Lammers M.O.,Hawaii Institute of Marine Biology |
Lammers M.O.,Oceanwide Science Institute |
Pack A.A.,University of Hawaii at Hilo |
Pack A.A.,Dolphin Institute |
And 2 more authors.
Journal of Cetacean Research and Management | Year: 2013
Injury from collisions with vessels is a growing threat worldwide for many species of whales. Thirty seven years of historical records were examined for evidence of vessel collisions with humpback whales in the main Hawaiian Islands. Between 1975 and 2011,68 collisions between vessels and whales were reported including 59 witnessed collisions and 9 observed whale injuries that were consistent with a recent vessel collision. No collisions were immediately lethal. The waters between Maui, Molokai, Lanai and Kahoolawc, which arc known to have one of the highest concentrations of humpback whales in the Hawaiian Islands, had the highest incidence of collisions. Over 63% of the collisions involved calves and subadults, suggesting a greater susccptability towards collisions among younger animals. The rate of collisions increased significantly over the final twelve breeding seasons of the study and was greater than predicted by the estimated annual increase in the whale population, suggesting that the rising number of reported collisions cannot be explained solely by the annual increase in whale abundance. Although the total number of registered vessels and shipping traffic in Hawaii remained relatively constant between 2000 and 2010, there was a significant increase in the number of vessels between 7.9m and 19.8m in length. Vessels within this size range were also the most commonly involved in collisions during the study period, accounting for approximately two thirds of recorded incidents. It is concluded that from 1975-2011, there was a significant increase in reports of non-Icthal collisions between vessels and humpback whales, especially calves and subadults, in the main Hawaiian Islands that likely reflects a combination of factors including the recovery of the population of North Pacific humpback whales, increases in traffic of particular vessel types, and increased reporting practices by operators of vessels.
Parsons E.C.M.,George Mason University |
Baulch S.,Environmental Investigation Agency |
Bechshoft T.,University of Alberta |
Bechshoft T.,University of Aarhus |
And 24 more authors.
Endangered Species Research | Year: 2015
Limited resources and increasing environmental concerns have prompted calls to identify the critical questions that most need to be answered to advance conservation, thereby providing an agenda for scientific research priorities. Cetaceans are often keystone indicator species but also high profile, charismatic flagship taxa that capture public and media attention as well as political interest. A dedicated workshop was held at the conference of the Society for Marine Mammalogy (December 2013, New Zealand) to identify where lack of data was hindering cetacean conservation and which questions need to be addressed most urgently. This paper summarizes 15 themes and component questions prioritized during the workshop. We hope this list will encourage cetacean conservation-orientated research and help agencies and policy makers to prioritize funding and future activities. This will ultimately remove some of the current obstacles to science-based cetacean conservation. © The authors 2015.
PubMed | Oceanwide Science Institute, Clymene Enterprises, Hong Kong Cetacean Research Project and Texas A&M University
Type: Journal Article | Journal: The Journal of the Acoustical Society of America | Year: 2016
Long-term passive acoustic monitoring (PAM) was conducted to study Indo-Pacific humpback dolphins, Sousa chinensis, as part of environmental impact assessments for several major coastal development projects in Hong Kong waters north of Lantau Island. Ecological acoustic recorders obtained 2711 days of recording at 13 sites from December 2012 to December 2014. Humpback dolphin sounds were manually detected on more than half of days with recordings at 12 sites, 8 of which were within proposed reclamation areas. Dolphin detection rates were greatest at Lung Kwu Chau, with other high-occurrence locations northeast of the Hong Kong International Airport and within the Lung Kwu Tan and Siu Ho Wan regions. Dolphin detection rates were greatest in summer and autumn (June-November) and were significantly reduced in spring (March-May) compared to other times of year. Click detection rates were significantly higher at night than during daylight hours. These findings suggest high use of many of the proposed reclamation/development areas by humpback dolphins, particularly at night, and demonstrate the value of long-term PAM for documenting spatial and temporal patterns in dolphin occurrence to help inform management decisions.
