Reference Article

from Wikipedia, the free encyclopedia

Population dynamics of fisheries

A fishery is an area with an associated fish or aquatic population which is harvested for its commercial or recreational value.

Fisheries can be wild or farmed.

Population dynamics describes the ways in which a given population grows and shrinks over time, as controlled by birth, death, and emigration or immigration.

It is the basis for understanding changing fishery patterns and issues such as habitat destruction, predation and optimal harvesting rates.

The population dynamics of fisheries is used by fisheries scientists to determine sustainable yields A fishery population is affected by three dynamic rate functions: Birth rate or recruitment.

Recruitment means reaching a certain size or reproductive stage.

With fisheries, recruitment usually refers to the age a fish can be caught and counted in nets.

Growth rate.

This measures the growth of individuals in size and length.

This is important in fisheries where the population is often measured in terms of biomass.

Mortality.

This includes harvest mortality and natural mortality.

Natural mortality includes non-human predation, disease and old age.

If these rates are measured over different time intervals, the harvestable surplus of a fishery can be determined.

The harvestable surplus is the number of individuals that can be harvested from the population without affecting long term stability (average population size).

The harvest within the harvestable surplus is called compensatory mortality, where the harvest deaths are substituting for the deaths that would otherwise occur naturally.

Harvest beyond that is additive mortality, harvest in addition to all the animals that would have died naturally.

Note: This article excerpts material from the Wikipedia article "Population dynamics of fisheries", which is released under the GNU Free Documentation License.

See the following related content on ScienceDaily:


Related Videos

last updated on 2014-09-30 at 5:25 pm EDT

Invasive Alien Fruit Flies Confirmed in New Brunswick

Invasive Alien Fruit Flies Confirmed in New Brunswick

CBC (July 30, 2013) An invasive vinegar fly has been spotted at three sites across the province, according to the Department of Agriculture, Aquaculture and Fisheries.
Powered by NewsLook.com
Fishers Suing US Fish and Wildlife Service Over Otters

Fishers Suing US Fish and Wildlife Service Over Otters

Newsy (Aug. 3, 2013) A group of California fishers is suing the US Fish and Wildlife Service for unofficially ending a program to keep otters away from fisheries.
Powered by NewsLook.com
Cod Population Growing, but Still In Danger

Cod Population Growing, but Still In Danger

CBC (Sep. 21, 2010) New fisheries figures show Atlantic cod stocks are recovering in the Grand Banks — although they're still only one-tenth of what they were in the 1960s, according to the World Wildlife Fund Canada.
Powered by NewsLook.com
The Politics of Shark Protection

The Politics of Shark Protection

FORA.tv (Dec. 9, 2011) With recent events such as oil spills, failing fisheries, bitter debates over climate change, and a controversial new ocean policy, science is increasingly in the public spotlight, yet technical subject matter can be tricky for scientists to convey to journalists, policymakers, or even the general public.
Powered by NewsLook.com

Related Stories


Share This



Search ScienceDaily

Number of stories in archives: 140,361

Find with keyword(s):
Enter a keyword or phrase to search ScienceDaily for related topics and research stories.

Save/Print:
Share:

Breaking News:
from the past week

In Other News

... from NewsDaily.com

Science News

Health News

Environment News

Technology News



Save/Print:
Share:

Free Subscriptions


Get the latest science news with ScienceDaily's free email newsletters, updated daily and weekly. Or view hourly updated newsfeeds in your RSS reader:

Get Social & Mobile


Keep up to date with the latest news from ScienceDaily via social networks and mobile apps:

Have Feedback?


Tell us what you think of ScienceDaily -- we welcome both positive and negative comments. Have any problems using the site? Questions?
Mobile: iPhone Android Web
Follow: Facebook Twitter Google+
Subscribe: RSS Feeds Email Newsletters
Latest Headlines Health & Medicine Mind & Brain Space & Time Matter & Energy Computers & Math Plants & Animals Earth & Climate Fossils & Ruins