Preliminary assessments of stocks of the Western Australian crayfish, Panulirus cygnus George

1966 ◽  
Vol 17 (1) ◽  
pp. 93 ◽  
Author(s):  
BK Bowen ◽  
RG Chittleborough
Keyword(s):  
Western Australia ◽  
Fishing Effort ◽  
Total Catch ◽  
Catch Per Unit Effort ◽  
Stock Size ◽  
Unit Effort ◽  
Exploitation Rate ◽  
Panulirus Cygnus ◽  
Western Australian ◽  
Closed Period

Total catch of Panulirus cygnus in Western Australia rose from 0.6 million lb in 1944-45 to 21.4 million Ib in 1962-63. Fishing effort increased rapidly with the result that the catch per unit effort declined progressively. Effort has been limited by regulation since 1963. From records of catch and effort from specified areas at intervals of one month throughout each season, estimates were made of mortality coefficients (Z1, F, and M1) and catchability coefficient (q). Stock size, recruitment, and exploitation rates were then estimated. As the seasonal catch per unit effort followed the same trend throughout all fishing areas, the detailed results from the selected areas have been applied to the whole fishery. The fishable stock, originally of approximately 140 million lb, had declined to some 35 million lb by 1963. Exploitation rate rose as effort was increased, and then levelled off (generally at above 60%), further increase in fishing effort resulting in a fall in the catchability coefficient rather than a change in the exploitation rate. Because of the high exploitation rate in recent years, the fishable stock available on the grounds at the opening of a season is largely dependent on recruitment (by growth) of juveniles during the preceding closed period. This recruitment has been diminishing from year to year, apparently because of mortality of undersize (pre-recruit) crayfish handled in fishing pots. Provision of escape gaps in all fishing pots is recommended. A sustainable level of catch might be 16,000,000±2,000,0001b per year if recruitment can be stabilized. Some further restriction of fishing effort might be necessary.

scholarly journals Effect of hook and bait type on catch per unit effort in the Aegean Sea demersal longline fishery

2021 ◽  
Vol 38 (2) ◽  
pp. 181-188
Author(s):  
Ozan Soykan ◽  
Cemil Sağlam ◽  
İlker Aydın ◽  
Hasan Tuncay Kınacıgil
Keyword(s):  
Sparus Aurata ◽  
Length Distribution ◽  
Aegean Sea ◽  
Fishing Effort ◽  
Longline Fishery ◽  
Total Catch ◽  
Catch Per Unit Effort ◽  
Unit Effort ◽  
Catch Composition ◽  
The Impact

This study aimed to determine the impact of hook and bait type on the catch composition and catch per unit effort. Effects of hook and bait types on catch composition, catch per unit effort (CPUE), length and weight distributions in demersal longline fishery were determined by experimental surveys on demersal longline sets in the Aegean Sea. A total of 12 samplings corresponding to 4800 hook fishing effort were performed between April 2014 and September 2014. Two bait types; sardine (Sardina pilchardus) and grooved razor shell (Solen marginatus) and two hook types; J-hook and C-hook were tested. CPUE values were calculated for each species and assessed between different hook-bait combinations. A total of 623 individuals were captured belonging to 3 families and 9 species. It was found that more than 60% of total catch was captured by grooved razor shell and more than 50% of the total catch was caught with J type hook. J hook was found to be close to significant (p=0.06) and grooved razor shell was found significant (p=0.02) for CPUE. The effect of bait type was found to be more significant than that of hook type for CPUE and length distribution. Hook-bait combination differed according to species and C hook baited with sardine was determined to be the best combination for Sparus aurata as the most targeted fish in the study area. Discard ratio was calculated to be 34% in terms of weight and 42.5% in terms of total number of individuals for pooled data. The condition value (K) of the species ranged from 1.05 to 1.68 and differed according to bait type. Most of the high commercial value species caught with any hook-bait combination experimented within this study are larger than minimum fishing length according to minimum landing size regulations of Turkish fishery and maturity studies.

scholarly journals The effect of escape gaps of cylinder folding traps on fish catch at the coastal waters of Tuban Regency

2021 ◽  
Vol 322 ◽  
pp. 03002
Author(s):  
Farrel Nafis Adyatama ◽  
Ghassan Nurul Huda ◽  
Nahla Alfiatunnisa ◽  
Faizal Rachman ◽  
Supardjo Supardi Djasmani ◽  
...  
Keyword(s):  
Coastal Waters ◽  
Marine Organisms ◽  
Total Weight ◽  
Total Catch ◽  
Catch Per Unit Effort ◽  
Unit Effort ◽  
Significant Difference ◽  
Fish Catch ◽  
Swimming Crabs

