Combining scientific survey and commercial catch data to map fish distribution

Fish harder; catch more?

Perhaps the most fundamental insight from fishery science is that ecosystems impose important and predictable constraints on food production from the sea. The familiar hump-shaped growth curve implies that the growth rate and carrying capacity of a species limit its production: Once stocks are depleted, further increasing fishing pressure will only lead to decreases in catch. This logic underpi...

Estimating catch-at-age by combining data from different sources

Estimating the catch-at-age of commercial fish species is an important part of the quota-setting process for many different species and almost all countries with a fishing fleet. Current procedures are usually very timeconsuming and somewhat ad hoc, and the estimates have no measure of uncertainty. We previously developed a method for catch-at-age of Norwegian Atlantic cod (Gadus morhua), but t...

Counting fish: a typology for fisheries catch data

Study on biodiversity, catch composition and length frequency distribution around the fish aggregation device in Qeshm Island Persian Gulf

The objective of the present study was to determine the effects of fish aggregation device (FAD) deployment on biodiversity, catch composition and length frequency distribution in the Qeshm Island handline fishery. Two FADs were deployed in the Qeshm Island. Four biodiversity indices including Margalef, Shannon-Weaver, Simpson and Pielou and also catch composition and length frequency distribut...

modeling loss data by phase-type distribution

بیمه گران همیشه بابت خسارات بیمه نامه های تحت پوشش خود نگران بوده و روش هایی را جستجو می کنند که بتوانند داده های خسارات گذشته را با هدف اتخاذ یک تصمیم بهینه مدل بندی نمایند. در این پژوهش توزیع های فیزتایپ در مدل بندی داده های خسارات معرفی شده که شامل استنباط آماری مربوطه و استفاده از الگوریتم em در برآورد پارامترهای توزیع است. در پایان امکان استفاده از این توزیع در مدل بندی داده های گروه بندی ...