نتایج جستجو برای: natural and fishing mortality

تعداد نتایج: 16915710  

Journal: :IOP conference series 2021

Bleeker's Parrotfish Chlorurus bleekeri (de Beufort, 1940) is a Scaridae lives in coral reef ecosystems tropical and subtropical waters. very abundant the Indo-Pacific region. can be found from shallow water to depth of 30 meters. herbivorous fish. Herbivorous fish are important ecosystem because ecologically they control competitor. Therefore, exploitation needs regulated keep sustainable use ...

2010
Henrik Österblom U. Rashid Sumaila Örjan Bodin Jonas Hentati Sundberg Anthony J. Press

BACKGROUND Illegal, Unreported and Unregulated (IUU) fishing is a problem for marine resource managers, leading to depletion of fish stocks and negative impacts on marine ecosystems. These problems are particularly evident in regions with weak governance. Countries responsible for sustainable natural resource management in the Southern Ocean have actively worked to reduce IUU fishing in the reg...

2000
Daniel B. Hayes

Manuscript accepted 17 August 1999. Fish. Bull. 98:75–85 (2000). Abstract.–For fish populations with an annual breeding cycle, a biological reference point based on the Leslie matrix is presented and compared with percent maximum spawning potential (%MSP) and Fmed reference points. For deterministic population projections, the reference point is defined as the level of fishing mortality (Fst) t...

پایان نامه :وزارت علوم، تحقیقات و فناوری - دانشگاه اراک - دانشکده علوم 1392

the history of plant’s used for mankind is as old as the start of humankind. initially, people used plants for their nutritional proposes but after the discovery of medicinal properties, this natural ?ora became a useful source of disease cure and health improvement across various human communities. berberis vulgaris is one of the medicinal plants used in iranian traditional medicine. berberis ...

1999
Yongshun Xiao Lauren P. Brown Terence I. Walker André E. Punt

Tags are markers placed on or in animals to identify an individual. Animals are tagged to estimate their abundance as well as rates of growth, fishing mortality, natural mortality, and movement. In many studies, a tagged animal is assumed to retain its tag permanently. This assumption, however, is not valid for certain types of tags. Consequently, many attempts have been made to estimate tag sh...

پایان نامه :وزارت علوم، تحقیقات و فناوری - دانشگاه صنعتی اصفهان - دانشکده منابع طبیعی 1392

nowadays, air pollution is a global problem that has had significant growth by technology development, population growth andindustrial development. industrial development brought natural resources deterioration, more manufacturing products, and more environmental pollutants. if pollutant won’t be controlled, human-being and wildlife will face the critical risks. significant release and critical...

پایان نامه :وزارت علوم، تحقیقات و فناوری - دانشگاه اصفهان - دانشکده زبانهای خارجی 1390

apart from other aspects, desert is a natural environment and is one of the appealing terrestrial elements. putting its symbolic and fictional senses aside, the term “desert” bears mystic sense more than material sense. in addition to the worlds materialistic experiences, desert has attracted the attention of writers because it creates a kind of inner experience, which returns the individual in...

2009

The flesh-footed shearwater Puffinus carneipes is a medium-sized seabird with a single eastern Australian population breeding on Lord Howe Island. Other breeding populations exist in New Zealand, south-western Western Australia and St. Paul Island in the Indian Ocean. Tagging and banding studies indicate that breeding birds of the Lord Howe Island population inhabit waters mainly to the west of...

Journal: :Current Biology 2007
Ransom A. Myers Stephanie A. Boudreau Robert D. Kenney Michael J. Moore Andrew A. Rosenberg Scott A. Sherrill-Mix Boris Worm

The North Atlantic right whale is one of the most critically endangered marine species. Drastic overexploitation has driven this large, slow-swimming baleen whale to virtual extinction in Europe, while a small remnant population of ~350 individuals remains on the US and Canadian east coast. Although this species has been protected for 70 years, recovery has been slight and extinction is still l...

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