A fisheries perspective of behavioural variability: differences in movement behaviour and extraction rate of an exploited sparid, snapper (Pagrus auratus)

2011 ◽  
Vol 68 (4) ◽  
pp. 632-642 ◽  
Author(s):  
Darren M. Parsons ◽  
Mark A. Morrison ◽  
Jeremy R. McKenzie ◽  
Bruce W. Hartill ◽  
Richard Bian ◽  
...  
Keyword(s):  
Population Size ◽  
Fisheries Management ◽  
Fishing Effort ◽  
Extraction Rate ◽  
Movement Behaviour ◽  
Pagrus Auratus ◽  
The Status ◽  
Likelihood Model ◽  
Lower Population ◽  
Fishery Species

Intraspecific variation in movement patterns are well established for many species, but poorly appreciated in fisheries management. In this study we dart-tagged snapper ( Pagrus auratus ), an important fishery species, across different areas and habitats in the Hauraki Gulf, New Zealand. Tag returns were used to quantify movement behaviour and extraction rates using a maximum likelihood model that corrected for spatial variability in population size and fishing effort. Residency was high (~90%) in two strata and lower (75%) in the remaining stratum. The stratum with the highest residency also appeared to experience the highest extraction rate (likely due to a lower population size). These results confirm the existence of differences in movement behaviour within the snapper population, suggesting that localized areas may become depleted regardless of the status of the overall stock. This has consequences for the scale of fisheries management and the size of marine reserves implemented in different regions. Understanding why variation in movement behaviour exists (i.e., genetic vs. environmental) is the next step in addressing the influence of animal behaviour on fisheries management.

scholarly journals Evaluation of Fisheries Management Techniques in Three Wetlands in Bangladesh

2020 ◽  
pp. 1-14
Author(s):  
Md Golam Mustafa
Keyword(s):  
Fisheries Management ◽  
Fishing Effort ◽  
Baseline Survey ◽  
Fish Production ◽  
Community Based ◽  
Annual Fish ◽  
Assessment Approach ◽  
The Status ◽  
Management Techniques ◽  
The Impact

Aim: To evaluate the impact of community-based co-management and fisheries management techniques on fisheries production and biodiversity in three large wetlands in Bangladesh. Study Design: A robust catch assessment approach to measure fisheries production, species composition and biodiversity in large wetlands. Place and Duration of Study: The study sites are located in three wetlands in Bangladesh, namely Hail Haor, Kangsha-Malijhee and Turag-Bangshi for a period of two years (2010 and 2011) covering MACH and IPAC working area. Methodology: Species wise catch and efforts by gear type was monitored through the regular sampling to estimate the annual total catch and fishing effort. Randomly selected samples of the catch by species and effort by gear are recorded for each gear type observed to be operated on the same day. The numbers and weight of all fish species in the catch were recorded. The study also compared results in the last years of MACH initiatives to observe the status of fisheries production (kg/ha) and biodiversity Index (H´). Results: The study indicated that the 2011 annual fish production (kg/ha) increased by 125 and 271% compared to the baseline survey in 1999 in Hail Haor and Kangsho-Malijhee respectively. The results suggested that Hail Haor and Kangsha-Malijhee wetlands showed considerably enriched biodiversity over 12 years, whilst, Turag-Bangshi showed upwards from 1999 to 2006 and decreased in 2010 and 2011. In 2010, fish production was 393, 322 and 139 kg/ha, and in 2011 fishes production was 370, 556 and 88 kg/ha in Hail Haor, Kangsho-Malijhee and Turagh-Bangshi wetlands, respectively. Conclusions: The assessment indicated that the overall fish production and biodiversity has been improved due to community-based co-management and this lesson could be replicated widely to sustain wetland resources.

scholarly journals POTENSI DAN TINGKAT PEMANFAATAN SUMBER DAYA IKAN DI WILAYAH PENGELOLAAN PERIKANAN NEGARA REPUBLIK INDONESIA (WPP NRI) TAHUN 2015 SERTA OPSI PENGELOLAANNYA

