Tagged whales

Census finds West Coast may be hotspot for top ocean predators

great white shark photo
The great white shark was one of 23 species tracked by the TOPP study.

The Washington Post reports that The Census of Marine Life’s Tagging of Pacific Predators (TOPP) project reveals that a region of the eastern Pacific Ocean just off the West Coast may be one the top "hotspot" for open ocean predators. The study, which involved researchers from five different countries, was recently published online at the journal of Nature.

The study tracked movement patterns of 23 species of ocean predators. Notable data included an elephant seal diving to a depth of 5,492 ft, and shearwater seabirds traveling over 39,790 miles over the course of 262 days. However, it was the nutrient rich waters of the California Current that garnered the most attention in the Post article, due to the fact that draws various marine animals from far and wide to a common meeting place. In the spring months, turtles, whales, sharks, tuna, and seabirds from throughout the Pacific converge off the West Coast to partake in the "nutrient upwelling."

For more information, check out the Washington Post article, and read the Nature journal article (PDF).

Queensland shark nets to be fitted with alarms for whales

Shark nets in Queensland will be fitted with “pingers” designed to alert migrating whales to the presence of shark nets, according to the Sydney Morning Herald. The move marks an attempt to help prevent whales from becoming entangled in the nets. In 2009, six whales were trapped in the shark nets, which have stirred up controversy in the past. All six of the whales trapped last year were successfully freed.

The shark nets are already equipped with pingers designed to alert dolphins. The whale pingers will a “longer and louder noise” as compared to the dolphin pingers, according to Primary Industries Minister Tim Mulherin, who went on to note that the pingers are designed only to alert the whales of the presence of the nets not to scare them away.

Multiple prototypes will be fitted to the nets this week as a test run. The goal is to have the alarms on all the shark nets by August when younger whales are more likely to come in close proximity to the nets.

Queens land government introduces five-year plan to monitor bull, tiger, and white sharks

White sharks are among the sharks that will be monitored by a Queensland government plan.
White sharks are one of the three species that will be monitored by a Queensland government plan.
The Brisbane Times is reporting that the Queensland government will be spending $125,000 on a five-year program to tag and monitor bull, tiger, and white sharks in an effort to "reduce the risk of attacks." Acoustic tags will be used to report data to monitoring stations when tagged sharks are nearby. Shark control program manager, Tony Ham, said that they expected to tag 150 sharks in three years (which seems like an odd statement, considering that the article reports the duration of the study to be five years).

In addition to the shark monitoring aspect, the Queensland government will also invest in new and improved acoustic alarms to alert whales and dolphins of the existence of shark nets." The new alarms will use a longer lower pitch signal at a louder volume to give cetaceans a more advanced warning of the nets. The shark nets have come under criticism due to whales and other marine life becoming entangled in them.