Potential egg production, recruitment, and closed fishing season of the Peruvian anchovy (Engraulis ringens): Implications for fisheries management

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.

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Presence-Absence Sampling for Fisheries Management

Canadian Journal of Fisheries and Aquatic Sciences ◽

10.1139/f90-212 ◽

1990 ◽

Vol 47 (10) ◽

pp. 1875-1887 ◽

Cited By ~ 28

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.

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POTENTIAL FISHING GROUND MAPPING BASED ON GIS HOTSPOT MODEL AND TIME SERIES ANALYSIS: A CASE STUDY ON LIFT NET FISHERIES IN SERIBU ISLAND

Jurnal Ilmu dan Teknologi Kelautan Tropis ◽

10.29244/jitkt.v9i1.17948 ◽

2017 ◽

Vol 9 (1) ◽

pp. 337-356

Author(s):

Andi Alamsyah Rivai ◽

Vincentius P. Siregar ◽

Syamsul B. Agus ◽

Hiroki Yasuma

Keyword(s):

Time Series ◽

Fisheries Management ◽

Fishing Ground ◽

Effective Management ◽

Target Species ◽

Fishing Activity ◽

Fishing Season ◽

Spatio Temporal ◽

West Monsoon

Information on the spatial and temporal of fishing activity can optimize a fisheries management and increase their economical and biological benefit. For effective management and good understanding of fishing activities, information about fishing ground is crucial. In this study, we aimed to analyze the spatio-temporal of lift net fisheries in Kepulauan Seribu by analyzing their fishing season, investigating their hotspot of fishing ground using GIS-based hotspot model, and mapping the potential fishing ground of each target species. We found that anchovy and scad could be caught throughtout the year, while sardine and squid had high fishing season in west monsoon. Hotspot of fishing ground of lift net fisheries in Kepulauan Seribu waters generally was concentrated around Lancang Island and in southern part of Kotok Island. Potential fishing ground for sardines was located in around Lancang Island on west monsoon. Squids were highly distributed around Lancang Island in December to January and around Lancang and Rambut Islands in November. Anchovy and scad had more potential fishing ground in around Kepulauan Seribu waters. Keywords: fishing ground, lift net, hotspot, fishing season

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Comment on: “Managing fisheries from space: Google Earth improves estimates of distant fish catches” by Al-Abdulrazzak and Pauly

ICES Journal of Marine Science ◽

10.1093/icesjms/fsu079 ◽

2014 ◽

Vol 71 (7) ◽

pp. 1921-1926 ◽

Cited By ~ 8

Author(s):

Luca Garibaldi ◽

Jennifer Gee ◽

Sachiko Tsuji ◽

Piero Mannini ◽

David Currie

Keyword(s):

Fisheries Management ◽

Google Earth ◽

National Data ◽

Gulf Region ◽

Fishing Season ◽

National Statistics ◽

Ground Validation ◽

Catch Rates ◽

The Impact ◽

Adequate Ground

This Comment was prompted by the substantial difference in weir catch estimates in the Gulf between (i) those reported by Al-Abdulrazzak and Pauly (2014. Managing fisheries from space: Google Earth improves estimates of distant fish catches. ICES Journal of Marine Science, 71(3), 450–454), who used Google Earth to count weir numbers, and (ii) those available from official national statistics provided by two major weir fishing countries (Bahrain and Iran). Satellite imageries, including Google Earth, are powerful tools for collecting data on visible structures when verified with adequate ground validation. However, an extension of their contribution to improving overall catch estimates is rather limited without having solid information on daily catch, which will substantially differ according to time and area, and fishing season lengths. It was noted that Al-Abdulrazzak and Pauly (2013) introduced positive biases through their interpretation of Google Earth images and data treatment. They included several assumptions, such as removing the impact of poor visibility, correcting grids of low resolutions, estimating number of unseen weirs, and applying daily catch rates higher than referenced observed values. The overall extent of such potential positive bias could be more than six times that which we considered reasonable. This Comment also corrects misconceptions about “FAO catch data”, discusses other available national data, and introduces the existence of the Regional Commission for Fisheries (RECOFI), a mechanism for fisheries management in the Gulf region, and its recent activities to collect more complete catch and effort data separated by gear.