2017 ◽  
Vol 8 (2) ◽  
pp. 97 ◽  
Author(s):  
Ali Suman ◽  
Hari Eko Irianto ◽  
Fayakun Satria ◽  
Khairul Amri
Keyword(s):  
Fisheries Management ◽  
Fishing Effort ◽  
Pelagic Fish ◽  
Management Options ◽  
Small Pelagic Fish ◽  
Fish Resources ◽  
Exploitation Rate ◽  
Management Area ◽  
The Status ◽  
Arafura Sea

Sumber daya ikan di perairan Indonesia merupakan salah satu modal menuju kemakmuran bagi bangsa, apabila dikelola secara berkelanjutan.Kajian potensi dan tingkat pemanfaatan tahun 2015, merupakan salah satu dasar utama dalam merumuskan pengelolaan tersebut menuju pemanfaatan sumber daya yang lestari bagi kesejahteraan bangsa. Secara keseluruhan komposisi jenis sumber daya ikan di perairan Indonesia didominasi kelompok ikan pelagis kecil sebesar 36 % dan ikan pelagis besar sebesar 25 %. Potensi sumber daya ikan di perairan Indonesia adalah sebesar 9,931 juta ton per tahun dengan potensi tertinggi terdapat di WPP 718 (Laut Arafura) sebesar 1,992 juta ton/tahun (20%), di WPP 572 (Samudera Hindia sebelah barat Sumatera dan Selat Sunda) sebesar 1,228 juta/tahun (12 %) dan di WPP 711 (Selat Karimata, Laut Natuna dan Laut Cina Selatan) sebesar 1,143 juta ton/tahun (12 %). Tingkat pemanfaatan secara keseluruhan terlihat didominasi kondisi overfishing (indikator warna merah) sekitar 49 %, diikuti kondisi fully-exploited (indkator warna kuning) sekitar 37 % dan kondisi moderat (indikator warna hijau) hanya 14 %. Kelompok ikan yang mengalami kondisi overfishing paling tinggi adalah kelompok udang Penaeid, lobster, kepiting dan rajungan, yang mencapai 63 % dari kondisi overfishing saat ini. Dalam perspektif yang demikian, opsi pengelolaan yang harus segera dilakukan adalah mengurangi jumlah upaya penangkapan pada WPP yang mengalami kondisi overfishing serta meningkatkan upaya pada WPP yang tingkat pemanfaatannya masih moderat dan fully exploited.Fish resources within Indonesian waters (i.e. teritorial and archipelagic waters) including Indonesian Economic Exclusive Zone if under sustainably management it would contribute a significant role as a source of nation welfare. Scientific advice on stock status and its exploitation rate are required as an input to support an apropriate fisheries management. Generally, fish resources in these waters are dominated by two main fish groups such as small pelagic fish by 36 % and large pelagic fish by 25 %. Indonesia fish resource in 2015 was estimated for 9,931 million tons/year with comprises of 1,992 million ton/year (20 %) in fisheries management area (FMA) 718 (Arafura sea), 1,228 million/year (12 %) in FMA 572 (western of Sumatera of Indian ocean and Sunda strait) and 1,143 million tons/year (12 %) in FMA 711 (Karimata strait, Natuna sea, and south China sea). Most of fish resources (49 %) were in the status of overfishing with red indicator, folowed by fully-exploited state(37 %) in yellow indicator and only 14 % in the moderate state (green indicator). Among all nine fish groups, the overfishing state (up to 63%) is recorded from group of shrimps (Penaidae), lobster, and crabs. The management options in these prespective is urgently suggested to reduce fishing effort at the level of f.opt (fishing optimum) for overfishing fish groups. Whilts possibly to increase effort for fish groups with fully and moderate exploited state at the level off opt.

scholarly journals The wildcat Felis silvestris in northern Turkey: assessment of status using camera trapping

Oryx ◽  
2011 ◽  
Vol 45 (1) ◽  
pp. 112-118 ◽  
Author(s):  
Özgün Emre Can ◽  
İrfan Kandemi̇r ◽  
İnci̇ Togan
Keyword(s):  
Population Size ◽  
Camera Traps ◽  
Sampling Effort ◽  
Felis Silvestris ◽  
Forest Patch ◽  
Western Turkey ◽  
Lack Of Information ◽  
The Status ◽  
Capture Recapture ◽  
Estimate Population Size

