escaped offspring can be matched.
Tracking the deep sea paths of tiger sharks
Using satellite and acoustic transmitters, researchers followed the movement of 33 tiger sharks (Galeocerdo cuvier) across the Coral Sea between New Caledonia and the Great Barrier Reef for four years. They found that the range of movement varied with the age and sex of the shark. One 3.7m female was recorded at a previously unknown depth of 1136m. The study also reveals that coastal marine parks provide only brief protection for the sharks, while oceanic reefs, which are vital to the tiger shark’s ecology, remain unprotected. A better understanding of the tiger shark’s habitat use and migration patterns and extremely important for assessing the effectiveness of MPAs and management strategies. For more on tiger sharks, check out this post: New Documentary Reveals the Private Lives of Tiger Sharks.
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