12.07.2015 Views

Oceans of noise - Whale and Dolphin Conservation Society

Oceans of noise - Whale and Dolphin Conservation Society

Oceans of noise - Whale and Dolphin Conservation Society

SHOW MORE
SHOW LESS
  • No tags were found...

Create successful ePaper yourself

Turn your PDF publications into a flip-book with our unique Google optimized e-Paper software.

• Humpback whales appeared tolerant <strong>of</strong> transient blasting activity <strong>and</strong> frequent vessel traffic.• The whales were affected (numbers decreased) by continuous dredging activity concurrentwith vessel traffic.• There was a significant decrease in the return rate <strong>of</strong> humpback whales to the feeding groundsdisturbed by industrial activity, indicating ab<strong>and</strong>onment <strong>of</strong> the disturbed area which is apossible long-term effect <strong>of</strong> exposure to blasting.Ref: Borggaard et al. 1999.Location: Hawaii• Humpback whale song structure was studied when whales were approached by boats.Although largely the song structure <strong>and</strong> characteristics were not greatly affected, the duration<strong>of</strong> some song elements changed.Ref: Norris 1994.Location: West Indies• Some humpback whales avoided boat traffic on the breeding grounds; in particular motherswith calves were sensitive to the approach <strong>of</strong> boats.Ref: Clapham <strong>and</strong> Mattila 1993.Location: Hawaii• When a boat approached within 0.5 miles <strong>of</strong> humpback whales, significant decreases in theamount <strong>of</strong> time spent at the surface <strong>and</strong> increases in dive duration were recorded.• In addition, humpback whales changed direction, avoiding vessels.• These effects persisted for more than 20 minutes after the vessels had departed.Ref: Green <strong>and</strong> Green 1990.Location: Hawaii• Humpback whales moved out <strong>of</strong> a preferred area on days when fast boats operatingparasailing rides occurred nearby.Ref: Green 1990.Location: Cape Cod, Massachusetts, USA• Humpback whales that are approached by whale-watching vessels travelling at a slow speed<strong>and</strong> according to established guidelines for whale-watching display no “adverse reactions”149

Hooray! Your file is uploaded and ready to be published.

Saved successfully!

Ooh no, something went wrong!