AbstractThe wildcat Felis silvestris is a protected species in Turkey but the lack of information on its status is an obstacle to conservation initiatives. To assess the status of the species we interviewed local forestry and wildlife personnel and conducted field surveys in selected sites in northern, eastern and western Turkey during 2000–2007. In January–May 2006 we surveyed for the wildcat using 16 passive infrared-trigged camera traps in Yaylacı k Research Forest, a 50-km2 forest patch in Yenice Forest in northern Turkey. A total sampling effort of 1,200 camera trap days over 40 km2 yielded photo-captures of eight individual wildcats over five sampling occasions. Using the software MARK to estimate population size the closed capture–recapture model M0, which assumes a constant capture probability among all occasions and individuals, best fitted the capture history data. The wildcat population size in Yaylacı k Research Forest was estimated to be 11 (confidence interval 9–23). Yenice Forest is probably one of the most important areas for the long-term conservation of the wildcat as it is the largest intact forest habitat in Turkey with little human presence, and without human settlements, and with a high diversity of prey species. However, it has been a major logging area and is not protected. The future of Yenice Forest and its wildcat population could be secured by granting this region a protection status and enforcing environmental legislation.

scholarly journals Sustainable exploitation of temperate fish stocks

2009 ◽  
Vol 6 (1) ◽  
pp. 124-127 ◽  
Author(s):  
Henrik Sparholt ◽  
Robin M. Cook
Keyword(s):  
Species Interactions ◽  
Fishery Management ◽  
Regional Scale ◽  
Single Species ◽  
Fishing Effort ◽  
Theoretical Concept ◽  
Maximum Sustainable Yield ◽  
Production Model ◽  
The Status ◽  
Long Time

The theory of maximum sustainable yield (MSY) underpins many fishery management regimes and is applied principally as a single species concept. Using a simple dynamic biomass production model we show that MSY can be identified from a long time series of multi-stock data at a regional scale in the presence of species interactions and environmental change. It suggests that MSY is robust and calculable in a multispecies environment, offering a realistic reference point for fishery management. Furthermore, the demonstration of the existence of MSY shows that it is more than a purely theoretical concept. There has been an improvement in the status of stocks in the Northeast Atlantic, but our analysis suggests further reductions in fishing effort would improve long-term yields.

scholarly journals AN ANALYSIS ON SUSTAINABILITY OF SHARK UTILIZATION USING FISH RESOURCES AND FISHING TECHNIQUES APPROACH IN SELAYAR ISLAND REGENCY

2020 ◽  
Vol 6 (1) ◽  
pp. 26
Author(s):  
Ziaul Haq Nawawi ◽  
Natsir Nessa ◽  
Dewi Yanuarita ◽  
Muhammad Yusfi Yusuf ◽  
Sainal Sainal
Keyword(s):  
Resource Management ◽  
Fisheries Management ◽  
Research Method ◽  
Sampling Technique ◽  
Purposive Sampling ◽  
Fish Resources ◽  
Indicator Approach ◽  
The Status

The research aims to record the types of shark utilization in Selayar Islands Regency, explore the spread and shark status of the Regency of Selayar Islands, and examine the sustainability status of shark utilization by fisherman in Selayar Islands. The research method was based on the assessment of EAFM indicator assessments to assess the performance of shark resource management on Tarupa Island, Rajuni Island, Polassi Island and Kayuadi Island Selayar Islands Regency with an indicator approach involving two domains, i.e (1) Fish resources and (2) Fishing technique. The methods of obtaining the data were survey by extracting the data through interviews/questionnaire. The sample was determined using purposive sampling technique. The results of the research indicate that the status of utilizing shark fishery in Selayar Islands Regency is currently in medium category. The main issues indicated are a decrease in catch size and the catch of sharks that are not feasible to catch (50% of catch <Lm). The domains that need to get primary attention in the management of sharks fisheries are the domains of fish resources and fishing technique. The efforts of management carried out in each fields are based on central issues that emerge. Connectivity efforts between communities and institutions are needed to produce functional fisheries management status so that the sustainability of shark resources in Selayar Islands Regency can be sustainable

scholarly journals Appraising the Status of Fish Community Structure in the Yellow Sea Based on an Indicator-Testing Framework

