Sentences with phrase «many whale populations»

Killing whales for commercial purposes had driven Australian whale populations, especially those of sperm and humpback whales, frighteningly close to the edge of extinction.

Shane Gero of Dalhousie University in Halifax, Nova Scotia, Canada, and his colleagues tracked sperm whale populations in the Caribbean and Sargasso seas to see what happened when mothers dived for food.

Nevertheless, it appears that the whale population was once vastly bigger than we thought, and that our slaughter of them was more thorough than history records (see «Lost leviathans: Hunting the world's missing whales»).

The special group makes up 1 percent of the total gray whale population of 20,000.

The old estimates were based on 20th - century data from the whaling industry itself, which estimated a worldwide sperm - whale population of about 1.8 million, a number that few scientists found credible.

The genetic data also revealed that the Antarctic minke whale population may be the oldest surviving whale population on Earth.

Most estimates of historic whale population size have been extrapolated from old whaling figures, but this method is often very inaccurate, argues marine biologist Steve Palumbi of Stanford University's Hopkins Marine Station in California, US.

The first comprehensive genetic study of humpback whale populations in the North Pacific Ocean has identified five distinct populations — at the same time a proposal to designate North Pacific humpbacks as a single «distinct population segment» is being considered under the Endangered Species Act.

Such a recovery in the whale population is under way among some species, but it still has a very long way to go.

He later said that the minke whale population estimate was mistaken and noted that there was little compelling evidence showing that killer whales were significantly reducing minke whale numbers in that region.

In the largest study of its kind to date, researchers used mitochondrial DNA microsatellites from skin samples gathered from more than 3,000 individual humpback whales across the Southern Hemisphere and the Arabian Sea to examine how whale populations are related to one another, a question that is difficult to answer with direct observations of whales in their oceanic environment.

The research results build on previous regional studies of genetic diversity and will help scientists to better understand how humpback whale populations evolve over time and how to best advise international management authorities.

«Our findings give us insights into how fidelity to breeding and feeding destinations persist over many generations, resulting in differences between whale populations, and why some populations are more genetically differentiated from the rest.

«Our increased understanding of how whale populations are structured can help governments and inter-governmental organizations like the International Whaling Commission improve management decisions in the future,» said Dr. C. Scott Baker of Oregon State University's Marine Mammal Institute and a member of the South Pacific Whale Research Consortium that contributed to the study.

It is fundamental for evaluating the status of killer whale populations.

This is intended to take account of some of the uncertainties inherent in data on whale populations, and requires only two kinds of data: current estimates and their statistical error; and historical details of catches.

IWC enacted the ban in 1986 after commercial whaling drove many whale populations to the brink of extinction.

In the subsequent Marine Mammal Science paper just out, the catches were among the key pieces of information used to model the size of the California blue whale population over time — a model previously used by other groups to estimate populations of hundreds of fish and various other whale species.

If we hadn't, the population might have been pushed to near extinction — an unfortunate fate suffered by other blue whale populations.»

For example, the new study notes that restoring whale populations could help increase the ocean's capacity to absorb climate - warming carbon dioxide.

Norway will itself update its population estimates in July with a «sighting survey», an approved method of extrapolating whale populations from the number spotted from ships.

Some researchers think that a similar process is occurring in the killer whale populations of the Northeast Atlantic.

New lice species would have arisen precisely when the right - whale populations diverged.

In the 1970s and 1980s, for example, researchers argued that reducing certain whale populations would aid stocks of krill, a ubiquitous crustacean in the Southern Ocean that is a key food source for baleen whales and other marine species.

As it turns out, whales exchange lice so readily — and so thoroughly scramble the lice ancestry in each whale population — that lice genetics reveal nothing about how contemporary whales interact.

The samples were then analyzed with a technique called polymerase chain reaction (PCR), used to amplify specific nuclear «microsatellites» for statistically measuring gene flow between the different populations and subpopulations located in the western South Atlantic (Breeding Stock A) and the eastern South Atlantic and Indian Ocean populations (Breeding Stocks B and C, and the Arabian Sea humpback whale population, respectively).

Now the trio has created a model to examine in more detail how a cap - and - trade market might impact whale populations and how the costs and benefits would change for people who want to hunt or conserve them.

The model combines whale population dynamics with an economic model of demand for whales and shows what happens to prices and populations when whalers and nongovernmental organizations (NGOs) exchange shares.

Using data generated from more than 3,000 skin samples from individual whales ranging from the South Atlantic to the Indian Oceans, the research team has uncovered previously unknown degrees of relatedness between different whale populations.

«After 50 years of international protection, a number of humpback whale populations are beginning to recover in the Southern Hemisphere and other regions,» said Dr. Howard Rosenbaum of WCS's Ocean Giants Program.

A massive genetic study of humpback whale populations will help inform ongoing conservation reassessments of humpback whale populations, and reaffirms the highly distinct nature of a small, non-migratory population of humpback whales living in the Arabian Sea in need on continued protection.

The East African humpback whale population is growing, so we might see more shark attacks in future, Dicken's paper suggests.

«Future challenges in Australia will be to protect a marine environment that contains growing humpback whale populations and to develop alternative approaches to ecological sustainability,» said Dr. David Johnston of Duke University USA, co-author of the study.

As of 2012, both the East and West Coast whale populations had more than 63 % (East Coast) and 90 % (West Coast) of the number of whales estimated in each population before the whaling era (approximately 1912 - 1972).

Scat collection rates rose significantly, allowing Rolland to track stress hormones in the right whale population.

However, according to Professor Lars Bejder at Murdoch University Australia, School of Veterinary and Life Sciences and his international co-authors, data reveals that these whale populations are increasing at remarkable rates (9 % for West Coast and 10 % for East Coast; as of 2012), the highest documented worldwide.

The scientists say they will need several years before they can complete their surveys and come up with a credible management plan for all the whale populations currently being targeted.

Catch - limit models have been run for several of the whale populations currently being hunted — such as the western North Pacific Bryde's whales and the North Atlantic common minke whales.

Failure to account for the effects of climate change on these dynamics will undermine our ability to understand changes in the standing biomass of Antarctic krill and also to predict the recovery of whale populations from a century of mismanagement and overexploitation [37].

At the same time, baleen whale populations in the Southern Ocean, which feed primarily on krill, are recovering from past exploitation.

The few remaining killer whale populations in European waters have very low, or zero rates of reproduction, and are close to extinction in industrialised parts of Europe.

Every year at the start of Fall more than 60 % of the North Pacific Humpback Whale population will begin their migration from Alaska to Hawaii, with many of them choosing to stay in the waters off of Maui during their visit.

It's important to note that the gray whale population along our coast is thriving, and gray whale calves provide vital sustenance for transient killer whales.

Large quantities of ambergris nay have washed up on the shores of Ambergris Caye before intense whaling of the - 1800's and early 190O's decimated the sperm whale populations.

The Californian Gray whale population is around 26,000, and is now at the point where there are surplus numbers which could be transferred to the waters off Britain.

By the 1990's, the gray whale population had come back.

An international ban on commercial whaling was instituted in 1964 and the whale population has since rebounded.

One key concern from environmental groups is that the Sakhalin - 2 project will harm the western gray whale population.

The blue whale population is estimated to be around 14,000.

Most hunted whales are now threatened, with some great whale populations exploited to the brink of extinction.