Crustacean egg production and fisheries management

2020 ◽  
pp. 379-394
Author(s):  
Louis W. Botsford
Keyword(s):  
Fisheries Management ◽  
Egg Production

The fisheries management implications of maternal-age-dependent larval survival

2006 ◽  
Vol 63 (10) ◽  
pp. 2249-2258 ◽  
Author(s):  
Michael R O'Farrell ◽  
Louis W Botsford
Keyword(s):  
Mortality Rate ◽  
Fisheries Management ◽  
Maternal Age ◽  
Egg Production ◽  
Larval Mortality ◽  
Reproductive Potential ◽  
Larval Survival ◽  
Age Effects ◽  
Fishing Mortality ◽  
Black Rockfish

A common goal of conventional fisheries management is to maintain fishing mortality at a rate that ensures an adequate level of lifetime egg production (LEP) for population sustainability. However, larvae from young spawners can experience higher mortality rates than larvae of older spawners, reducing the effect of egg production by young females (hereafter, maternal age effects). This reduction leads to an error in LEP that can be accounted for by reducing the fishing mortality rate, but raises the question of the magnitude of these errors if they are present but not accounted for. Calculations using parameters from a typical long-lived fish demonstrated that maternal age effects resulted in large errors in estimates of lifetime reproduction when there was a large contrast in the larval mortality rate extending over the reproductive life span. Errors were small when maternal age effects reduced the reproductive potential of only the very youngest spawners, at ages when a small fraction of females are mature. A specific example using the empirically derived maternal age effect for black rockfish (Sebastes melanops) indicated that errors in traditional management would be small for this species.

Presence-Absence Sampling for Fisheries Management

1990 ◽  
Vol 47 (10) ◽  
pp. 1875-1887 ◽  
Author(s):  
Marc Mangel ◽  
Paul E. Smith
Keyword(s):  
Fisheries Management ◽  
Habitat Structure ◽  
Egg Production ◽  
Fish Stock ◽  
Search Process ◽  
Pelagic Species ◽  
Alternative Method ◽  
Probabilistic Description ◽  
Spawning Biomass

It is often important to estimate the abundance of a fish stock when the stock is somewhat depleted. For pelagic species this presents great operational difficulties, because adult surveys may be prohibitively expensive and time consuming. Here we introduce a method for estimating the spawning biomass of a stock by means of egg or larval surveys. In particular, we develop a series of models for presence-absence sampling of eggs or larvae and show how presence-absence data can be used to estimate adult spawning biomass. The models are based on an underlying probabilistic description of the aggregation of eggs or larvae, a search process, and a description of habitat structure. Methodologies are given for estimating the distribution of the size of the spawning biomass from presence-absence data. A case study of sardine is used to justify a number of the assumptions. The methods are applied to a 1985 survey for sardine eggs and are compared to an alternative method based on egg production.

Source populations in coastal crabs: population parameters affecting egg production

2009 ◽  
Vol 7 ◽  
pp. 31-43 ◽  
Author(s):  
AAV Flores ◽  
CC Gomes ◽  
WF Villano
Keyword(s):  
Egg Production ◽  
Population Parameters ◽  
Source Populations

Role of trophic models and indicators in current marine fisheries management

2015 ◽  
Vol 538 ◽  
pp. 257-272 ◽  
Author(s):  
C Longo ◽  
S Hornborg ◽  
V Bartolino ◽  
MT Tomczak ◽  
L Ciannelli ◽  
...  
Keyword(s):  
Fisheries Management ◽  
Marine Fisheries ◽  
Trophic Models

ПРЕРЫВИСТОЕ ОСВЕЩЕНИЕ ПОВЫШАЕТ ЭФФЕКТИВНОСТЬ ИСКУССТВЕННОГО ОСЕМЕНЕНИЯ КУР В КЛЕТКАХ

2019 ◽  
Keyword(s):  
Reproductive Performance ◽  
Artificial Insemination ◽  
Egg Production ◽  
Laying Hens ◽  
Electric Energy ◽  
Productive Performance ◽  
Feed Conversion ◽  
Scientific Center ◽  
Academy Of Sciences ◽  
Egg Fertility

Intermittent Lighting Improves the Efficiency of Artificial Insemination in Cage Housed Laying Hens Kavtarashvili A.Sh., Kolokolnikova T.N. Federal Scientific Center “All-Russian Research and Technological Poultry Institute” of Russian Academy of Sciences Omsk Agrarian Scientific Center Summary: The effects of different lighting regimes on the oviposition schedule, productive performance, and reproductive efficiency in cage housed laying hens of layer parental flock (Hisex White-R) were studied; the reasonable regime of artificial insemination (AI) under intermittent lighting is proposed. It was found that intermittent lighting regime 1L:4D:4L:1D:4L:10D compared to the constant lighting significantly alters oviposition schedule: under this regime 82.3% of all daily eggs were laid until 9 am (vs. 66.6% in control). This regime and AI at 10 am improved the productive and reproductive performance compared to control (constant lighting 16L:8D and AI at 12 am): mortality by 1.9%, egg production per initial hen by 3.8%, egg weight by 1.1%, percentage of eggs suitable for incubation by 1.9%, egg fertility by 0.9%, hatchability by 2.3%, hatch of chicks by 2.9%, feed conversion ratio (kg of feed per 10 eggs) by 5.3%, the expenses of electric energy for lighting (per 1000 eggs suitable for incubation) by 54.5%. Key words: INTERMITTENT LIGHTING, CAGE HOUSED LAYERS, ARTIFICIAL INSEMINATION (AI), OVIPOSITION SCHEDULE, AI TIMING, PRODUCTIVE PERFORMANCE, REPRODUCTIVE PERFORMANCE

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