2021 ◽  
Vol 8 ◽  
Author(s):  
Yuru Li ◽  
Shuyang Ma ◽  
Caihong Fu ◽  
Yongjun Tian ◽  
Jianchao Li ◽  
...  
Keyword(s):  
Climate Change ◽  
Fisheries Management ◽  
Fish Community ◽  
Large Scale ◽  
The Yellow Sea ◽  
Total Catch ◽  
Fish Community Structure ◽  
Testing Framework ◽  
The Status ◽  
Ecosystem Based Fisheries Management

Fish community structure (FCS) of the Yellow Sea (YS) is affected by multiple pressures. Quantifying the responses of indicators of FCS (IFCSs) to pressures is a key aspect of ecosystem-based fisheries management. Quantitative methodology has hitherto been rarely applied to evaluate the performance of ecological indicators in response to physical and anthropogenic pressures and management actions. In this study, we adopted a quantitative and flexible framework to quantify the performance of IFCSs in the YS as well as to identify a suite of operational IFCSs to evaluate the status of the FCS via two state-space approaches. A total of 22 IFCSs were tested for their responses to three types of pressures including anthropogenic activities (fishing), large-scale climate change, and regional environmental variables. Our results indicate that the majority of IFCSs have good performance in terms of sensitivity in their responses to pressures, but weak performance in terms of robustness. The IFCSs tend to respond stronger to fishing than to large-scale climatic indices and regional environmental indices both in terms of sensitivity and robustness. A final indicator suite of five best-performing IFCSs was identified. The five IFCSs include total catch (ToC), mean trophic level (MTL), the ratio of catch of large predatory groups to total catch (LPC/ToC), mean temperature of catch (MTC) [or alternatively catch of small pelagic groups (SPC)], and functional evenness based on thermal groups (T-J′FD), all of which show regime shift patterns consistent with climate change. Compared to a reference period (1960–1964), the status of the current FCS has been obviously changed, and the long-term trajectories of the final indicator suite is consistent with that of fishing pressure. This study demonstrates the applicability of the indicator-testing framework in appraising the status of FCS, and facilitates moving towards ecosystem-based fisheries management in the YS.

Tagging studies reveal restricted movement of snapper (Pagrus auratus) within Shark Bay, supporting fine-scale fisheries management

2012 ◽  
Vol 63 (11) ◽  
pp. 1191 ◽  
Author(s):  
Jeffrey V. Norriss ◽  
Michael Moran ◽  
Gary Jackson
Keyword(s):  
Fisheries Management ◽  
Site Fidelity ◽  
Zone Boundary ◽  
Limited Evidence ◽  
Restricted Movement ◽  
Management Zones ◽  
Shark Bay ◽  
Community Acceptance ◽  
Spawning Site ◽  
Pagrus Auratus

The snapper (Pagrus auratus) fisheries of Shark Bay’s complex inner gulfs are managed on a fine spatial scale (tens of kilometres). Following the splitting of the Western Gulf into two management zones, results from an earlier 1980s tagging study were revisited to assess the suitability of management arrangements. Recaptures up to 15 years at liberty showed highly restricted movement, with 300 of 491 occurring within 5 nautical miles of the tagging site and only 3.3% crossing the new zone boundary. A simple stock-trajectory model simulating the two Western Gulf populations demonstrated a negligible impact from a 1% per annum level of mixing. The 1980s study was repeated between 1998 and 2003 by tagging 2558 snapper, mainly in areas previously under-represented. Recaptures up to 2 years at liberty again showed highly restricted movement, with 181 of 197 recaptures occurring at the tagging site. Juveniles were more sedentary than adults, the latter showing limited evidence of inter-annual spawning-site fidelity. Together, both studies support the use of three small management zones. Community acceptance of these complex arrangements was aided by collaborating with volunteers on research programs, which improved their understanding of the population structure.

scholarly journals Reporting time period matters: quantifying catch rates and exploring recall bias from fisher interviews in Thailand

2018 ◽  
Vol 75 (12) ◽  
pp. 2114-2122 ◽  
Author(s):  
Lindsay Aylesworth ◽  
Ting-Chun Kuo
Keyword(s):  
Fisheries Management ◽  
Data Sets ◽  
Multiple Time ◽  
Recall Bias ◽  
External Data ◽  
Time Period ◽  
The Status ◽  
The Mean ◽  
Catch Rates ◽  
Reported Data

