Navigation Links
Competition with humans responsible for decline of New Zealand's endangered sea lions, study shows
Date:8/14/2011

Marine researchers in New Zealand have identified the direct impact of fishing as the largest known human factor in the decline of the endangered native sea lion population. The team's findings, published in Mammal Review, discount non-human factors, such as disease and identifies resource competition and by-catch incidents as the most likely causes.

The New Zealand sea lion Phocarctos hookeri is the country's only native pinniped species and is listed as 'nationally critical'. The species breeds in the sub-Antarctic, south of New Zealand's mainland, with 71% of the population on the Auckland Islands and the remaining 29% on Campbell Island.

Breeding at the Auckland Islands has declined by 40% since 1998 with only 1501 pups being born in 2009. This decline is directly linked to females not returning to breeding areas. However, while the Auckland Island population has declined, the Campbell Island population appears to be slowly increasing.

Potential reasons for the decline in the Auckland Island population, but not in the Campbell Island colony, include non-human factors such as disease, predation, migration or environmental change. However, possible human factors include population 'overshoot', the effects of contaminants, resource competition and by-catch deaths.

Of the nine potential reasons for the decline of the sea lion population the team discounted six by comparing the Auckland island population with the colony on Campbell Island.

"The most plausible hypotheses based on available evidence is that the decline of breeding females in the Auckland Island population is caused by fisheries-induced resource competition and by-catch incidents" said author Dr Bruce Robertson, from the University of Otago. "Resource competition can lead to nutrient stress and decreased reproductive ability in sea lions and this should be a priority area for future research."

"A fundamental component of assessing and managing any species in decline is the long-term monitoring of changes in numbers and population dynamics in each population of the species," said Robertson. "Both human and natural influences must be taken into account and our study indicates the need for further research and greater conservation management to protect the species."


'/>"/>

Contact: Ben Norman
Lifesciencenews@wiley.com
44-012-437-70375
Wiley-Blackwell
Source:Eurekalert

Related biology news :

1. Competition with humans responsible for decline of New Zealands endangered sea lions, study shows
2. Evolutionary kings of the hill use good, bad and ugly mutations to speed ahead of competition
3. New study supports Darwins hypothesis on competition between species
4. Competition between females leads to infanticide in some primates
5. Stevens thoracic catheter senior design team takes 1st place at regional ISPE competition
6. Parascript SignatureXpert Wins Forensic Signature Verification Competition
7. Winners announced in 2010 Collegiate Inventors Competition
8. Snap of fruit fly embryo wins scientific photo competition
9. Image of mosquitos heart wins first place in Nikons Small World photomicrography competition
10. Winners of plant-biology video contest announced -- new competition begins at Penn State University
11. Europe ready to launch 3-D TV outperforming the competition
Post Your Comments:
*Name:
*Comment:
*Email:
(Date:3/28/2017)... , March 28, 2017 The ... Hardware (Camera, Monitors, Servers, Storage Devices), Software (Video Analytics, ... Region - Global Forecast to 2022", published by MarketsandMarkets, ... 2016 and is projected to reach USD 75.64 Billion ... and 2022. The base year considered for the study ...
(Date:3/24/2017)... 24, 2017 The Controller General of Immigration from ... Abdulla Algeen have received the prestigious international IAIR Award for the ... Continue Reading ... ... Controller Abdulla Algeen (small picture on the right) have received the IAIR ...
(Date:3/23/2017)... The report "Gesture Recognition and Touchless Sensing Market by Technology (Touch-based ... to 2022", published by MarketsandMarkets, the market is expected to be worth USD ... 2022. Continue Reading ... ... ...
Breaking Biology News(10 mins):
(Date:10/11/2017)... and LAGUNA HILLS, Calif. , Oct. ... Cancer Research, London (ICR) and University ... SKY92, SkylineDx,s prognostic tool to risk-stratify patients with multiple myeloma ... MUK nine . The University of Leeds ... partly funded by Myeloma UK, and ICR will perform the ...
(Date:10/10/2017)... ... 2017 , ... San Diego-based team building and cooking events company, Lajollacooks4u, has ... The bold new look is part of a transformation to increase awareness, appeal to ... period. , It will also expand its service offering from its signature gourmet cooking ...
(Date:10/10/2017)... 10, 2017 International research firm Parks Associates announced ... at the TMA 2017 Annual Meeting , October 11 in ... residential home security market and how smart safety and security products impact ... Parks Associates: Smart Home ... "The residential security market has ...
(Date:10/9/2017)... DIEGO , Oct. 9, 2017  BioTech ... biological mechanism by which its ProCell stem cell ... critical limb ischemia.  The Company, demonstrated that treatment ... amount of limbs saved as compared to standard ... the molecule HGF resulted in reduction of therapeutic ...
Breaking Biology Technology: