Letteratura scientifica selezionata sul tema "Fishery management Groundfishes Habitat conservation Fishers"

We examined the extent to which the 2000 Pacific Fishery Management Council footrope restriction shifted and reduced trawl fishing effort on Oregon fishing grounds, related these changes to the seafloor habitat type over which they occurred, and developed methods for enhancing spatial review of fishing effort. Density analysis of trawl start locations demonstrated how fishing efforts increased and decreased in relation to habitat distribution and fishery management actions between 1995 and 2002. Trawl effort patterns exhibited significant interannual variability and were patchy in distribution. Tow end-point locations from 1998 to 2001 were retrieved from manual logbooks for five reference sites located in proximity to rocky habitat. Trawl towlines were mapped and demonstrated a marked enhancement of fine-scale fishing effort resolution. Spatial shifts in fishing intensity (measured as kilometres towed) away from rock habitat were evident at all reference sites after the footrope restriction, with an average reduction of 86%. Some slight shifts into surrounding unconsolidated sediments also occurred. Our results indicate that the footrope restriction, in conjunction with associated landing limits, was effective in protecting rocky habitats from trawl fishing impacts. Continued spatial monitoring of trawl data would assist in fishery management assessment of conservation objectives for depleted groundfish and essential fish habitat protection.

The management of fisheries in European Union (EU) waters has generally been regulated through government institutions and agreed quota allocations. This top-down management approach may have contributed to the continued decline of targeted fish stocks by forcing fishers to compete for limited resources without engendering a sense of resource stewardship. In attempting to reverse this decline, scientists and managers should examine management systems that do not solely depend on top-down approaches, and the Inshore Potting Agreement (IPA) is an example. The IPA is a voluntary fishery management system designed and operated by inshore fishers of south Devon, England. The IPA was conceived to reduce conflict between static-gear (pot and net) and towed-gear (trawl and dredge) fishers, and is regarded as a successful fisheries management regime by fishers and managers because it has effectively allowed fishers from both sectors to operate profitably on traditional fishing grounds. Another study determined that the IPA has incidentally protected benthic habitat complexity. Fishers from the static-gear and towed-gear sectors were interviewed to determine the evolution and function of the IPA, and to establish the factors that ensure the high level of regulatory compliance amongst fishers from both sectors. Towed-gear fishers gave significantly different responses to the same questions asked of static-gear fishers, and were generally less satisfied with the existence of the IPA. Multivariate analyses of the interview data suggested that fishers who thought the IPA was a good system also thought the system provided pot protection, but had experienced inter-sector conflict. Fishers who thought the IPA provided no personal benefit also thought that static-gear fishers should be more restricted, and that towed-gear corridors or more seasonal-use areas should be established within the existing IPA area. However, fishers from both sectors agreed that the IPA has maintained traditional practices of the local fishing industry, and that the system has conserved target finfish and scallop species. A number of factors were identified as critical to the success of the IPA. These included the voluntary nature of the agreement, the limited number of organizations representing fishers and very high level of membership of those organizations, and the simplicity of the system. Regulatory compliance is enhanced through the ability of fishers' organizations to respond rapidly to inter-sector conflict issues.

The spatial dynamics of catch and effort data are often overlooked in fisheries research despite its well-documented utility in understanding the distribution and abundance of fish. We apply a recently developed fisheries isodar model to an otter trawl groundfish fishery on the Scotian Shelf and compare its predictive performance with a more traditional discrete choice model random utility model. Isodars represent the expected distribution of foragers between two habitats when fitness is equal and can be a representation of the ideal free distribution. Here, fitness was defined with relative catch rates, cost differentials, and interference effects between habitats. Random utility models were constructed as mixed logit models to give the expected probability of fishing in a particular area based on a collection of predictors. The predictions of the isodar models consistently outperformed the mixed logit for both in-sample and out-of-sample forecasts and the isodar was determined to be the preferred model based on its increased accuracy and simplicity. The isodar model can provide a statistically powerful and easily implemented tool in effort studies, especially in situations of aggregated or limited data, which can inform conservation and management decisions.