Catch rates reported by fishers are commonly used to understand the status of a fishery, but the reliability of fisher-reported data is affected by how they recall such information. Recalling catch may be influenced by the choice of reporting time period. Using interview data from fishers in Thailand, we investigated (1) how the time period for which fishers report their catch rates (e.g., per day or month) correlates with annual catch estimates and (2) the potential of recall bias when fishers reported multiple catch rates. We found that the annual catch estimates of fishers who reported on a shorter time period (haul, day) were significantly higher than those reported on a longer time period (month, year). This trend held true when individual fishers reported over multiple time periods, suggesting recall bias. By comparing fisher reports with external data sets, we identified that the mean across all reports was most similar to other data sources, rather than any time period. Our research has strong implications in using fishers’ knowledge for fisheries management.

Benthic Habitats and the Effects of Fishing

2005 ◽  
Keyword(s):  
Fisheries Management ◽  
Large Scale ◽  
Scale Effects ◽  
Ecosystem Processes ◽  
Fishing Effort ◽  
Habitat Types ◽  
Benthic Habitats ◽  
Management Actions ◽  
Ecosystem Effects ◽  
Ecosystem Based Fisheries Management

<strong><em>Abstract. </em></strong>We review the impacts of towed gears on benthic habitats and communities and predict the consequences of these impacts for ecosystem processes. Our emphasis is on the additive and synergistic large-scale effects of fishing, and we assess how changes in the distribution of fishing activity following management action are likely to affect production, turnover time, and nutrient fluxes in ecosystems. Analyses of the large-scale effects of fishing disturbance show that the initial effects of fishing on a habitat have greater ecosystem consequences than repeated fishing in fished areas. As a result, patchy fishing effort distributions have lower total impacts on the ecosystem than random or uniform effort distributions. In most fisheries, the distribution of annual fishing effort within habitats is more patchy than random, and patterns of effort are maintained from year to year. Our analyses suggest that many vulnerable species and habitats have only persisted in heavily fished ecosystems because effort is patchy. Ecosystem-based fisheries management involves taking account of the ecosystem effects of fishing when setting management objectives. One step that can be taken toward ecosystem-based fisheries management is to make an a priori assessment of the ecosystem effects of proposed management actions such as catch controls, effort controls, and technical measures. We suggest a process for predicting the ecosystem consequences of management action. This requires information on habitat distributions, models to predict changes in the spatial distribution of fleets following management action, and models of the impacts of trawling disturbance on ecosystem processes. For each proposed management action, the change in disturbance affecting different habitat types would be predicted and used to forecast the consequences for the ecosystem. These simulations would be used to produce a decision table, quantifying the consequences of alternative management actions. Actions that minimize the ecosystem effects of fishing could then be identified. In data-poor situations, we suggest that management strategies that maintain or maximize the patchiness of effort within habitat types are more consistent with the precautionary approach than those that lead to more uniform fishing effort distributions.

scholarly journals Costs and Returns of Fishermen in the Massachusetts Inshore Lobster Fishery

1975 ◽  
Vol 4 (2) ◽  
pp. 195-210 ◽  
Author(s):  
J. M. Gates ◽  
J. M. D'Eugenio
Keyword(s):  
Fisheries Management ◽  
Fishing Effort ◽  
The State ◽  
Economic Factors ◽  
Sufficient Criterion ◽  
Fish Stocks ◽  
The Past ◽  
Resource Managers ◽  
Lobster Fishery

The inshore lobster fishery is one of the more important ones in the Commonwealth of Massachusetts, accounting for approximately 14 percent of the total landed value of all species in Massachusetts in 1971. Until recent years this fishery accounted for virtually all the pot landings in the state. Despite numerous attempts at conservation such as gear regulation, size restrictions, and prohibitions on harvesting egg-bearing females, the fishery has been subject to rapidly increasing effort and virtually constant landings. In the past decade it has become obvious to many fishery biologists and economists that conservation of fish stocks is a necessary but not sufficient criterion for fisheries management. Resource managers have become increasingly aware of the interdependence between economic factors and the intensity, location and composition of fishing effort.

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