Castellote M.,Complutense University of Madrid |
Castellote M.,National Oceanic and Atmospheric Administration |
Clark C.W.,Cornell University |
Lammers M.O.,Hawaii Institute of Marine Biology |
Lammers M.O.,Oceanwide Science Institute
Marine Mammal Science | Year: 2012
Archival bottom-mounted audio recorders were deployed in nine different areas of the western Mediterranean Sea, Strait of Gibraltar, and adjacent North Atlantic waters during 2006-2009 to study fin whale (Balaenoptera physalus) seasonal presence and population structure. Analysis of 29,822 recording hours revealed typical long, patterned sequences of 20 Hz notes (here called "song"), back-beats, 135-140 Hz notes, and downsweeps. Acoustic parameters (internote interval, note duration, frequency range, center and peak frequencies) were statistically compared among songs and song notes recorded in all areas. Fin whale singers producing songs attributable to the northeastern North Atlantic subpopulation were detected crossing the Strait of Gibraltar and wintering in the southwestern Mediterranean Sea (Alboran basin), while songs attributed to the Mediterranean were detected in the northwest Mediterranean basin. These results suggest that the northeastern North Atlantic fin whale distribution extends into the southwest Mediterranean basin, and spatial and temporal overlap may exist between this subpopulation and the Mediterranean subpopulation. This new interpretation of the fin whale population structure in the western Mediterranean Sea has important ecological and conservation implications. The conventionally accepted distribution ranges of northeastern North Atlantic and Mediterranean fin whale subpopulations should be reconsidered in light of the results from this study. © 2011 by the Society for Marine Mammalogy.
Sousa-Lima R.S.,Cornell University |
Sousa-Lima R.S.,Federal University of Minas Gerais |
Sousa-Lima R.S.,Federal University of Rio Grande do Norte |
Norris T.F.,Bio Waves Inc. |
And 3 more authors.
Aquatic Mammals | Year: 2013
Fixed autonomous acoustic recording devices (autonomous recorders [ARs]) are defined as any electronic recording system that acquires and stores acoustic data internally (i.e., without a cable or radio link to transmit data to a receiving station), is deployed semi-permanently underwater (via a mooring, buoy, or attached to the sea floor), and must be retrieved to access the data. More than 30 ARs were reviewed. They varied greatly in capabilities and costs, from small, hand-deployable units for detecting dolphin and porpoise clicks in shallow water to larger units that can be deployed in deep water and can record at high-frequency bandwidths for over a year, but must be deployed from a large vessel. The capabilities and limitations of the systems reviewed herein are discussed in terms of their effectiveness in monitoring and studying marine mammals.
Oswald J.N.,Hawaii Institute of Marine Biology |
Oswald J.N.,Oceanwide Science Institute |
Au W.W.L.,Hawaii Institute of Marine Biology |
Duennebier F.,University of Hawaii at Manoa
Journal of the Acoustical Society of America | Year: 2011
Minke whales (Balaenoptera acutorostrata) in the tropical North Pacific are elusive and difficult to detect visually. The recent association of a unique sound called the boing to North Pacific minke whales has made it possible to use passive acoustics to investigate the occurrence of this species in Hawaiian waters. One year of recordings (17 February 2007-18 February 2008) made at the Station ALOHA Cabled Observatory were examined to investigate the characteristics of boings and temporal patterns in their occurrence at this site, located 100 km north of Oahu. Characteristics of boings exhibited low variability. Pulse repetition rate and duration measurements matched those for central or Hawaii boing types. Boings were detected from October until May, with a peak in March. Although no boings were detected from June to September, the absence of boings does not necessarily indicate the absence of minke whales. Significant diel variation in boing rate was not observed. The absence of a diel pattern in boing production suggests that day- or night-time acoustic surveys are equally acceptable methods for studying minke whale occurrence. Future research should include efforts to determine what other sounds are produced by minke whales in this area, and which age/sex classes produce boings. © 2011 Acoustical Society of America.