Deep-sea corals in Southern California are diverse and abundant but subject to multiple stressors, including bottom-contact fisheries using mobile and fixed gear. There is a need for more information on the distribution of these taxa in relation to the distribution of demersal fishing effort, and the distribution of marine protected areas, in order to improve spatial planning. There are many marine managed areas in Southern California, including essential fish habitat (EFH) areas, conservation areas, and a national marine sanctuary, but specific areas of overlap between bottom fishing and benthic epifauna are poorly known. Groundfish surveys were conducted by the National Marine Fisheries Service using a remotely operated vehicle throughout Southern California between 2003 and 2011 to document abundance and distribution of deep-water rockfish and flatfish to a depth of 500 m. Corals and sponges were also common in these images, providing an opportunity to examine these communities. Analyses of 34,792 still images revealed abundance and diversity of coral and sponge taxa, as well as frequency of fishing debris. The occurrence data were overlaid in a geographic information system with landings data for deep-water (>50 m) demersal fisheries to identify areas of spatial overlap. Corals or sponges were observed in 23% of images. A total of 15 coral genera and six sponge morphotypes were identified. A total of 70 species codes were targeted by deep-water demersal fisheries operating below 50 m for years 2007–2011. A novel priority-setting algorithm was developed to identify areas of high richness, abundance, and fishing intensity (RAFi). Several highly-ranked areas were already protected as EFH (Footprint, Piggy Bank). Other highly-ranked sites (West Catalina Island, San Clemente Island, 9-Mile Bank, Santa Rosa Flats) were encompassed by transient gear restrictions, such as Rockfish conservation areas, but are now recommended for permanent protection by the Pacific Fishery Management Council.

Abstract Habitat and fisheries usage data are key components for ecosystem-based approach to fisheries management (EBFM). Significant gaps in knowledge remain for fisheries–habitat interactions, particularly in inshore fisheries where vessels are <12 m in length. Here, we show changes in inshore fishing effort distribution (<12 m) and habitat use over the decade 2004–2013. Sightings data of fishing vessel activity recorded by the Northumberland Inshore Fishery and Conservation Authority (NIFCA) were combined with landings data to estimate and map pot-fishing activity between 2004 and 2013. Spatial temporal changes were investigated using Monte Carlo simulation of randomly sampled fishing effort maps. High resolution (1 m) broadscale (EUNIS level 3) predictive habitat maps of the Coquet to St Marys’ Marine Conservation Zone (CQSM MCZ) were used to investigate spatial temporal changes in fishers’ habitat selection using compositional analysis. Fishing effort in Northumberland increased between 2004 and 2013 (233 642–354 193 pots year−1). Fishing effort distribution differed between individual years, decreasing over large areas between 2004 and 2007, followed by increases, especially inshore, between 2008 and 2013. Fishers in the CQSM MCZ showed a preference for rocky habitats over sediment habitats. Habitat preference did not vary between years although all habitats experienced increasing fishing pressure. Spatial temporal changes in fishing effort and habitat use were discussed in relation to EBFM.

Pengertian dasar untuk pengelolaan perikanan terkait dengan fungsi fungsi biologi, sosial, teknologi, ekonomi serta lingkungan sumber daya sebagai komponen yang saling berhubungan untuk terjaminnya pengelolaan secara berkelanjutan. Stok ikan, ekosistem dan masyarakat nelayan merupakan salah satu kesatuan yang tidak dapat dipisahkan dalam sistem yang dinamis, dimana perubahan taktik dan strategi pemanfaatan masih merupakan suatu hal yang banyak dilakukan dalam rangka penyesuaian antara faktor teknis dan ekonomis yang sering kali mengabaikan pertimbangan bio-ekologi sumberdaya ikan. Sasaran pendekatan dan kebijakan pengelolaan perikanan di berbagai negara sudah mulai berubah, diawali dengan pendekatan memaksimalkan tangkapan tahunan dan ketenaga-kerjaan menuju ke konservasi dan pengelolaan berbasis pelayanan ekosistem. Konsep pengelolaan berbasis masyarakat dan ko-manajemen masih terbatas pada pengelolaan kawasan konservasi dan habitat terumbu karang. Adanya kesenjangan dan perbedaan antara kepentingan kawasan konservasi sebagai akibat kurangnya pemahaman kolektif terhadap tujuan pengelolaan, dan kerapkali menyebabkan aktifitas perikanan tangkap sebagai bagian dari kebutuhan ekonomis berbenturan dengan fungsi kawasan konservasi dalam jangka panjang. Pengendalian upaya penangkapan dan memahami dinamika perikanan, serta mengelola nelayan menjadi prioritas untuk pengelolaan sumber daya ikan, sedangkan konsep pengelolaan berbasis masyarakat dan ko-manajemen ditempatkan sebagai pelengkap untuk menutupi kelemahan aspek legal wilayah pengelolaan perikanan atau sumber daya ikan.Basic understanding of fisheries management related to biology, social, technology and economic function of fish resources. Fish stocks, ecosystem and fishers community are the integrated component under the dynamic of fisheries system, where as changing and on fishing tactic and strategy still exist to adjust between biology, technics and economics aspects. It is obvious that all technological creeps oftenly ignored the bio-ecological consideration of fish resources. The fisheries management and its policy were gradually shifting from maximize the catch, job opportunity become conservation and ecosystem based fisheries management. The concept of community-based management and co management is still limited to the management of conservation areas and coral reef habitats. The existence of gaps and differences between the interests of the conservation area as a result of a lack of understanding collective to the management objectives and often causing fishing activities as part of the economic needs clash with the function of conservation areas in the long term. Control efforts to capture and understand the dynamics of fisheries, as well as managing fishing is a priority for the management of fish resources, while the concept of community-based management and co management issued as a supplement to cover the weakness of legal aspects of the fishery management area or fishery resource.