The purpose of this study is to determine the effect of the escape gap of cylinder folding trap on catch per unit effort (CPUE), trap rate, composition, and size of fish caught in the coastal waters of Tuban Regency. The research was conducted in November 2019 by deploying 60 units in ten experimental fishing trips at different locations. The traps were 20 units without escape gap, 20 units with an escape gap of 3 cm x 6 cm, and 20 units with an escape gap of 4 cm x 7 cm. Overall, the experiments resulted in a collection of 22 species of marine organisms, such as swimming crabs (33% of total weight), snails, shrimps, crabs, fishes (55% of total weight), and cuttlefish. The highest CPUE was found for the traps with escape gaps of 4 cm x 7 cm, i.e., 9.18 gr/trap/trip. There was no significant difference in the total catch, the weight of catches, trap rate, and catch per unit effort (CPUE) among the three types of traps.

Shore-based recreational angling in the Rottnest Island Reserve, Western Australia: Spatial and temporal distribution of catch and fishing effort

2006 ◽  
Vol 12 (3) ◽  
pp. 238 ◽  
Author(s):  
C. B. Smallwood ◽  
L. E. Beckley ◽  
N. R. Sumner
Keyword(s):  
Western Australia ◽  
Temporal Distribution ◽  
Fishing Effort ◽  
Recreational Fishing ◽  
Temporal Data ◽  
Target Species ◽  
Southwestern Australia ◽  
Recreational Angling ◽  
Western Australian ◽  
Support Decision Making

The Rottnest Island Reserve, located off southwestern Australia, is one of the most popular recreational fishing locations in Western Australia. In the reserve, standard Western Australian recreational fishing regulations apply and there are two small "no-take" conservation sanctuary areas. A roving creel survey of shore-based recreational angling in the reserve was conducted from January to December 2003. In total, 1 053 anglers were recorded which included individuals, families, school groups and angling club members. The total annual shore-based angling effort for Rottnest island was calculated to be 23 899 angler outings and the total catch estimated at 53 994 retained fish. Fishing effort was concentrated in the settlement area on the eastern side of the island and the highest levels of catch and effort were recorded in April, May and July. During the survey, 33 fish species were identified in the catch and the small, pelagic species Australian Herring dominated with 7.27 tonnes caught during the study. Shore-based anglers also caught and released a large number of non-target species. The survey has provided spatial and temporal data that can be used as a benchmark and to support decision making by the Rottnest Island Authority with respect to biodiversity conservation and the Department of Fisheries with regard to management of shore-based recreational angling in the Rottnest Island Reserve.

scholarly journals POTENTIALS YIELD AND FISHERIES OF MALAHAYU RESERVOIR, BREBES

2019 ◽  
Vol 25 (1) ◽  
pp. 11
Author(s):  
Setiya Triharyuni ◽  
Aisyah Aisyah ◽  
Chairulwan Umar ◽  
Husnah Husnah
Keyword(s):  
Native Fish ◽  
Fish Production ◽  
Catch Per Unit Effort ◽  
Introduced Fish ◽  
Potential Production ◽  
Fishing Activity ◽  
Unit Effort ◽  
Exploitation Rate ◽  
Long Time ◽  
Average Catch

Fishing activity in Malahayu Reservoir has been done since long time. Unlimited fishing may impact to the decresing of fish resources of those waters. This study presents an assessment of fishing practices in Malahayu reservoir between 2008-2016 periods. Data of potential fish production and catch per unit effort were estimated by using different estimate models, catch per unit effort was analyzed annually, while potential fish production was analyzed by using five models namely model by Henderson & Welcome (1974), Teows & Griffith (1979), Marshal (1984), Moreau & De Silva (1991) and Crul (1992). The results show that changes of fish composition has accured, which was originally dominated by native fish while for now it is dominated by 72,05% of tilapia (Oreochromis niloticus) as an introduced fish. Furthermore, the average catch per unit effort (CPUE) in Malahayu reservoir is about 11,82 kg / fisherman, while the average potential production is about 198,55 kg / year. CPUE value and potential production indicate that exploitation rate in Malahayu Reservoir are in fully-exploited or perhaps over-exploited condition. Related to those conditions, not to increase the number of efforts (fishermen) as a management option towards sustainable fisheries.

scholarly journals Pêche Et Caractéristiques Morphologiques D’un Poisson-Chat Endémique Synodontis Punctifer (Daget, 1964) Dans Le Barrage Électrique De Taabo (Côte d’Ivoire)