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Movements of female lumpfish (Cyclopterus lumpus) around Iceland

ICES Journal of Marine Science ◽

10.1093/icesjms/fsu170 ◽

2014 ◽

Vol 72 (3) ◽

pp. 880-889 ◽

Cited By ~ 19

Author(s):

James Kennedy ◽

Sigurður Þ. Jónsson ◽

Jacob M. Kasper ◽

Halldór G. Ólafsson

Keyword(s):

Fisheries Management ◽

Negative Relationship ◽

Coastal Areas ◽

Clear Pattern ◽

Female Fish ◽

Fishing Season ◽

Cyclopterus Lumpus ◽

Homing Behaviour

Abstract Lumpfish (Cyclopterus lumpus) migrate from their offshore feeding areas to the coastal areas of Iceland during March and April where they remain for several months before spawning. Their movements during this time are poorly documented. Using the results of an extensive tag-recapture study (the largest documented for lumpfish) which took place between 2008 and 2014, the movement of female lumpfish around Iceland was investigated and the implications for fisheries management were considered. Of 9710 female fish tagged, 880 were recaptured and 82 of these were recaptured after more than 250 days at liberty (DAL). There was a negative relationship between length at tagging and recapture rate indicating that between 2008 and 2014, the fishery was selecting for smaller fish. Lumpfish showed extensive movements with fish tagged in coastal areas being recaptured up to 587 km from their tagging location and were capable of swimming up to 49 km day−1. Fish were most frequently caught in the area in which they were tagged; however, movement between areas was common. There were indications of homing behaviour with 75% of the fish, which were recaptured after 250 DAL, caught within 80 km of their tagging location. Fish which were tagged offshore before the fishing season showed no clear pattern of where they would be recaptured. These extensive movements and homing behaviour are discussed in the context of the management of the lumpfish fishery.

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Crustacean egg production and fisheries management

Crustacean Egg Production ◽

10.1201/9781003072560-27 ◽

2020 ◽

pp. 379-394

Author(s):

Louis W. Botsford

Keyword(s):

Fisheries Management ◽

Egg Production

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PHYTOPLANKTON IN HABITATES OF CEMPEDIC FISH (Osteochilus spilurus) IN LENGGANG RIVER, EAST BELITUNG

Samakia : Jurnal Ilmu Perikanan ◽

10.35316/jsapi.v9i2.225 ◽

2018 ◽

Vol 9 (2) ◽

pp. 45-52

Author(s):

Jeny Setiawan ◽

Ardiansyah Kurniawan ◽

Suci Puspita Sari ◽

Andri Kurniawan ◽

Yulian Fakhrurrozi

Keyword(s):

Fisheries Management ◽

Natural Habitat ◽

Moderate Level ◽

Fishing Season ◽

Fish Catch ◽

Quantitative Descriptive ◽

Descriptive Method

Lenggang River in East Belitung regency becomes the natural habitat of Cempedik Fish (Osteochilus spilurus) which is an important economical plankton-feeder fish and has close to the culture of society. The production which still dependent of natural catch makes the description of phytoplankton can be the foundation in fisheries management and developing aquaculture of Cempedik Fish. This study aims to obtain a description of phytoplankton in Lenggang River using quantitative descriptive method. Phytoplankton sampling was conducted during the Cempedik Fishing season in December 2016 with four stations on the Lenggang River based on Cempedik Fish catching location. The abundance of phytoplankton showed values between 3,710 - 8,676 individuals / liter and correlated with the location of Cempedik Fish catch. The dominant index of phytoplankton showed a low value (0.16-0.21) and the uniformity index at the moderate level (0.66 - 0.79) with the Bacillariophyceae Class having the highest dominance.

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POTENTIAL FISHING GROUND MAPPING BASED ON GIS HOTSPOT MODEL AND TIME SERIES ANALYSIS: A CASE STUDY ON LIFT NET FISHERIES IN SERIBU ISLAND

Jurnal Ilmu dan Teknologi Kelautan Tropis ◽

10.28930/jitkt.v9i1.17948 ◽

2017 ◽

Vol 9 (1) ◽

pp. 337

Author(s):

Andi Alamsyah Rivai ◽

Vincentius P. Siregar ◽

Syamsul B. Agus ◽

Hiroki Yasuma

Keyword(s):

Time Series ◽

Fisheries Management ◽

Fishing Ground ◽

Effective Management ◽

Target Species ◽

Fishing Activity ◽

Fishing Season ◽

Spatio Temporal ◽

West Monsoon

Information on the spatial and temporal of fishing activity can optimize a fisheries management and increase their economical and biological benefit. For effective management and good understanding of fishing activities, information about fishing ground is crucial. In this study, we aimed to analyze the spatio-temporal of lift net fisheries in Kepulauan Seribu by analyzing their fishing season, investigating their hotspot of fishing ground using GIS-based hotspot model, and mapping the potential fishing ground of each target species. We found that anchovy and scad could be caught throughtout the year, while sardine and squid had high fishing season in west monsoon. Hotspot of fishing ground of lift net fisheries in Kepulauan Seribu waters generally was concentrated around Lancang Island and in southern part of Kotok Island. Potential fishing ground for sardines was located in around Lancang Island on west monsoon. Squids were highly distributed around Lancang Island in December to January and around Lancang and Rambut Islands in November. Anchovy and scad had more potential fishing ground in around Kepulauan Seribu waters. Keywords: fishing ground, lift net, hotspot, fishing season

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