SUMMARYMany sea cucumber fisheries have dramatically declined worldwide due to rapid overexploitation and ineffective management. This study designed an innovative management strategy for small-scale, data-limited sea cucumber fisheries in Pacific Island countries. Firstly, a local quota-based comanagement system was implemented in New Caledonia to manage a small-scale sandfishHolothuria scabrafishery. A habitat map derived from high-resolution satellite imagery was used to stratify survey sampling and assess the harvestable stock biomass. The latter has been monitored as the reference biomass (RB) since 2008 and repeatedly used by the local fishers’ organization and Fisheries Department officers to set adaptive total allowable catches and regulations of fishing effort. Results showed the excellent performance of this fishery between 2008 and 2012, both biologically (167% increase in total stock biomass) and economically (146% increase in annual returns from catches). Secondly, the assessment of the RB was generalized to multispecies sea cucumber fisheries in Vanuatu in 2011 before the proposed lifting of a five-year national moratorium. Building upon these practical case studies in New Caledonia and Vanuatu, this paper outlines an operational framework to inform sea cucumber fisheries policy in these two countries and discusses the upscaling of the proposed management strategy.

Kawasan Konservasi Perairan Daerah (KKPD) ditetapkan untuk berbagai tujuan, termasuk melindungi spesies dan habitat laut, melestarikan keanekaragaman hayati laut, memulihkan stok perikanan, mengelola kegiatan pariwisata, dan meminimalkan konflik di antara beragam pengguna sumber daya. Oleh karena itu, timbul pertanyaan apakah pengelolaan Kawasan Konservasi Perairan Daerah (KKPD) di Selat Dampier Raja Ampat telah dilakukan secara efektif untuk memperoleh hasil yang berkelanjutan serta meningkatkan status sosial ekonomi masyarakat yang ada di kawasan tersebut.Analisis penerapan zonasi dalam pengelolaan kawasan konservasi laut Selat Dampier diukur dengan memetakan kelimpahan dan biomasa ikan karang, memotret persepsi nelayan tentang zonasi serta menilai tingkat kepatuhan nelayan pada batas-batas zonasi. Penelitian ini dilakukan di kawasan konservasi Selat Dampir, Kabupaten Raja Ampat, Provinsi Papua Barat, antara November 2016 dan Oktober 2017. Data dikumpulkan dengan menggunakan metode survei, termasuk data primer dan sekunder. Metode transek sabuk, dilakukan pada kedalaman 3 m, digunakan untuk mengukur kelimpahan dan biomasa ikan. Responden adalah nelayan terumbu karang yang tinggal di Desa Saonek, Desa Yenbuba, Desa Friwen dan Desa Arborek. Data sekunder diperoleh dari beberapa sumber (Dinas Perikanan Kabupaten, BPS, jurnal ilmiah, dan laporan penelitian). Data dianalisis secara deskriptif dan metode tabulasi silang. Hasil penelitian menunjukkan bahwa sistem zonasi pada pengelolaan kawasan konservasi di perairan Selat Dampier, Raja Ampat dapat dikatakan cukup efektif terlihat dari kelimpahan ikan dan biomasa yang cukup tinggi pada zona inti dan zona wisata (sebagai Daerah Perlindungan Laut/DPL) dimana pada kedua zona tersebut nilainya 1.5 sampai 2 kali dibandingkan dengan zona perikanan (Non DPL). Rata-rata tingkat kesadaran dan kepatuhan nelayan untuk tidak melakukan penangkapan ikan di daerah zona inti dan zona wisata cukup tinggi yakni 95%, Persepsi sebagian besar nelayan mengekspresikan kesadaran lingkungan dan pengetahuan yang baik tentang kawasan konservasi.Title: EFEKTIVITAS ZONASI DALAM PENGELOLAAN PERIKANAN KARANG DI KAWASAN KONSERVASI PERAIRAN SELAT DAMPIER, RAJA AMPAT Marine Protected Areas (MPAs) are defined for various purposes, including to protect marine species and habitats, to conserve marine biodiversity, to restore fishery stocks, to manage tourism activities, and to minimize conflicts among diverse resource users. Therefore, question arises whether there has been effective management of the Marine protected Area in the Raja Ampat Dampier Strait in order to achieve sustainable results and improve the socio-economic status of its society. Analysis of the zoning system in the management of the Dampier Strait was measured by mapping the abundance and biomass of reef fish, capturing fishers’ perception towards zoning and assessing the level of fishers’ compliance at zoning boundaries. This research was conducted in the Dampir Strait conservation area, Raja Ampat District, West Papua Province, from November 2016 to October 2017. Primary and secondary data were collected through surveys. The belt transect method was carried out to a depth of 3 m to measure the abundance and biomass of fish. Primary data were collected from coral reef fishers living in Saonek Village, Yenbuba Village, Friwen Village and Arborek Village. Secondary data were taken from several sources (District Fisheries Service, BPS, scientific journals, and research reports). Data were analyzed descriptively and cross tabulated method. The results showed that the zoning system was effective to manage the conservation areas in the Dampier Strait waters, Raja Ampat since there are abundance of fish and high biomass in the core zone and tourist zo9ne (as Marine Protected Areas) with 1.5 to 2 times amount compared with the fisheries zone (Non DPL). The average level of awareness and average compliance of fishers to prevent themselves from fishing activities in the core zone and tourism zone is 95 %. Most fishers express high environmental awareness and good knowledge toward conservation areas.