2018 ◽  
Vol 14 (15) ◽  
pp. 101
Author(s):  
Hervé Oussou Koffi ◽  
Diaha N’guessan Constance ◽  
Soro Yaya ◽  
N’Da Konan
Keyword(s):  
Sex Ratio ◽  
Condition Factor ◽  
Morphological Characteristics ◽  
Fishing Effort ◽  
Annual Production ◽  
Allometric Growth ◽  
Catch Per Unit Effort ◽  
Large Size ◽  
Unit Effort ◽  
Significant Difference

A study of Synodontis punctifer (family: Mochokidae) of Taabo Lake was conducted from October 2015 to September 2016. This was carried out so as to evaluate its quantity (biomass) caught by fishing and also its morphological characteristics. The fish were caught using gillnets at 4 sites of the lake and different measurements were made. The fishing effort was 23 to 11 fishermen / day in Taabo city, 17 to 11 fishermen / day in Courandjourou, 13 to 5 fishermen / day in Ahondo, and 8 to 3 fishermen / day in Taabo village. The catch per unit effort (CPUE) ranged from 17.7 to 3.7 g / fisherman / day, 9.2 to 1.2 g / fisherman / day, 8.3 to 0.7 g / fisherman /day, 8 to 1g / fisherman / day at Ahondo, Courandjourou, Taabo city and Taabo village, respectively. The overall annual production was estimated at 2199.3 kg, i.e. 817 kg (40%) at Ahondo, 788.3 kg (35%) at Courandjourou, 462.5 kg (20%) at Taabo, and 131.5 kg (5%) in Taabo village. The overall sex ratio (1: 1.33) was in favor of females. Individuals have negative allometric growth at all sites with values ranging from 1.72 to 2.89. The condition factor does not vary significantly between different categories of individuals (ANOVA, F = 2.79, p ˃ 0.05). A significant difference was observed between the average sizes of the individuals of the different sites (test, p˂0,05). The large size specimens were captured at Ahondo, mean (avg = 15.38 ± 1.68 cm FL). In Courandjourou, the sizes were intermediate (avg = 13.63 ± 1.64 cm LF). Smalls sizes have been observed in Taabo city (mean= 12.37 ± 1.24 cm FL) and Taabo village (mean= 15.58 ± 1.58 cm FL).

scholarly journals Fishing Effort and Associated Catch per Unit Effort for Small-Scale Fisheries in the Mozambique Channel Region: 1950–2016

2021 ◽  
Vol 8 ◽  
Author(s):  
Dirk Zeller ◽  
Gabriel M. S. Vianna ◽  
Matthew Ansell ◽  
Angie Coulter ◽  
Brittany Derrick ◽  
...  
Keyword(s):  
Fishing Effort ◽  
Small Scale ◽  
Catch Per Unit Effort ◽  
Important Species ◽  
Small Scale Fisheries ◽  
Mozambique Channel ◽  
Fishing Vessels ◽  
Unit Effort ◽  
Fishing Capacity ◽  
Channel Region

The Mozambique Channel region in East Africa has diverse marine ecosystems and serves as a migratory corridor for economically important species. Local and foreign industrial fisheries operate in the Mozambique Channel, but regional small-scale fisheries are the crucially important fisheries that provide food security, livelihoods, and economic opportunities for rural coastal communities. This study reconstructed and investigated trends in the fishing effort and catch per unit effort (CPUE) of small-scale marine fisheries in four Exclusive Economic Zones (EEZ) that constitute the Mozambique Channel, i.e., Union of Comoros, Madagascar, Mayotte, and Mozambique, from 1950 to 2016. Effective fishing effort for small-scale fisheries in the form of fishing capacity in kWdays (i.e., kilowatt days) was derived using the number, length, motorization (engine power) by fishing vessels, as well as an approximate human-powered equivalent for shore-based fishers without vessels, as well as days of fishing per year. Effective small-scale fishing effort in the Mozambique Channel increased by nearly 60 times from just over 386,000 kWdays in 1950 to over 23 million kWdays in 2016. Correspondingly, the overall small-scale CPUE, based on previously and independently reconstructed catch data declined by 91% in the region as a whole, from just under 175 kg⋅kWday–1 in the early 1950s to just over 15 kg⋅kWday–1 in recent years. All four EEZs showed the strongest declines in the small-scale CPUE in the earlier decades, driven by motorization and growth in vessel numbers impacting effective fishing effort. Increased motorization combined with a substantial growth in overall vessel numbers were the drivers of the increasing fishing effort and decreasing CPUE, and clearly suggest that continuing to increase the fishing capacity of small-scale fisheries in the absence of effective and restrictive management actions may exacerbate overexploitation risk.