Credit systems for mitigation of bycatch and habitat impact, incentive-based approaches, incentivize changes in fishery operator behavior and decision-making and allow flexibility in a least-cost method. Three types of credit systems, originally developed to address environmental pollution, are presented and evaluated as currently underutilized incentive-based approaches. The first, a cap-and-trade approach, evolved out of direct regulation through restricted limits with flexibility through the creation of tradeable unused portion of the limit, called credits. The second, a penalty-reward system, incentivizes bycatch- and habit-impact- reducing vessel behavior through rewards for positive behavior, and penalties for negative behavior. The third is a hybrid of the first two. All three systems can be used in the context of both absolute (fixed) and relative (rate-based or proportional) credits. Transferable habitat impact credit systems are developed for area management. The cap-and-trade credit system is directly compared to a comparable property rights system in terms of characteristics, strengths, weakness, and applicability. The Scottish Conservation Scheme and halibut bycatch reduction in the Alaskan multispecies groundfish fishery provide real-world examples of success with credit systems. The strengths, weaknesses, and applicability of credit systems are summarized, along with a set of recommendations. Cap-and-trade credit systems provide an important alternative to property rights, such as when rights are not feasible, and for this reason should prove useful for international fisheries. Penalty-reward and hybrid credit systems can substitute for cap-and-trade credit systems or property rights or complement them by addressing a related but otherwise unaddressed issue.

Marine conservation areas are an important tool for the sustainable management of multispecies, small-scale fisheries. Effective spatial management requires a proper understanding of the spatial distribution of target species and the identification of its environmental drivers. Small-scale fisheries, however, often face scarcity and low-quality of data. In these situations, approaches for the prioritization of conservation areas need to deal with scattered, biased, and short-term information and ideally should quantify data- and model-specific uncertainties for a better understanding of the risks related to management interventions. We used a Bayesian hierarchical species distribution modeling approach on annual landing data of the heavily exploited, small-scale, and data-poor fishery of Chwaka Bay (Zanzibar) in the Western Indian Ocean to understand the distribution of the key target species and identify potential areas for conservation. Few commonalities were found in the set of important habitat and environmental drivers among species, but temperature, depth, and seagrass cover affected the spatial distribution of three of the six analyzed species. A comparison of our results with information from ecological studies suggests that our approach predicts the distribution of the analyzed species reasonably well. Furthermore, the two main common areas of high relative abundance identified in our study have been previously suggested by the local fisher as important areas for spatial conservation. By using short-term, catch per unit of effort data in a Bayesian hierarchical framework, we quantify the associated uncertainties while accounting for spatial dependencies. More importantly, the use of accessible and interpretable tools, such as the here created spatial maps, can frame a better understanding of spatio-temporal management for local fishers. Our approach, thus, supports the operability of spatial management in small-scale fisheries suffering from a general lack of long-term fisheries information and fisheries independent data.

<strong><em>Abstract. </em></strong>The topic of this symposium, effects of fishing activities on benthic habitats, is a subject charged with controversy, complexity, and socioeconomic significance. Concern about the effects of fishing comes at a time when the sustainability of fisheries and maintenance of healthy ecosystems are being questioned. Are fishing activities detrimental to habitat? When and where might they be more or less damaging? The U.S. Congress, under the Magnuson-Stevens Fishery Conservation and Management Act, has directed us to address the issue. This symposium is one of the means by which we gain new information for future evaluation and appropriate management of fishing activities that affect benthic habitat. We also are addressing the issue through research. With the appropriate information, we will move forward together—fishers, scientists, managers, environmentalists, and other stakeholders.