Use of the daily egg production method to estimate the stock size of Western Australian sardines (Sardinops sagax)

1996 ◽  
Vol 47 (6) ◽  
pp. 819 ◽  
Author(s):  
WJ Fletcher ◽  
NCH Lo ◽  
EA Hayes ◽  
RJ Tregonning ◽  
SJ Blight
Keyword(s):  
Western Australia ◽  
Egg Production ◽  
Production Method ◽  
Purse Seine ◽  
Batch Fecundity ◽  
Stock Size ◽  
Production Values ◽  
Sardinops Sagax ◽  
Western Australian ◽  
Spawning Biomass

The daily egg production method was used to estimate the spawning biomass of the sardine Sardinops sagax in the Albany region of Western Australia. Plankton surveys covering 10000 - 14000 km² were completed in July of 1991 and 1992 in three to five days using up to three boats. Adult sardines were obtained from the local purse-seine fleet. The spawning area was similar in both years at approximately 3800 km² (1100 nmile²), but the number of eggs collected was larger in 1991 with egg production values of 6.5 per 0.05 m2 day-1 compared with 3.9 per 0.05 m2 day-1 in 1992. The average batch fecundity values were similar (approximately 11000 eggs female-1) as were the proportions spawning (0.13 in 1991; 0.09 in 1992). The calculated biomass estimates were 23 121 t (CV = 0.51) and 16 121 t (CV = 0.44) in 1991 and 1992 respectively.

Utilization rate of fish resources in Banggai Laut waters

2020 ◽  
Vol 1 (2) ◽  
Author(s):  
Aswad Eka Putra
Keyword(s):  
Fishing Effort ◽  
Utilization Rate ◽  
Catch Per Unit Effort ◽  
Surplus Production ◽  
Fish Resources ◽  
Unit Effort ◽  
Rate Of Increase ◽  
Increasing Trend ◽  
Fish Group ◽  
Method Approach

Capture fisheries is one of the leading sectors that drive the economy of Banggai Laut Regency. Improved fishing technology is related to fishing efforts that will affect the sustainability of fish resource stocks in the waters of Banggai Laut Regency. This study aims to identify the rate of utilization of fish resources in an effort to develop a sustainable fisheries sector in Banggai Laut waters. The method approach used is "Surplus Production". This method serves as an estimator of the relative abundance of a fish resource in the waters of Banggai Laut Regency which is based on the catch per unit of fishing effort. The results showed that the capability of the fishing fleet in Banggai Laut Regency has not been able to reach potential fishing areas. The catch per unit effort (CPUE) of fish resources in Banggai Laut Regency still shows an increasing trend with the highest rate of increase by other fish group including crustaceans and mollusks, about 0.160 tons/unit in the 2014-2016 period. Meanwhile, the catch per unit effort of the large pelagic fish group showed an increasing trend with the lowest rate of increase, about 0.001 tons/unit in the 2014-2016 period. Therefore the utilization rate of fish resources in the waters of Banggai Laut Regency is still classified as under exploited.

scholarly journals Reliability of a model based on a short fishery statistics survey: application to the Northeast Atlantic monkfish fishery

2004 ◽  
Vol 61 (1) ◽  
pp. 25-34 ◽  
Author(s):  
Francisco Rocha ◽  
Joaquín Gracia ◽  
Ángel F González ◽  
Carlos M Jardón ◽  
Ángel Guerra
Keyword(s):  
Fishing Ground ◽  
Total Catch ◽  
Market Information ◽  
Catch Per Unit Effort ◽  
Northeast Atlantic ◽  
Model Based ◽  
Fish Market ◽  
Unit Effort

Abstract A model based on a short fishery statistics survey was applied to estimate catch and catch per unit effort (cpue) of the Galician monkfish (Lophius spp.) trawl fleet during 1998. In all, 35 interviews were conducted with fisheries personnel in ICES Divisions IXa, VIIIc, VIIId, and VIIIe (coastal offshore fishing grounds) and 44 in VIIb, VIIc, VIIj, and VIIk (Grand Sole fishing ground). Reliability of the model estimates was tested using: (i) registered fish market landings at 38 ports; (ii) landings data from sale invoices at six of these ports (93.8% of total landings of the species); (iii) 29 observers' trips made on board coastal offshore trawlers and the logbook of one Grand Sole trawler. Estimated mean total catch from the model was 5110 t (602 t coastal offshore, 4508 t in Grand Sole) and cpue values were 36.2 kg haul−1 vessel−1 coastal offshore and 104.4 kg haul−1 vessel−1 Grand Sole. Differences between the values of cpue estimated by the model and those determined directly in both fisheries were not significant. However, there were differences between the total catch estimated by the model and the total landings deduced from sale invoices and Galician fish market information.

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